WO2014141377A1

WO2014141377A1 - Gear pump or motor

Info

Publication number: WO2014141377A1
Application number: PCT/JP2013/056730
Authority: WO
Inventors: 勇紀萩野
Original assignee: 株式会社島津製作所
Priority date: 2013-03-12
Filing date: 2013-03-12
Publication date: 2014-09-18
Also published as: JPWO2014141377A1; JP5950020B2

Abstract

Provided is a hydraulic pump or motor equipped with an external gear pair composed of a drive-side helical gear and driven-side helical gear in meshed engagement with one another, a casing having at the interior a gear-housing chamber for housing the external gear pair and also having a bearing for housing a drive shaft and a driven shaft, a hydraulic mechanism which has a hydraulic chamber and with which the drive shaft and the driven shaft are pressed in an anti-thrust direction by hydraulic pressure introduced to the hydraulic chamber, and a high-pressure operating liquid introduction path for guiding an operating liquid from a high-pressure side to the hydraulic chamber of the hydraulic mechanism; the bearing is provided with a bushing for receiving the action in the radial direction of the drive shaft or driven shaft. The present invention employs a configuration wherein the hydraulic mechanism is provided with the hydraulic chamber which faces the drive shaft or the driven shaft and is located on the side opposite to the drive-side helical gear or the driven-side helical gear, and a hydraulic receiving section that is disposed inside the hydraulic chamber and that is integrated with the drive shaft or driven shaft and is pressed in the anti-thrust direction by the operating liquid pressure, and wherein the hydraulic receiving section forms a gap that extends along a thrust direction between itself and an inner wall of the hydraulic chamber, and the hydraulic receiving section has an annular recess formed in the vertical direction of the shafts and a sealing member housed in the interior of the annular recess.

Description

Gear pump or motor

The present invention relates to a gear pump or a motor provided with an external gear pair composed of a drive gear and a driven gear each utilizing helical gears that mesh with each other, and a casing having a gear storage chamber for storing the external gear pair therein. .

2. Description of the Related Art Conventionally, a gear pump or a motor including an external gear pair that includes a drive gear and a driven gear that mesh with each other and a casing that internally includes a gear storage chamber that stores the external gear pair has been widely used. The spur gear in which teeth parallel to the axis are formed around the drive gear and driven gear of such a gear pump or motor is the mainstream. However, when a spur gear is used for the drive gear and the driven gear, there are the following problems. Specifically, when the teeth of the drive gear and the teeth of the driven gear mesh with each other, they mesh simultaneously over the entire tooth width. Further, when the meshing between the teeth of the drive gear and the teeth of the driven gear is terminated, the meshing is simultaneously terminated over the entire tooth width. This can cause noise and vibration. In order to solve this problem, a contrivance has been proposed in which helical gears are used as the drive gear and the driven gear (see, for example, Patent Document 1).

Such a gear pump or motor has the following configuration, for example. That is, as shown in FIG. 3, an external gear pair X1 including a driving gear X6 and a driven helical gear X7 that mesh with each other, and a gear storage chamber X2a that stores the external gear pair X1 are included. A casing X2 having a bearing for housing a drive shaft X8 that pivotally supports the helical gear X6 and a driven shaft X9 that pivotally supports the driven helical gear X7, and the casing X2 accommodates the drive side. A rear bearing case X3a and a front bearing case X3b which serve as a pair of side plates which are in contact with both side surfaces X6a, X6b, X7a and X7b of the helical gears X6 and X7, respectively. The hydraulic shafts X41a and X41b have hydraulic chambers X41a and X41b, and the drive shaft X8 and the driven shaft X9 are anti-thrusted by the hydraulic pressure introduced into the hydraulic chambers X41a and X41b. A hydraulic mechanism X4 for pressing, hydraulic chambers X41a of the hydraulic mechanism X4, formed by and a high-pressure hydraulic fluid introducing passage X5 for guiding hydraulic fluid from the high pressure side X41b. The casing X2 includes a cylindrical body X23 having the gear housing chamber X2a, a front cover X22 attached to the front side of the body X23, and a rear cover X24 attached to the rear side of the body X23. Inside the body X23, there is a bearing case X3a on the rear side that also serves as one side plate and the rear end side of the drive shaft X8 and the rear end side of the driven shaft X9, and the front end of the drive shaft X8 that also serves as the other side plate. And a rear bearing case X3b that pivotally supports the front end side of the driven shaft X9.

In a state where the gear pump having such a configuration is operated, a thrust load due to a component of rotational torque and a thrust load due to hydraulic pressure are generated on the driving side helical gear X6 and the driven side helical gear X7. . As a result of synthesizing the thrust load due to the component force of the rotational torque and the thrust load due to the hydraulic pressure, as shown in FIG. 3, the driving side is different in the helical gear X6 and the driven side is different in the helical gear X7. (Hereinafter, the direction of the thrust load is referred to as “thrust direction” and the opposite direction is referred to as “anti-thrust direction”).

The bearing case X3a on the rear side receives a large surface pressure due to the thrust load. For the purpose of reducing the load, the balance pistons X43a and X43b of the hydraulic mechanism X4 are arranged on the rear end side of the drive shaft X8 and the driven shaft X9. Are brought into contact with each other and balanced by liquid pressure. As a result, the balance pistons X43a and X43b can apply a pressing force proportional to the fluid pressure against the thrust load.

However, since the hydraulic mechanism X4 has a configuration in which the balance pistons X43a and X43b of the hydraulic mechanism X4 are in contact with the rear ends of the drive shaft X8 and the driven shaft X9, the following problems may occur. . That is, in such a configuration, friction occurs between the balance pistons X43a and X43b as the drive shaft X8 and the driven shaft X9 rotate, and the balance pistons X43a and X43b transmit torque from the drive shaft X8 and the driven shaft X9. May rotate in response. At that time, there is a problem that mechanical loss occurs due to friction between the balance pistons X43a and X43b and the drive shaft X8 and the driven shaft X9 and friction between the side surfaces of the balance pistons X43a and X43b and the casing. .

Special table 2012-519798 gazette

The present invention focuses on the above points, and in a gear pump or motor having a pair of external gears composed of a helical gear on the driving side and a helical gear on the driven side that mesh with each other, the piston is used as the driving shaft and the driven shaft. The intended purpose is to eliminate the problem that mechanical loss occurs when the drive shaft and the driven shaft are pressed in the anti-thrust direction in the contacted state.

That is, the gear pump or motor according to the present invention has the following configuration. That is, the gear pump or motor according to the present invention has an external gear pair composed of a driving side helical gear and a driven side helical gear meshing with each other, and a gear storage chamber for storing the external gear pair, and the drive. A casing having a drive shaft for supporting the helical gear on the side and a bearing for housing the driven shaft for supporting the driven helical gear on the driven side, and a hydraulic chamber are introduced into the hydraulic chamber. A hydraulic mechanism that presses the drive shaft and the driven shaft in the anti-thrust direction by hydraulic pressure, and a high-pressure hydraulic fluid introduction path that guides hydraulic fluid from the high-pressure side to the hydraulic pressure chamber of the hydraulic mechanism, A bearing is a gear pump or motor having a bush that receives a radial action of the drive shaft or driven shaft, wherein the hydraulic mechanism faces the drive shaft or driven shaft and the drive side is Gear or driven side helical gear A hydraulic chamber for pressing the drive shaft or the driven shaft in the anti-thrust direction by a hydraulic pressure that is located on the opposite side and introduced into the inside, and the drive shaft or the driven shaft that is disposed in the hydraulic chamber and that is disposed in the hydraulic chamber And a hydraulic pressure receiving portion that is pressed in the anti-thrust direction by the hydraulic pressure, and this hydraulic pressure receiving portion forms a gap extending along the thrust direction with the inner wall of the hydraulic pressure chamber. In addition, an annular recess formed in the vertical direction of the shaft, and a seal member housed in the annular recess.

According to such a configuration, the hydraulic pressure receiving portion is integrated with the driving shaft or the driven shaft, and the hydraulic pressure receiving portion is pressed in the anti-thrust direction by the operating hydraulic pressure, while the driving shaft or the driven shaft is radial. If the bush is acted on in the direction, the bush is acted in the radial direction, and there is a gap extending along the thrust direction between the hydraulic pressure receiving portion and the inner wall of the hydraulic pressure chamber, so that the hydraulic pressure receiving portion and the hydraulic pressure chamber There is no contact between the inner wall and the friction between them. Thus, it is possible to suppress the occurrence of mechanical loss due to friction between the piston and the drive shaft or the driven shaft in the conventional configuration and between the piston and the inner wall of the hydraulic chamber.

According to the present invention, in a gear pump or motor having a pair of external gears composed of a helical gear on the driving side and a helical gear on the driven side that mesh with each other, the driving shaft in a state where the piston is in contact with the driving shaft and the driven shaft. And the malfunction which mechanical loss generate | occur | produces by pressing a driven shaft to an anti-thrust direction can be eliminated.

Schematic which shows the gear pump or motor which concerns on one Embodiment of this invention. The enlarged view of the principal part in FIG. Schematic which shows the conventional gear pump or motor.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the gear pump P <b> 1 according to the present embodiment accommodates an external gear pair 1 including a driving-side helical gear 6 and a driven-side helical gear 7 that mesh with each other, and the external gear pair 1. A casing 2 having a gear housing chamber 2a therein and a bearing for housing the drive shaft 8 that supports the helical gear 6 on the driving side and the driven shaft 9 that supports the helical gear 7 on the driven side. A rear plate 3a and a front plate 3b, which are housed in the casing 2 and make a pair respectively contacting the both

side surfaces

6a, 6b, 7a, 7b of the helical gears 6, 7; A hydraulic mechanism 4 having

pressure chambers

41a and 41b and pressing the drive shaft 8 and the driven shaft 9 in the anti-thrust direction by the hydraulic pressure introduced into the

hydraulic chambers

41a and 41b; The hydraulic fluid is guided to the

pressure chambers

41a and 41b from the high pressure side. Comprising a pressure hydraulic fluid introducing passage 5.

The driving-side helical gear 6 and the driven-side helical gear 7 constituting the external gear pair 1 are helical gears that are well known as those used in this type of gear pump. Here, the teeth on the driving side of the helical gear 6 and the teeth on the driven side of the helical gear 7 are operated as a gear pump in a state where they are engaged with each other. The helical gear 6 receives a thrust load going backward, and the driven gear 7 receives a thrust load going forward. The helical gear 6 on the driving side and the helical gear 7 on the driven side receive thrust loads directed rearward by the hydraulic pressure while operating as a gear pump. As a result of synthesizing the thrust load due to the component force of the rotational torque and the thrust load due to the hydraulic pressure, as shown in FIG. 1, the driving side is different in the helical gear 6 and the driven side is different in the helical gear 7. The thrust load is applied toward the rear. In the present embodiment, the drive side is provided with the helical gear 6 and the drive shaft 8 integrally. The drive shaft 8 extends from the center of the helical gear 6 on the drive side in the rotational axis direction. One end of the drive shaft 8 extends to the outside of the casing 2. Further, the driven side is provided integrally with the helical gear 7 and the driven shaft 9. The driven shaft 9 extends from the center of the driven helical gear 7 in the direction of the rotational axis.

The casing 2 includes a casing body 21 having a gear housing chamber 2a that opens forward, and a front cover 22 that is mounted on the front side of the casing body 21.

The casing main body 21 has a substantially eyeglass-shaped gear housing chamber 2a in which the external gear pair 1, that is, the driving-side helical gear 6 and the driven-side helical gear 7 are housed in an engaged state, and the gear housing chamber 2a. Is formed integrally with a cylindrical body 23 having a hydraulic fluid inlet and a hydraulic fluid outlet 2b (not shown) that communicate with the outside, and a rear cover 24 that closes the rear end of the body 23. The body 23 includes a bearing 25 that supports the rear end sides of the drive shaft 8 and the driven shaft 9 behind the gear housing chamber 2a. Each bearing 25 is provided with a bearing hole 25x into which the rear end side of the drive shaft 8 and the driven shaft 9 can be respectively fitted, and is slidable on the drive shaft 8 and the driven shaft 9 provided on the inner periphery of the bearing hole 25x. And a bush 25y that pivotally supports the shaft. The bush 25y receives a radial action when the drive shaft 8 or the driven shaft 9 receives a radial action, and functions as a bush in the claims. Have

The front cover 22 is detachably attached to the casing body 21 with bolts or the like, and closes the opening surface of the gear housing chamber 2a. The front cover 22 includes a bearing 26 that pivotally supports the front end sides of the drive shaft 8 and the driven shaft 9. Each bearing 26 is provided with a bearing hole 26x in which the front end sides of the drive shaft 8 and the driven shaft 9 can be respectively fitted, and an inner periphery of the bearing hole 26x so that the drive shaft 8 and the driven shaft 9 can slide. A supporting bush 26y is provided. The front end of the drive shaft 8 passes through the bearing hole 26x and protrudes to the outside of the casing 2.

As shown in FIGS. 1 and 2, the hydraulic mechanism 4 includes a pair of

hydraulic chambers

41a and 41b formed inside the rear cover 24 so as to correspond to the drive shaft 8 and the driven shaft 9, respectively. The

hydraulic chambers

41a and 41b are arranged in the

hydraulic chambers

41a and 41b, and are integrated with the drive shaft 8 or the driven shaft 9, respectively, and are pressed in the anti-thrust direction by the operating hydraulic pressure. Fluid

pressure receiving portions

42a and 42b having gaps extending along the thrust direction are provided.

The fluid

pressure receiving portions

42a and 42b are provided with annular recesses 42a1 and 42b1 that are provided in the middle portion in the longitudinal direction, that is, in the thrust direction intermediate portion and formed in the vertical direction of the shaft.

Seal members

42x and 42y are housed inside 42b1. The

seal members

42x and 42y are elastically deformable and are in close contact with the inner walls of the

hydraulic chambers

41a and 41b by elastic force. A gap is provided between the

seal members

42x and 42y and the bottom surfaces of the annular recesses 42a1 and 42b1. Further, in the present embodiment, a gap is also provided between the

seal members

42x and 42y and the side surface opposite to the gears 2 and 3.

The high-pressure hydraulic fluid introduction path 5 is for guiding the hydraulic fluid from the high-pressure side to the

hydraulic chambers

41 a and 41 b of the hydraulic mechanism 4 and is formed in the casing body 21.

Here, when the driving-side helical gear 6 and the driven-side helical gear 7 are driven synchronously and reversely through the driving shaft 8 of the gear pump P1, the hydraulic fluid suction port and the hydraulic fluid discharge are driven. A high and low pressure difference is generated between the outlet 2b. At this time, in the space inside the body 21, the side where the teeth of the helical gear 6 on the driving side and the helical gear 7 on the driven side are gradually separated from each other, that is, the space on the hydraulic fluid suction port side is a low pressure region. At the same time, the space where the teeth gradually mesh, that is, the space on the hydraulic fluid discharge port 2b side, becomes a high pressure region. At that time, the hydraulic fluid is guided from the hydraulic fluid discharge port 2b side to the

hydraulic chambers

41a and 41b. The action derived from the hydraulic pressure of the hydraulic fluid is applied to the hydraulic

pressure receiving portions

42a and 42b, and the drive shaft 8 and the driven shaft 9 formed integrally with the hydraulic

pressure receiving portions

42a and 42b are pressed in the anti-thrust direction. The On the other hand, when the drive shaft 8 or the driven shaft 9 receives a radial action, the width of the gap between the fluid

pressure receiving portions

42a and 42b and the inner walls 41a1 and 41b1 of the

fluid pressure chambers

41a and 41b. The driving shaft 8 or the driven shaft 9 comes into close contact with the bush 25y before the hydraulic

pressure receiving portions

42a, 42b come into contact with the inner walls of the

hydraulic pressure chambers

41a, 41b. Therefore, the hydraulic

pressure receiving portions

42a and 42b do not contact the inner walls of the

hydraulic pressure chambers

41a and 41b.

The gear pump P1 introduces high-pressure hydraulic fluid from the hydraulic fluid discharge port 2b, thereby taking out rotational torque from the drive shaft 8 and driving an external load, and at the same time, operating the hydraulic fluid at low pressure in the operation. It goes without saying that it can also function as a gear motor that performs the motor action of discharging from the liquid suction port.

As described above, according to the configuration of the gear pump P1 according to the present embodiment, the hydraulic

pressure receiving portions

42a and 42b are integrated with the drive shaft 8 or the driven shaft 9, and the hydraulic

pressure receiving portions

42a and 42b. Is pressed in the anti-thrust direction by the hydraulic pressure, so that the occurrence of mechanical loss due to friction between the piston and the drive shaft or the driven shaft in the conventional configuration can be suppressed. Further, when the drive shaft 8 or the driven shaft 9 is acted in the radial direction, the bush 25y is acted in the radial direction, and the hydraulic

pressure receiving portions

42a, 42b and the inner walls 41a1, 41b1 of the

hydraulic pressure chambers

41a, 41b Since there is a gap extending in the thrust direction between the hydraulic

pressure receiving portions

42a and 42b and the inner walls of the

hydraulic pressure chambers

41a and 41b as described above, there is no friction between them. Thus, it is possible to suppress the occurrence of mechanical loss due to friction between the piston and the drive shaft or the driven shaft in the conventional configuration and between the piston and the inner wall of the hydraulic chamber.

Furthermore, in the present embodiment, a gap is provided between the

seal members

42x, 42y and the bottom surfaces of the annular recesses 42a1, 42b1 provided in the hydraulic

pressure receiving portions

42a, 42b and the side surfaces opposite to the gears 2, 3. The

seal members

42x and 42y are pressed toward the inner walls of the

hydraulic chambers

41a and 41b and the side surfaces of the annular recesses 42a1 and 42b1 on the side of the gears 2 and 3 by the force resulting from the hydraulic pressure of the hydraulic fluid introduced into the gap. The By utilizing this, the

hydraulic pressure chambers

41a and 41b can be more reliably sealed.

Note that the present invention is not limited to the above-described embodiment, and may be variously modified.

For example, in the above-described embodiment, the body is integrally formed with a body including a gear storage chamber that stores the external gear pair and a rear cover that closes the rear end of the body. You may apply this invention to what comprised the rear cover separately. When the body and the rear cover are configured separately, the body and a front cover that closes the front end of the body may be configured integrally.

In addition, in the above-described embodiment, a configuration in which the front cover also serves as the front side plate may be employed.

The annular recess of the hydraulic pressure receiving portion may be provided at any location of the hydraulic pressure receiving portion as long as it is formed in the direction perpendicular to the shaft.

Other various modifications may be made without departing from the spirit of the present invention.

In the gear pump or motor having a pair of external gears composed of a helical gear on the driving side and a helical gear on the driven side that are meshed with each other, if the configuration of the gear pump or motor of the present invention is adopted, the piston is connected to the driving shaft and driven shaft. It is possible to eliminate a problem that mechanical loss occurs due to pressing of the drive shaft and the driven shaft in the anti-thrust direction in a state where they are in contact with each other.

P1 ... Gear pump 1 ... External gear pair 2 ... Case 2a ... Gear housing chamber 25y ... Bush 4 ...

Hydraulic mechanism

41a, 41b ...

Hydraulic chamber

42a, 42b ... Hydraulic pressure receiving part 5 ... High pressure hydraulic fluid introduction path 6 ... Drive side Helical gear 7 ... Driven side helical gear 8 ... Drive shaft 9 ... Driven shaft

Claims

A drive shaft that has an external gear pair composed of a helical gear and a driven helical gear that mesh with each other, and a gear housing chamber that houses the external gear pair, and that supports the helical gear on the drive side. And a casing having a bearing for housing a driven shaft for supporting the helical gear on the driven side, and a hydraulic chamber having a hydraulic pressure chamber, the drive shaft and the driven shaft being counteracted by the hydraulic pressure introduced into the hydraulic pressure chamber. A hydraulic mechanism that pushes in a thrust direction, and a high-pressure hydraulic fluid introduction passage that guides hydraulic fluid from a high-pressure side to a hydraulic chamber of the hydraulic mechanism, and the bearing is a radial of the drive shaft or the driven shaft A gear pump or motor comprising a bushing subjected to a direction action,
The hydraulic pressure mechanism is opposed to the drive shaft or driven shaft, the drive side is located on the opposite side of the helical gear or the driven side is located on the opposite side of the helical gear, and the drive shaft or driven shaft is driven by the hydraulic pressure introduced inside. And a hydraulic pressure receiving portion disposed in the hydraulic pressure chamber and integrated with the drive shaft or the driven shaft and pressed in the anti-thrust direction by the operating hydraulic pressure. The hydraulic pressure receiving portion forms a gap extending along the thrust direction between the inner wall of the hydraulic pressure chamber and an annular recess formed in a direction perpendicular to the shaft, and an inner portion of the annular recess. A gear pump or a motor having a stored sealing member.