JP5030768B2 - Oil-cooled screw compressor - Google Patents

Oil-cooled screw compressor Download PDF

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JP5030768B2
JP5030768B2 JP2007337651A JP2007337651A JP5030768B2 JP 5030768 B2 JP5030768 B2 JP 5030768B2 JP 2007337651 A JP2007337651 A JP 2007337651A JP 2007337651 A JP2007337651 A JP 2007337651A JP 5030768 B2 JP5030768 B2 JP 5030768B2
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JP2009156225A (en
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雅紀 板谷
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HOKUETSU INDUSTRIES CO., LTD.
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Description

本発明は，油冷式スクリュ圧縮機に関し，より詳細には，油冷式スクリュ圧縮機の軸封部より漏出した潤滑油を回収して，潤滑油の循環系に戻すための潤滑油の回収手段を備えた油冷式スクリュ圧縮機に関する。   The present invention relates to an oil-cooled screw compressor. More specifically, the present invention relates to the recovery of lubricating oil for recovering the lubricating oil leaked from the shaft seal of the oil-cooled screw compressor and returning it to the lubricating oil circulation system. The present invention relates to an oil-cooled screw compressor provided with means.

油冷式スクリュ圧縮機１は，ケーシング１１内に形成されたシリンダ１２内にオス，メス一対のスクリュロータ１３，１４を噛み合い回転可能に収容し，前記一対のスクリュロータ１３，１４の噛み合い回転により被圧縮気体と潤滑油を圧縮して気液混合流体として吐出する油冷式のスクリュ圧縮機本体１０と，前記圧縮機本体１０より吐出された気液混合流体を導入して，圧縮気体と潤滑油とに分離するレシーバタンク２０を備え，レシーバタンク２０で圧縮気体と分離された潤滑油をオイルクーラ２１やオイルフィルタ２２等を備えた給油配管９１を介して再度圧縮機本体１０の給油口１５に導入して，前記潤滑油を循環して使用する，潤滑油の循環系が形成されている。   The oil-cooled screw compressor 1 accommodates a pair of male and female screw rotors 13 and 14 in a cylinder 12 formed in a casing 11 so as to be able to mesh and rotate, and by the meshing rotation of the pair of screw rotors 13 and 14. An oil-cooled screw compressor main body 10 that compresses compressed gas and lubricating oil and discharges it as a gas-liquid mixed fluid, and a gas-liquid mixed fluid discharged from the compressor main body 10 are introduced to compress the compressed gas and lubricate. A receiver tank 20 that separates into oil is provided, and the lubricating oil separated from the compressed gas in the receiver tank 20 is supplied again via an oil supply pipe 91 including an oil cooler 21 and an oil filter 22, and the oil supply port 15 of the compressor body 10. Thus, a lubricating oil circulation system in which the lubricating oil is circulated and used is formed.

そして，モータやエンジン等の駆動源（図示の例ではモータＭ）によって前記ロータ１３，１４を回転するために，前述の圧縮機本体１０のいずれか一方のロータ１４のロータ軸１４ａを前記ケーシング１１を貫通させて突出し，この突出したロータ軸１４ａに駆動源からの回転駆動力を入力するように構成されている（図８参照）。   Then, in order to rotate the rotors 13 and 14 by a drive source (motor M in the illustrated example) such as a motor or an engine, the rotor shaft 14a of one of the rotors 14 of the compressor body 10 is connected to the casing 11. And a rotational driving force from a driving source is input to the protruding rotor shaft 14a (see FIG. 8).

なお，このような圧縮機１には，圧縮機本体１０の吸入通路１９を開閉する吸入弁３０が設けられており，この吸入弁３０の開閉操作によって消費側における圧縮気体の消費が行われているとき，すなわちレシーバタンク２０内の圧力が所定の圧力未満である場合，前記吸入通路１９を開いて圧縮機本体１０に被圧縮気体を導入して圧縮・吐出させる負荷運転を行うと共に，消費側における圧縮気体の消費が停止して，レシーバタンク２０内の圧力が所定の圧力以上に上昇すると，吸入弁３０によって前記吸入通路１９を閉じ，圧縮機本体１０に対する被圧縮気体の導入を停止することで，レシーバタンク２０に対する圧縮気体の吐出を停止すると共に，圧縮機本体１０の負荷を軽減して消費動力の軽減された無負荷運転に移行する容量制御が行われている。   The compressor 1 is provided with a suction valve 30 that opens and closes the suction passage 19 of the compressor body 10, and compressed gas is consumed on the consumption side by opening and closing the suction valve 30. When the pressure in the receiver tank 20 is lower than a predetermined pressure, the load passage operation is performed in which the suction passage 19 is opened and the compressed gas is introduced into the compressor body 10 to be compressed and discharged, and the consumption side When the consumption of compressed gas in the engine stops and the pressure in the receiver tank 20 rises above a predetermined pressure, the intake valve 19 is closed by the intake valve 30 and the introduction of the compressed gas to the compressor body 10 is stopped. Then, the discharge control of the compressed gas to the receiver tank 20 is stopped, and the load control of the compressor body 10 is reduced to shift to the no-load operation with reduced power consumption. It has been made.

この容量制御を可能とするために，図８に示す例では，前述の吸入弁３０を受圧室に対する圧縮気体の導入により吸入通路１９を閉じる閉弁受圧型のものとし，レシーバタンク２０内の圧縮気体を前記吸入弁３０の受圧室に導入する制御配管９２を設けると共に，この制御配管９２中に電磁開閉弁９３を設けて前記制御配管９２の開閉を可能としている。   In order to enable this capacity control, in the example shown in FIG. 8, the above-described suction valve 30 is a valve-pressure-receiving type that closes the suction passage 19 by introducing compressed gas into the pressure-receiving chamber, and the compression in the receiver tank 20 is performed. A control pipe 92 for introducing gas into the pressure receiving chamber of the suction valve 30 is provided, and an electromagnetic on-off valve 93 is provided in the control pipe 92 to allow the control pipe 92 to be opened and closed.

そして，レシーバタンク２０と消費側とを連通する配管内の圧力を検出する，圧力センサ等の圧力検出手段９４と，この圧力検出手段９４の検出信号に基づいて，前記電磁開閉弁９３を開閉制御する制御信号を出力するコントローラ９５を設けて，前述の容量制御を行うことができるように構成されている。   Then, pressure detection means 94 such as a pressure sensor for detecting the pressure in the pipe communicating with the receiver tank 20 and the consuming side, and on-off control of the electromagnetic on-off valve 93 based on the detection signal of the pressure detection means 94. A controller 95 that outputs a control signal is provided so that the above-described capacity control can be performed.

以上のように構成された油冷式スクリュ圧縮機１において，前述のようにモータＭ等の動力源からの回転駆動力を入力するために，ロータ軸の一本１４ａがケーシング１１を貫通して突出していることから，このようにケーシング１１を貫通するロータ軸１４ａの周りから潤滑油や圧縮気体の漏出が生じることを防止するための構成を備えている。   In the oil-cooled screw compressor 1 configured as described above, in order to input the rotational driving force from the power source such as the motor M as described above, one rotor shaft 14a passes through the casing 11 to input the rotational driving force. Since it protrudes, the structure for preventing leakage of lubricating oil or compressed gas from the periphery of the rotor shaft 14a penetrating the casing 11 is provided.

このような構成として，ケーシング１１を貫通したロータ軸１４ａを包囲するシール室１６を設け，このシール室１６内にメカニカルシール等の軸封装置５１を収容し，このシール室１６に隣接して，ケーシング１１のシリンダ１２側に前述のロータ軸１４ａを支承するための軸受５２を設けている。   As such a configuration, a seal chamber 16 surrounding the rotor shaft 14 a penetrating the casing 11 is provided, and a shaft sealing device 51 such as a mechanical seal is accommodated in the seal chamber 16, and adjacent to the seal chamber 16, A bearing 52 for supporting the rotor shaft 14a is provided on the cylinder 12 side of the casing 11.

そして，シール室１６内にレシーバタンク２０からの潤滑油を注油して，この潤滑油によって前記軸封装置５１の摺動部を潤滑すると共に軸受５２を潤滑している。   Then, lubricating oil from the receiver tank 20 is poured into the seal chamber 16, and the sliding portion of the shaft seal device 51 is lubricated and the bearing 52 is lubricated by the lubricating oil.

このようにして供給された潤滑油は，前述の軸封装置５１によってケーシング１１を貫通して突出したロータ軸１４ａの周囲からケーシング１１外に漏出することが防止されているが，シール室１６内に注油された潤滑油は，前述の軸封装置５１の存在によってもケーシング１１の外側に僅かずつ漏出する。   The lubricating oil supplied in this way is prevented from leaking out of the casing 11 from the periphery of the rotor shaft 14a protruding through the casing 11 by the above-described shaft sealing device 51. Lubricating oil injected into is leaked little by little to the outside of the casing 11 due to the presence of the shaft seal device 51 described above.

そこで，前述のシール室１６のシリンダ１２側とは反対側において，ロータ軸１４ａの軸穴内周面に，このようにして漏出した潤滑油を捕集するための溝１７を設けると共に，この溝１７と連通する潤滑油の排出流路１８を形成し，この排出流路１８を介して漏れ出た潤滑油を回収すると共に，回収された潤滑油を，潤滑油の回収配管７０を介して前述の潤滑油の循環系内に戻すことが行われている。   Therefore, a groove 17 for collecting the lubricating oil leaked in this way is provided on the inner peripheral surface of the rotor shaft 14a on the opposite side of the seal chamber 16 from the cylinder 12 side. A lubricating oil discharge passage 18 communicating with the exhaust passage 18 is formed, the lubricating oil leaking through the discharge passage 18 is collected, and the collected lubricating oil is passed through the lubricating oil collecting pipe 70 as described above. Returning to the circulation system of the lubricating oil is performed.

このように，軸封装置５１より漏出した潤滑油を潤滑油の循環系内に戻すために，図８に示す構成にあっては，前記潤滑油の排出流路１８と圧縮機本体１０の吸入通路１９を開閉する前述の吸入弁３０の一次側を回収配管７０を介して連通し，圧縮機本体１０の吸気によって生じる負圧によって，潤滑油の排出流路１８を介して排出された潤滑油を圧縮機本体１０内に取り込み，前述した潤滑油の循環系内に回収できるよう構成している（特許文献１の「従来の技術」欄）。   In this way, in order to return the lubricating oil leaked from the shaft seal device 51 into the lubricating oil circulation system, the lubricating oil discharge flow path 18 and the suction of the compressor main body 10 are used in the configuration shown in FIG. The primary side of the intake valve 30 that opens and closes the passage 19 communicates with the recovery pipe 70, and the lubricating oil discharged through the lubricating oil discharge passage 18 by the negative pressure generated by the intake air of the compressor body 10 In the compressor body 10 and can be recovered in the above-described lubricating oil circulation system ("Prior Art" column of Patent Document 1).

また，前述のように排出流路１８に一端を連通した回収配管７０を吸入弁３０の一次側に連通する場合，吸入弁３０による容量調整時には潤滑油の回収作用を有する負圧が軽減して回収が不十分となり，特に吸入空気量がゼロの状態（吸気閉塞状態）が連続すると潤滑油の十分な回収ができなくなり，軸孔より洩れ出た潤滑油が外部へ飛散するという問題を解消するために，図８に示すように，潤滑油の排出流路１８に一端を連通された回収配管７０の他端を二方向に分岐して一方の分岐管７０ａを吸入弁３０の一次側に，他方の分岐管７０ｂを吸入弁３０の二次側にそれぞれ連通し，吸入弁３０が開いた負荷運転時，分岐された２つの分岐管７０ａ，７０ｂの双方によって軸封装置５１より漏出した潤滑油の回収を行うと共に，吸入弁３０が閉じた無負荷運転時において，他方の分岐管７０ｂを介して排出流路１８を介して排出された潤滑油の回収を行うと共に，吸入弁３０の一次側の被圧縮気体を分岐管７０ａ及び７０ｂを介して吸入弁３０の二次側に導入することで，圧縮機本体１０の吸入側における負圧の緩和を行うことができるように構成した油冷式スクリュ圧縮機も提案されている（特許文献１参照。なお，図８，９において９６は逆止弁であり，この逆止弁９６を設けることにより圧縮機本体の停止時，回収配管７０を介して排出流路１８に潤滑油が逆流することを防止している。   Further, when the recovery pipe 70 having one end communicating with the discharge flow path 18 is communicated with the primary side of the suction valve 30 as described above, the negative pressure having the function of recovering the lubricating oil is reduced when the capacity is adjusted by the suction valve 30. Insufficient recovery, especially when the intake air amount is zero (intake closed state), the lubricant cannot be recovered sufficiently and the problem of the lubricant leaking from the shaft hole being scattered outside is solved. Therefore, as shown in FIG. 8, the other end of the recovery pipe 70 connected at one end to the lubricating oil discharge flow path 18 is bifurcated in two directions, and one branch pipe 70 a is placed on the primary side of the intake valve 30. The other branch pipe 70b communicates with the secondary side of the suction valve 30, and the lubricating oil leaked from the shaft seal device 51 by both of the two branch pipes 70a and 70b branched during the load operation when the suction valve 30 is opened. And the suction valve 30 During the closed no-load operation, the lubricating oil discharged through the discharge passage 18 through the other branch pipe 70b is recovered, and the compressed gas on the primary side of the suction valve 30 is supplied to the branch pipes 70a and 70b. An oil-cooled screw compressor configured to relieve negative pressure on the suction side of the compressor main body 10 by being introduced to the secondary side of the suction valve 30 via a valve is also proposed (patent) 8 and 9, reference numeral 96 denotes a check valve, and by providing this check valve 96, when the compressor main body is stopped, the lubricating oil flows back into the discharge passage 18 via the recovery pipe 70. To prevent it.

この発明の先行技術文献情報としては次のものがある。
特開２００１−１７３５８５号公報 Prior art document information of the present invention includes the following.
JP 2001-173585 A

以上のように構成された油冷式スクリュ圧縮機１において，図８に示したように潤滑油の排出流路１８を回収配管７０を介して吸入弁３０の一次側に連通した構成では，無負荷運転時に潤滑油の回収量が減少し，又は潤滑油の回収が行われないことから，軸封装置５１より潤滑油が漏れ出るおそれがあるという欠点を有することは前述した通りである。   In the oil-cooled screw compressor 1 configured as described above, the configuration in which the lubricating oil discharge passage 18 is communicated with the primary side of the suction valve 30 via the recovery pipe 70 as shown in FIG. As described above, there is a drawback that the lubricating oil may leak from the shaft seal device 51 because the amount of collected lubricating oil decreases during the load operation or the lubricating oil is not collected.

そこで，無負荷運転時においても潤滑油の回収を確実に行うことができるように，一端を排出流路１８に連通した前述の回収配管７０の他端を，例えば図１０に示すように吸入弁３０の二次側に連通することも考えられる。   Therefore, the other end of the above-described recovery pipe 70 having one end communicating with the discharge flow path 18 is connected to a suction valve as shown in FIG. 10, for example, so that the lubricant can be reliably recovered even during no-load operation. It is also possible to communicate with the secondary side of 30.

しかし，この構成を採用した場合には，吸入弁３０の一次側に排出流路１８を連通する場合とは逆に，無負荷運転時の方が，負荷運転時に比べて排出流路１８と吸入通路１９間の圧力差が大きくなって潤滑油の回収能力が増加するため，無負荷運転時における回収油量に合わせて回収配管７０の径を調整（小さめに調整）すると，無負荷運転時に比較して排出流路１８と吸入通路１９間の圧力差が少なく，潤滑油の回収能力が低下する負荷運転時には，漏出する潤滑油を全量回収することができず，溝１７から溢れた潤滑油が，ケーシング１１外に漏れ出て飛散するおそれがあるという問題が生じる。   However, when this configuration is adopted, contrary to the case where the discharge passage 18 is communicated with the primary side of the suction valve 30, the discharge passage 18 and the suction passage in the no-load operation than in the load operation. Since the pressure difference between the passages 19 increases and the lubricating oil recovery capability increases, adjusting the diameter of the recovery pipe 70 according to the amount of recovered oil during no-load operation (adjusting it to a smaller value) Thus, during a load operation in which the pressure difference between the discharge passage 18 and the suction passage 19 is small and the recovery capability of the lubricant is reduced, the leaked lubricant cannot be recovered in its entirety, and the lubricant overflowing from the groove 17 is not recovered. , There arises a problem that the casing 11 may leak out and scatter.

逆に負荷運転時における潤滑油の回収量に合わせて回収配管７０の径を調整（大きめに調整）すると，吸入弁３０の二次側における負圧が高まる無負荷運転時には，軸封装置５１より漏出する潤滑油量を越えて吸入が行われることから，この回収配管７０を介して潤滑油の他にも外気が吸い込まれることとなる。   Conversely, when the diameter of the recovery pipe 70 is adjusted (adjusted to a larger value) in accordance with the amount of recovered lubricant during load operation, the shaft seal device 51 causes the negative pressure on the secondary side of the intake valve 30 to increase. Since suction is performed beyond the amount of lubricating oil that leaks, outside air is sucked in addition to the lubricating oil through the recovery pipe 70.

このように，軸封装置５１の外溝１７から回収配管７０を介してエアフィルタを通していない外気を吸い込むと，ゴミ等が圧縮機本体１０に入ったり，回収配管７０内にゴミが詰まる等して圧縮機１の故障や作動不良の原因となり好ましくない。   In this way, if outside air that has not passed through the air filter is sucked from the outer groove 17 of the shaft seal device 51 through the recovery pipe 70, dust or the like enters the compressor body 10, and the recovery pipe 70 is clogged with dust. It becomes a cause of failure and malfunction of the compressor 1, which is not preferable.

また，無負荷運転時にこのようにして回収配管７０から外気を吸い込むと，無負荷運転時でありながら圧縮機本体１０はこの吸い込んだ外気を圧縮するために負荷がかかり，その結果，無負荷運転時における消費動力が増加する。   In addition, when outside air is sucked from the recovery pipe 70 in this way during no-load operation, the compressor main body 10 is loaded to compress this sucked outside air even during no-load operation. As a result, no-load operation is performed. Power consumption at the time increases.

前記構成に対し，前掲の特許文献１として紹介した油冷式スクリュ圧縮機にあっては，図９に示したように排出流路１８からの回収配管７０を二方向に分岐して一方の分岐管７０ａを吸入弁３０の一次側，他方の分岐管７０ｂを吸入弁３０の二次側に連通するものであることから，吸入弁３０が閉じた無負荷運転時においても他方の分岐管７０ｂを介して潤滑油の回収を行うことができる。   In contrast to the above configuration, in the oil-cooled screw compressor introduced as the above-mentioned Patent Document 1, as shown in FIG. 9, the recovery pipe 70 from the discharge passage 18 is branched in two directions, and one branch is formed. Since the pipe 70a communicates with the primary side of the suction valve 30 and the other branch pipe 70b communicates with the secondary side of the suction valve 30, the other branch pipe 70b is connected even during no-load operation when the suction valve 30 is closed. The lubricating oil can be recovered via

しかし，図９に示す特許文献１に記載の構成にあっては，無負荷運転時，吸入弁３０の一，二次側空間の連通が遮断された場合であっても，吸入弁３０の一次側と二次側とが２つの分岐管７０ａ，７０ｂによって直接連通された状態となり，この分岐管７０ａ，７０ｂを介して吸入弁３０の一次側の外気を積極的に吸入弁３０の二次側に導入するものとしているために，図１０を参照して説明した装置構成のように，軸孔の僅かな隙間から外気を吸入する場合に比較してより大量の外気が無負荷運転時の圧縮機本体１０に対して導入されることとなる。そのため，無負荷運転時における動力損失が更に増大することとなる。   However, in the configuration described in Patent Document 1 shown in FIG. 9, the primary of the intake valve 30 even when the communication of the primary side of the intake valve 30 and the secondary space is interrupted during no-load operation. The secondary side and the secondary side are in direct communication with each other through the two branch pipes 70a and 70b, and the primary air on the primary side of the suction valve 30 is actively passed through the branch pipes 70a and 70b. Therefore, as in the apparatus configuration described with reference to FIG. 10, a larger amount of outside air is compressed during no-load operation than when outside air is sucked through a slight gap in the shaft hole. It will be introduced to the machine body 10. As a result, power loss during no-load operation further increases.

しかも圧縮機が無負荷運転の状態にあるときは，消費側における圧縮気体の消費が停止している状態にあることから，前述のように潤滑油の排出流路１８や吸入弁３０の二次側より圧縮機本体１０に外気を導入してこれを圧縮，吐出すると，レシーバタンク内の圧力が徐々に上昇する。   In addition, when the compressor is in a no-load operation, the consumption of compressed gas on the consumption side is in a stopped state, so that the secondary passage of the lubricating oil discharge passage 18 and the intake valve 30 as described above. When the outside air is introduced into the compressor body 10 from the side and compressed and discharged, the pressure in the receiver tank gradually increases.

その結果，図９，１０に示す構成の圧縮機において長時間無負荷運転を継続すると，レシーバタンク２０に取り付けた安全弁が噴気してしまい，噴気した圧縮気体の圧縮に費やされた動力が無駄になると共に，噴気の度に発生する排気音が煩わしい。   As a result, when the no-load operation is continued for a long time in the compressor having the configuration shown in FIGS. 9 and 10, the safety valve attached to the receiver tank 20 blows, and the power consumed for compressing the compressed gas is wasted. In addition, the exhaust noise that occurs every time the fumarole blows is bothersome.

そこで本発明は，上記従来技術における欠点を解消するためになされたものであり，圧縮機本体１０に設けた潤滑油の排出流路１８を吸入弁３０の二次側に連通する構成を採用するものでありながら，無負荷運転時に潤滑油と共に外気やゴミを吸い込むことを防止して，ゴミ等の吸入に伴う故障や作動不良を防止して圧縮機の信頼性を向上させることができると共に，無負荷運転時に外気を吸入することに伴い生じる消費動力の増大や，安全弁の噴気やこれに伴う排気音の発生等を防止し得る油冷式スクリュ圧縮機を提供することを目的とする。   Accordingly, the present invention has been made to eliminate the above-described drawbacks of the prior art, and employs a configuration in which the lubricating oil discharge passage 18 provided in the compressor body 10 communicates with the secondary side of the suction valve 30. In spite of this, it is possible to prevent the intake of outside air and dust together with the lubricating oil during no-load operation, and to improve the reliability of the compressor by preventing failure and malfunction due to the suction of dust etc. It is an object of the present invention to provide an oil-cooled screw compressor that can prevent an increase in power consumption caused by inhaling outside air during no-load operation, a safety valve fuming, and the generation of exhaust noise associated therewith.

上記目的を達成するために，図８に示すように，本発明の油冷式スクリュ圧縮機１は，ケーシング１１のシリンダ１２内に収容されたオス，メス一対のスクリュロータの噛み合い回転により被圧縮気体を圧縮するときに潤滑油を注入し，圧縮気体と潤滑油との気液混合流体を吐出すると共に，前記ケーシング１１を貫通して突出するロータ軸１４ａの軸封装置５１と，前記軸封装置５１を通過して漏出した潤滑油を排出する排出流路１８を設けた油冷式のスクリュ圧縮機本体１０と，前記圧縮機本体１０の吸入通路１９を開閉制御する吸入弁３０を備えた油冷式スクリュ圧縮機１において，
前記排出流路１８と前記吸入弁３０の二次側に位置する吸入通路１９間を連通する回収流路４０を設け，前記回収流路４０に前記吸入弁３０の開放時のみ前記吸入通路１９との連通側端部と成る第１流路と，少なくとも前記吸入弁３０の閉塞時，前記吸入通路１９との連通側端部と成る第２流路を設け，
前記吸入弁３０の開閉に伴って前記回収流路４０の連通パターンを切り換えて，前記吸入弁３０の閉塞時，前記回収流路４０を縮小すると共に前記吸入通路１９と前記排出流路１８間のみの連通を確立し，前記吸入弁３０の開放時，前記吸入通路１９に連通する前記回収流路４０を拡大する回収流路調整手段を設けたことを特徴とする（請求項１）。 In order to achieve the above object, as shown in FIG. 8, the oil-cooled screw compressor 1 of the present invention is compressed by a meshing rotation of a pair of male and female screw rotors housed in a cylinder 12 of a casing 11. Lubricating oil is injected when gas is compressed, and a gas-liquid mixed fluid of compressed gas and lubricating oil is discharged, and a shaft sealing device 51 of a rotor shaft 14a protruding through the casing 11 and the shaft sealing An oil-cooled screw compressor main body 10 provided with a discharge flow path 18 for discharging lubricating oil leaked through the device 51, and a suction valve 30 for controlling the opening and closing of the suction passage 19 of the compressor main body 10 are provided. In the oil-cooled screw compressor 1,
A recovery passage 40 is provided that communicates between the discharge passage 18 and a suction passage 19 positioned on the secondary side of the suction valve 30, and the recovery passage 40 is connected to the suction passage 19 only when the suction valve 30 is opened. A first flow path serving as a communication-side end portion and a second flow path serving as a communication-side end portion connected to the suction passage 19 at least when the suction valve 30 is closed,
As the suction valve 30 is opened and closed, the communication pattern of the recovery flow path 40 is switched, and when the suction valve 30 is closed, the recovery flow path 40 is reduced and only between the suction passage 19 and the discharge flow path 18. And a recovery flow path adjusting means for enlarging the recovery flow path 40 communicating with the suction passage 19 when the suction valve 30 is opened (Claim 1).

前記構成の油冷式スクリュ圧縮機１において，前記回収流路４０の前記第１及び第２流路が，前記回収流路４０を二方向に分岐して形成された第１及び第２分岐流路４１，４２であり，
前記第１，第２分岐流路４１，４２のいずれも前記吸入通路１９に連通すると共に，前記吸入弁３０による吸入通路１９の閉塞時，前記第１分岐流路４１を閉じる開閉手段を前記流路調整手段として設け，
前記第２分岐流路４２を，前記吸入弁３０の二次側において前記吸入通路１９に連通したものとしても良い（請求項２，図１〜４，７）。 In the oil-cooled screw compressor 1 configured as described above, the first and second branch flows formed by branching the recovery passage 40 in two directions are the first and second passages of the recovery passage 40. Roads 41 and 42,
Both the first and second branch passages 41 and 42 communicate with the suction passage 19, and open / close means for closing the first branch passage 41 when the suction passage 19 is closed by the suction valve 30. Provided as a route adjustment means,
The second branch flow path 42 may be communicated with the suction passage 19 on the secondary side of the suction valve 30 (Claim 2, FIGS. 1 to 4 and 7).

前述の構成の油冷式スクリュ圧縮機１において，前記第１分岐流路４１を，前記吸入弁３０の弁座３３において開口し，前記吸入弁３０の弁体３４によって前記開口（出口３２２）を開閉する，前述の開閉手段を実現するものとしても良い（請求項３，図１〜４参照）。   In the oil-cooled screw compressor 1 having the above-described configuration, the first branch passage 41 is opened at the valve seat 33 of the suction valve 30, and the opening (outlet 322) is opened by the valve body 34 of the suction valve 30. The above-described opening / closing means that opens and closes may be realized (see claims 3 and 4).

また，別の構成としては，前記回収流路４０が，一端を前記排出流路１８に連通し，他端を前記吸入弁３０の弁座３３において開口３２２’する前記第１流路４５と，
前記第１流路４５の前記開口３２２’に対して狭い流路面積を有し，前記吸入弁３０の弁体３３に形成された前記第２流路４６を備え，
前記第２流路４６の一端開口４６１を，前記吸入弁３０の弁体３４が弁座３３に対して着座した際，すなわち，前記吸入弁３０の閉塞時，前記弁座３３に形成された前記第１流路４５の開口３２２’と連通する位置に設けると共に，前記第２流路４６の他端開口４６２を前記吸入弁３０の二次側に連通して前記吸入弁３０の弁体３４によって前記回収流路調整手段を実現しても良い（請求項４，図５参照）。 As another configuration, the recovery flow path 40 includes a first flow path 45 having one end communicating with the discharge flow path 18 and the other end opening 322 ′ in the valve seat 33 of the suction valve 30;
The second passage 46 having a narrow passage area with respect to the opening 322 ′ of the first passage 45 and formed in the valve body 33 of the suction valve 30;
The one end opening 461 of the second flow path 46 is formed in the valve seat 33 when the valve body 34 of the suction valve 30 is seated on the valve seat 33, that is, when the suction valve 30 is closed. It is provided at a position communicating with the opening 322 ′ of the first flow path 45, and the other end opening 462 of the second flow path 46 is communicated with the secondary side of the suction valve 30 by the valve body 34 of the suction valve 30. You may implement | achieve the said collection | recovery flow-path adjustment means (refer Claim 4, FIG. 5).

また，上記油冷式スクリュ圧縮機１の別の構成としては，前記第１，第２分岐流路４１，４２のいずれ共前記吸入弁３０の二次側において前記吸入通路１９に連通すると共に，前記開閉手段として，前記第１分岐流路４１中に開閉弁４４を設けた構成とすることができる（請求項５，図７参照）。   As another configuration of the oil-cooled screw compressor 1, both the first and second branch flow paths 41 and 42 communicate with the suction passage 19 on the secondary side of the suction valve 30, and As the opening / closing means, an opening / closing valve 44 may be provided in the first branch channel 41 (see claim 5 and FIG. 7).

さらに，前記油冷式スクリュ圧縮機１の別の構成としては，前記回収流路４０の前記第１及び第２流路が，前記回収流路４０を二方向に分岐して形成された第１及び第２分岐流路４１，４２であり，
前記第１，第２分岐流路４１，４２のいずれも前記吸入通路１９に連通すると共に，前記吸入弁３０による吸入通路１９の開放時，前記排出流路１８を前記第１分岐流路４１を介して前記吸入通路１９に連通すると共に第２分岐流路４２を介した連通を遮断し，前記吸入弁３０による吸入通路１９の閉塞時，前記排出流路１８を前記第２分岐流路４２を介して前記吸入通路１９に連通すると共に前記第１分岐流路４１を介した連通を遮断する切換手段を前記流路調整手段として設け，
前記第２分岐流路４２を，前記第１分岐流路４１に対して絞られた流路面積に形成すると共に，少なくとも前記第２分岐流路４２を前記吸入弁３０の二次側に連通した構成とすることができる（請求項６，図６参照）。 Furthermore, as another configuration of the oil-cooled screw compressor 1, the first and second flow paths of the recovery flow path 40 are formed by branching the recovery flow path 40 in two directions. And second branch passages 41 and 42,
Both of the first and second branch channels 41 and 42 communicate with the suction passage 19, and when the suction passage 19 is opened by the suction valve 30, the discharge channel 18 is connected to the first branch channel 41. And the communication through the second branch flow path 42 is blocked, and when the suction passage 19 is closed by the suction valve 30, the discharge flow path 18 is passed through the second branch flow path 42. A switching means for communicating with the suction passage 19 via the first branch flow path 41 and blocking the communication via the first branch flow path 41 is provided as the flow path adjusting means,
The second branch channel 42 is formed with a channel area narrowed with respect to the first branch channel 41, and at least the second branch channel 42 is communicated with the secondary side of the suction valve 30. It can be set as a structure (refer Claim 6 and FIG. 6).

この場合，前記第１，第２分岐流路４１，４２をいずれ共に前記吸入弁３０の二次側において前記吸入通路１９に連通すると共に，前記切換手段として，前記第１，第２分岐流路４１，４２の分岐点に三方切換弁４３を設けた構成としても良い（請求項７，図６参照）。   In this case, both the first and second branch flow paths 41 and 42 communicate with the suction passage 19 on the secondary side of the suction valve 30, and the first and second branch flow paths serve as the switching means. A configuration in which a three-way switching valve 43 is provided at a branch point between 41 and 42 (see claim 7 and FIG. 6) is also possible.

なお，前記油冷式スクリュ圧縮機１が，消費側に供給される圧縮気体の圧力を検出する圧力検出手段９４と，前記圧力検出手段９４の検知信号を受信して前記吸入弁３０の開閉動作を制御する制御信号を出力するコントローラ９５を備える構成である場合（図８参照），
前記開閉弁（図７の４４）又は前記三方切換弁（図６の４３）を，前記コントローラ９５が出力する前記制御信号により動作が制御される電磁弁とすれば好適である（請求項８）。 The oil-cooled screw compressor 1 receives pressure detection means 94 for detecting the pressure of the compressed gas supplied to the consumer side, and a detection signal from the pressure detection means 94 to open / close the intake valve 30. When the configuration includes a controller 95 that outputs a control signal for controlling (see FIG. 8),
Preferably, the on-off valve (44 in FIG. 7) or the three-way switching valve (43 in FIG. 6) is an electromagnetic valve whose operation is controlled by the control signal output from the controller 95 (Claim 8). .

以上説明した本発明の構成により，本発明の油冷式スクリュ圧縮機にあっては，以下の顕著な効果を得ることができた。   With the configuration of the present invention described above, the following remarkable effects can be obtained in the oil-cooled screw compressor of the present invention.

（１）前記排出流路１８と前記吸入弁３０の二次側に位置する吸入通路１９間を連通する回収流路４０を設け，前記回収流路４０に前記吸入弁３０の開放時のみ前記吸入通路１９との連通側端部となる第１流路と，少なくとも前記吸入弁３０の閉塞時，前記吸入通路１９との連通側端部となる第２流路を設け，前記吸入弁３０の開閉に伴って前記回収流路４０の連通パターンを切り換えて，前記吸入弁３０の閉塞時，前記回収流路４０を縮小すると共に前記吸入通路１９と前記排出流路１８間のみの連通を確立し，前記吸入弁３０の開放時，前記吸入通路１９に連通する前記回収流路４０を拡大する回収流路調整手段を設けたことにより，吸入弁３０の一次側の被圧縮気体が無負荷運転時の圧縮機本体１０に導入されることがなく，被圧縮気体の導入により無負荷運転時の圧縮機本体１０に負荷がかかることによる消費動力の増加，圧縮機本体１０がこのようにして導入された被圧縮気体を圧縮して吐出することにより生じるレシーバタンク２０内の圧力上昇や，これに伴う安全弁作動による噴気の発生を防止することができた。 (1) A recovery passage 40 is provided that communicates between the discharge passage 18 and a suction passage 19 positioned on the secondary side of the suction valve 30, and the suction passage 30 is provided in the recovery passage 40 only when the suction valve 30 is opened. A first flow path serving as an end on the communication side with the passage 19 and a second flow path serving as an end on the communication side with the suction passage 19 are provided at least when the suction valve 30 is closed. Accordingly, the communication pattern of the recovery flow path 40 is switched, and when the suction valve 30 is closed, the recovery flow path 40 is reduced and communication between the suction passage 19 and the discharge flow path 18 is established. When the suction valve 30 is opened, a recovery flow path adjusting means for enlarging the recovery flow path 40 communicating with the suction passage 19 is provided, so that the compressed gas on the primary side of the suction valve 30 is not in a no-load operation. Compressed air is not introduced into the compressor body 10 The receiver tank 20 is generated by the increase in power consumption due to the load applied to the compressor main body 10 during no-load operation due to the introduction of the compressor, and the compressor main body 10 compressing and discharging the compressed gas thus introduced. It was possible to prevent the occurrence of fumarole due to the internal pressure rise and the accompanying safety valve operation.

また，吸入弁３０による吸入通路１９の開放時，排出流路１８に連通する回収流路４０が前記吸入通路１９に連通する流路の流路面積を拡大することから，吸入弁３０が吸入通路１９を開いた状態にある負荷運転時において，無負荷運転時に比較して排出流路１８と吸入通路１９間の圧力差が減少した場合であっても，必要量の潤滑油を回収することが可能であった。   Further, when the suction passage 19 is opened by the suction valve 30, the recovery passage 40 communicating with the discharge passage 18 increases the flow passage area of the passage communicating with the suction passage 19. Even when the pressure difference between the discharge passage 18 and the suction passage 19 is reduced in the load operation with the 19 open, compared to the no-load operation, the required amount of lubricating oil can be recovered. It was possible.

その結果，圧縮機１の運転状態の如何に拘わらず，適正量の潤滑油を回収することができ，負荷運転時に軸封装置より漏出した潤滑油がケーシング１１外に溢れ出て飛散したり，又は，無負荷運転時において潤滑油の回収量以上の吸引を行うことにより，ゴミ等を含む外気を吸入することによって生じる前述の弊害が発生することを好適に防止することができた。   As a result, an appropriate amount of lubricating oil can be recovered regardless of the operating state of the compressor 1, and the lubricating oil leaked from the shaft seal device during load operation overflows out of the casing 11 and scatters. Alternatively, the above-described adverse effects caused by inhaling outside air including dust etc. can be suitably prevented by performing suction more than the amount of lubricant recovered during no-load operation.

（２）前記回収流路４０を分岐して形成した第１，第２分岐流路４１，４２を設けると共に，吸入弁３０の閉塞時，前記第１分岐流路４１を閉じる開閉手段を前記流路調整手段として設けたことにより（図１〜４，７参照），前記開閉手段の操作により比較的簡単に圧縮機の運転状態に対応して流路面積を調整することができた。 (2) First and second branch passages 41 and 42 formed by branching the recovery passage 40 are provided, and opening / closing means for closing the first branch passage 41 when the intake valve 30 is closed is provided in the flow path. By providing it as a path adjusting means (see FIGS. 1 to 4 and 7), it was possible to adjust the flow path area corresponding to the operating state of the compressor relatively easily by operating the opening and closing means.

（３）また，第１分岐流路４１を，吸入弁３０の弁座３３において開口した構成（図１〜４参照）にあっては，吸入弁３０の弁体３４が弁座３３に着座すると前記開口（回収孔３２の一方の出口３２２）が閉じ，又は弁体３４が弁座３３から離間することにより前記開口（回収孔３２の一方の出口３２２）を開放し，吸入弁３０の弁体３４によって前述の開閉手段を兼ねることができることから，部品の共用によって装置構成の簡略化が可能であると共に，吸入弁３０の動作状態，従って，負荷運転と無負荷運転という運転状態の切り換えに伴って，確実に流路面積の調整を行うことができた。 (3) Further, in the configuration in which the first branch passage 41 is opened at the valve seat 33 of the intake valve 30 (see FIGS. 1 to 4), when the valve body 34 of the intake valve 30 is seated on the valve seat 33. The opening (one outlet 322 of the recovery hole 32) is closed, or the valve body 34 is separated from the valve seat 33 to open the opening (one outlet 322 of the recovery hole 32). 34 can also serve as the aforementioned opening / closing means, so that the configuration of the apparatus can be simplified by sharing the parts, and the operation state of the intake valve 30, and accordingly, according to the switching of the operation state between the load operation and the no-load operation. Thus, the channel area could be adjusted reliably.

（４）吸入弁３０の弁体３４に第１流路４５と連通する第２流路４６を設けた構成（図５参照）にあっては，吸入弁３０の弁体３４が弁座３３に着座すると前記第１流路４５の開口（出口４６１）が第２流路４６に連通して潤滑油の回収流路４０を絞り，前記流路４０を縮小することができ，一方，弁体３４が弁座３３から離間することにより前記第１流路４５の開口（出口４６１）が絞られることなく開放し，吸入弁３０の弁体３４の動作に連動して流路面積の調整を行うことができた。これにより部品の共用によって装置構成の簡略化が可能であると共に，吸入弁３０の動作状態，従って，負荷運転と無負荷運転という運転状態の切り換えに伴って，確実に流路面積の調整を行うことができた。 (4) In the configuration (see FIG. 5) in which the valve body 34 of the suction valve 30 is provided with the second flow path 46 communicating with the first flow path 45, the valve body 34 of the suction valve 30 is connected to the valve seat 33. When seated, the opening (exit 461) of the first flow path 45 communicates with the second flow path 46 to restrict the lubricant recovery flow path 40 and reduce the flow path 40, while the valve element 34 Is separated from the valve seat 33 so that the opening (exit 461) of the first flow path 45 is opened without being throttled, and the flow area is adjusted in conjunction with the operation of the valve body 34 of the suction valve 30. I was able to. As a result, the configuration of the apparatus can be simplified by sharing the parts, and the flow path area can be reliably adjusted in accordance with the switching of the operation state of the intake valve 30, and hence the operation state between the load operation and the no-load operation. I was able to.

（５）更に，前記開閉手段として第１分岐流路４１に開閉弁４４を設けた構成（図７参照）にあっては，開閉弁４４の開閉という比較的簡単な操作によって流路面積の調整が可能であった。また，この開閉弁４４を電磁弁等とすることにより，電子制御化が容易であった。 (5) Further, in the configuration (see FIG. 7) in which the opening / closing valve 44 is provided in the first branch passage 41 as the opening / closing means, the passage area can be adjusted by a relatively simple operation of opening / closing the opening / closing valve 44. Was possible. Also, electronic control can be facilitated by using an on-off valve 44 as a solenoid valve.

（６）前述の第１，第２分岐流路４１，４２をそれぞれ異なる流路面積とすると共に，切換手段（図示の例では三方切換弁４３）によって前記排出流路１８を択一的に選択された第１，第２いずれか一方の分岐流路４１，４２を介して前記吸入通路１９と連通することにより容易に流路面積の変更を行うことができた（図６参照）。 (6) The first and second branch channels 41 and 42 described above have different channel areas, and the discharge channel 18 is alternatively selected by switching means (three-way switching valve 43 in the illustrated example). The flow passage area could be easily changed by communicating with the suction passage 19 via either the first or second branch flow passage 41, 42 (see FIG. 6).

（７）また，前記切換手段として，第１，第２分岐流路４１，４２の分岐点に三方切換弁４３を設けた構成（図６参照）にあっては，三方切換弁の操作という比較的簡単な操作によって流路面積の調整が可能であり，また，この三方切換弁として電磁弁を採用することにより，電子制御化が容易であった。 (7) If the three-way switching valve 43 is provided at the branch point of the first and second branch flow paths 41, 42 as the switching means (see FIG. 6), the comparison of the operation of the three-way switching valve The flow area can be adjusted by simple operation, and electronic control is easy by adopting a solenoid valve as this three-way switching valve.

（８）圧縮機が，図８を参照して説明したように消費側に供給される圧縮気体の圧力を検出する圧力センサ等の圧力検出手段９４と，前記圧力検出手段９４の検知信号を受信して前記吸入弁３０の開閉動作を制御する制御信号を出力する，電子制御装置であるコントローラ９５を備える構成である場合，前述の開閉弁４４（図７参照）や三方切換弁４３（図６参照）を電磁弁として構成することにより，この電磁弁を，前記コントローラ９５が出力する吸入弁３０の開閉を制御するための制御信号によって作動させることにより，吸入弁３０の開閉動作，従って負荷運転，無負荷運転という圧縮機の運転状態の変化に対応して，確実に流路面積を調整することができると共に，コントローラの共用による部品点数の減少と装置構成の簡略化を実現することができた。 (8) The compressor receives the pressure detection means 94 such as a pressure sensor for detecting the pressure of the compressed gas supplied to the consumption side as described with reference to FIG. 8, and the detection signal of the pressure detection means 94. When the controller 95 is an electronic control unit that outputs a control signal for controlling the opening / closing operation of the intake valve 30, the above-described opening / closing valve 44 (see FIG. 7) or the three-way switching valve 43 (see FIG. 6). Is configured as a solenoid valve, and this solenoid valve is operated by a control signal for controlling the opening and closing of the suction valve 30 output from the controller 95, so that the opening and closing operation of the suction valve 30, and therefore the load operation is performed. In response to changes in compressor operating conditions such as no-load operation, the flow path area can be adjusted reliably, and the number of parts can be reduced and the system configuration can be simplified by sharing the controller. I was able to be present.

次に，本発明の実施形態につき添付図面を参照しながら以下説明する。   Next, embodiments of the present invention will be described below with reference to the accompanying drawings.

〔油冷式スクリュ圧縮機の全体構成〕
本発明の油冷式スクリュ圧縮機１は，吸入弁３０を介して導入された被圧縮気体を吸入して圧縮するときに潤滑油を注入し，圧縮気体と潤滑油との気液混合流体を吐出する圧縮機本体１０と，この気液混合流体の状態で吐出された圧縮気体を導入して気液分離するレシーバタンク２０を備え，前記レシーバタンク２０内で分離された潤滑油が，レシーバタンク２０内の圧力によってオイルクーラ２１，オイルフィルタ２２を備えた給油配管９１を介して圧縮機本体１０の給油口１５に導入して循環する潤滑油の循環系が形成されている点において，図８を参照して説明した油冷式スクリュ圧縮機１と同様の構成である。 [Overall configuration of oil-cooled screw compressor]
The oil-cooled screw compressor 1 of the present invention injects lubricating oil when the compressed gas introduced through the intake valve 30 is sucked and compressed, and a gas-liquid mixed fluid of the compressed gas and the lubricating oil is supplied. A compressor main body 10 to be discharged and a receiver tank 20 for introducing a compressed gas discharged in the state of the gas-liquid mixed fluid to separate the gas and liquid are provided, and the lubricating oil separated in the receiver tank 20 is a receiver tank. The point that the circulation system of the lubricating oil that is introduced into the oil supply port 15 of the compressor body 10 through the oil supply pipe 91 provided with the oil cooler 21 and the oil filter 22 and circulates is formed by the pressure in the engine 20. This is the same configuration as the oil-cooled screw compressor 1 described with reference to FIG.

また，前述の圧縮機本体１０には，ケーシング１１を貫通して突出するロータ軸１４ａが設けられており，このロータ軸１４ａの外周にシール室１６を設けてこのシール室１６内にメカニカルシール等の軸封装置５１を収容して軸封を行っていると共に，この軸封装置５１を通過して漏出した潤滑油を捕集するための溝１７と，この溝１７に連通する排出流路１８が設けられている点においても，図８を参照して説明した油冷式スクリュ圧縮機１と同様の構成を備えている。   Further, the above-described compressor body 10 is provided with a rotor shaft 14a protruding through the casing 11, a seal chamber 16 is provided on the outer periphery of the rotor shaft 14a, and a mechanical seal or the like is provided in the seal chamber 16. The shaft sealing device 51 is accommodated to seal the shaft, and the groove 17 for collecting the lubricating oil leaked through the shaft sealing device 51 and the discharge flow path 18 communicating with the groove 17 are collected. Is provided with the same configuration as the oil-cooled screw compressor 1 described with reference to FIG.

〔潤滑油回収手段〕
本発明の油冷式スクリュ圧縮機１にあっては，前記軸封装置５１を通過して漏出した潤滑油を，前記潤滑油の循環系に回収するために，本発明の油冷式スクリュ圧縮機１には，前記排出流路１８と吸入通路１９間を連通する，潤滑油の回収流路４０が設けられていると共に，前記吸入弁３０による吸入通路１９の閉塞時，前記排出流路１８に連通する回収流路４０を前記吸入弁３０の二次側にのみ連通し，前記吸入弁３０による吸入通路１９の開放時，前記排出流路１８に連通する回収流路を前記吸入通路１９の閉塞時に対して拡大された流路面積で前記吸入通路１９に連通する回収流路調整手段を設けており，この回収流路４０と回収流路調整手段とによって潤滑油回収手段が構成されている。 [Lubricating oil recovery means]
In the oil-cooled screw compressor 1 of the present invention, the oil-cooled screw compressor of the present invention is used to collect the lubricating oil leaked through the shaft seal device 51 in the lubricating oil circulation system. The machine 1 is provided with a lubricating oil recovery passage 40 that communicates between the discharge passage 18 and the suction passage 19, and when the suction passage 19 is closed by the suction valve 30, the discharge passage 18. The recovery passage 40 communicating with the discharge passage 18 is communicated only with the secondary side of the suction valve 30, and when the suction passage 19 is opened by the suction valve 30, the collection passage communicating with the discharge passage 18 is connected to the suction passage 19. A recovery flow path adjusting means communicating with the suction passage 19 is provided with a flow path area enlarged with respect to the closed time, and the recovery flow path adjusting means is constituted by the recovery flow path 40 and the recovery flow path adjusting means. .

以下，本発明の油冷式スクリュ圧縮機で採用する前記潤滑油回収手段の構成例を，実施形態１〜３として説明する。   Hereinafter, the structural example of the said lubricating oil collection | recovery means employ | adopted with the oil-cooled screw compressor of this invention is demonstrated as Embodiment 1-3.

（１）実施形態１
本発明の油冷式スクリュ圧縮機１に設けられる潤滑油回収手段は，前述のように，圧縮機本体１０のケーシング１１を貫通して突設されたロータ軸１４ａの軸孔に設けられた溝１７と連通する排出流路１８に連通する回収流路４０を圧縮機本体１０の吸入通路１９に連通回収流路４０によって回収するもので，負荷運転，無負荷運転という圧縮機の運転状態の変化に伴って，前記回収流路４０の連通パターンを切り換える回収流路調整手段によって流路面積を可変として，いずれの運転状態においても適正量の潤滑油を回収することができるように構成されている。 (1) Embodiment 1
As described above, the lubricating oil recovery means provided in the oil-cooled screw compressor 1 of the present invention is a groove provided in the shaft hole of the rotor shaft 14a protruding through the casing 11 of the compressor body 10. The recovery flow path 40 communicating with the discharge flow path 18 communicating with 17 is recovered by the communication recovery flow path 40 to the suction passage 19 of the compressor body 10, and changes in the compressor operating state between load operation and no load operation Accordingly, the flow area is made variable by the recovery flow path adjusting means for switching the communication pattern of the recovery flow path 40 so that an appropriate amount of lubricating oil can be recovered in any operating state. .

このように，回収流路４０の流路面積を可変とするために，本実施形態の油冷式スクリュ圧縮機１では，圧縮機本体１０の潤滑油の排出流路１８に連通する回収流路４０を二方向に分岐して，いずれとも圧縮機本体１０の吸入通路１９に連通する第１，第２分岐流路４１，４２を設け，この分岐流路の一方である第１分岐流路４１を開閉可能とすることにより，分岐流路の他方である第２分岐流路４２のみを介した潤滑油の回収と，第１，第２の２つの分岐流路４１，４２を介した，拡大された流路面積での潤滑油の回収を行うことかできるように構成している。   Thus, in order to make the flow path area of the recovery flow path 40 variable, in the oil-cooled screw compressor 1 of the present embodiment, the recovery flow path communicating with the lubricating oil discharge flow path 18 of the compressor body 10. 40 is bifurcated in both directions, and both are provided with first and second branch passages 41 and 42 communicating with the suction passage 19 of the compressor body 10, and the first branch passage 41 is one of the branch passages. Can be opened and closed to collect the lubricating oil only through the second branch channel 42, which is the other of the branch channels, and to expand through the first and second branch channels 41, 42. The lubricating oil can be recovered in the flow path area thus formed.

前述の回収流路４０は，図１に示す実施形態にあっては，前記排出流路１８に一端を連通された回収配管７０と，前記回収配管７０の他端に連通された，吸入弁３０の弁箱３１内外を連通する回収孔３２によって構成されていると共に，前記回収流路調整手段としてこの回収孔３２の後述する一方の出口３２２を開閉する開閉手段を設けている。   In the embodiment shown in FIG. 1, the aforementioned recovery flow path 40 has a recovery pipe 70 having one end connected to the discharge flow path 18 and a suction valve 30 connected to the other end of the recovery pipe 70. In addition, a recovery hole 32 communicating between the inside and the outside of the valve box 31 is provided, and an opening / closing means for opening and closing one outlet 322 described later of the recovery hole 32 is provided as the recovery flow path adjusting means.

図１及び図２に示す実施形態において，この回収孔３２は，弁箱３１の肉厚内において二方向に分岐して前述の第１，第２分岐流路４１，４２を設けた構成とされており，弁箱３１の外側において開口した単一の入口３２１に対し，弁箱３１の内側において開口する２つの出口３２２，３２３を備えている。   In the embodiment shown in FIGS. 1 and 2, the recovery hole 32 is configured to branch in two directions within the thickness of the valve box 31 and to provide the first and second branch channels 41 and 42 described above. In contrast, a single inlet 321 opened outside the valve box 31 is provided with two outlets 322 and 323 opened inside the valve box 31.

そして，この回収孔３２中に形成された第１分岐流路４１を，前記入口３２１から一定の径を有する流路として形成すると共に，吸入弁３０の弁箱３１内に設けられた弁座３３の形成位置において出口３２２を開口し，第２分岐流路４２を，前記第１分岐流路４１に対して絞られた流路面積を持つ流路として形成すると共に前記吸入弁３０の二次側において弁箱３１内の空間に出口３２３を形成した。   The first branch passage 41 formed in the recovery hole 32 is formed as a passage having a constant diameter from the inlet 321 and a valve seat 33 provided in the valve box 31 of the suction valve 30. The second branch channel 42 is formed as a channel having a narrowed channel area with respect to the first branch channel 41 and the secondary side of the intake valve 30 is opened. The outlet 323 was formed in the space inside the valve box 31.

従って，第２分岐流路４２の出口３２３は，吸入弁３０の開閉状態如何に拘わらず，圧縮機本体１０の吸入通路１９に常時連通した状態にある。   Therefore, the outlet 323 of the second branch passage 42 is always in communication with the suction passage 19 of the compressor body 10 regardless of whether the suction valve 30 is open or closed.

なお，図２に示す実施形態にあっては，前記回収孔３２を弁箱３１の肉厚内に形成した回収孔３２を分岐して第１，第２分岐流路４１，４２を形成するものと説明したが，例えば図３に示すように流路面積の異なる二つの回収孔３２ａ，３２ｂをそれぞれ別個に形成すると共に，回収配管７０の他端を分岐して形成された分岐管７０ａ，７０ｂのそれぞれを前記２つの回収孔３２ａ，３２ｂに連通する構成として，一方の分岐管７０ａと回収孔３２ａによって第１分岐流路４１を形成し，他方の分岐管７０ｂと回収孔３２ｂによって第２分岐流路４２を形成するものとしても良い。   In the embodiment shown in FIG. 2, the first and second branch passages 41 and 42 are formed by branching the recovery hole 32 in which the recovery hole 32 is formed within the thickness of the valve box 31. However, for example, as shown in FIG. 3, two recovery holes 32a and 32b having different flow channel areas are formed separately, and branch pipes 70a and 70b formed by branching the other end of the recovery pipe 70 are formed. Are connected to the two recovery holes 32a and 32b, the first branch flow path 41 is formed by one branch pipe 70a and the recovery hole 32a, and the second branch is formed by the other branch pipe 70b and the recovery hole 32b. The flow path 42 may be formed.

この場合，図示の例では一方，他方の回収孔３２ａ，３２ｂ共に弁箱３１の肉圧内に形成するものとして示したが，他方の回収孔３２ｂは，これを吸入通路１９を画成する部分の圧縮機本体１０のケーシング１１肉厚を貫通して形成するものとしても良い。   In this case, in the illustrated example, one of the other recovery holes 32 a and 32 b is shown as being formed in the wall pressure of the valve box 31, but the other recovery hole 32 b is a part that defines the suction passage 19. It is good also as what penetrates and forms the casing 11 thickness of the compressor main body 10 of this.

更には，図２を参照した説明では，回収孔３２に形成した第２分岐流路４２の流路面積を第１分岐流路４１の流路面積に対して減少された流路面積に形成するものとして説明したが，例えば図４に示すように，第１分岐流路４１の流路面積を，第２分岐流路４２の流路面積と同面積に形成するものとしても良い。   Furthermore, in the description with reference to FIG. 2, the flow passage area of the second branch flow passage 42 formed in the recovery hole 32 is formed to be a flow passage area reduced with respect to the flow passage area of the first branch flow passage 41. As described above, for example, as shown in FIG. 4, the flow path area of the first branch flow path 41 may be formed to the same area as the flow path area of the second branch flow path 42.

以上のように構成された回収流路４０において，弁座３３に出口３２２を開口した第１分岐流路４１は，吸入弁３０の弁体３４が弁座３３に着座したとき閉塞され，また，弁体３４が弁座３３より離間した際に開放されることとなり，吸入弁３０の弁体３４によって，第１分岐流路４１の開閉を行う開閉手段が実現される。   In the recovery flow path 40 configured as described above, the first branch flow path 41 having the outlet 322 opened in the valve seat 33 is closed when the valve body 34 of the suction valve 30 is seated on the valve seat 33, and When the valve body 34 is separated from the valve seat 33, the valve body 34 is opened, and the valve body 34 of the intake valve 30 realizes an opening / closing means for opening and closing the first branch flow path 41.

その結果，別途第１分岐流路４１を開閉する開閉手段を設ける必要がなく，部品の共用による部品点数の減少と装置構成の簡略化が可能であると共に，吸入弁３０の弁体３３は，負荷運転，無負荷運転という圧縮機１の運転状態の変化に対応して出口３２２を開閉することができる。   As a result, it is not necessary to separately provide an opening / closing means for opening / closing the first branch flow path 41, the number of parts can be reduced by sharing the parts, and the device configuration can be simplified. The outlet 322 can be opened and closed in response to changes in the operating state of the compressor 1 such as load operation and no-load operation.

そして，前述の吸入弁３０の弁体３４は，圧縮機１が無負荷運転にあるとき弁座３３に着座して吸入通路１９を閉じ，圧縮機１が負荷運転にあるとき弁座３３より離間して吸入通路１９を開いた状態となる。   The valve body 34 of the suction valve 30 is seated on the valve seat 33 when the compressor 1 is in a no-load operation and closes the suction passage 19, and is separated from the valve seat 33 when the compressor 1 is in a load operation. Thus, the suction passage 19 is opened.

その結果，圧縮機１が負荷運転を行っているとき，すなわち，排出流路１８と吸入通路１９間の圧力差が小さい時には，第１分岐流路４１と，第２分岐流路４２の双方から成る前記回収流路４０の吸入通路側端部を介して潤滑油の回収が行われ，両流路４１，４２の流路面積の和である拡大された流路面積の流路によって排出流路１８が圧縮機本体１０の吸入通路１９に連通する。   As a result, when the compressor 1 is performing a load operation, that is, when the pressure difference between the discharge passage 18 and the suction passage 19 is small, both the first branch passage 41 and the second branch passage 42 are used. The recovery of the lubricating oil is performed via the suction passage side end of the recovery passage 40, and the discharge passage is expanded by the passage having an enlarged passage area which is the sum of the passage areas of both passages 41 and 42. 18 communicates with the suction passage 19 of the compressor body 10.

一方，圧縮機１が無負荷運転を行っているとき，すなわち，排出流路１８と吸入通路１９間の圧力差が大きい時には，第１分岐流路４１の出口３２２は弁体３４によって閉塞され，流路面積が絞られた第２分岐流路４２のみから成る前記回収流路４０の吸入通路側端部を介して潤滑油の回収が行われる。   On the other hand, when the compressor 1 is performing no-load operation, that is, when the pressure difference between the discharge passage 18 and the suction passage 19 is large, the outlet 322 of the first branch passage 41 is blocked by the valve body 34, Lubricating oil is recovered through the suction passage side end of the recovery flow path 40, which is composed of only the second branch flow path 42 with a reduced flow path area.

従って，第２分岐流路４２の流路面積を絞り，前記流路を縮小して，無負荷運転時の吸入通路１９内で生じる負圧に対応した流路面積とすることにより，排出流路１８を介して排出される潤滑油量を越える吸入が行われることを防止でき，潤滑油と共にゴミ等を含む外気が圧縮機本体１０内に導入されることを防止することができる。   Accordingly, the discharge flow path is reduced by reducing the flow area of the second branch flow path 42 and reducing the flow path to a flow area corresponding to the negative pressure generated in the suction path 19 during no-load operation. It is possible to prevent intake exceeding the amount of the lubricating oil discharged through 18, and to prevent outside air including dust and the like from being introduced into the compressor body 10 together with the lubricating oil.

その結果，圧縮機１の故障や作動不良の発生を防止することができると共に，圧縮機本体１０が吸入した外気を圧縮することによって生じる不要な動力消費が低減される。   As a result, the compressor 1 can be prevented from malfunctioning or malfunctioning, and unnecessary power consumption caused by compressing the outside air sucked by the compressor body 10 is reduced.

また，無負荷運転時に圧縮機本体１０が吸入された外気を圧縮して吐出することを防止できることから，レシーバタンク２０の安全弁が作動して噴気することも防止できる。   Further, since the compressor main body 10 can be prevented from being compressed and discharged during no-load operation, it can be prevented that the safety valve of the receiver tank 20 is operated and blown.

これに対し，第１分岐流路４１の流路面積と，第２分岐流路４２の流路面積の合計を，負荷運転時において吸入通路１９内で発生する負圧に対応した流路面積とすることにより，無負荷運転時に比較して排出流路１８と吸入通路１９間の圧力差が減少する負荷運転時においても，潤滑油の回収量が減少することを防止でき，潤滑油の回収量が排出量に対して減少することにより生じる潤滑油の漏出や飛散を好適に防止することができる。   On the other hand, the total of the flow area of the first branch flow path 41 and the flow area of the second branch flow path 42 is the flow area corresponding to the negative pressure generated in the suction passage 19 during load operation. By doing so, it is possible to prevent the recovery amount of the lubricating oil from being reduced even during the load operation in which the pressure difference between the discharge passage 18 and the suction passage 19 is reduced as compared with the no-load operation. Can be suitably prevented from leaking or scattering of the lubricating oil caused by a decrease in the amount of oil discharged.

なお，吸入弁３０の弁体３４の動作に連動して潤滑油を回収する回収流路の流路面積を調整する構成としては，図５に示すように前記図３を参照して説明した回収孔３２ａ，３２ｂの一方３２ａに対応する回収孔３２ａ’のみを形成し，この回収孔３２ａ’の入口３２１’に，排出通路１８に連通した回収配管７０の他端を連通して，前記回収配管７０と回収孔３２ａ’によって第１流路４５を形成すると共に，この回収孔３２ａ’の出口３２２’の形成位置に対応して，弁体３４に前記出口３２２’の開口径に対して細径に形成された第２流路４６を設け，弁体３４が弁座３３に着座することにより，この第２流路４６の一端開口４６１が前記第１流路４５を構成する回収孔３２ａ’の出口４５２に連通すると共に，他端開口４６２が吸入弁３０の二次側空間に連通して，この第２流路４６によって回収流路４０の吸入通路１９側端部を形成して回収流路４０を縮小するように形成するものとしても良い。   In addition, as a structure which adjusts the flow-path area of the collection | recovery flow path which collect | recovers lubricating oil in response to operation | movement of the valve body 34 of the suction valve 30, as shown in FIG. 5, the collection | recovery demonstrated with reference to the said FIG. Only the recovery hole 32a ′ corresponding to one of the holes 32a and 32b is formed, and the other end of the recovery pipe 70 communicated with the discharge passage 18 is connected to the inlet 321 ′ of the recovery hole 32a ′. 70 and the recovery hole 32a ′ form the first flow path 45, and the valve body 34 has a smaller diameter than the opening diameter of the outlet 322 ′ corresponding to the formation position of the outlet 322 ′ of the recovery hole 32a ′. And the valve element 34 is seated on the valve seat 33, so that one end opening 461 of the second flow path 46 is formed in the recovery hole 32 a ′ constituting the first flow path 45. The other end opening 462 communicates with the outlet 452 and sucks Communicates with the 30 of the secondary space may be as forming so as to reduce the recovery flow path 40 to form a suction passage 19 side end portion of the recovery flow passage 40 by the second flow path 46.

この構成により，吸入弁３０の弁体３４が弁座３３より離間した際，すなわち，圧縮機１の負荷運転時には回収孔３２ａ’は第２流路４６を介さず圧縮機本体１０の吸入通路１９と連通して，第１流路４５が回収流路４０の吸入通路１９側の端部を形成し，これにより拡大された流路面積によって潤滑油の回収を行うことが可能である。   With this configuration, when the valve body 34 of the suction valve 30 is separated from the valve seat 33, that is, during the load operation of the compressor 1, the recovery hole 32 a ′ does not pass through the second flow path 46 and the suction passage 19 of the compressor body 10. The first flow path 45 forms the end of the recovery flow path 40 on the suction passage 19 side, and the lubricant can be recovered by the expanded flow path area.

（２）実施形態２
以上，図１〜４を参照して説明した構成にあっては，吸入弁３０の弁箱３１の肉圧を貫通して形成した回収孔３２に第１，第２分岐流路４１，４２を設け，第１分岐流路４１に連通する出口３２２を，吸入弁３０の弁座３３において開口し，吸入弁３０の弁体３４によって第１分岐流路４１の出口３２２を開閉することができるように構成したが，図６を参照して説明する本発明の別の実施形態にあっては，別個に形成された２つの回収孔３２ａ，３２ｂを，吸入通路１９を画成する圧縮機本体１０のケーシング１１の肉厚を貫通して形成し，いずれの回収孔３２ａ，３２ｂの出口３２２，３２３共に，吸入弁３０の二次側において圧縮機本体１０の吸入通路１９内で開口するように構成している。 (2) Embodiment 2
As described above, in the configuration described with reference to FIGS. 1 to 4, the first and second branch flow paths 41 and 42 are provided in the recovery hole 32 formed through the wall pressure of the valve box 31 of the intake valve 30. An outlet 322 provided to communicate with the first branch passage 41 is opened at the valve seat 33 of the suction valve 30 so that the outlet 322 of the first branch passage 41 can be opened and closed by the valve body 34 of the suction valve 30. However, in another embodiment of the present invention described with reference to FIG. 6, the compressor body 10 defining the suction passage 19 is formed by two recovery holes 32 a and 32 b formed separately. The outlets 322 and 323 of any of the recovery holes 32 a and 32 b are configured to open in the suction passage 19 of the compressor body 10 on the secondary side of the suction valve 30. is doing.

この回収孔３２ａ，３２ｂは，一方の回収孔３２ａが，他方の回収孔３２ｂに対して拡大された流路面積を有しており，このうちのいずれか一方を択一的に選択して，回収配管７０を介して前述の排出流路１８と連通することで，潤滑油の回収流路４０の流路面積を調整することができるように構成されている。   The recovery holes 32a and 32b have one of the recovery holes 32a having an enlarged flow passage area with respect to the other of the recovery holes 32b. By communicating with the above-described discharge flow path 18 via the recovery pipe 70, the flow path area of the recovery path 40 for the lubricating oil can be adjusted.

このように，前記排出流路１８に対して回収孔３２ａ，３２ｂのいずれか一方を択一的に連通することができるようにするために，図６に示す実施形態にあっては，回収配管７０を二方向に分岐して，一方の分岐管７０ａを流路面積の大きい一方の回収孔３２ａの入口３２１ａに連通し，分岐管７０ａと回収孔３２ａで第１分岐流路４１を形成すると共に，回収配管７０の他方の分岐管７０ｂを，流路面積の小さい他方の回収孔３２ｂの入口３２１ｂに連通して分岐管７０ｂと回収孔３２ｂで第２分岐流路４２を形成し，前記分岐管７０ａ，７０ｂの分岐点に三方切換弁４３を設け，この三方切換弁４３の操作により圧縮機本体１０に設けられた排出流路１８を，第１分岐流路４１又は第２分岐流路４２のいずれか一方を介して圧縮機本体１０の吸入通路１９に連通することができるように構成し，第１，第２いずれの分岐流路４１，４２を選択するかにより流路面積を可変とすることができるように構成した。   As described above, in the embodiment shown in FIG. 6, in order to be able to selectively communicate one of the recovery holes 32 a and 32 b with the discharge flow path 18, the recovery pipe 70 is branched in two directions, and one branch pipe 70a communicates with the inlet 321a of one recovery hole 32a having a larger flow path area, and the first branch flow path 41 is formed by the branch pipe 70a and the recovery hole 32a. The other branch pipe 70b of the recovery pipe 70 is communicated with the inlet 321b of the other recovery hole 32b having a small flow area, and the second branch flow path 42 is formed by the branch pipe 70b and the recovery hole 32b. A three-way switching valve 43 is provided at the branch point of 70a and 70b, and the discharge flow path 18 provided in the compressor body 10 by the operation of the three-way switching valve 43 is connected to the first branch flow path 41 or the second branch flow path 42. Compressor body 1 through either one And configured to be able to communicate with the suction passage 19, the first, and the flow area by either selecting a second one of the branch flow path 41 is configured to be variable.

本実施形態にあっては，この三方切換弁４３を電磁弁（三方電磁弁）として形成し，コントローラ９５からの制御信号の入力によって，前記第１，第２いずれかの分岐流路４１，４２を介して選択的に排出流路１８を回収通路１９に連通可能とした。   In the present embodiment, the three-way switching valve 43 is formed as a solenoid valve (three-way solenoid valve), and the first or second branch flow path 41, 42 is input by the input of a control signal from the controller 95. The discharge channel 18 can be selectively communicated with the recovery passageway 19 via the.

この三方電磁弁４３に対して制御信号を出力するコントローラ９５としては，一例として図８を参照して説明したように，吸入弁３０の開閉制御を行うための制御信号を出力するコントローラ９５を共用することができ，これにより吸入弁３０の開閉動作，従って，負荷運転，無負荷運転という圧縮機１の運転状態の変化に対応して三方電磁弁４３の切換動作を行うことができる。   As the controller 95 that outputs a control signal to the three-way solenoid valve 43, as described with reference to FIG. 8 as an example, the controller 95 that outputs a control signal for controlling the opening and closing of the intake valve 30 is shared. Thus, the switching operation of the three-way solenoid valve 43 can be performed in response to the opening / closing operation of the intake valve 30, and accordingly, the operating state of the compressor 1 such as the load operation and the no-load operation.

前述の図８を参照して説明した油冷式スクリュ圧縮機１にあっては，閉弁受圧型の吸入弁３０を採用すると共に，制御配管９２に設けた電磁開閉弁９３をノーマリクローズ型として，コントローラ９５からの制御信号の入力時，制御配管９２を開いて吸入弁３０の閉弁受圧室内にレシーバタンク２０内の圧縮気体を導入して吸入通路１９を閉じることができるように構成されている。すなわち，コントローラ９５は，無負荷運転時に制御信号を出力するように形成されている。   In the oil-cooled screw compressor 1 described with reference to FIG. 8 described above, the valve-closing pressure-receiving suction valve 30 is adopted, and the electromagnetic on-off valve 93 provided in the control pipe 92 is normally closed. When the control signal is inputted from the controller 95, the suction pipe 19 can be closed by opening the control pipe 92 and introducing the compressed gas in the receiver tank 20 into the closed pressure receiving chamber of the suction valve 30. ing. That is, the controller 95 is configured to output a control signal during no-load operation.

従って，前記回収配管７０の分岐点７１に設けられた三方電磁弁４３の共通ポート（ＣＯＭ）を，回収配管７０を介して圧縮機本体１０の排出流路１８に連通すると共に，ノーマリオープンのポート（ＮＯ）を第１分岐流路４１を構成する分岐管７０ａに，ノーマリクローズのポート（ＮＣ）を第２分岐流路４２を構成する分岐管７０ｂにそれぞれ連通して，コントローラ９５の制御信号の入力がないとき（負荷運転時），第１分岐流路４１を前記回収流路４０の吸入通路１９側端部と成し，この第１分岐流路４１を介して排出流路１８と吸入通路１９との連通が行われると共に，コントローラ９５の制御信号の入力時（無負荷運転時），第２分岐流路４２を前記回収流路４０の吸入通路１９側端部と成し，この第２回収流路４２を介して排出流路１８と吸入通路１９との連通が行われるように構成した。   Accordingly, the common port (COM) of the three-way solenoid valve 43 provided at the branch point 71 of the recovery pipe 70 is communicated with the discharge flow path 18 of the compressor body 10 via the recovery pipe 70 and is normally open. The port (NO) is communicated with the branch pipe 70a constituting the first branch flow path 41, and the normally closed port (NC) is communicated with the branch pipe 70b constituting the second branch flow path 42. When no signal is input (during load operation), the first branch passage 41 is formed as an end of the recovery passage 40 on the suction passage 19 side, and the discharge passage 18 is connected via the first branch passage 41. The communication with the suction passage 19 is performed, and when the control signal of the controller 95 is input (during no load operation), the second branch passage 42 is formed as the end of the recovery passage 40 on the suction passage 19 side. Drain through the second recovery channel 42 Communication between the passage 18 and the suction passage 19 is configured to be performed.

以上のように構成された油冷式スクリュ圧縮機１において，第１分岐流路４１（回収孔３２ａ），第２分岐流路４２（回収孔３２ｂ）共に，吸入弁３０の二次側において開口し，圧縮機１が負荷運転の状態にあるときには流路面積の大きい第１分岐流路４１（回収孔３２ａ）を介して潤滑油の回収を行うと共に，圧縮機１が無負荷運転の状態にあるときには，流路面積の小さい第２分岐流路４２（回収孔３２ｂ）を介して潤滑油の回収を行うことから，圧縮機１の運転状態に対応した流路面積で潤滑油を回収することができ，無負荷運転時に圧縮機本体にゴミ等を含んだ外気や吸入弁３０の一次側の被圧縮気体が導入されることがない。   In the oil-cooled screw compressor 1 configured as described above, both the first branch flow path 41 (recovery hole 32a) and the second branch flow path 42 (recovery hole 32b) are opened on the secondary side of the intake valve 30. When the compressor 1 is in a load operation state, the lubricating oil is recovered through the first branch passage 41 (recovery hole 32a) having a large channel area, and the compressor 1 is in a no-load operation state. In some cases, the lubricating oil is recovered via the second branch flow path 42 (recovery hole 32b) having a small flow path area, so that the lubricating oil is recovered with a flow path area corresponding to the operating state of the compressor 1. Thus, during the no-load operation, the outside air containing dust and the compressed gas on the primary side of the suction valve 30 are not introduced into the compressor body.

その結果，ゴミ等の吸入がないことに伴う圧縮機の信頼性の向上，圧縮機の消費動力の軽減，レシーバタンク２０内の圧力上昇に伴い安全弁の噴気等が発生することを好適に防止することができると共に，無負荷運転時において潤滑油の回収量が低下して潤滑油がケーシング１１より外部に漏出したり，飛散したりすることが防止できる点については，前述した実施形態１における油冷式スクリュ圧縮機と同様である。   As a result, the reliability of the compressor is improved due to the absence of inhalation of dust, the consumption power of the compressor is reduced, and the occurrence of a safety valve blow or the like due to a rise in pressure in the receiver tank 20 is suitably prevented. In the first embodiment described above, it is possible to prevent the amount of lubricant recovered during the no-load operation from decreasing and preventing the lubricant from leaking out of the casing 11 and scattering. It is the same as a cold screw compressor.

更に，本実施形態の油冷式スクリュ圧縮機にあっては，油冷式スクリュ圧縮機１に設けられた容量制御装置のコントローラ９５を，潤滑油回収手段４０に設けた三方電磁弁４３の動作制御にも使用したことにより，構成部品の共有により使用する部品点数の減少と，装置構成の簡略化についても実現することができるものとなっている。   Furthermore, in the oil-cooled screw compressor of this embodiment, the controller 95 of the capacity control device provided in the oil-cooled screw compressor 1 is operated by the operation of the three-way solenoid valve 43 provided in the lubricating oil recovery means 40. Since it is also used for control, it is possible to reduce the number of parts to be used by sharing the components and to simplify the device configuration.

（３）実施形態３
図６を参照して説明した前述の実施形態２の構成にあっては，第１分岐流路４１（回収孔３２ａ）の流路面積を大きく，第２分岐流路４２（回収孔３２ｂ）を前記第１分岐流路４１（回収孔３２ａ）に対して流路面積を小さく構成しているが，図７を参照して説明する本実施形態の構成にあっては，第１，第２いずれの分岐流路４１，４２（回収孔３２ａ，３２ｂ）の流路面積共に，同一の流路面積（図６における第２分岐流路４２の回収孔３２ｂと同程度の比較的狭い流路面積）に形成すると共に，図６を参照して説明した実施形態２では回収配管７０の分岐点７１に設けていた三方電磁弁４３に代え，分岐された一方の分岐管７０ａ中にノーマリオープン型の電磁開閉弁４４を設け，この電磁開閉弁４４によって，コントローラ９５による制御信号の出力時，前記一方の分岐管７０ａを閉じるように構成したものであり，その他の構成は，図６を参照して説明した実施形態２に記載の構成と同様である。 (3) Embodiment 3
In the configuration of the above-described second embodiment described with reference to FIG. 6, the flow area of the first branch flow path 41 (recovery hole 32a) is increased, and the second branch flow path 42 (recovery hole 32b) is provided. The flow path area is configured to be smaller than that of the first branch flow path 41 (recovery hole 32a). However, in the configuration of the present embodiment described with reference to FIG. Both of the flow passage areas of the branch flow passages 41 and 42 (recovery holes 32a and 32b) have the same flow passage area (a relatively narrow flow passage area similar to that of the recovery holes 32b of the second branch flow passage 42 in FIG. 6). In the second embodiment described with reference to FIG. 6, instead of the three-way solenoid valve 43 provided at the branch point 71 of the recovery pipe 70, a normally open type is provided in one branch pipe 70a. An electromagnetic opening / closing valve 44 is provided. When the output of the control signal, the are those configured to close one of the branch pipes 70a, other configuration is the same as described in the second embodiment described with reference to FIG.

以上のように構成された油冷式スクリュ圧縮機１において，コントローラ９５が制御信号を出力していない状態，すなわち，吸入弁３０が開いた負荷運転の状態にあるときには，２つの分岐流路４１，４２が共に前記回収流路４０の吸入通路１９側端部を構成し，排出流路１８からの潤滑油はこの２つの分岐流路４１，４２の双方を介して圧縮機本体１０の吸入通路１９に導入される。   In the oil-cooled screw compressor 1 configured as described above, when the controller 95 does not output a control signal, that is, when the intake valve 30 is in an open load operation state, the two branch passages 41 are provided. , 42 constitute the end of the recovery passage 40 on the suction passage 19 side, and the lubricating oil from the discharge passage 18 passes through both of the two branch passages 41, 42 to the suction passage of the compressor body 10. 19 introduced.

その結果，潤滑油の回収は，２つの分岐流路４１，４２に設けられた回収孔３２ａ，３２ｂの流路面積の和から成る比較的広い流路面積を介して回収される。   As a result, the recovery of the lubricating oil is recovered through a relatively wide channel area that is the sum of the channel areas of the recovery holes 32 a and 32 b provided in the two branch channels 41 and 42.

これに対し，コントローラ９５が制御信号を出力して吸入弁３０を閉じている状態，すなわち無負荷運転の状態にあるときには，この制御信号によって電磁開閉弁４４が回収配管７０の一方の分岐管７０ａを閉じる。   On the other hand, when the controller 95 outputs a control signal to close the intake valve 30, that is, in a no-load operation state, the electromagnetic on / off valve 44 is caused to turn on one branch pipe 70a of the recovery pipe 70 by this control signal. Close.

その結果，回収流路４０の吸入通路１９側の端部は第２分岐流路４２のみによって構成され，潤滑油の回収は，他方の分岐管７０bを備える第２分岐流路４２のみを介して行われ，負荷運転時における流路面積の１／２の流路面積で行われる。   As a result, the end of the recovery passage 40 on the suction passage 19 side is constituted by only the second branch passage 42, and the recovery of the lubricating oil is performed only through the second branch passage 42 provided with the other branch pipe 70b. It is carried out with a channel area that is ½ of the channel area during load operation.

以上のように構成された潤滑油回収手段を備えた油冷式スクリュ圧縮機１では，図６を参照して説明した実施形態２の潤滑油回収手段を備えた油冷式スクリュ圧縮機１と同様，圧縮機本体に対するゴミ等を含んだ外気の導入，このような外気の導入に伴う故障や作動不良，圧縮機の動力損失，レシーバタンクの安全弁の噴気や，潤滑油の回収量不良による潤滑油の漏出や飛散が防止できると共に，コントローラの共有等に伴う部品点数の減少と装置構成の簡略化を実現することができる。   In the oil-cooled screw compressor 1 provided with the lubricating oil recovery means configured as described above, the oil-cooled screw compressor 1 provided with the lubricating oil recovery means of Embodiment 2 described with reference to FIG. Similarly, lubrication due to the introduction of outside air containing dust etc. into the compressor body, failure and malfunction due to the introduction of such outside air, power loss of the compressor, the jet of the safety valve of the receiver tank, and poor recovery of the lubricating oil Oil leakage and scattering can be prevented, and the number of parts can be reduced and the device configuration can be simplified due to the sharing of the controller.

実施形態１における潤滑油回収手段の全体説明図。1 is an overall explanatory diagram of a lubricating oil recovery unit according to Embodiment 1. FIG. 図１における回収孔部分の拡大説明図。The expansion explanatory view of the recovery hole part in Drawing 1. 回収孔の変形例を示す拡大説明図。Expansive explanatory drawing which shows the modification of a collection | recovery hole. 回収孔の更に別の変形例を示す拡大説明図。The expanded explanatory view which shows another modification of a collection | recovery hole. 潤滑油回収手段の別の構成例を示す概略説明図。Schematic explanatory drawing which shows another structural example of a lubricating oil collection | recovery means. 実施形態２における潤滑油回収手段の概略説明図。FIG. 6 is a schematic explanatory diagram of a lubricating oil recovery unit in Embodiment 2. 実施形態３における潤滑油回収手段の概略説明図。FIG. 5 is a schematic explanatory diagram of a lubricating oil recovery unit in Embodiment 3. 油冷式スクリュ圧縮機の全体構成を示す説明図。Explanatory drawing which shows the whole structure of an oil-cooled screw compressor. 従来技術（特許文献１）における管路構成を示す説明図。Explanatory drawing which shows the pipe line structure in a prior art (patent document 1). 潤滑油回収配管の管路接続の変形例を示す概略説明図。Schematic explanatory drawing which shows the modification of the pipe line connection of lubricating oil collection | recovery piping.

符号の説明Explanation of symbols

１ 油冷式スクリュ圧縮機
１０ 圧縮機本体
１１ ケーシング（圧縮機本体の）
１２ シリンダ
１３，１４ スクリュロータ
１５ 給油口
１６ シール室
１７ 溝
１８ 排出流路
１９ 吸入通路
２０ レシーバタンク
２１ オイルクーラ
２２ オイルフィルタ
３０ 吸入弁
３１ 弁箱
３２，３２ａ，３２ｂ，３２ａ’ 潤滑油の回収孔
３２１，３２１ａ，３２１ｂ，３２１’ 回収孔の入口
３２２，３２３，３２２’ 回収孔の出口
３３ 弁座
３４ 弁体
３５ 受圧室
４０ 潤滑油の回収流路
４１ 第１分岐流路
４２ 第２分岐流路
４３ 三方切換弁（三方電磁弁）
４４ 開閉弁（電磁開閉弁）
４５ 第１流路
４６ 第２流路
４６１ 一端開口（第２流路の）
４６２ 他端開口（第２流路の）
５１ 軸封装置
５２ 軸受
７０ 潤滑油回収の配管
７０ａ 分岐管（一方）
７０ｂ 分岐管（他方）
９１ 給油配管
９２ 制御配管
９３ 電磁開閉弁
９４ 圧力検出手段
９５ コントローラ
９６ 逆止弁 1 Oil-cooled screw compressor 10 Compressor body 11 Casing (of compressor body)
DESCRIPTION OF SYMBOLS 12 Cylinders 13 and 14 Screw rotor 15 Oil supply port 16 Seal chamber 17 Groove 18 Discharge flow path 19 Suction passage 20 Receiver tank 21 Oil cooler 22 Oil filter 30 Suction valve 31 Valve box 32, 32a, 32b, 32a 'Recovery hole of lubricating oil 321, 321 a, 321 b, 321 ′ recovery hole inlet 322, 323, 322 ′ recovery hole outlet 33 valve seat 34 valve body 35 pressure receiving chamber 40 lubricating oil recovery flow path 41 first branch flow path 42 second branch flow path 43 Three-way switching valve (three-way solenoid valve)
44 On-off valve (electromagnetic on-off valve)
45 1st flow path 46 2nd flow path 461 One end opening (2nd flow path)
462 Opening the other end (of the second flow path)
51 Shaft seal device 52 Bearing 70 Lubricating oil recovery pipe 70a Branch pipe (one side)
70b Branch pipe (the other)
91 Oil supply pipe 92 Control pipe 93 Electromagnetic on-off valve 94 Pressure detection means 95 Controller 96 Check valve

Claims (8)

ケーシングのシリンダ内に収容されたオス，メス一対のスクリュロータの噛み合い回転により被圧縮気体を圧縮するときに潤滑油を注入し，圧縮気体と潤滑油との気液混合流体を吐出すると共に，前記ケーシングを貫通して突出するロータ軸の軸封装置と，前記軸封装置を通過して漏出した潤滑油を排出する排出流路を設けた油冷式のスクリュ圧縮機本体と，前記圧縮機本体の吸入通路を開閉制御する吸入弁を備えた油冷式スクリュ圧縮機において，
前記排出流路と前記吸入弁の二次側に位置する吸入通路間を連通する回収流路を設け，前記回収流路に前記吸入弁の開放時のみ前記吸入通路との連通側端部と成る第１流路と，少なくとも前記吸入弁の閉塞時，前記吸入通路との連通側端部と成る第２流路を設け，
前記吸入弁の開閉に伴って前記回収流路の連通パターンを切り換えて，前記吸入弁の閉塞時，前記回収流路を縮小すると共に前記吸入通路と前記排出流路間のみの連通を確立し，前記吸入弁の開放時，前記吸入通路に連通する前記回収流路を拡大する回収流路調整手段を設けたことを特徴とする油冷式スクリュ圧縮機。 Lubricating oil is injected when compressing compressed gas by meshing rotation of a pair of male and female screw rotors housed in a casing cylinder, and a gas-liquid mixed fluid of compressed gas and lubricating oil is discharged. A shaft seal device for the rotor shaft that protrudes through the casing, an oil-cooled screw compressor main body provided with a discharge passage for discharging the lubricating oil leaked through the shaft seal device, and the compressor main body In an oil-cooled screw compressor equipped with a suction valve that controls the opening and closing of the suction passage of
A recovery channel that communicates between the discharge channel and the suction passage located on the secondary side of the suction valve is provided, and the recovery channel serves as a communication side end with the suction channel only when the suction valve is opened. A first flow path and a second flow path serving as an end portion on the communication side with the suction passage when at least the suction valve is closed;
The communication pattern of the recovery flow path is switched with the opening and closing of the suction valve, and when the suction valve is closed, the recovery flow path is reduced and communication between the suction passage and the discharge flow path is established. An oil-cooled screw compressor, comprising a recovery flow path adjusting means for enlarging the recovery flow path communicating with the suction passage when the intake valve is opened. 前記回収流路の前記第１及び第２流路が，前記回収流路を二方向に分岐して形成された第１及び第２分岐流路であり，
前記第１，第２分岐流路のいずれも前記吸入通路に連通すると共に，前記吸入弁による吸入通路の閉塞時，前記第１分岐流路を閉じる開閉手段を前記回収流路調整手段として設け，
前記第２分岐流路を，前記吸入弁の二次側において前記吸入通路に連通したことを特徴とする請求項１記載の油冷式スクリュ圧縮機。 The first and second flow paths of the recovery flow path are first and second branch flow paths formed by branching the recovery flow path in two directions;
Both the first and second branch flow paths communicate with the suction passage, and when the suction passage is closed by the suction valve, an opening / closing means for closing the first branch flow path is provided as the recovery flow path adjusting means,
2. The oil-cooled screw compressor according to claim 1, wherein the second branch passage is communicated with the suction passage on the secondary side of the suction valve. 前記第１分岐流路を，前記吸入弁の弁座において開口し，前記吸入弁の弁体によって前記開口を開閉する前記開閉手段を実現したことを特徴とする請求項２記載の油冷式スクリュ圧縮機。   3. The oil-cooled screw according to claim 2, wherein the first branch passage is opened at a valve seat of the suction valve, and the opening / closing means for opening and closing the opening is realized by a valve body of the suction valve. Compressor. 前記回収流路が，一端を前記排出流路に連通し，他端を前記吸入弁の弁座において開口する前記第１流路と，
前記第１流路の前記開口に対して狭い流路面積を有し，前記吸入弁の弁体に形成された前記第２流路を備え，
前記第２流路の一端開口を，吸入弁の閉塞時，前記弁座に形成された前記第１流路の開口と連通する位置に設けると共に，前記第２流路の他端開口を前記吸入弁の二次側に連通して前記吸入弁の弁体によって前記回収流路調整手段を実現したことを特徴とする請求項１記載の油冷式スクリュ圧縮機。 The recovery flow path, the first flow path having one end communicating with the discharge flow path and the other end opened at a valve seat of the suction valve;
The second passage having a narrow passage area with respect to the opening of the first passage and formed in a valve body of the suction valve;
One end opening of the second flow path is provided at a position communicating with the opening of the first flow path formed in the valve seat when the suction valve is closed, and the other end opening of the second flow path is connected to the suction port. 2. The oil-cooled screw compressor according to claim 1, wherein the recovery flow path adjusting means is realized by a valve body of the suction valve in communication with a secondary side of the valve. 前記第１，第２分岐流路のいずれ共前記吸入弁の二次側において前記吸入通路に連通すると共に，前記開閉手段として，前記第１分岐流路中に開閉弁を設けたことを特徴とする請求項２記載の油冷式スクリュ圧縮機。   Both the first and second branch flow paths communicate with the suction passage on the secondary side of the suction valve, and an opening / closing valve is provided in the first branch flow path as the opening / closing means. The oil-cooled screw compressor according to claim 2. 前記回収流路の前記第１及び第２流路が，前記回収流路を二方向に分岐して形成された第１及び第２分岐流路であり，
前記第１，第２分岐流路のいずれも前記吸入通路に連通すると共に，前記吸入弁による前記吸入通路の開放時，前記排出流路を前記第１分岐流路を介して前記吸入通路に連通すると共に第２分岐流路を介した連通を遮断し，前記吸入弁による吸入通路の閉塞時，前記排出流路を前記第２分岐流路を介して前記吸入通路に連通すると共に前記第１分岐流路を介した連通を遮断する切換手段を前記回収流路調整手段として設け，
前記第２分岐流路を，前記第１分岐流路に対して絞られた流路面積に形成すると共に，少なくとも前記第２分岐流路を前記吸入弁の二次側に連通したことを特徴とする請求項１記載の油冷式スクリュ圧縮機。 The first and second flow paths of the recovery flow path are first and second branch flow paths formed by branching the recovery flow path in two directions;
Both the first and second branch flow paths communicate with the suction passage, and when the suction passage is opened by the suction valve, the discharge flow path communicates with the suction passage via the first branch flow path. In addition, the communication via the second branch flow path is blocked, and when the suction passage is closed by the suction valve, the discharge flow path is communicated with the suction passage via the second branch flow path and the first branch A switching means for blocking communication through the flow path is provided as the recovery flow path adjusting means;
The second branch channel is formed in a channel area narrowed with respect to the first branch channel, and at least the second branch channel is communicated with the secondary side of the suction valve. The oil-cooled screw compressor according to claim 1. 前記第１，第２分岐流路のいずれ共に前記吸入弁の二次側において前記吸入通路に連通すると共に，前記切換手段として，前記分岐流路の分岐点に設けられた三方切換弁を設けたことを特徴とする請求項６記載の油冷式スクリュ圧縮機。   Both the first and second branch flow paths communicate with the suction passage on the secondary side of the suction valve, and a three-way switching valve provided at the branch point of the branch flow path is provided as the switching means. The oil-cooled screw compressor according to claim 6. 前記油冷式スクリュ圧縮機が，消費側に供給される圧縮気体の圧力を検出する圧力検出手段と，前記圧力検出手段の検知信号を受信して前記吸入弁の開閉動作を制御する制御信号を出力するコントローラを備えると共に，
前記開閉弁又は前記三方切換弁を，前記コントローラが出力する前記制御信号により動作が制御される電磁弁としたことを特徴とする請求項５又は７記載の油冷式スクリュ圧縮機。 The oil-cooled screw compressor has a pressure detection means for detecting the pressure of the compressed gas supplied to the consumer side, and a control signal for receiving the detection signal of the pressure detection means and controlling the opening / closing operation of the suction valve. It has a controller to output,
8. The oil-cooled screw compressor according to claim 5, wherein the on-off valve or the three-way switching valve is an electromagnetic valve whose operation is controlled by the control signal output from the controller.
JP2007337651A 2007-12-27 2007-12-27 Oil-cooled screw compressor Active JP5030768B2 (en)

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