200920945 九、發明說明： 【發明所屬之技術領域】 本發明係提供一種空壓機，尤指一種由馬達帶動活寒 在壓縮请内作在彳是運動以產生加壓氣體的空壓機。 【先前技術】 參閱第六圖及第七圖，顯示一習用的空壓機i，該空 壓機1包含一基座11、結合在該基座上的一壓縮筒12、 組裝在該基座上的一馬達13及可受該馬達13帶動而在該 壓縮筒12内作往復運動的一活塞（未圖示）。透過馬達 13帶動活塞在壓縮筒12内作往復運動以完成氣體的吸 入、屢縮及加壓氣體的排出。關於習用空壓機的結構可參 考申請人所設計之美國專利第6，146112號及第6,551，〇77 號案來進一步了解。 構b及一曲柄機構的傳動來驅使該活塞作往復運動1 齒輪機構15包含裝設在該馬達13心轴（未圖示）上的第 :齒輪（原動齒輪）151及與該第—齒輪⑸㈣合的一 -齒輪（從動齒輪）152,而該曲柄機構包含一重力塊 =、一-軸桿162及-連桿163，該軸桿162的一端穿過 =i輪152並安裝在該基座u上所設之—軸孔内（未 ^ ’於_孔内通常設有—金屬套筒或軸承），且該連 二由^ 一端係連接至該活塞之活塞桿141的-外端 於該連桿163相對該軸桿162係為偏心、，因而， 200920945 當該第二齒輪152受該第一齒輪151帶動時，活塞就會在 該壓縮筒12内作往復運動。 然而，習用空壓機1之活塞在壓縮筒12内作往復運 動的過程中，常常會有變形運動的產生，以致影響該空壓 機的效率及降低該空壓機的使用壽命。經發明人深入研究 之後，發現原因之一來自於該壓縮筒12與該基座11之間 的距離過長造成，亦即，如第七圖所示，受限於該齒輪機 構15設在該壓縮筒12與該基座11之間的緣故，在該壓 縮筒12之中心與該基座11内側緣之間具有一較長的距離 (D)’由於該較長距離（D)的存在，造成該連桿163之 離心方向的運動會大大地影響該軸桿162的轉動，使得當 活塞在進行往復運動時，提供該軸桿162安裝的軸孔之内 壁會因受力不平均而在某一點先形成磨損，又當該軸孔磨 損之後，該軸桿162的旋轉（如第八圖之標號A所示） 便形成非定點圓心之運動，一旦產生此種現象，該連桿 163的旋轉（如第八圖之標號C所示）亦隨著形成非圓狀 之運動，進而使得活塞之閥頭在壓縮筒12内進行往復運 動時便會產生變形運動（如第七圖之假想線所示），導致 活塞的閥頭及軸孔内的軸承容易破壞，壽命降低。 【發明内容】 本發明人有鑑於此，乃悉心從事設計，於今有本發明 產生。緣此，本發明之主要目的在提供一種可提高活塞運 動穩定性的空壓機，藉以改善上述習用空壓機的缺點，進 6 200920945 而提高空壓機及活塞的使用壽命。 依據本發明一實施例構成的空壓機，係包含一基座、 結合在該基座上的一壓縮筒、可在該壓縮筒内作往復運動 的一活塞及組裝在該基座上的一馬達；該馬達之心軸上組 裝一第一齒輪，該第一齒輪連接一第二齒輪用以帶動該活 塞在該壓縮筒内作往復運動，且該第一齒輪之至少部分係 位在該壓縮筒所投影的區域内，藉以縮短該壓縮筒中心與 該基座之間的分隔距離，使得活塞在壓縮筒内的運動能順 暢，並避免活塞在運動時產生震動，進而提高該空壓機之 使用壽命者。 在一實施例中，該筒體具有一下端，該下端具有一開 口，且該第一齒輪之内侧端緣係位在該筒體開口的投影區 内。 在一實加例中，該第一齒輪具有一軸向厚度，且該第 一齒輪延伸至該壓縮筒投影區内的距離約等於該第一齒 輪之軸向寬度的1/3。 在一實施例中，該壓縮筒之下端係較該第一齒輪之一 頂端高，且該第一齒輪及該第二齒輪之至少部分係位在該 筒體下端所延伸的投影區内。 在一實施例中，該第二齒輪上裝有一重力塊，該重力 塊上具有一軸桿及一偏心的連桿，該軸桿穿過該從動齒輪 並裝在该定位板上所設之—軸孔内，且該連桿連接至該活 塞桿之外端，又該第二齒輪之部分係位在該壓縮筒之下端 所延伸的投影區内。 7 200920945 關於本發明之其他目的、優點及特徵，將可由以下較 佳實施例的詳細說明並參照所附圖式來了解。 乂 【實施方式】 有關本發明的構造設計，將經由僅為例子但非用以限 制的實施例並參照所附圖式作進一步說明： 請了解文中諸如“第一，，、“第二，，、“上，， “下”、“前”、“後”、“内，，、“外”、“長度”、 ”周圍”、”側”範圍”、，’軸向’’等等及類似用ς係僅 用於便於看®者參考圖巾構造以及僅用於f助描述本發 明而已。 請參閱第一圖至第三圖，顯示依據本發明一實施例構 成的空壓機2;該空壓機2包含一基座2卜結合在該基座 21上的一壓縮筒22、組裝在該基座上的一馬達23及可受 該馬達23帶動而在該壓縮筒22内作往復運動的一活塞 24。 ι 該基座21具有一定位板211，該定位板211上具有 分隔開的第-孔212及一第二孔213,該第二孔内裝設一 金屬套筒或軸承214。 該壓縮筒22係可一體地或是利用連接技術來結合在 δ亥基座21上，且該壓縮筒22包含與該定位板211呈分隔 開的一圓筒體221及輸送氣體用的管路222或接頭，該筒 體221具有一下端223 ’該下端具有一開口 224。 該活塞24係自該開口 224伸入該壓縮筒22内，且該 8 200920945 活塞24之一端（圖中下端）具有一活塞桿241，該活塞 桿之外端242延伸出該筒體221。 該馬達23具有一心軸231，該心軸231穿過該定位 板211上的第一孔212，且該心軸231延伸出該定位板的 外端232上套裝一第一齒輪25卜該第一齒輪251嚙接一 第二齒輪252，該第二齒輪252上結合一重力塊261，該 重力塊261上設有一軸桿262及一連桿263，該軸桿262 的一知牙過§亥第一齒輪252並樞接在該套筒214内，而該 連桿263之一端係連接至該活塞桿241的外端242，當該 馬達23運轉之後，該第一齒輪251會帶動該第二齒輪 252 ’使得該活塞24會在該壓縮筒22的筒體221内作往 復運動。 配合第三圖至第五圖所示，本發明的特徵在於該第一 齒輪251之至少部分係配置在該筒體221之下端223所延 伸的投影區s内，如此結構設計，將使得該筒體221之中 心（X)與該基座定位板211之間的距離（di )會較第七 圖所示之分隔距離（D )縮短，亦即，該筒體221 —外壁 周緣與該基座定位板211之間的距離（D2)會較習用空 壓機之對應距離短。 如第三圖及第五圖所示，該壓縮筒22之下端223係 較該第一齒輪251之頂端高，使得該第一齒輪251及該第 二齒輪252之至少部分係位在該筒體下端223延伸的投影 區s内，在本實施例中，該第一齒輪251延伸至該筒體 221投影區S内的距離（W1)約等於該第一齒輪251之 200920945 軸向寬度（W)的1/3，且該第一齒輪251之内側端緣253 係位在該筒體開口 224的投影區域内。 依據本發明構成的空壓機2,藉由該第一齒輪251設 在該壓縮筒22所投影的區域内，使得該壓縮筒22中心與 該基座定位板21之間的距離可以縮短，因而該連桿263 之離心方向的運動對該軸桿262的轉動影響將會大大地 降低，如此，當活塞24在進行往復運動時便不會產生變 形運動，又該第二孔213不易磨損，且該轴桿262的旋轉 也不會形成非定點圓心之運動，因而可提高該壓縮筒22 與該活塞24的使用壽命。 前述是對本發明之構造作較佳實施例的說明，而依本 發明的設計精神是可作多種變化或修改的實施例。是以， 對於熟悉此項技藝人士可作之明顯替換與修飾，仍將併入 於本發明所主張的專利範圍之内。 200920945 【圖式簡單說明】 第一圖：係依據本發明構成的空壓機之元件分解略圖。 第二圖·係第一圖之一組合立體圖。 第三圖：係第二圖之—平面圖，並以假想線顯示活塞 桿之運動狀態。 第四圖：係與第三圖相同之平面圖，並顯示部分元件 移除以便了解壓縮筒中心與該基座之間 的分隔距離（D1)較習用空壓機之對應 距離縮減。 第五圖 係第二圖之一上視 以便了解第一 的投影區内。 圖並顯示部分元件移除 齒輪之局部係位在壓縮筒 第六圖：係習用空壓機之一立體略圖。 第七圖.係第六圖之一平面圖 桿之運動狀態後想線顯示活塞 第八圖：係顯=七圖之轉與連桿料轉運動示意 200920945 【主要元件符號說明】 (1)空壓機 (11)基座 (12)壓縮筒 (13)馬達 (141)活塞桿 (142)外端 (15)齒輪機構 (151)第一齒輪 (152)第二齒輪 (161)重力塊 (162)軸桿 (163)連桿 (2)空壓機 (21)基座 (211)定位板 (212)第一孔 (213)第二孔 (214)軸承 (22)壓縮筒 (221)筒體 (222)管路 (223)下端 (224)開口 (23)馬達 (231)心軸 (232)外端 (24)活塞 (241)活塞桿 (242)外端 (251)第一齒輪 (252)第二齒輪 (253)内側端緣 (261)重力塊 (262)軸桿 (263)連桿 (S)投影區 12200920945 IX. INSTRUCTIONS: [Technical Field] The present invention provides an air compressor, and more particularly, an air compressor that is driven by a motor to perform a cold operation in a compression process to generate a pressurized gas. [Prior Art] Referring to the sixth and seventh figures, a conventional air compressor i is shown. The air compressor 1 includes a base 11 and a compression cylinder 12 coupled to the base. A motor 13 and a piston (not shown) that can be reciprocated in the compression cylinder 12 by the motor 13 are provided. The piston 13 is driven by the motor 13 to reciprocate in the compression cylinder 12 to complete the suction of the gas, the contraction of the gas, and the discharge of the pressurized gas. The structure of the conventional air compressor can be further understood by referring to the applicant's U.S. Patent Nos. 6,146,112 and 6,551, 〇77. The b and a crank mechanism drive to reciprocate the piston 1 The gear mechanism 15 includes a gear (primary gear) 151 mounted on the motor 13 spindle (not shown) and the first gear (5) (four) a gear-gear (driven gear) 152, and the crank mechanism includes a gravity block=, a-shaft 162 and a link 163, one end of which is passed through the =i wheel 152 and mounted on the base The shaft u is provided in the shaft hole (not normally provided in the hole) - and the end is connected to the outer end of the piston rod 141 of the piston The link 163 is eccentric with respect to the shaft 162. Therefore, when the second gear 152 is driven by the first gear 151, the piston reciprocates within the compression cylinder 12. However, in the process of reciprocating movement of the piston of the conventional air compressor 1 in the compression cylinder 12, deformation motion is often generated, thereby affecting the efficiency of the air compressor and reducing the service life of the air compressor. After intensive research by the inventors, one of the reasons is that the distance between the compression cylinder 12 and the base 11 is too long, that is, as shown in the seventh figure, the gear mechanism 15 is limited to Between the compression cylinder 12 and the base 11, there is a long distance (D) between the center of the compression cylinder 12 and the inner edge of the base 11 due to the existence of the longer distance (D). The movement causing the centrifugal direction of the link 163 greatly affects the rotation of the shaft 162, so that when the piston is reciprocating, the inner wall of the shaft hole provided for the shaft 162 is provided at a certain point due to uneven force. First, wear is formed, and when the shaft hole is worn, the rotation of the shaft 162 (as indicated by the symbol A in FIG. 8) forms a motion of the center of the non-fixed point. Once this phenomenon occurs, the rotation of the link 163 ( As shown by the reference numeral C in the eighth figure, the deformation of the valve head of the piston in the compression cylinder 12 occurs as a result of the non-circular motion (as shown by the imaginary line of the seventh diagram). ), which makes the valve head of the piston and the bearing in the shaft hole easy Destruction, reduced life. SUMMARY OF THE INVENTION The present inventors have made it in mind that the present invention has been made in view of the above. Accordingly, the main object of the present invention is to provide an air compressor which can improve the stability of the piston movement, thereby improving the shortcomings of the conventional air compressor described above, and improving the service life of the air compressor and the piston. An air compressor according to an embodiment of the present invention includes a base, a compression cylinder coupled to the base, a piston reciprocable in the compression cylinder, and a piston assembled on the base a motor; a first gear is assembled on the mandrel of the motor, the first gear is coupled to a second gear for driving the piston to reciprocate within the compression cylinder, and at least a portion of the first gear is coupled to the compression In the area projected by the cylinder, the separation distance between the center of the compression cylinder and the base is shortened, so that the movement of the piston in the compression cylinder can be smooth, and the vibration of the piston during movement is avoided, thereby improving the air compressor. The service life. In one embodiment, the barrel has a lower end, the lower end having an opening, and the inner end edge of the first gear is positioned within the projection area of the barrel opening. In an embodiment, the first gear has an axial thickness, and the distance of the first gear extending into the projection area of the compression cylinder is approximately equal to 1/3 of the axial width of the first gear. In one embodiment, the lower end of the compression barrel is higher than the top end of the first gear, and at least a portion of the first gear and the second gear are tied in a projection area in which the lower end of the barrel extends. In an embodiment, the second gear is equipped with a gravity block having a shaft and an eccentric link, and the shaft passes through the driven gear and is mounted on the positioning plate - The shaft is bored, and the connecting rod is connected to the outer end of the piston rod, and the portion of the second gear is tied to the projection area extending at the lower end of the compression cylinder. Other objects, advantages and features of the present invention will become apparent from the following detailed description of the preferred embodiments. [Embodiment] The structural design of the present invention will be further described by way of example only, but not by way of limitation, and reference to the accompanying drawings: FIG. , "up,", "down", "before", "after", "inside,", "outside", "length", "around", "side" range, "axial", etc. and similar The use of the tether is only for the convenience of the reference material construction and only for the purpose of describing the invention. Referring to the first to third figures, an air compressor 2 constructed in accordance with an embodiment of the present invention is shown; The air compressor 2 includes a base 2 coupled to a compression cylinder 22 coupled to the base 21, a motor 23 assembled to the base, and reciprocable within the compression cylinder 22 by the motor 23 The piston 21 has a positioning plate 211 having a spaced apart first hole 212 and a second hole 213, and a metal sleeve or bearing is disposed in the second hole. 214. The compression cylinder 22 can be integrated on the ΔHai base 21 integrally or by using a connection technique, and the compression The cylinder 22 includes a cylindrical body 221 spaced apart from the positioning plate 211 and a pipe 222 or joint for conveying gas. The cylindrical body 221 has a lower end 223 '. The lower end has an opening 224. The piston 24 is from the The opening 224 extends into the compression cylinder 22, and one end of the piston 20 (the lower end in the figure) has a piston rod 241, and the outer end 242 of the piston rod extends out of the cylinder 221. The motor 23 has a spindle 231. The mandrel 231 passes through the first hole 212 of the positioning plate 211, and the mandrel 231 extends out of the outer end 232 of the positioning plate to fit a first gear 25, and the first gear 251 is engaged with a second gear. a gear 252, the second gear 252 is coupled to a gravity block 261. The gravity block 261 is provided with a shaft 262 and a connecting rod 263. The shaft 262 is pivotally connected to the first gear 252. In the sleeve 214, one end of the connecting rod 263 is connected to the outer end 242 of the piston rod 241. After the motor 23 is operated, the first gear 251 will drive the second gear 252' so that the piston 24 will Reciprocating movement in the cylinder 221 of the compression cylinder 22. In conjunction with the third to fifth figures, The invention is characterized in that at least part of the first gear 251 is disposed in the projection area s extending from the lower end 223 of the cylinder 221, so that the center (X) of the cylinder 221 and the base are positioned. The distance (di) between the plates 211 is shortened compared to the separation distance (D) shown in the seventh figure, that is, the distance (D2) between the circumference of the outer wall of the cylindrical body 221 and the base positioning plate 211 is higher. The corresponding distance of the conventional air compressor is short. As shown in the third and fifth figures, the lower end 223 of the compression cylinder 22 is higher than the top end of the first gear 251, so that the first gear 251 and the second gear 252 At least part of the portion is located in the projection area s of the lower end 223 of the barrel. In the embodiment, the distance (W1) of the first gear 251 extending into the projection area S of the barrel 221 is approximately equal to the first gear. 200920945 of 251 is 1/3 of the axial width (W), and the inner end edge 253 of the first gear 251 is positioned in the projected area of the barrel opening 224. The air compressor 2 constructed according to the present invention is provided in the region projected by the compression cylinder 22 by the first gear 251, so that the distance between the center of the compression cylinder 22 and the base positioning plate 21 can be shortened. The influence of the movement of the connecting rod 263 in the centrifugal direction on the rotation of the shaft 262 is greatly reduced, so that when the piston 24 is reciprocating, no deformation motion occurs, and the second hole 213 is not easily worn, and The rotation of the shaft 262 also does not form a motion of the non-fixed center, thereby increasing the service life of the compression cylinder 22 and the piston 24. The foregoing is a description of the preferred embodiments of the present invention, and the embodiments of the invention may be modified or modified. Therefore, obvious substitutions and modifications may be made by those skilled in the art, which are still within the scope of the claimed invention. 200920945 [Simple description of the drawings] First figure: an exploded view of the components of the air compressor constructed in accordance with the present invention. The second figure is a combined perspective view of one of the first figures. The third picture is a plan view of the second figure, and the movement state of the piston rod is shown by an imaginary line. Figure 4: The same plan as in the third figure, showing some components removed to see the separation distance between the center of the compression cylinder and the base (D1) is reduced compared to the corresponding distance of the conventional air compressor. Figure 5 is a top view of the second figure to understand the first projection area. The figure shows some parts removed. The local part of the gear is in the compression cylinder. Figure 6: A stereoscopic sketch of one of the conventional air compressors. The seventh figure is the sixth figure of the piston of the plan view bar in the sixth figure. The figure shows the piston in the eighth picture: the system shows the rotation of the seven figure and the movement of the connecting rod. 200920945 [Description of main components] (1) Air pressure Machine (11) base (12) compression cylinder (13) motor (141) piston rod (142) outer end (15) gear mechanism (151) first gear (152) second gear (161) gravity block (162) Shaft (163) connecting rod (2) air compressor (21) base (211) positioning plate (212) first hole (213) second hole (214) bearing (22) compression cylinder (221) cylinder ( 222) Pipe (223) lower end (224) opening (23) motor (231) mandrel (232) outer end (24) piston (241) piston rod (242) outer end (251) first gear (252) Two gears (253) inner end edge (261) gravity block (262) shaft (263) link (S) projection area 12