JP2016023581A - Gear pump and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a sufficient amount of liquid supplied for lubrication between a shaft and a bushing, and attain a sufficient thickness of a liquid film formed between these elements so as to perform a lubrication between the shaft and the bushing and further shorten a size of each of the bushing, shaft, and casing, respectively.SOLUTION: This invention relates to a gear pump or a motor comprising: a pair of gears engaged to each other; a shaft for supporting each of these gears; a casing having a gear storing chamber for storing the gears therein and having bearing holes for rotatably supporting the shafts through bushing; and a side plate adjacent to and contacted with the side face of the gear, and in which a part of liquid in the gear storing chamber is guided into a part between the shaft and the bushing to attain lubricating action, and there is provided liquid biasing means for use in biasing the liquid toward a clearance between the shaft and the bushing through utilization of rotating action of the shaft in respect to the side plate at a location where the outer circumference of the shaft and the inner circumference of the side plate are oppositely faced to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gear pump or a motor that feeds hydraulic fluid using a tooth gap of a pair of gears.

  Conventionally, as shown in FIG. 4, a side plate a6 is disposed between the gears a2, a3 and the casing a1, and the shafts a4, a5 for pivotally supporting the gears a2, a3 are provided as bearing holes in the casing a1. In a gear pump or motor that is rotatably supported by a11x, a11y, a12x, a12y via a bush a7, as shown in FIG. 5, the liquid leaking from the gap between the gear a2 (, a3) and the side plate a6 As shown by the arrow ff in the figure, a liquid film is formed by introducing the liquid film into the gap ss between the shaft a4 (, a5) and the bush a7, and lubrication between the shaft a4 (, a5) and the bush a7. The structure which aims at has been employ | adopted.

  In such a gear pump or motor, as shown in FIGS. 4 and 6, a gasket a8 for partitioning the high-pressure side and the low-pressure side is provided between the side plate a6 and the casing a1, in more detail. The gasket a8 is attached to the surface of the side plate a6 opposite to the surface facing the gear a2 (, a3). As shown in FIG. 6, the gasket a8 is located in the region XX near the low pressure port communicating with the low pressure side. Is not arranged, a gap communicating with the low pressure side is generated. Therefore, a part of the liquid is not led to the gap ss between the shafts a4, a5 and the bush a7, but is led directly to the low pressure port from the gap between the region XX near the low pressure port of the side plate a6 and the casing a1. Therefore, there is a problem that the liquid used for lubrication between the shafts a2 and a3 and the bush a7 decreases, and a sufficient liquid film that should be formed by this liquid is not formed. Therefore, a sufficient amount of liquid to be provided for lubrication between the shafts a2 and a3 and the bush a7 is secured, and the liquid film is stably formed so that the lubrication between the shaft and the bush is performed more suitably. There is a desire to make it. Also, if a sufficient amount of liquid is provided for lubrication between the shafts a2 and a3 and the bush a7 to form a liquid film having a sufficient thickness, the bush a7 can be cooled more effectively, Combined with the stable formation, the pressure receiving area of the bush for obtaining a desired strength can be reduced. Utilizing this, there is a demand for shortening the bush, shortening the drive shaft and the driven shaft, and shortening the casing having the bearing hole.

  On the other hand, as a gear pump or motor having another configuration, a bearing member is disposed between the gear and the casing, and a shaft for supporting the gear is rotatably supported in a bearing hole provided in the bearing member. It is known that a spiral groove which is a means for biasing the liquid in a direction away from the gear is provided over the entire longitudinal dimension of the outer surface of the shaft facing the inner surface of the bearing hole (for example, , See Patent Document 1). If such a structure is employ | adopted, a liquid will be introduce | transduced into the clearance gap between a shaft and a bearing member, and this liquid will flow in the direction spaced apart from a gearwheel. However, in the configuration described in Patent Document 1, the liquid is urged in a direction away from the gear over the entire gap between the shaft and the bearing member, and the liquid is guided to the low pressure port as it is through the gap. Therefore, the configuration described in Patent Document 1 ensures a sufficient amount of liquid to be provided for lubrication between the shaft and the bush, and ensures a sufficient thickness of the liquid film formed outside the shaft. It cannot be said that the liquid film is stably formed, the lubrication between the shaft and the bush is more suitably performed, and the shaft and the like are shortened.

Japanese Utility Model Publication No. 4-105985

  The present invention pays attention to the above points, and sufficiently secures the amount of liquid provided for lubrication between the shaft and the bush to sufficiently secure the thickness of the liquid film formed in the gap between the shaft and the bush. The object of the present invention is to suitably lubricate the shaft and the bush, and to shorten the bush, shorten the drive shaft and the driven shaft, and shorten the casing.

  In order to solve the above problems, the gear pump or motor of the component according to the present invention has a configuration as described below. That is, the gear pump or motor according to the present invention includes a pair of gears that mesh with each other, shafts that respectively support these gears, a gear storage chamber that stores the gears therein, and the bushes through the bushes. A casing having a bearing hole for rotatably supporting the shaft; and a side plate that contacts the side surface of the gear; and a portion of the liquid in the gear housing chamber is guided between the shaft and the bush for lubrication A gear pump or a motor, wherein the liquid is supplied to the shaft and the bush using a rotational movement of the shaft with respect to the side plate at a portion where the outer periphery of the shaft and the inner periphery of the side plate face each other. Liquid urging means for urging toward the gap between the two is provided.

  In such a case, the liquid is guided to the gap between the shaft and the bush with the rotation of the shaft with respect to the side plate, so that more liquid is guided to the gap between the shaft and the bush. Further effective lubrication can be achieved while further lubrication can be achieved. In other words, it is possible to ensure a sufficient amount of liquid that is provided for lubrication between the shaft and the bush. In addition, since the liquid urging means is provided at a portion where the shaft and the side plate face each other, a liquid film having a sufficient thickness can be stably formed. In addition, since the pressure receiving area of the bush for obtaining a desired strength can be reduced, the bush can be shortened, and the drive shaft and the driven shaft can be shortened. As a result, the casing has a bearing hole. Can be shortened.

  As an aspect for realizing such a liquid urging means with a simple configuration, there may be mentioned one provided with a spiral groove formed on the outer periphery of the shaft or the inner periphery of the side plate.

  According to the present invention, a sufficient amount of liquid is provided for lubrication between the shaft and the bush to ensure a sufficient thickness of the liquid film formed in the gap between the shaft and the bush. The bushing can be suitably lubricated, the bushing can be shortened, the drive shaft and the driven shaft can be shortened, and the casing can be shortened.

The figure which shows the gear pump or motor which concerns on one Embodiment of this invention. The figure which shows the gearwheel and shaft of the gear pump or motor which concern on the embodiment. The figure which shows the principal part of the gear pump or motor which concerns on the same embodiment. The figure which shows the conventional gear pump or motor. The figure which shows the principal part of the conventional gear pump or a motor. The figure which shows the side plate of the conventional gear pump or a motor.

  An embodiment of the present invention will be described below with reference to FIGS.

  The gear pump P according to the present embodiment is provided in a hydraulic path, and mainly, as shown in FIG. 1, a drive gear 2 and a driven gear 3 that form a pair of external gears that mesh with each other, and the drive gear 2 and the driven gear. 3, a body 11 having a gear housing chamber 11 a for housing the driving gear 2 and the driven gear 3, and a gear housing chamber 11 a of the body 11 are closed. A casing 1 formed by joining a cover 12 and having bearing holes 11x, 11y, 12x, 12y for rotatably supporting the drive shaft 4 and the driven shaft 5 via the bush 7, the drive gear 2 and the driven A side plate 6 that contacts the side surfaces 2a and 3a of the gear 3 and a gasket 8 that is a seal member disposed between the body 11 and the cover 12 are provided. Hereinafter, the drive gear 2 and the driven gear 3 are collectively referred to as “gears 2 and 3” without distinction. The drive shaft 4 and the driven shaft 5 are collectively referred to as “shafts 4 and 5” without distinction. In the present embodiment, as shown in FIG. 3, the liquid in the gear housing chamber 11 a, that is, a part of the hydraulic fluid that circulates in the hydraulic path, is passed through the gap s between the shafts 4, 5 and the bush 7. To guide the lubrication.

  The drive gear 2 and the driven gear 3 are well-known ones in which a plurality of tooth bodies are provided at predetermined intervals along the outer peripheral surface. In the present embodiment, the drive shaft 4 is integrally extended from the center of the drive gear 2 in the rotational axis direction, and the driven shaft 5 is integrally extended from the driven gear 3 in the rotational axis direction. However, the drive gear 2 and the drive shaft 4 may be configured separately, and the driven gear 3 and the driven shaft 5 may be configured separately.

  The casing 1 is formed by joining a body 11 and a cover 12 with a bolt 10 which is a fastening tool.

  As shown in FIG. 3, the body 11 has a gear housing chamber 11a for housing the gears 2 and 3, a high-pressure side port (not shown) communicating with the gear housing chamber 11a, and a gear housing chamber 11a. A low-pressure side port (not shown) that communicates with each other and shaft holes 11x and 11y through which the drive shaft 4 and the driven shaft 5 are respectively inserted are formed. As described above, the bush 7 is disposed between the inner surfaces of the shaft holes 11x and 11y and the shafts 4 and 5.

  As shown in FIGS. 3 and 4, the cover 12 is provided with shaft holes 12 x and 12 y through which the drive shaft 2 and the driven shaft 3 are inserted. As described above, the bush 7 is disposed between the inner surfaces of the shaft holes 12x and 12y and the shafts 4 and 5.

  As shown in FIGS. 1 to 3, the side plate 6 is disposed at two locations so as to be brought into contact with both side surfaces 2 a and 3 a of the gears 2 and 3, and the side surfaces 2 a and 3 a of the gears 2 and 3 are respectively connected. It is for sealing. Here, in the sliding surface 6 a side of the side plate 6, high-pressure hydraulic fluid is introduced from the discharge port into the high-pressure region, and the gears 2 and 3 and the movable side plates 6 and 6 are stored in the casing 1. A seal portion capable of introducing a high-pressure fluid is formed between the non-sliding surface 6 b of the movable side plate 6 and the casing 1. Further, the side plate 6 is provided with a shaft hole 6c for allowing the drive shaft 4 or the driven shaft 5 to pass therethrough.

  As described above and as shown in FIGS. 1 and 3, the bush 7 is formed between the shafts 4 and 5 and the bearing holes 11x, 11y, 12x, and 12y of the body 11 and the front cover 12. It is arranged in between. That is, the shafts 4 and 5 are rotatably supported by the bearing holes 11x, 11y, 12x and 12y via the bush 7.

  The gasket 8 is made of an elastic material. The gasket 8 is mounted in a state of being in contact with a gasket mounting protrusion provided on the non-sliding surface 6b of the side plate 6, and is crimped to the non-sliding surface 6b and the casing 1, A space between the casing 1 and the casing 1 is divided into a low pressure side region, that is, a suction port side region, and a high pressure side region, that is, a discharge port side region.

  In addition, in the present embodiment, as shown in FIGS. 1 to 3, the shafts 4, 5 and the inner periphery of the side plate 6, that is, the inner peripheral surface of the shaft hole 6 c are opposed to the shaft. Using the rotational movement of the side plates 6 of 4 and 5 with liquid for biasing the liquid in the gear housing chamber 11a, that is, hydraulic oil, toward the gap between the shafts 4 and 5 and the bush 7. Force means F is provided. In the present embodiment, the liquid urging means F uses spiral grooves 4a and 5a formed in a portion of the outer periphery of the shafts 4 and 5 facing the inner peripheral surface of the shaft hole 6c of the side plate 6. . Further, in the present embodiment, the liquid urging means F is provided only at a portion where the outer periphery of the shafts 4 and 5 and the inner peripheral surface of the shaft hole 6c face each other. This is because the reduction of the bearing action is suppressed by limiting to a portion that does not affect the capability as a bearing.

  Here, the operation of the liquid urging means F will be described. As shown in FIG. 2, when the drive shaft 4 receives power from a power source (not shown) and rotates in the arrow X direction, the hydraulic oil in the spiral groove 4a moves in the spiral groove 4a in the arrow Y direction. Receives moving action. As a result, as shown in FIG. 3, the hydraulic oil is guided to the gap s between the drive shaft 4 and the bush 7, and forms a liquid film between the drive shaft 4 and the bush 7.

  Although illustration is omitted, when the driven shaft 5 receives power from the drive shaft 4 via the drive gear 2 and the driven gear 3, the hydraulic oil in the spiral groove 5a is removed from the spiral groove 5a. The inside is subjected to an action in a direction away from the driven gear 3, that is, in a direction toward the gap s between the driven shaft 5 and the bush 7. As a result, the hydraulic oil is guided to the gap s between the driven shaft 5 and the bush 7, and forms a liquid film between the driven shaft 5 and the bush 7.

  As described above, according to the present embodiment, hydraulic oil is guided to the gap s between the shafts 4, 5 and the bush 7 through the spiral grooves 4 a, 5 a as the shafts 4, 5 rotate. Since a flow is formed, more hydraulic fluid is introduced into the gap s. That is, it is possible to ensure a sufficient amount of hydraulic fluid that is used for lubrication between the shafts 4 and 5 and the bush 7. Therefore, lubrication between the shafts 4 and 5 and the bush 7 can be achieved more effectively, and more effective cooling can be performed. In addition, the spiral grooves 4a and 5a are provided only at portions where the shafts 4 and 5 and the side plate 6 face each other, and are not provided at other portions. A liquid film with a sufficient thickness can be stably formed.

  Further, since the hydraulic oil is urged toward the gap s between the shafts 4 and 5 and the bush 7 by the liquid urging means F, the pressure receiving area of the bush 7 for obtaining a desired strength. Can be reduced. Accordingly, the bush 7 can be shortened and the shafts 4 and 5 can be shortened. As a result, the casing 1 having the bearing holes 11x, 11y, 12x, and 12y for housing the shafts 4 and 5 can be shortened. Can be achieved.

  In addition, the liquid urging means F can be formed with a simple structure by providing the spiral grooves 4a and 5a at the portions of the outer periphery of the shafts 4 and 5 facing the inner peripheral surface of the shaft hole 6c of the side plate 6. Can do.

  The present invention is not limited to the embodiment described above.

  For example, in the above-described embodiment, the liquid urging means is formed by providing a spiral groove in a portion facing the inner periphery of the side plate on the outer periphery of the shaft, but a portion facing the outer periphery of the shaft on the inner periphery of the side plate. The liquid urging means may be formed by providing a spiral groove on the surface. Moreover, you may employ | adopt the thing of other structures, such as not only using a spiral groove but the blade provided protruding from the outer surface of a shaft, or the inner surface of a side plate as a hydraulic fluid urging means. In addition, in the above-described embodiment, the liquid urging means is provided only at a portion facing the inner periphery of the side plate on the outer periphery of the shaft, but the liquid urging means is provided at a portion facing the inner periphery of the side plate on the outer periphery of the shaft. If the liquid urging means extends over a portion that does not face the portion that faces the inner periphery of the side plate, the effect according to the present invention can be obtained to some extent.

  In the above-described embodiment, the casing includes the body and a cover that covers the front surface of the body. However, the casing covers the body, the front cover that covers the front surface of the body, and the rear surface of the body. You may employ | adopt the structure provided with a rear cover. Moreover, you may employ | adopt the structure with which a casing is provided with a body and the cover which coat | covers the rear surface of a body.

  Furthermore, in the above-described embodiment, the liquid in the gear housing chamber is a working oil that circulates in the hydraulic path, but the liquid in the gear housing chamber is not limited to the working oil and may be other liquids such as water. .

  The present invention is applied not only to a gear pump that receives power from a power source and conveys liquid from the low pressure side to the high pressure side, but also to a gear motor that drives the shaft and gears by receiving liquid supply from the high pressure port. Of course.

  In addition, various modifications may be made without departing from the spirit of the present invention.

P ... gear pump 1 ... casing 2 ... drive gear 3 ... driven gear 4 ... drive shaft 5 ... driven shaft 4a, 5a ... spiral groove 6 ... side plate 7 ... bush F ... liquid biasing means

Claims (2)

A pair of gears that mesh with each other, shafts that respectively support these gears, and a gear hole that accommodates the gears therein, and a bearing hole for rotatably supporting the shafts via bushes A gear pump or motor that includes a casing having a side plate and a side plate that comes into contact with a side surface of the gear, and guides a part of the liquid in the gear housing chamber between the shaft and the bush. And
A liquid for urging the liquid toward the gap between the shaft and the bush at a portion where the outer periphery of the shaft and the inner periphery of the side plate face each other by using a rotation operation of the shaft with respect to the side plate. A gear pump or motor provided with urging means. The gear pump or motor according to claim 1, wherein the liquid biasing means includes a spiral groove formed on an outer periphery of the shaft or an inner periphery of the side plate.

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