WO2024024035A1 - External gear pump - Google Patents

External gear pump Download PDF

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Publication number
WO2024024035A1
WO2024024035A1 PCT/JP2022/029130 JP2022029130W WO2024024035A1 WO 2024024035 A1 WO2024024035 A1 WO 2024024035A1 JP 2022029130 W JP2022029130 W JP 2022029130W WO 2024024035 A1 WO2024024035 A1 WO 2024024035A1
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WO
WIPO (PCT)
Prior art keywords
gear
pump
slit
pump casing
driven gear
Prior art date
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PCT/JP2022/029130
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French (fr)
Japanese (ja)
Inventor
興史 石本
Original Assignee
株式会社Ihi
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Publication date
Application filed by 株式会社Ihi filed Critical 株式会社Ihi
Priority to PCT/JP2022/029130 priority Critical patent/WO2024024035A1/en
Publication of WO2024024035A1 publication Critical patent/WO2024024035A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
    • F04C2/18—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with similar tooth forms

Definitions

  • the present disclosure relates to an external gear pump.
  • Patent Document 1 discloses an external gear pump.
  • the external gear pump includes a pair of driving gear and driven gear within the pump casing. Gear teeth are formed on the outer periphery of each of the driving gear and the driven gear.
  • the drive gear and the driven gear are held between side plates from both sides in the axial direction in a mutually meshed state.
  • An inlet chamber to which fluid is supplied is formed on one side of the mesh portion of the driving gear and the driven gear, and an outlet chamber to discharge fluid is formed on the other side of the mesh portion. It is formed.
  • the outer peripheries of the driving gear and the driven gear that do not face the suction chamber and the discharge chamber are surrounded by a pump casing.
  • the fluid between the gear teeth is carried in the circumferential direction, thereby delivering the fluid from the suction chamber to the discharge chamber. Due to flow path resistance downstream of the discharge chamber, the pressure of the fluid in the discharge chamber is higher than the pressure of the fluid in the suction chamber. Therefore, the external gear pump can pump the fluid while increasing the pressure of the fluid.
  • the gear is pushed towards the suction chamber by high pressure fluid in the discharge chamber. Therefore, if the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing is made too narrow, there is a risk that the gear tooth will come into contact with the inner circumferential surface of the pump casing. Therefore, the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing is usually made larger than the bearing clearance. However, since the actual displacement of the gear is small, theoretically the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing should be made narrower than the bearing gap, and the gear tooth should not come into contact with the inner circumferential surface of the pump casing. is also possible.
  • the bearing is a journal plain bearing
  • the position of the shaft center may be significantly displaced due to the load on the bearing. It is not easy to keep the gear teeth from coming into contact with the inner peripheral surface of the pump casing while making the gap narrower than the gap.
  • An objective of the external gear pump according to the present disclosure is to provide an external gear pump that can improve pump efficiency.
  • the external gear pump includes a pair of driving gears and driven gears, a pump casing, a gear storage chamber formed inside the pump casing and housing the driving gear and the driven gear in a meshed state, and the
  • the pump includes a suction chamber formed inside the pump casing on one side of the meshing portion of the driving gear and the driven gear, and a discharge chamber formed on the other side of the meshing portion inside the pump casing.
  • a slit with only one end open is formed in the circumferential direction inside a sliding wall of the pump casing near the suction chamber that connects with the drive gear or the driven gear. By forming the slit, a cantilevered sliding piece is provided on the sliding wall.
  • FIG. 1 is a sectional view perpendicular to the gear axis of the external gear pump according to the first embodiment.
  • FIG. 2 is a partial sectional view including the gear shaft of the external gear pump.
  • FIG. 3 is an enlarged sectional view showing a driven gear and a part of the pump casing of the external gear pump.
  • FIG. 4 is an enlarged sectional view showing a part of the driven gear and pump casing of the external gear pump according to the second embodiment.
  • FIG. 5 is an enlarged sectional view showing a part of the driven gear and pump casing of the external gear pump according to the third embodiment.
  • FIG. 1 to 3 show an external gear pump according to a first embodiment.
  • the external gear pump will also be simply referred to as a gear pump.
  • FIG. 2 is a sectional view taken along line II-II in FIG.
  • the gear pump of this embodiment is used as a pump for delivering liquid fuel to an aircraft engine, and high pump efficiency is required.
  • the fluid sent by the gear pump will be referred to as working fluid. That is, the working fluid in this embodiment is liquid fuel.
  • the gear pump includes a pair of driving gears 2 and a driven gear 3 inside a pump casing 1.
  • Gear pumps have various sizes depending on their uses, but in the gear pump of this embodiment, each of the driving gear 2 and the driven gear 3 has an outer diameter of about 30 mm.
  • the drive gear 2 includes a drive gear main body 20 on which gear teeth are formed and a drive shaft 21. One end of the drive shaft 21 passes through the pump casing 1 and is connected to an external drive source.
  • a shaft seal 4 is provided in a portion of the pump casing 1 through which the drive shaft 21 passes.
  • the driven gear 3 also includes a driven gear main body 30 on which gear teeth are formed and a rotating shaft 31. In this embodiment, the drive shaft 21 is solid, but the rotating shaft 31 is hollow.
  • the pump casing 1 is composed of a main body 10, a divided block 11, and an end plate 12.
  • a gear storage chamber 13 is formed inside the divided block 11 to store the driving gear 2 and the driven gear 3 in an engaged state.
  • the gear storage chamber 13 has a figure-eight shape in a cross section perpendicular to the drive shaft 21 and the rotation shaft 31.
  • a suction chamber 14 to which working fluid is supplied is formed on one side of the constriction portion of the gear storage chamber 13, that is, the meshing portion between the driving gear body 20 and the driven gear body 30, and a discharge chamber 14 is formed on the other side.
  • a chamber 15 is formed.
  • the working fluid discharged from the gear pump is discharged from the discharge chamber 15.
  • the pressure of the working fluid in the discharge chamber 15 becomes higher than the pressure of the working fluid in the suction chamber 14 due to flow path resistance downstream of the discharge chamber 15 and the like.
  • the divided block 11 is fitted into a recess formed in the main body 10 and sandwiched between the end plates 12.
  • the end plate 12 is fixed to the main body 10 with bolts.
  • Both ends of the drive shaft 21 are rotatably held by the pump casing 1 via cylindrical flat bearings 5.
  • Each outer diameter of the flat bearings 5 is equal to the outer diameter of the drive gear body 20, and the flat bearings 5 are also housed in the gear storage chamber 13 together with the drive gear body 20.
  • the space between the outer circumferential surface of the drive shaft 21 and the inner circumferential surface of the flat bearing 5 is filled with working fluid, and as the drive shaft 21 rotates, the drive shaft 21 floats up.
  • Both ends of the rotating shaft 31 are also rotatably held by the pump casing 1 via the flat bearings 5, similarly to the drive shaft 21.
  • the outer circumferential surface of the flat bearing 5 corresponding to this meshing part is formed as a flat surface, and the flat bearing 5 of the driving gear main body 20 and the driven gear main body
  • the 30 plain bearings 5 face each other on this plane.
  • the flat bearing 5 is held within the pump casing 1 by this surface portion, with rotation thereof being suppressed.
  • the driving gear 2 and the driven gear 3 rotate in opposite directions, as shown by the arrows in FIG.
  • Gear specifications such as the shape and number of gear teeth of the drive gear 2 and the driven gear 3 of this embodiment are the same.
  • the working liquid in the suction chamber 14 is carried along the inner circumferential surface of the gear storage chamber 13 while being held between adjacent gear teeth of the driving gear 2 and the driven gear 3, and is transferred to the discharge chamber 15. Sent.
  • a slit 16 with only one end open is provided in the sliding wall of the pump casing 1 near the suction chamber 14 and the driven gear 3 in the circumferential direction. is formed.
  • the slit 16 is not formed only inside the sliding wall near the suction chamber 14, but is formed inside almost the entire area of the sliding wall.
  • a cantilevered sliding piece 17 is provided on the sliding wall.
  • the high-pressure working fluid in the discharge chamber 15 may leak into the low-pressure suction chamber 14 from between the tips of the gear teeth and the inner peripheral surface of the pump casing 1 .
  • the high-pressure working fluid in the discharge chamber 15 may leak into the low-pressure suction chamber 14 from between the side surfaces of the drive gear 2 and the driven gear 3 and the end surface of the flat bearing 5. This is called “lateral leak.”
  • the sliding piece 17 is provided to prevent leakage of working fluid from between the tip of the gear tooth and the inner peripheral surface of the pump casing 1, that is, to prevent leakage from the peripheral surface.
  • the slit 16 is formed from near the suction chamber 14 to reach the discharge chamber 15. That is, the slit 16 is open to the high-pressure discharge chamber 15.
  • the sliding piece 17 has a base end on the suction chamber 14 side and an open end on the discharge chamber 15 side.
  • FIG. 3 shows the sliding piece 17 on the driven gear 3 side in detail, a similar structure is also constructed on the driving gear 2 side symmetrically with respect to the meshing portion. The following will explain the sliding piece 17 on the driven gear 3 side as an example.
  • the outer diameter of the driven gear 3 of this embodiment is about 30 mm
  • the width of the slit 16 is about several ⁇ m to more than ten ⁇ m
  • the thickness of the sliding piece 17 is about 1 to 2 mm.
  • these values are not limited to the values exemplified here.
  • the thickness of the sliding piece 17 is constant, and the width of the slit 16 when the gear pump is stopped is also constant.
  • the divided block 11 which is the part where the sliding piece 17 and the slit 16 are formed, can be attached to and removed from the main body 10. It has a possible structure. Therefore, in order to form the slit 16, first, a through hole is formed at the starting end of the slit 16 of the divided block 11 by drilling or electrical discharge machining. Thereafter, a wire is passed through the through hole and a slit 16 is formed in the circumferential direction until it reaches the discharge chamber 15 by electrical discharge machining. Electric discharge machining using a wire is also called wire cut machining.
  • the driven gear 3 is pushed toward the suction chamber 14 by the high-pressure working fluid in the discharge chamber 15. Therefore, the driven gear 3 can also be displaced within the range of the bearing gap of the plain bearing 5.
  • the bearing clearance is about 10 to more than ten ⁇ m. Since the driven gear 3 is displaced within this range, the tips of its gear teeth can also be displaced.
  • the sliding piece 17 can be elastically deformed within the width of the slit 16. Therefore, even if the pressure of the working fluid in the discharge chamber 15 increases and the driven gear 3 is displaced toward the suction chamber 14, the sliding piece 17 is pushed by the tip of the gear tooth of the rotating driven gear 3. It deforms flexibly and elastically, and always maintains an appropriate sliding state between the tip of the gear tooth and the inner peripheral surface of the sliding wall. Therefore, leakage of the working fluid to the low pressure side can be suppressed, and furthermore, wear of the tips of the gear teeth and the inner circumferential surface of the sliding wall can be reduced.
  • the working fluid Since high-pressure working fluid is introduced into the inside of the slit 16 from the discharge chamber 15, the working fluid also exerts a buffering function, and absorbs shock and vibration when the driven gear 3 slideably contacts the sliding piece 17. Alleviate. Furthermore, in this embodiment, since the direction of rotation of the driven gear 3 and the extending direction of the sliding piece 17 from the base end to the free end match, the sliding piece 17 does not obstruct the rotation of the driven gear 3. .
  • the slit 16 and the sliding piece 17 are formed symmetrically on the drive gear 2 side, and the same effect is realized on the drive gear 2 side as well.
  • a slit 16 with only one end open is formed in the circumferential direction inside the sliding wall of the pump casing 1 near the suction chamber 14 between the driven gear 3 or the driving gear 2, and the sliding wall A cantilever-shaped sliding piece 17 is provided on. Therefore, the sliding state between the tips of the gear teeth of the driven gear 3 or the driving gear 2 and the inner circumferential surface of the sliding wall can always be maintained optimally regardless of pressure fluctuations in the discharge chamber 15. Therefore, leakage of the working fluid can be suppressed, and as a result, pump efficiency can be improved.
  • the divided block 11 in which the sliding piece 17 and the slit 16 are formed is removable from the pump casing 1. Therefore, it is easy to form the sliding piece 17 and the slit 16. That is, manufacturing of the gear pump does not become difficult.
  • the end of the slit 16 in the circumferential direction closer to the discharge chamber 15 is open. Therefore, by introducing the high-pressure working fluid in the discharge chamber 15 into the slit 16, the tips of the gear teeth of the driven gear 3 and the driving gear 2 and the inner periphery of the sliding wall are adjusted according to pressure fluctuations of the high-pressure working fluid.
  • the gap with the surface can be controlled. As a result, pump efficiency can be further improved.
  • FIG. 4 shows a diagram corresponding to FIG. 3 of the second embodiment. Below, only configurations different from the first embodiment will be described. The same or equivalent configurations as in the first embodiment are given the same reference numerals, and detailed explanation thereof will be omitted.
  • the sliding wall of the gear storage chamber 13 of the pump casing 1 near the discharge chamber 15 is formed so as not to reliably come into contact with the tips of the gear teeth of the driven gear 3.
  • the slit 16 is formed in almost the entire area of the sliding wall, but in this embodiment, the slit 16 is formed only near the suction chamber 14 of the gear storage chamber 13.
  • the sliding wall is formed only in a range of about 60 degrees around the center angle of the driven gear 3 near the suction chamber 14. In other words, within the range where the sliding wall is not formed, the inner circumferential surface of the pump casing 1 and the tips of the gear teeth are sufficiently apart. Accordingly, the lengths of the slit 16 and the sliding piece 17 in the circumferential direction are shorter than those of the first embodiment.
  • the driven gear 3 is pushed by the high pressure in the discharge chamber 15, and is pushed in a direction connecting the discharge chamber 15 and the center of the driven gear 3, that is, toward the suction chamber 14 and slightly downward to the right in FIG. Therefore, the driven gear 3 can be displaced to the right and slightly downward in FIG.
  • the slit 16 and the sliding piece 17 are formed only in the minimum range necessary to receive this displacement. In other words, the slits 16 and the sliding pieces 17 are formed only in the most effective range for suppressing leakage of the working fluid.
  • the high pressure of the working fluid in the discharge chamber 15 reaches the open end of the slit 16, so the high pressure working fluid in the discharge chamber 15 is introduced into the inside of the slit 16. Therefore, the effects associated with the introduction of the high-pressure working fluid into the slit 16 described in the first embodiment described above are also brought about in this embodiment.
  • FIG. 5 shows a diagram corresponding to FIG. 4 of the third embodiment. Below, only the configuration different from the second embodiment will be described. The same or equivalent configurations as in the second embodiment are given the same reference numerals, and detailed description thereof will be omitted.
  • the direction in which the slit 16 and the sliding piece 17 extend is opposite to that in the second embodiment. That is, the slit 16 is open to the suction chamber 14, and the free end of the sliding piece 17 is located near the suction chamber 14.
  • the movable range of the free end of the sliding piece 17 can be made wider than the movable range of the portion near the base end, and the sliding piece 17 can be displaced toward the suction chamber 14 of the driven gear 3. This allows for more flexible tracking. As a result, leakage of working fluid can be suppressed and pump efficiency can be improved.
  • the high-pressure working fluid in the discharge chamber 15 cannot be introduced into the slit 16 as in the first and second embodiments. Therefore, the effects associated with the introduction of the high-pressure working fluid into the slit 16 described in the first and second embodiments described above are not brought about in this embodiment. However, as described above, the ability of the sliding piece 17 to follow the driven gear 3 can be improved.
  • the slits 16 and the sliding pieces 17 are symmetrically formed on the drive gear 2 side, so that the same effect can be achieved on the drive gear 2 side as well. Ru. Other than the effect of introducing the high-pressure working fluid into the slit 16, this embodiment also provides the same effects as the second embodiment described above.
  • the slit 16 is open on the suction chamber 14 side in the circumferential direction. Therefore, the sliding piece 17 can be made to flexibly follow the displacement of the driven gear 3 and the driving gear 2. As a result, pump efficiency can be improved.
  • the present disclosure is not limited to the above embodiments.
  • the above-mentioned sliding piece 17 is provided on both sides of the drive gear 2 and the driven gear 3. It may be provided only on either side.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)

Abstract

This external gear pump is provided with: a pair of a driving gear (2) and a driven gear (3); a pump casing (1); a gear accommodation room (13) that is formed inside the pump casing (1) and accommodates the driving gear (2) and the driven gear (3) in a meshed state; an inlet chamber (14) that is formed on one side of a mesh portion between the driving gear (2) and the driven gear (3) inside the pump casing (1); and an outlet chamber (15) that is formed on the other side of the mesh portion inside the pump casing (1). A slit (16) of which only one end is opened is formed in a circumferential direction inside a sliding wall of the pump casing 1 that slides with the driving gear (2) or the driven gear (3) nearer the inlet chamber (14). By the formation of the slit (16), a cantilevered sliding piece (17) is provided in the sliding wall.

Description

外接ギヤポンプexternal gear pump
　本開示は、外接ギヤポンプ[external gear pump]に関する。 The present disclosure relates to an external gear pump.
　下記特許文献１は、外接ギヤポンプを開示している。外接ギヤポンプは、ポンプケーシング内に一対の駆動ギヤ及び従動ギヤを備えている。駆動ギヤ[driving gear]及び従動ギヤ[driven gear]の各外周上にはギヤ歯が形成されている。駆動ギヤ及び従動ギヤは、互いに噛み合った状態で、それらの軸方向両側からサイドプレートで挟持されている。駆動ギヤ及び従動ギヤの噛み合い部[mesh portion]の一側には流体が供給される吸入室[inlet chamber]が形成され、噛み合い部の他側には流体を排出する吐出室[outlet chamber]が形成される。吸入室及び吐出室に面していない駆動ギヤ及び従動ギヤの外周は、ポンプケーシングに囲まれている。 Patent Document 1 below discloses an external gear pump. The external gear pump includes a pair of driving gear and driven gear within the pump casing. Gear teeth are formed on the outer periphery of each of the driving gear and the driven gear. The drive gear and the driven gear are held between side plates from both sides in the axial direction in a mutually meshed state. An inlet chamber to which fluid is supplied is formed on one side of the mesh portion of the driving gear and the driven gear, and an outlet chamber to discharge fluid is formed on the other side of the mesh portion. It is formed. The outer peripheries of the driving gear and the driven gear that do not face the suction chamber and the discharge chamber are surrounded by a pump casing.
　各ギヤの回転に伴ってギヤ歯の間の流体が周方向に運ばれることで流体が吸入室から吐出室に送られる[delivered]。吐出室下流の流路抵抗などによって、吐出室内の流体の圧力は吸入室内の流体の圧力よりも高い。従って、外接ギヤポンプは、流体を昇圧させつつ流体を送ることができる。 As each gear rotates, the fluid between the gear teeth is carried in the circumferential direction, thereby delivering the fluid from the suction chamber to the discharge chamber. Due to flow path resistance downstream of the discharge chamber, the pressure of the fluid in the discharge chamber is higher than the pressure of the fluid in the suction chamber. Therefore, the external gear pump can pump the fluid while increasing the pressure of the fluid.
日本国特開２００５－１３３５５７号公報Japanese Patent Application Publication No. 2005-133557
　ギヤポンプの用途にもよるが、ポンプ効率を向上させたいという要求がある。ギヤポンプの内部では、吐出室内の高圧流体が、ギヤ歯の先端とポンプケーシング内周面との間から低圧の吸入室に漏れたり、ギヤ側面とギヤを支持する平軸受の端面との間から低圧の吸入室に漏れたりする。ポンプ効率向上時には、これらの漏れを抑止する必要がある。 Although it depends on the purpose of the gear pump, there is a demand for improving pump efficiency. Inside a gear pump, high-pressure fluid in the discharge chamber leaks into the low-pressure suction chamber from between the tips of the gear teeth and the inner peripheral surface of the pump casing, and low-pressure fluid leaks from between the side of the gear and the end face of the plain bearing that supports the gear. may leak into the suction chamber. When improving pump efficiency, it is necessary to suppress these leaks.
　ギヤは、吐出室内の高圧流体によって吸入室に向けて押される。このため、ギヤ歯の先端とポンプケーシング内周面との隙間を狭くしすぎると、ギヤ歯がポンプケーシング内周面に接触するおそれが生じる。そこで、通常は、ギヤ歯の先端とポンプケーシング内周面との隙間は、軸受隙間[bearing clearance]よりも大きくされる。ただし、実際のギヤの変位は僅かであるので、理論上は、ギヤ歯の先端とポンプケーシング内周面との隙間を軸受隙間より狭くしつつ、ギヤ歯をポンプケーシング内周面に接触させないことも可能である。しかし、特に軸受が平軸受[journal plain bearing]の場合には、軸受への負荷によって軸心の位置が大きく変位する可能性があり、ギヤ歯の先端とポンプケーシング内周面との隙間を軸受隙間より狭くしつつ、ギヤ歯をポンプケーシング内周面に接触させないようにすることは容易ではない。 The gear is pushed towards the suction chamber by high pressure fluid in the discharge chamber. Therefore, if the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing is made too narrow, there is a risk that the gear tooth will come into contact with the inner circumferential surface of the pump casing. Therefore, the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing is usually made larger than the bearing clearance. However, since the actual displacement of the gear is small, theoretically the gap between the tip of the gear tooth and the inner circumferential surface of the pump casing should be made narrower than the bearing gap, and the gear tooth should not come into contact with the inner circumferential surface of the pump casing. is also possible. However, especially when the bearing is a journal plain bearing, the position of the shaft center may be significantly displaced due to the load on the bearing. It is not easy to keep the gear teeth from coming into contact with the inner peripheral surface of the pump casing while making the gap narrower than the gap.
　本開示に係る外接ギヤポンプの目的は、ポンプ効率を向上させることのできる外接ギヤポンプを提供することにある。 An objective of the external gear pump according to the present disclosure is to provide an external gear pump that can improve pump efficiency.
　本開示に係る外接ギヤポンプは、一対の駆動ギヤ及び従動ギヤと、ポンプケーシングと、前記ポンプケーシングの内部に形成され、前記駆動ギヤ及び前記従動ギヤを噛み合った状態で収納するギヤ収納室と、前記ポンプケーシング内部の、前記駆動ギヤ及び前記従動ギヤの噛み合い部の一側に形成された吸入室と、前記ポンプケーシング内部の、前記噛み合い部の他側に形成された吐出室と、を備えている。前記吸入室寄りの前記ポンプケーシングの前記駆動ギヤ又は前記従動ギヤとのしゅう動壁の内部に、一端のみが開放されたスリットが周方向に形成されている。前記スリットの形成により、前記しゅう動壁に片持ち状のしゅう動片が設けられている。 The external gear pump according to the present disclosure includes a pair of driving gears and driven gears, a pump casing, a gear storage chamber formed inside the pump casing and housing the driving gear and the driven gear in a meshed state, and the The pump includes a suction chamber formed inside the pump casing on one side of the meshing portion of the driving gear and the driven gear, and a discharge chamber formed on the other side of the meshing portion inside the pump casing. . A slit with only one end open is formed in the circumferential direction inside a sliding wall of the pump casing near the suction chamber that connects with the drive gear or the driven gear. By forming the slit, a cantilevered sliding piece is provided on the sliding wall.
　本開示に係る外接ギヤポンプによれば、ポンプ効率を向上させることができる。 According to the external gear pump according to the present disclosure, pump efficiency can be improved.
図１は、第１実施形態に係る外接ギヤポンプのギヤ軸に垂直な断面図である。FIG. 1 is a sectional view perpendicular to the gear axis of the external gear pump according to the first embodiment. 図２は、上記外接ギヤポンプのギヤ軸を含む部分断面図である。FIG. 2 is a partial sectional view including the gear shaft of the external gear pump. 図３は、上記外接ギヤポンプの従動ギヤ及びポンプケーシングの一部を示す拡大断面図である。FIG. 3 is an enlarged sectional view showing a driven gear and a part of the pump casing of the external gear pump. 図４は、第２実施形態に係る外接ギヤポンプの従動ギヤ及びポンプケーシングの一部を示す拡大断面図である。FIG. 4 is an enlarged sectional view showing a part of the driven gear and pump casing of the external gear pump according to the second embodiment. 図５は、第３実施形態に係る外接ギヤポンプの従動ギヤ及びポンプケーシングの一部を示す拡大断面図である。FIG. 5 is an enlarged sectional view showing a part of the driven gear and pump casing of the external gear pump according to the third embodiment.
　以下、実施形態について、図面を参照しつつ説明する。 Hereinafter, embodiments will be described with reference to the drawings.
　図１～図３は、第１実施形態に係る外接ギヤポンプを示している。以下、外接ギヤポンプを単にギヤポンプとも言う。図１は図２中のＩ－Ｉ線断面図であり、図２は図１中のＩＩ－ＩＩ線断面図である。本実施形態のギヤポンプは、航空機のエンジンに液体燃料を送るポンプとして用いられており、高いポンプ効率が要望される。以下、ギヤポンプによって送られる流体を作動流体と呼ぶ。即ち、本実施形態における作動流体は液体燃料である。 1 to 3 show an external gear pump according to a first embodiment. Hereinafter, the external gear pump will also be simply referred to as a gear pump. 1 is a sectional view taken along line II in FIG. 2, and FIG. 2 is a sectional view taken along line II-II in FIG. The gear pump of this embodiment is used as a pump for delivering liquid fuel to an aircraft engine, and high pump efficiency is required. Hereinafter, the fluid sent by the gear pump will be referred to as working fluid. That is, the working fluid in this embodiment is liquid fuel.
　ギヤポンプは、ポンプケーシング１内に一対の駆動ギヤ２及び従動ギヤ３を備えている。ギヤポンプはその用途により様々な大きさがあるが、本実施形態のギヤポンプは、駆動ギヤ２及び従動ギヤ３の各外径は３０ｍｍ程度である。駆動ギヤ２は、ギヤ歯が形成された駆動ギヤ本体２０と駆動軸２１とからなる。駆動軸２１の一端は、ポンプケーシング１を貫通して外部の駆動源に接続される。ポンプケーシング１における駆動軸２１が貫通する部分には、軸シール４が設けられている。従動ギヤ３も、ギヤ歯が形成された従動ギヤ本体３０と回転軸３１とからなる。本実施形態では、駆動軸２１は中実であるが回転軸３１は中空である。 The gear pump includes a pair of driving gears 2 and a driven gear 3 inside a pump casing 1. Gear pumps have various sizes depending on their uses, but in the gear pump of this embodiment, each of the driving gear 2 and the driven gear 3 has an outer diameter of about 30 mm. The drive gear 2 includes a drive gear main body 20 on which gear teeth are formed and a drive shaft 21. One end of the drive shaft 21 passes through the pump casing 1 and is connected to an external drive source. A shaft seal 4 is provided in a portion of the pump casing 1 through which the drive shaft 21 passes. The driven gear 3 also includes a driven gear main body 30 on which gear teeth are formed and a rotating shaft 31. In this embodiment, the drive shaft 21 is solid, but the rotating shaft 31 is hollow.
　ポンプケーシング１は、メインボディ１０、分割ブロック１１及びエンドプレート１２によって構成されている。分割ブロック１１の内部には、噛み合った状態の駆動ギヤ２及び従動ギヤ３を収納するギヤ収納室１３が形成されている。ギヤ収納室１３は、駆動軸２１及び回転軸３１に直角な断面において８字形を有している。 The pump casing 1 is composed of a main body 10, a divided block 11, and an end plate 12. A gear storage chamber 13 is formed inside the divided block 11 to store the driving gear 2 and the driven gear 3 in an engaged state. The gear storage chamber 13 has a figure-eight shape in a cross section perpendicular to the drive shaft 21 and the rotation shaft 31.
　ギヤ収納室１３のくびれ部[constriction portion]、即ち、駆動ギヤ本体２０と従動ギヤ本体３０との噛み合い部の一側には作動流体が供給される吸入室１４が形成され、他側には吐出室１５が形成されている。ギヤポンプから排出される作動流体は吐出室１５から排出される。吐出室１５下流の流路抵抗などによって、吐出室１５内の作動流体の圧力は吸入室１４内の作動流体の圧力よりも高くなる。分割ブロック１１は、メインボディ１０に形成された凹部に嵌め込まれ、エンドプレート１２によって挟み込まれる。エンドプレート１２は、メインボディ１０にボルトによって固定される。 A suction chamber 14 to which working fluid is supplied is formed on one side of the constriction portion of the gear storage chamber 13, that is, the meshing portion between the driving gear body 20 and the driven gear body 30, and a discharge chamber 14 is formed on the other side. A chamber 15 is formed. The working fluid discharged from the gear pump is discharged from the discharge chamber 15. The pressure of the working fluid in the discharge chamber 15 becomes higher than the pressure of the working fluid in the suction chamber 14 due to flow path resistance downstream of the discharge chamber 15 and the like. The divided block 11 is fitted into a recess formed in the main body 10 and sandwiched between the end plates 12. The end plate 12 is fixed to the main body 10 with bolts.
　駆動軸２１の両端は、円筒形の平軸受５を介して、ポンプケーシング１によってそれぞれ回転可能に保持される。平軸受５の各外径は駆動ギヤ本体２０の外径に等しく、平軸受５も駆動ギヤ本体２０と共にギヤ収納室１３内に収納される。駆動軸２１の外周面と平軸受５の内周面との間は作動流体で満たされ、駆動軸２１の回転に伴い、駆動軸２１が浮き上がる。回転軸３１の両端も、駆動軸２１と同様に、平軸受５を介して、ポンプケーシング１によってそれぞれ回転可能に保持される。 Both ends of the drive shaft 21 are rotatably held by the pump casing 1 via cylindrical flat bearings 5. Each outer diameter of the flat bearings 5 is equal to the outer diameter of the drive gear body 20, and the flat bearings 5 are also housed in the gear storage chamber 13 together with the drive gear body 20. The space between the outer circumferential surface of the drive shaft 21 and the inner circumferential surface of the flat bearing 5 is filled with working fluid, and as the drive shaft 21 rotates, the drive shaft 21 floats up. Both ends of the rotating shaft 31 are also rotatably held by the pump casing 1 via the flat bearings 5, similarly to the drive shaft 21.
　なお、駆動ギヤ本体２０と従動ギヤ本体３０とは噛み合っているため、この噛み合い部分に対応する平軸受５の外周面は平面として形成されており、駆動ギヤ本体２０の平軸受５と従動ギヤ本体３０の平軸受５とはこの平面で互いに面接される。この面接部分によって、平軸受５はそれらの回転が抑止されてポンプケーシング１内に保持される。 Note that since the driving gear main body 20 and the driven gear main body 30 are meshed, the outer circumferential surface of the flat bearing 5 corresponding to this meshing part is formed as a flat surface, and the flat bearing 5 of the driving gear main body 20 and the driven gear main body The 30 plain bearings 5 face each other on this plane. The flat bearing 5 is held within the pump casing 1 by this surface portion, with rotation thereof being suppressed.
　駆動ギヤ２及び従動ギヤ３は、図１中の矢印に示されるように、互いに反対方向に回転する。本実施形態の駆動ギヤ２及び従動ギヤ３のギヤ歯の形状及び数などの歯車諸元は同じである。吸入室１４内の作動液体は、駆動ギヤ２及び従動ギヤ３の隣接するギヤ歯の間に保持された状態で、ギヤ収納室１３の内周面に沿って運ばれて、吐出室１５へと送られる。 The driving gear 2 and the driven gear 3 rotate in opposite directions, as shown by the arrows in FIG. Gear specifications such as the shape and number of gear teeth of the drive gear 2 and the driven gear 3 of this embodiment are the same. The working liquid in the suction chamber 14 is carried along the inner circumferential surface of the gear storage chamber 13 while being held between adjacent gear teeth of the driving gear 2 and the driven gear 3, and is transferred to the discharge chamber 15. Sent.
　本実施形態では、図３に示されるように、吸入室１４寄りのポンプケーシング１の従動ギヤ３とのしゅう動壁[slidably contactable wall]の内部に、一端のみが開放されたスリット１６が周方向に形成されている。なお、本実施形態では、スリット１６は、吸入室１４寄りのしゅう動壁の内部だけに形成されるのでなく、しゅう動壁のほぼ全域の内部に形成されている。このようにスリット１６が形成されることで、しゅう動壁に片持ち状のしゅう動片１７が設けられる。吐出室１５内の高圧の作動流体は、ギヤ歯の先端とポンプケーシング１の内周面との間から低圧の吸入室１４に漏れる可能性がある。これを「周面漏れ[circumferential leak]」と呼ぶ。また、吐出室１５内の高圧の作動流体は、駆動ギヤ２及び従動ギヤ３の側面と平軸受５の端面との間から低圧の吸入室１４に漏れる可能性がある。これを「側面漏れ[lateral leak]」と呼ぶ。しゅう動片１７は、ギヤ歯先端とポンプケーシング１の内周面との間からの作動流体の漏れ、即ち、周面漏れを抑止するために設けられる。 In this embodiment, as shown in FIG. 3, a slit 16 with only one end open is provided in the sliding wall of the pump casing 1 near the suction chamber 14 and the driven gear 3 in the circumferential direction. is formed. In this embodiment, the slit 16 is not formed only inside the sliding wall near the suction chamber 14, but is formed inside almost the entire area of the sliding wall. By forming the slit 16 in this manner, a cantilevered sliding piece 17 is provided on the sliding wall. The high-pressure working fluid in the discharge chamber 15 may leak into the low-pressure suction chamber 14 from between the tips of the gear teeth and the inner peripheral surface of the pump casing 1 . This is called "circumferential leak." Further, the high-pressure working fluid in the discharge chamber 15 may leak into the low-pressure suction chamber 14 from between the side surfaces of the drive gear 2 and the driven gear 3 and the end surface of the flat bearing 5. This is called "lateral leak." The sliding piece 17 is provided to prevent leakage of working fluid from between the tip of the gear tooth and the inner peripheral surface of the pump casing 1, that is, to prevent leakage from the peripheral surface.
　なお、本実施形態では、スリット１６は、吸入室１４の近傍から吐出室１５に達するまで形成されている。即ち、スリット１６は高圧の吐出室１５に開放されている。このようにスリット１６を形成することで、しゅう動片１７は、吸入室１４側に基端を有し、吐出室１５側に開放端を有する。また、図３は、従動ギヤ３側のしゅう動片１７を詳細に示しているが、駆動ギヤ２側にも噛み合い部分に対して対称に同様の構造が構築されている。以下、従動ギヤ３側のしゅう動片１７を例にして説明する。 Note that in this embodiment, the slit 16 is formed from near the suction chamber 14 to reach the discharge chamber 15. That is, the slit 16 is open to the high-pressure discharge chamber 15. By forming the slit 16 in this way, the sliding piece 17 has a base end on the suction chamber 14 side and an open end on the discharge chamber 15 side. Further, although FIG. 3 shows the sliding piece 17 on the driven gear 3 side in detail, a similar structure is also constructed on the driving gear 2 side symmetrically with respect to the meshing portion. The following will explain the sliding piece 17 on the driven gear 3 side as an example.
　上述したように、本実施形態の従動ギヤ３の外径は３０ｍｍ程度であり、スリット１６の幅は数μｍ～十数μｍ程度であり、しゅう動片１７の厚さは１～２ｍｍ程度である、ただし、これらの値はここで例示された値に限定されない。本実施形態では、しゅう動片１７の厚さは一定であり、ギヤポンプ停止時のスリット１６の幅も一定である。 As mentioned above, the outer diameter of the driven gear 3 of this embodiment is about 30 mm, the width of the slit 16 is about several μm to more than ten μm, and the thickness of the sliding piece 17 is about 1 to 2 mm. However, these values are not limited to the values exemplified here. In this embodiment, the thickness of the sliding piece 17 is constant, and the width of the slit 16 when the gear pump is stopped is also constant.
　スリット１６によるしゅう動片１７の形成方法であるが、上述したように、ポンプケーシング１は、しゅう動片１７及びスリット１６が形成される部分である分割ブロック１１を、メインボディ１０に対して着脱可能な構造を有している。従って、スリット１６を形成するには、まず、分割ブロック１１のスリット１６の開始端となる位置にドリル加工又は放電加工によって貫通孔を形成する。その後、貫通孔にワイヤを通して放電加工によってスリット１６を周方向に吐出室１５に達するまで形成する。ワイヤを用いた放電加工は、ワイヤカット加工とも呼ばれる。 Regarding the method of forming the sliding piece 17 using the slit 16, as described above, in the pump casing 1, the divided block 11, which is the part where the sliding piece 17 and the slit 16 are formed, can be attached to and removed from the main body 10. It has a possible structure. Therefore, in order to form the slit 16, first, a through hole is formed at the starting end of the slit 16 of the divided block 11 by drilling or electrical discharge machining. Thereafter, a wire is passed through the through hole and a slit 16 is formed in the circumferential direction until it reaches the discharge chamber 15 by electrical discharge machining. Electric discharge machining using a wire is also called wire cut machining.
　従動ギヤ３は、吐出室１５内の高圧の作動流体によって吸入室１４に向けて押される。このため、従動ギヤ３も平軸受５の軸受隙間の範囲内で変位し得る。軸受隙間は１０～十数μｍ程度である。従動ギヤ３はこの範囲内で変位するので、そのギヤ歯の先端も変位し得る。 The driven gear 3 is pushed toward the suction chamber 14 by the high-pressure working fluid in the discharge chamber 15. Therefore, the driven gear 3 can also be displaced within the range of the bearing gap of the plain bearing 5. The bearing clearance is about 10 to more than ten μm. Since the driven gear 3 is displaced within this range, the tips of its gear teeth can also be displaced.
　しかし、本実施形態ではしゅう動片１７は、スリット１６の幅の範囲で弾性変形が可能である。従って、吐出室１５内の作動流体の圧力が高くなって従動ギヤ３が吸入室１４に向けて変位しても、しゅう動片１７は、回転する従動ギヤ３のギヤ歯の先端で押されて柔軟に弾性変形し、ギヤ歯の先端としゅう動壁の内周面とのしゅう動状態を常に適切に維持する。このため、作動流体の低圧側への漏れを抑制することができ、さらに、ギヤ歯の先端及びしゅう動壁の内周面の摩耗を低減することもできる。 However, in this embodiment, the sliding piece 17 can be elastically deformed within the width of the slit 16. Therefore, even if the pressure of the working fluid in the discharge chamber 15 increases and the driven gear 3 is displaced toward the suction chamber 14, the sliding piece 17 is pushed by the tip of the gear tooth of the rotating driven gear 3. It deforms flexibly and elastically, and always maintains an appropriate sliding state between the tip of the gear tooth and the inner peripheral surface of the sliding wall. Therefore, leakage of the working fluid to the low pressure side can be suppressed, and furthermore, wear of the tips of the gear teeth and the inner circumferential surface of the sliding wall can be reduced.
　スリット１６の内部には吐出室１５から高圧の作動流体が導入されるため、作動流体が緩衝機能も発揮し、従動ギヤ３がしゅう動片１７としゅう接[slidably contact]する際の衝撃及び振動を緩和する。さらに、本実施形態では、従動ギヤ３の回転方向としゅう動片１７の基端から自由端への延設方向が一致するため、しゅう動片１７が従動ギヤ３の回転を阻害することはない。なお、本実施形態では駆動ギヤ２側にも対称にスリット１６及びしゅう動片１７が形成されており、駆動ギヤ２側でも同様の効果が実現される。 Since high-pressure working fluid is introduced into the inside of the slit 16 from the discharge chamber 15, the working fluid also exerts a buffering function, and absorbs shock and vibration when the driven gear 3 slideably contacts the sliding piece 17. Alleviate. Furthermore, in this embodiment, since the direction of rotation of the driven gear 3 and the extending direction of the sliding piece 17 from the base end to the free end match, the sliding piece 17 does not obstruct the rotation of the driven gear 3. . In addition, in this embodiment, the slit 16 and the sliding piece 17 are formed symmetrically on the drive gear 2 side, and the same effect is realized on the drive gear 2 side as well.
　本実施形態によれば、吸入室１４寄りのポンプケーシング１の従動ギヤ３又は駆動ギヤ２とのしゅう動壁の内部に一端のみが開放されたスリット１６が周方向に形成されて、しゅう動壁に片持ち状のしゅう動片１７が設けられる。このため、従動ギヤ３又は駆動ギヤ２のギヤ歯の先端としゅう動壁の内周面とのしゅう動状態を吐出室１５内の圧力変動によらず常に最適に維持することができる。従って、作動流体の漏れを抑止でき、その結果、ポンプ効率を向上させることができる。 According to this embodiment, a slit 16 with only one end open is formed in the circumferential direction inside the sliding wall of the pump casing 1 near the suction chamber 14 between the driven gear 3 or the driving gear 2, and the sliding wall A cantilever-shaped sliding piece 17 is provided on. Therefore, the sliding state between the tips of the gear teeth of the driven gear 3 or the driving gear 2 and the inner circumferential surface of the sliding wall can always be maintained optimally regardless of pressure fluctuations in the discharge chamber 15. Therefore, leakage of the working fluid can be suppressed, and as a result, pump efficiency can be improved.
　ここで、本実施形態では、しゅう動片１７及びスリット１６が形成された分割ブロック１１がポンプケーシング１から脱着可能である。このため、しゅう動片１７及びスリット１６を形成しやすい。即ち、ギヤポンプの製造が困難になることがない。 Here, in this embodiment, the divided block 11 in which the sliding piece 17 and the slit 16 are formed is removable from the pump casing 1. Therefore, it is easy to form the sliding piece 17 and the slit 16. That is, manufacturing of the gear pump does not become difficult.
　また、本実施形態では、スリット１６の周方向における吐出室１５寄りの端部が開放されている。従って、吐出室１５内の高圧の作動流体をスリット１６内に導入することで、高圧側作動流体の圧力変動に応じて従動ギヤ３及び駆動ギヤ２のギヤ歯の先端としゅう動壁の内周面との隙間を制御することができる。この結果、ポンプ効率をより一層向上させることができる。 Furthermore, in this embodiment, the end of the slit 16 in the circumferential direction closer to the discharge chamber 15 is open. Therefore, by introducing the high-pressure working fluid in the discharge chamber 15 into the slit 16, the tips of the gear teeth of the driven gear 3 and the driving gear 2 and the inner periphery of the sliding wall are adjusted according to pressure fluctuations of the high-pressure working fluid. The gap with the surface can be controlled. As a result, pump efficiency can be further improved.
　図４に、第２実施形態の図３相当図を示す。以下には、第１実施形態とは異なる構成についてのみ説明する。第１実施形態と同一及び同等の構成については同一の符号を付してそれらの詳しい説明を省略する。 FIG. 4 shows a diagram corresponding to FIG. 3 of the second embodiment. Below, only configurations different from the first embodiment will be described. The same or equivalent configurations as in the first embodiment are given the same reference numerals, and detailed explanation thereof will be omitted.
　本実施形態では、ポンプケーシング１のギヤ収納室１３の吐出室１５寄りのしゅう動壁が従動ギヤ３のギヤ歯の先端とは確実に接触しないように形成されている。言い換えれば、第１実施形態ではしゅう動壁のほぼ全域にスリット１６が形成されたが、本実施形態では、ギヤ収納室１３の吸入室１４寄りにのみスリット１６が形成されている。しゅう動壁は吸入室１４寄りに従動ギヤ３の中心角で約６０度の範囲のみに形成されている。言い換えれば、しゅう動壁が形成されていない範囲内では、ポンプケーシング１の内周面とギヤ歯の先端とは十分に離れている。これに伴って、スリット１６及びしゅう動片１７の周方向の長さは、第１実施形態よりも短い。 In this embodiment, the sliding wall of the gear storage chamber 13 of the pump casing 1 near the discharge chamber 15 is formed so as not to reliably come into contact with the tips of the gear teeth of the driven gear 3. In other words, in the first embodiment, the slit 16 is formed in almost the entire area of the sliding wall, but in this embodiment, the slit 16 is formed only near the suction chamber 14 of the gear storage chamber 13. The sliding wall is formed only in a range of about 60 degrees around the center angle of the driven gear 3 near the suction chamber 14. In other words, within the range where the sliding wall is not formed, the inner circumferential surface of the pump casing 1 and the tips of the gear teeth are sufficiently apart. Accordingly, the lengths of the slit 16 and the sliding piece 17 in the circumferential direction are shorter than those of the first embodiment.
　従動ギヤ３は、吐出室１５の高圧によって押されて、吐出室１５と従動ギヤ３の中心とを結ぶ方向、即ち、吸入室１４に向けて図４中右方やや下方に向けて押される。従って、従動ギヤ３は、図４中で右方やや下方に変位し得る。本実施形態では、この変位を受けるのに必要な最小限の範囲にのみスリット１６及びしゅう動片１７が形成されている。言い換えれば、作動流体の漏れを抑止するのに最も効果的な範囲にのみスリット１６及びしゅう動片１７が形成されている。 The driven gear 3 is pushed by the high pressure in the discharge chamber 15, and is pushed in a direction connecting the discharge chamber 15 and the center of the driven gear 3, that is, toward the suction chamber 14 and slightly downward to the right in FIG. Therefore, the driven gear 3 can be displaced to the right and slightly downward in FIG. In this embodiment, the slit 16 and the sliding piece 17 are formed only in the minimum range necessary to receive this displacement. In other words, the slits 16 and the sliding pieces 17 are formed only in the most effective range for suppressing leakage of the working fluid.
　本実施形態でも、吐出室１５内の作動液体の高圧はスリット１６の開放端にまで達するため、吐出室１５内の高圧の作動流体はスリット１６の内部に導入される。従って、上述した第１実施形態で説明したスリット１６内への高圧の作動流体の導入に伴う効果は本実施形態でももたらされる。 Also in this embodiment, the high pressure of the working fluid in the discharge chamber 15 reaches the open end of the slit 16, so the high pressure working fluid in the discharge chamber 15 is introduced into the inside of the slit 16. Therefore, the effects associated with the introduction of the high-pressure working fluid into the slit 16 described in the first embodiment described above are also brought about in this embodiment.
　なお、従動ギヤ３側を例示して説明したが、本実施形態では駆動ギヤ２側にも対称にスリット１６及びしゅう動片１７が形成されており、駆動ギヤ２側でも同様の効果が実現される。従って、本実施形態によっても、上述した第１実施形態によってもたらされる効果が同様にもたらされる。 Although the explanation has been given using the driven gear 3 side as an example, in this embodiment, the slits 16 and the sliding pieces 17 are symmetrically formed on the drive gear 2 side, so that the same effect can be achieved on the drive gear 2 side as well. Ru. Therefore, this embodiment also provides the same effects as the first embodiment described above.
　図５に、第３実施形態の図４相当図を示す。以下には、第２実施形態とは異なる構成についてのみ説明する。第２実施形態と同一及び同等の構成については同一の符号を付してそれらの詳しい説明を省略する。 FIG. 5 shows a diagram corresponding to FIG. 4 of the third embodiment. Below, only the configuration different from the second embodiment will be described. The same or equivalent configurations as in the second embodiment are given the same reference numerals, and detailed description thereof will be omitted.
　本実施形態では、スリット１６及びしゅう動片１７の延設方向が第２実施形態のそれとは逆方向である。即ち、スリット１６は吸入室１４に開放されており、しゅう動片１７の自由端は吸入室１４寄りに位置している。このようにすることで、しゅう動片１７の自由端の可動範囲を基端寄りの部分の可動領域よりも広くすることができ、しゅう動片１７は従動ギヤ３の吸入室１４に向けた変位により柔軟に追従することができる。この結果、作動流体の漏れを抑止してポンプ効率を向上させることができる。 In this embodiment, the direction in which the slit 16 and the sliding piece 17 extend is opposite to that in the second embodiment. That is, the slit 16 is open to the suction chamber 14, and the free end of the sliding piece 17 is located near the suction chamber 14. By doing so, the movable range of the free end of the sliding piece 17 can be made wider than the movable range of the portion near the base end, and the sliding piece 17 can be displaced toward the suction chamber 14 of the driven gear 3. This allows for more flexible tracking. As a result, leakage of working fluid can be suppressed and pump efficiency can be improved.
　ただし、本実施形態では、第１及び第２実施形態のように吐出室１５内の高圧の作動流体をスリット１６の内部に導入することはできない。従って、上述した第１及び第２実施形態で説明したスリット１６内への高圧の作動流体の導入に伴う効果は本実施形態ではもたらされない。しかし、上述したように、しゅう動片１７の従動ギヤ３への追従性を向上させることができる。 However, in this embodiment, the high-pressure working fluid in the discharge chamber 15 cannot be introduced into the slit 16 as in the first and second embodiments. Therefore, the effects associated with the introduction of the high-pressure working fluid into the slit 16 described in the first and second embodiments described above are not brought about in this embodiment. However, as described above, the ability of the sliding piece 17 to follow the driven gear 3 can be improved.
　なお、従動ギヤ３側を例示して説明したが、本実施形態では駆動ギヤ２側にも対称にスリット１６及びしゅう動片１７が形成されており、駆動ギヤ２側でも同様の効果が実現される。スリット１６への高圧作動流体導入による効果以外については、本実施形態によっても、上述した第２実施形態によってもたらされる効果が同様にもたらされる。 Although the explanation has been given using the driven gear 3 side as an example, in this embodiment, the slits 16 and the sliding pieces 17 are symmetrically formed on the drive gear 2 side, so that the same effect can be achieved on the drive gear 2 side as well. Ru. Other than the effect of introducing the high-pressure working fluid into the slit 16, this embodiment also provides the same effects as the second embodiment described above.
　また、本実施形態では、スリット１６が、周方向における吸入室１４側で開放されている。従って、しゅう動片１７を従動ギヤ３及び駆動ギヤ２の変位により柔軟に追従させることができる。この結果、ポンプ効率を向上させることができる。 Furthermore, in this embodiment, the slit 16 is open on the suction chamber 14 side in the circumferential direction. Therefore, the sliding piece 17 can be made to flexibly follow the displacement of the driven gear 3 and the driving gear 2. As a result, pump efficiency can be improved.
　なお、本開示は上記実施形態に限定されない。例えば、吐出室１５の高圧による変位は駆動ギヤ２側及び従動ギヤ３の双方で起こり得るので駆動ギヤ２及び従動ギヤ３の双方の側に上述したしゅう動片１７が設けられることが好ましいが、何れか一方の側にのみ設けられてもよい。 Note that the present disclosure is not limited to the above embodiments. For example, since displacement due to high pressure in the discharge chamber 15 can occur on both the drive gear 2 side and the driven gear 3, it is preferable that the above-mentioned sliding piece 17 is provided on both sides of the drive gear 2 and the driven gear 3. It may be provided only on either side.
１　ポンプケーシング
２　駆動ギヤ
３　従動ギヤ
１１　分割ブロック
１４　吸入室
１５　吐出室
１６　スリット
１７　しゅう動片 1 Pump casing 2 Drive gear 3 Driven gear 11 Divided block 14 Suction chamber 15 Discharge chamber 16 Slit 17 Sliding piece

Claims (4)

  1. 　外接ギヤポンプであって、
    　一対の駆動ギヤ及び従動ギヤと、
    　ポンプケーシングと、
    　前記ポンプケーシングの内部に形成され、前記駆動ギヤ及び前記従動ギヤを噛み合った状態で収納するギヤ収納室と、
    　前記ポンプケーシング内部の、前記駆動ギヤ及び前記従動ギヤの噛み合い部の一側に形成された吸入室と、
    　前記ポンプケーシング内部の、前記噛み合い部の他側に形成された吐出室と、を備えており、
    　前記吸入室寄りの前記ポンプケーシングの前記駆動ギヤ又は前記従動ギヤとのしゅう動壁の内部に、一端のみが開放されたスリットが周方向に形成されており、
    　前記スリットの形成により、前記しゅう動壁に片持ち状のしゅう動片が設けられている、外接ギヤポンプ。     An external gear pump,
    a pair of driving gears and driven gears;
    pump casing,
    a gear storage chamber formed inside the pump casing and housing the driving gear and the driven gear in an engaged state;
    a suction chamber formed inside the pump casing on one side of a meshing portion of the driving gear and the driven gear;
    a discharge chamber formed inside the pump casing on the other side of the meshing part,
    A slit with only one end open is formed in the circumferential direction inside a sliding wall of the pump casing near the suction chamber that connects with the drive gear or the driven gear,
    An external gear pump, wherein the sliding wall is provided with a cantilevered sliding piece due to the formation of the slit.
  2. 　前記スリットの前記周方向における前記吐出室寄りの端部が開放されている、請求項１に記載のギヤポンプ。 The gear pump according to claim 1, wherein an end of the slit closer to the discharge chamber in the circumferential direction is open.
  3. 　前記スリットの前記周方向における前記吸入室寄りの端部が開放されている、請求項１に記載のギヤポンプ。 The gear pump according to claim 1, wherein an end of the slit closer to the suction chamber in the circumferential direction is open.
  4. 　前記ポンプケーシングの前記しゅう動片及び前記スリットが形成された部分が、前記ポンプケーシングから脱着可能に構成されている、請求項１～３の何れか一項に記載のギヤポンプ。 The gear pump according to any one of claims 1 to 3, wherein the portion of the pump casing in which the sliding piece and the slit are formed is configured to be detachable from the pump casing.
PCT/JP2022/029130 2022-07-28 2022-07-28 External gear pump WO2024024035A1 (en)

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PCT/JP2022/029130 WO2024024035A1 (en) 2022-07-28 2022-07-28 External gear pump

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0861250A (en) * 1994-08-11 1996-03-08 Robert Bosch Gmbh Gear pump and method for running-in of said gear pump
KR101413694B1 (en) * 2012-12-28 2014-07-01 계명대학교 산학협력단 micro gear-pump with sheet spring

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0861250A (en) * 1994-08-11 1996-03-08 Robert Bosch Gmbh Gear pump and method for running-in of said gear pump
KR101413694B1 (en) * 2012-12-28 2014-07-01 계명대학교 산학협력단 micro gear-pump with sheet spring

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