JP2006250089A - Pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve transmission efficiency of a gear train housed in a housing by improving cooling efficiency of a pump main body housed in the housing, and reducing agitation resistance of the gear train. <P>SOLUTION: In this pump device, an introducing port 291 to introduce oil from the external to a pump housing chamber 200B, an oil passage to let oil in the pump housing chamber flow to a gear housing chamber 200A, and a discharge port to take our oil in the gear housing chamber to the external are provided in the housing 200. In a preferable embodiment, an air intake mechanism to take air into the gear housing chamber is provided which is composed to suck air into the gear housing chamber using pump action by at least one gear composing the gear train. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pump device having a housing in which an internal space in which oil can be stored is partitioned into a pump housing chamber and a gear housing chamber.

  A pump device in which the internal space of the housing can store oil and the internal space is divided by a partition wall into a pump storage chamber for storing a hydraulic pump body and a gear storage chamber for storing a gear train has been conventionally used as a working vehicle. Etc. (see, for example, Patent Document 1).

  In such a conventional pump device, the internal space of the housing can be used as an oil reservoir, and impurities such as iron powder generated from the gear train can be prevented or reduced from flowing into the pump storage chamber, while the oil can be stored by the stored oil. This is useful in that the hydraulic pump body can be cooled.

However, in the conventional pump device, sufficient consideration has not been given to improving the cooling performance of the hydraulic pump body by circulating the stored oil in the housing.
In addition, the stored oil in the housing provides a stirring resistance to the rotating body such as the gear train and the hydraulic pump main body.
Also regarding such a viewpoint, the conventional pump apparatus is not fully considered.
Japanese Patent Laid-Open No. 2003-291474

The present invention has been made in view of the prior art, and in a pump device having a housing in which the internal space is capable of storing oil, the stored oil in the housing is prevented from staying and stored in the housing. An object of the present invention is to provide a pump device that can improve the cooling efficiency of the pump body.
Another object of the present invention is to reduce the stirring resistance of the gear train accommodated in the housing while achieving the above object, and to improve the transmission efficiency of the gear train as much as possible.

  In order to achieve the above object, the present invention provides a housing in which an internal space in which oil can be stored is partitioned by a partition wall into a pump housing chamber and a gear housing chamber, a hydraulic pump body housed in the pump housing chamber, and the gear A pump device comprising a gear train housed in a housing chamber, wherein the housing has an inlet for introducing oil from the outside into the pump housing chamber, and oil in the pump housing chamber for the gear housing chamber. There is provided a pump device having an oil passage for flowing in and a discharge port for taking out oil in the gear housing chamber to the outside.

  In order to achieve the above object, the present invention provides a housing in which an internal space in which oil can be stored is partitioned by a partition wall into a pump storage chamber and a gear storage chamber, and the pump storage chamber through the partition wall and First and second pump shafts supported by the housing so as to extend into the gear housing chamber, and first and second hydraulic pressures supported by the first and second pump shafts so as to be positioned in the pump housing chamber, respectively. A pump device comprising a pump body and a gear train housed in the gear housing chamber, wherein the housing includes an inlet for introducing oil from outside into the pump housing chamber, There is provided a pump device having an oil passage for allowing oil to flow into the gear housing chamber and a discharge port for taking out the oil in the gear housing chamber to the outside.

In one aspect, the housing may have a partition wall that partitions the pump housing chamber into a first pump space and a second pump space through which oil can flow.
In such an aspect, preferably, the introduction port is provided in one of the first and second pump spaces, and the oil passage is provided in the other of the first and second pump spaces.

In another aspect, the pump housing chamber includes a first pump housing chamber and a second pump housing disposed on one side and the other side in the axial direction of the first and second pump shafts with the gear housing chamber interposed therebetween. Including chambers.
In such an aspect, preferably, the introduction port includes first and second introduction ports for introducing oil from outside into the first pump accommodation chamber and the second pump accommodation chamber, respectively, and The oil passage includes first and second oil passages for allowing oil in the first and second pump housing chambers to flow into the gear housing chamber, respectively.

The pump device according to the various aspects may include a PTO shaft supported by the housing and a PTO clutch mechanism that engages / blocks power transmission from the gear train to the PTO shaft.
In such an aspect, the housing may have a PTO accommodation chamber communicated with the gear accommodation chamber.

  In the various aspects, preferably, the oil passage is located at a position where the inflow of oil from the pump housing chamber to the gear housing chamber is performed using a pump action by at least one gear constituting the gear train. Provided.

Moreover, in order to achieve the said other objective, this invention can be equipped with the air intake mechanism which takes in air in the said gear accommodation chamber in the said various aspect.
The air intake mechanism is configured to suck air into the gear housing chamber using a pump action of at least one gear constituting the gear train.

  Preferably, the air intake mechanism is configured to use a pump action by a gear located at a lowermost position in the installed state of the pump device among the gears constituting the gear train.

The air intake mechanism has an air intake port provided in the housing so as to allow communication between the gear housing chamber and the outside, and a tubular member having a base end connected to the air intake port. Can do.
In one aspect, the tubular member may have a portion that is higher than the oil level of the reserve tank that is fluidly connected to the discharge port, based on the rotation stop state of the one gear.
In another aspect, the front-end | tip part of the said tubular member is connected to the air layer of the reserve tank fluid-connected to the said discharge port.

  The air intake mechanism includes an air intake port provided in the housing so as to allow communication between the gear storage chamber and the outside, and air to the gear storage chamber via the air intake port. And a one-way valve that prevents oil from flowing out of the gear housing chamber through the air intake port.

  In the various aspects, preferably, the air intake mechanism may include a filter that prevents foreign matter from being sucked into the gear housing chamber from the outside.

According to the pump device of the present invention, the housing having an internal space in which oil can be stored allows the oil from the outside to be introduced into the pump housing chamber, and the oil in the pump housing chamber flows into the gear housing chamber. For this reason, the oil stored in the housing is efficiently circulated to prevent the stored oil from staying. it can.
Therefore, the hydraulic pump main body accommodated in the pump accommodating chamber can be efficiently cooled.
In addition, since oil flow from the gear housing chamber to the pump housing chamber can be prevented, it is effective that impurities such as iron powder from the gear train housed in the gear housing chamber adversely affect the hydraulic pump body. Can be prevented.

  When the first and second hydraulic pump bodies are arranged in parallel, the housing is provided with a partition wall that divides the pump storage chamber into a first pump space and a second pump space through which oil can flow. In addition, if the introduction port is provided in one of the first and second pump spaces and the oil passage is provided in the other of the first and second pump spaces, the first and second hydraulic pump bodies Both can be efficiently cooled.

  When the first and second hydraulic pump bodies are arranged in series, the first inlet for introducing oil from the outside into the first pump storage chamber and the second pump storage chamber, respectively, as the introduction port. And the second introduction port, and as the oil passage, the first and second oil passages for allowing the oil in the first and second pump accommodation chambers to flow into the gear accommodation chamber, respectively, Both the first and second hydraulic pump bodies can be efficiently cooled.

If an air intake mechanism that sucks air into the gear housing chamber is provided by using the pump action of at least one gear constituting the gear train, the amount of stored oil in the gear housing chamber is reduced without providing an additional member. Can be made.
Therefore, it is possible to reduce the agitation resistance with respect to the gear train caused by the stored oil while improving the transmission efficiency of the gear train.

  Of the gears constituting the gear train, in the installed state of the pump device, if the pump action by the gear located at the lowermost part is utilized, the amount of stored oil can be evenly distributed over the entire region of the gear housing chamber. The transmission efficiency of the gear train can be improved more effectively.

  The air intake mechanism includes an air intake port provided in the housing so as to communicate the gear housing chamber and the outside, and a tubular member having a base end connected to the air intake port. If the tubular member has a portion higher than the oil level of the reserve tank fluidly connected to the discharge port with reference to the rotation stop state of the one gear, the pump device This is a case where the working vehicle equipped with is inclined on an inclined ground or the like, and the oil stored in the gear housing chamber can be effectively prevented from flowing out.

Further, if the distal end portion of the tubular member is connected to an air layer of a reserve tank fluidly connected to the discharge port, air can be taken into the gear housing space.
Therefore, it is possible to reliably prevent the oil stored in the gear housing chamber from flowing out.

  And a one-way valve that allows air to be taken into the gear housing chamber through the air intake and prevents oil from flowing out of the gear housing through the air intake. This can also reliably prevent the oil stored in the gear housing chamber from flowing out.

  Furthermore, if the air intake mechanism is provided with a filter that prevents foreign matter from being sucked into the gear housing chamber from the outside, it is possible to effectively prevent impurities from entering the housing.

Embodiment 1
Hereinafter, a preferred embodiment of a pump device according to the present invention will be described with reference to the accompanying drawings.
1 and 2 show a schematic side view and a hydraulic circuit diagram of a working vehicle 1 to which the pump device 100 according to the present embodiment is applied, respectively.
FIG. 3 shows a plan view and a front view of the pump device 100 according to the present embodiment.

  As shown in FIGS. 1 and 2, the working vehicle 1 includes a drive source 40 mounted in a rear region of a vehicle frame 30, the pump device 100 operatively connected to the drive source 40, and the pump device 100. A pair of first and second hydraulic motor units 10 and 20 fluidly connected to each other, and a pair of left and right drive wheels 50 respectively driven by the pair of first and second hydraulic motor units 10 and 20. Yes.

That is, the pump device 100 according to the present embodiment constitutes a traveling system transmission mechanism in cooperation with the pair of first and second hydraulic motor units 10 and 20 provided in the work vehicle 1. ing.
Specifically, as shown in FIG. 2, the pump device 100 includes a first hydraulic pump body 300a fluidly connected to the first hydraulic motor unit 10 via a pair of first hydraulic oil lines 400a, and the second hydraulic pump unit 100a. A first hydraulic pump body 300b fluidly connected to the hydraulic motor unit 20 via a pair of second hydraulic oil lines 400b, and a first and a second hydraulic pump body 300a, 300b for changing the intake and exhaust oil amount respectively. And the second output adjusting member 350a, 350b, the first hydraulic pump main body 300a and the hydraulic motor main body in the first hydraulic motor unit 10 constitute a first HST, and the second hydraulic pump main body. 300b and the hydraulic motor main body in the second hydraulic motor unit 20 constitute a second HST.
In the present embodiment, the first and second hydraulic motor units 10 and 20 are fixed displacement types (see FIG. 2), but these may be variable displacement types.

FIG. 4 shows a cross-sectional plan view of the pump device 100.
5 to 7 are longitudinal sectional views of the pump device 100 taken along lines VV, VI-VI, and VII-VII in FIG. 4, respectively.
As shown in FIGS. 4 to 7, the pump device 100 includes a housing 200, first and second pump shafts 310 a and 310 b that are rotatably supported by the housing 200 around the axis, and the first and second pump devices 100. The first and second hydraulic pump bodies 300a and 300b that are rotationally driven by pump shafts 310a and 310b, the first and second output adjusting members 350a and 350b, and the first and second pump shafts 310a and 310b, respectively. And a gear train 280 including first and second transmission gears 282a and 282b that are supported on the first and second pump shafts 310a and 310b so as not to rotate relative to each other, respectively.

The housing 200 is directly or indirectly supported by a support member such as the vehicle frame 30.
In the present embodiment, the housing 200 is connected to the drive source 40 via a connecting case 700 in a free state with respect to the vehicle frame 30 (see FIG. 1).
That is, as shown in FIG. 1, the drive source 40 is supported to be able to vibrate with respect to the vehicle frame 30 via an anti-vibration rubber, and the housing 200 can vibrate integrally with the drive source 40. As described above, the vehicle frame 30 is connected to the drive source 40 through the connection case 700 in a free state.

  The housing 200 has an internal space in which oil can be stored, and the internal space accommodates the first and second hydraulic pump bodies 300a and 300b by the partition wall 201, and the gear train. It is divided into a gear housing chamber 200 </ b> A for housing 280.

  In the present embodiment, the housing 200 includes a housing main body 230 and a plate member 360 (center section) that is detachably connected to the housing main body 230, and includes the first and second hydraulic pump main bodies 300a, And a plate member 360 having an intake / exhaust oil passage for 300b.

  As shown in FIGS. 4, 5, and 7, the housing body 230 includes a first housing member 240 that forms the pump housing chamber 200 </ b> B in cooperation with the plate member 360, and the first housing member 240. The second housing member 250 is detachably connected to the first housing member 240 and forms the gear housing chamber 200A in cooperation with the first housing member 240.

The first housing member 240 includes a first end wall portion 241 extending in a direction orthogonal to the axial direction of the first and second pump shafts 310a and 310b, and the first and second end portions from the first end wall portion 241. The first peripheral wall portion 242 extends in the axial direction of the pump shafts 310a and 310b, and the free end side of the first peripheral wall portion 242 opposite to the first end wall portion 241 is an opening.
The opening is sized such that the first and second hydraulic pump bodies 300a and 300b can be inserted therethrough and is liquid-tightly closed by the plate member 360.
That is, in the present embodiment, the pump housing chamber 200B is formed by the first end wall portion 241 and the first peripheral wall portion 242 of the first housing member 240 and the plate member 360. Yes.

The second housing member 250 has a second end wall portion 251 that is connected to the first housing member 240 and faces the first end wall portion 241 with a gap.
That is, in the present embodiment, the gap between the first end wall portion 241 and the second end wall portion 251 forms the gear housing chamber 200A, and the first end wall portion 241 is the pump. It functions as the partition wall 201 that partitions the storage chamber 200B and the gear storage chamber 200A.

In the present embodiment, in addition to the second end wall 251, the second housing member 250 is arranged in the axial direction of the first and second pump shafts 310 a and 310 b from the periphery of the second end wall 251. A second peripheral wall portion 252 extending to the first housing member 240, and a free end surface of the second peripheral wall portion 252 is joined to the first housing member 240.
That is, in the present embodiment, the gear housing chamber is constituted by the second end wall portion 251 and the second peripheral wall portion 252 of the second housing member 250 and the first end wall portion 241 of the first housing member 240. 200A is formed.

  As shown in FIGS. 2 and 5, the pump device 100 according to the present embodiment is a PTO that outputs power toward a work machine 70 (see FIG. 1) such as a mower attached to the work vehicle 1. A shaft 610 and a PTO clutch mechanism 600A inserted in a power transmission path from the drive source 40 to the PTO shaft 610 are provided.

Specifically, as shown in FIG. 5, the first housing member 240 is bulged at a position where a part of the first end wall portion 241 avoids the first peripheral wall portion 242.
The PTO shaft 610 includes the bulging portion 243 and the second end wall portion of the first end wall portion 241 such that the downstream end portion in the transmission direction extends outward from the first end wall portion 241. 251.
The PTO clutch mechanism 600A is accommodated in a PTO chamber 200C formed by the bulging portion 243 of the first end wall portion 241 and the second end wall portion 251 so as to communicate with the gear accommodating chamber 200A. Yes.

The first and second pump shafts 310a and 310b are supported by the common housing 200 substantially in parallel with each other while being rotated synchronously by the drive source 40.
Specifically, as shown in FIG. 4, the first and second pump shafts 310 a and 310 b are connected to the second end wall portion 251 of the second housing member 250 and the first end of the first housing member 240. The wall 241 and the plate member 360 are supported so as to extend over the gear housing chamber 200A and the pump housing chamber 200B.

As shown in FIGS. 4 and 7, the first transmission gear 282a is supported on a portion of the first pump shaft 310a located in the gear housing chamber 200A and is located in the pump housing chamber 200B. The first hydraulic pump main body 300a is supported on the portion to be operated.
Similarly, as shown in FIGS. 4 and 5, the second transmission gear 282b is supported on the portion of the second pump shaft 310b located in the gear housing chamber 200A, and the pump housing chamber 200B has the second housing. The second hydraulic pump main body 300b is supported on the position.

In addition to the above configuration, the pump device 100 according to the present embodiment includes an input shaft 210 that is operatively connected to the drive source 400 and a relative rotation with respect to the input shaft 210, as shown in FIGS. And an input gear 281 that is disabled.
The input gear 281 and the first and second transmission gears 281a and 281b constitute the gear train 280 that transmits the driving force of the input shaft 210 to the first and second pump shafts 310a and 310b. .

FIG. 8 shows a rear view of the pump device (an end view seen from the input side).
In addition, the arrow shown with the broken line in FIG. 8 has shown the rotation direction of each gear which comprises the said gear train 280. FIG.
As shown in FIGS. 6 to 8, the input shaft 210 is supported by the second end wall portion 251 and the first end wall portion 241 so that one end portion protrudes outward.
As shown in FIGS. 6 to 8, the input gear 281 cannot rotate relative to the input shaft 210 in the gear housing chamber 200A so as to mesh with the first and second transmission gears 282a and 282b. It is supported by.

In the pump device 100 according to the present embodiment, the PTO clutch mechanism 600A inputs the driving force from the driving source 40 via the PTO gear 283 that meshes with the input gear 281. .
The PTO gear 283 constitutes the gear train 280 together with the input gear 281, the first transmission gear and the second transmission gears 282 a and 282 b.
That is, as shown in FIGS. 5 and 8, the PTO clutch mechanism 600A is a drive side member 620 that is rotatably supported by the PTO shaft 610, and is provided with the PTO gear 283. 620, a driven-side member 630 supported by the PTO shaft 610 so as not to rotate relative to the PTO shaft 610, a drive-side friction plate supported so as not to rotate relative to the driving-side member 620, and a non-rotatable support supported by the driven-side member 630. A friction plate group 640 including a driven side friction plate and a pressing member 650 that selectively frictionally engages the driving side friction plate and the driven side friction plate by the action of hydraulic pressure. By turning ON / OFF the action of the hydraulic pressure on the 650, power transmission from the drive source 40 to the PTO shaft 610 can be engaged or interrupted.

  In the present embodiment, the PTO clutch mechanism 600A is a hydraulically operated type in which power transmission is performed when hydraulic pressure is supplied, and the friction plate group 640 is frictionally engaged unexpectedly when hydraulic pressure is not supplied. Further, an urging member 660 is provided.

  More preferably, the pump device 100 may include a PTO brake mechanism 600B that applies a braking force against the PTO shaft 610 in conjunction with the PTO clutch mechanism 600A (see FIGS. 2 and 5). .

  As described above, the pump device 100 according to the present embodiment includes the input shaft 210 that is separate from the first and second pump shafts 310a and 310b. It is also possible to extend the end of one of the second pump shafts 310a and 310b to the outside of the housing 200 and also use the pump shaft having the outwardly extending end as an input shaft. is there.

As shown in FIGS. 4 and 7, the first hydraulic pump main body 300a includes a first cylinder block 320a that is supported by the first pump shaft 310a so as not to rotate relative to the first pump shaft 310a, and the first cylinder block 320a. A first piston unit 330a is provided in the cylinder block 320a so as not to be relatively rotatable and to be slidable in the axial direction.
The second hydraulic pump main body 300b has substantially the same configuration as the first hydraulic pump main body 300a. Accordingly, the second hydraulic pump main body 300b is appropriately replaced with the detailed description of the first hydraulic pump main body 300a by changing the end of the reference numeral to b.

  As described above, in the pump device 100 according to the present embodiment, the internal space of the housing 200 can store oil. However, the pump device 100 has oil introduced into the housing 200 in the housing 200. In order to circulate efficiently without stagnation, the following configuration is provided.

That is, the housing 200 has an inlet 291 (see FIGS. 7 and 8) for introducing oil from the outside into the pump storage chamber 200B, and the oil in the pump storage chamber 200B is supplied to the gear storage chamber 200A. An oil passage 293 (see FIG. 5) for allowing the oil to flow in, and a discharge port 294 (see FIG. 6) for taking out the oil in the gear housing chamber 200A to the outside are provided. The oil introduced into the pump storage chamber 200B can be discharged to the outside through the discharge port 294 after flowing into the gear storage chamber 200A through the oil passage 293.
In the present embodiment, the discharge port 294 is fluidly connected to the external tank 90 via the external pipe 880b (see FIGS. 1, 2, and 8).
Preferably, the outer tank 90 is provided with a breather mechanism 91 as shown in FIG.

  In such a configuration, the oil supplied through the introduction port 291 cools the first and second hydraulic pump bodies 300a and 300b in the pump housing chamber 200B, and then the gear housing chamber 200A. As a result, the oil stored in the housing 200 is prevented from staying and the cooling efficiency of the first and second hydraulic pump bodies 300a and 300b can be improved.

Further, in such a configuration, the flow of oil from the gear housing chamber 200A to the pump housing chamber 200B is prevented.
Accordingly, impurities such as iron powder generated from the gear train 280 such as the first and second transmission gears 282a and 282b and the input gear 281 and the PTO clutch mechanism 600A are caused by the first and second hydraulic pump bodies 300a and 300b. Can be effectively prevented from being adversely affected.

  In the working vehicle 100 according to the present embodiment, the return oil of the working machine hydraulic oil discharged from the auxiliary pump unit 800 described later is cooled by the oil cooler 855 at the introduction port 291 of the housing 200. In this state, the cooling efficiency of the first and second hydraulic pump bodies 300a and 300b is further improved.

Preferably, as shown in FIGS. 7 and 8, the pump action by at least one gear constituting the gear train 280 can be used when oil flows from the pump housing chamber 200B into the gear housing chamber 200A. The oil passage 293 can be provided at any position.
In the present embodiment, as shown in FIGS. 7 and 8, the oil passage 293 is disposed so as to open to the end surface of the second transmission gear 282b, and the pump housing chamber 200B The inflow of oil into the gear housing chamber 200A is performed using not only mere overflow but also a pump action accompanying rotation of the second transmission gear 282b.

Furthermore, in addition to the above configuration, the pump device 100 according to the present embodiment includes an air intake mechanism 900 that takes air into the gear housing chamber 200A.
The air intake mechanism 900 is configured to suck air into the gear accommodating chamber 200 </ b> A using a pump action by at least one gear constituting the gear train 280.
By providing such an air intake mechanism 900, the cooling efficiency of the first and second hydraulic pump bodies 300a, 300b is improved and the backflow of oil from the gear housing chamber 200A to the pump housing chamber 200B is prevented. In addition, it is possible to reduce the loss horsepower due to the stored oil in the gear housing chamber 200A.

That is, the oil stored in the gear housing chamber 200 </ b> A provides agitation resistance to the gears constituting the gear train 280. Such a stirring resistance is proportional to the amount of stored oil in the gear housing chamber 200A.
The pump device 100 according to the present embodiment is provided with the air intake mechanism 900, paying attention to such a viewpoint, thereby reducing the amount of stored oil in the gear housing chamber 200A and reducing the loss of horsepower. We are also trying to reduce it.

  Specifically, as shown in FIGS. 5 and 8, the air intake mechanism 900 includes an air intake port 910 provided in the housing 200 so as to communicate the gear housing chamber 200 </ b> A and the outside. The base end portion has a tubular member 920 connected to the air intake port 910.

The air intake port 910 is provided at a position where air is sucked by the pumping action of the one gear.
That is, the air intake port 910 is formed in the housing 200 so as to open toward the end face of the one gear or to open near the outer peripheral surface of the one gear.
Preferably, the air intake port 910 can be provided at a position where the pump action of the gear located at the lowest position is utilized in the installed state of the pump device 100 among the gears constituting the gear train 280. .
By providing such a configuration, the air taken in from the air intake port 910 can be spread throughout the gear housing chamber 200A, and the amount of stored oil in the gear housing chamber 200A can be effectively reduced. Can be made.
In the present embodiment, as shown in FIGS. 5 and 8, the PTO gear 283 is located at the lowest position in the installed state of the pump device 100.
Therefore, the air intake port 910 is opened at the end face of the PTO gear 283 so that air is sucked by the pump action accompanying the rotation of the PTO gear 283.

The tubular member 920 has a proximal end connected to the air intake port 910 and a distal end bent into an inverted U shape and opened outward.
Preferably, the tubular member 920 has an oil level O.D. of the reserve tank 90 fluidly connected to the discharge port 294 between the base end portion and the tip end portion with reference to the rotation stop state of the one gear. L. May have a higher portion 921 (see FIG. 8).
By providing such a configuration, it is possible to prevent the stored oil in the gear accommodating chamber 200A from flowing out to the outside through the tubular member 920 when the rotation of the gear train 280 is stopped. .
In the present embodiment, the tubular member 920 is formed of a rigid material such as a steel pipe, and the base end portion of the tubular member 920 is connected to and supported by the housing 200. However, the tubular member is elastic pipe. In addition, it is possible to support the vehicle upright with another member such as a vehicle frame.

FIG. 9 shows an enlarged cross-sectional view of the distal end portion of the tubular member 920.
More preferably, as shown in FIG. 9, a one-way valve that allows air to be sucked in from the outside and prevents oil from flowing out of the gear housing chamber 200 </ b> A at the distal end portion of the tubular member 920. Can be provided.
By providing such a one-way valve, it is possible to effectively prevent oil from flowing out of the gear housing chamber 200A even when the working vehicle 1 to which the pump device 100 is applied tilts on an inclined ground or the like.

Specifically, the pump device 100 according to the present embodiment includes a one-way valve unit 950 including a ball member 960 acting as the one-way valve and a case member 970 in which the ball member 960 is housed. Yes.
In addition, the code | symbol 980 in FIG. 9 is a connection member for connecting the said case member 970 to the front-end | tip part of the said tubular member 920. FIG.

The case member 970 includes a proximal end portion 971 that is fluidly connected to an outer opening end portion of the tubular member 920, a distal end portion 972 that is opened outward, and a gap between the proximal end portion 971 and the distal end portion 972. It has a hollow shape having a through hole 975 therethrough.
The through hole 975 is provided on the base end portion 971 side and has a larger diameter portion 976 having a larger diameter than the ball member 960, and is provided on the distal end portion 972 side and has a smaller diameter than the ball member 960. The ball member 960 is housed in the large-diameter portion 976.
Furthermore, the case member 970 is provided with a holding plate 979 that holds the ball member 960 housed in the large diameter portion 976 so as to be movable within a predetermined distance within the large diameter portion 976.
The holding plate 979 is provided with an opening having a size that allows air to be sucked in while preventing the ball member 960 from being detached.

More preferably, the air intake mechanism 900 may be provided with a filter 990 that prevents foreign matter from being sucked into the gear housing chamber 200A from the outside.
In the present embodiment, as described above, the pump device 100 includes the one-way valve unit 950.
Therefore, the filter 990 is attached to the tip 972 of the case member 970 (see FIG. 9).

  In the present embodiment, the one-way valve unit 950 is attached to the distal end portion of the tubular member 920 (see FIG. 9). Of course, the one-way valve unit 950 is directly attached to the housing 200. Thus, the tubular member 920 can be omitted (see FIG. 10).

Furthermore, in the present embodiment, as shown in FIG. 5, the housing 200 is provided with a second discharge port 295 for taking out the oil in the pump storage chamber 200B to the outside.
As shown in FIGS. 2 and 8, the second discharge port 295 is fluidly connected to the external tank 90 via an external pipe 880c.
By providing such a second discharge port 295, the amount of oil introduced into the pump storage chamber 200B flows into the gear storage chamber 200A from the pump storage chamber 200B and flows out through the discharge port 294. When the amount of oil is larger than the amount of oil, the internal pressure of the stored oil in the pump housing chamber 200B rises, thereby preventing a problem from occurring in the hydraulic line connected to the introduction port 291.
That is, in the present embodiment, the oil passage 293 has a throttle shape so as to limit the amount of oil passing through so that a large amount of oil does not flow into the gear housing chamber 200A from the pump housing chamber 200B. Accordingly, since the amount discharged from the pump storage chamber 200B is smaller than the amount flowing into the pump storage chamber 200B, the second discharge port 295 is provided to discard the surplus.

  The pump device 100 according to the present embodiment includes first and second trunnion-type movable swash plates as the first and second output adjustment members 350a and 350b, and thereby the sliding friction of the output adjustment member is reduced. The force required for operating the output adjusting member is reduced.

Specifically, as shown in FIG. 4, the first trunnion-type movable swash plate 350a is supported on the housing 200 so as to be relatively rotatable around the first operation axis X1 while being accessible from the outside of the housing 200. The first operating end 351a thus arranged and the first base disposed opposite to the first operating end 351a with the first hydraulic pump body 300a interposed therebetween so as to be positioned coaxially with the first operating axis X1. An end 352a, a first swash plate portion 353a extending between the first operation end 351a and the first base end 352a, and is in contact with the first piston unit 330a, and the first piston unit 330a A first swash plate portion 353a that defines a sliding range of the first swash plate portion 353a, and the first operation end portion 351a is operated to tilt the first swash plate portion 353a about the first operation axis X1. so, So that the can be changed to intake oil amount of the serial first hydraulic pump body 300a.
The second trunnion type movable swash plate 350b has substantially the same configuration as the first trunnion type movable swash plate 350a. Therefore, for the second trunnion type movable swash plate 350b, the end of the reference numeral in the first trunnion type movable swash plate 350a is changed to b, and the detailed description thereof is omitted as appropriate.

In the pump device 100 according to the present embodiment, the first and second trunnion type movable swash plates 350a and 350b are supported by the housing 200 so that the operation end portions 351a and 351b face in opposite directions. Has been.
Specifically, as shown in FIG. 4, the housing 200 houses the pump housing chamber 200 </ b> B, the first pump space 200 </ b> B (1) that houses the first hydraulic pump body, and the second hydraulic pump body. A partition wall 202 is provided to partition the second pump space 200B (2).

The first and second trunnion-type movable swash plates 350a and 350b are supported by using the partition walls 202 so that the operation ends of the first and second trunnion-type movable swash plates 350a and 350b face in opposite directions. ing.
3 and 4 is a neutral position return unit for returning the corresponding trunnion type movable swash plates 350a and 350b to the neutral position.

Specifically, the partition wall 202 extends from the first end wall 241 in the axial direction of the first and second pump shafts 310a and 310b between the first and second hydraulic pump bodies 300a and 300b. It extends.
As shown in FIG. 4, a surface of the partition wall 202 facing the first hydraulic pump main body 300a is provided with a first bearing portion 203a that supports a base end portion 352a of the first trunnion type movable swash plate 350a. A second bearing portion 203b for supporting the base end portion 352b of the second trunnion type movable swash plate 350b is provided on the surface of the support wall 202 facing the second hydraulic pump main body 300b.

The first peripheral wall portion 242 is provided with first and second through holes 204a and 204b so as to face the first and second bearing portions 203a and 203b, respectively (see FIG. 4).
The first and second through holes 204a and 204b respectively connect the base end portions 352a and 352b and the swash plate portions 353a and 353b of the first and second trunnion type movable swash plates 350a and 350b in the pump housing chamber 200B. Acts as an insertion port for insertion.

The operation end portions 351a and 351b of the first and second trunnion-type movable swash plates 350a and 350b are externally connected through cap members 205 attached to the first and second through holes 204a and 204b, respectively. Are supported in such a manner that they are accessible from each other and face in opposite directions.
That is, the first trunnion-type movable swash plate 350a includes a first bearing portion 203a provided on the support wall 202 and a cap member 205 attached to the first through hole 204a of the first peripheral wall portion 242. The operation end 351a is supported so as to be swingable around the first operation axis X1 so that the operation end 351a faces one side in the vehicle width direction.
In contrast, the second trunnion-type movable swash plate 350b includes a second bearing portion 203b provided on the support wall 202, and a cap member 205 attached to the second through hole 204b of the first peripheral wall portion 242. Thus, the operation end 351b is supported so as to be swingable about the second operation axis X2 so that the operation end 351b faces the other side in the vehicle width direction.

Thus, in the aspect in which the pump storage chamber 200B is partitioned into the first and second pump spaces 200B (1) and 200B (2) by the partition wall 202, the first pump space 200B (1 ) And the second pump space 200B (2), and the introduction port 291 is provided in one of the first and second pump spaces 200B (1) and 200B (2), and the oil A passage 293 may be provided in the other of the first and second pump spaces 200B (1) and 200B (2).
In the present embodiment, the introduction port 291 is provided so that oil introduced from the outside flows into the first pump space (see FIGS. 3 and 7), and the oil passage 293 is provided as a pump. Oil in the storage chamber 200B is provided so as to flow into the gear storage chamber 200A from the second pump space 200B (2) (see FIG. 5).

With this configuration, oil introduced from the introduction port 291 into the first pump space 200B (1) of the pump storage chamber 200B flows into the second pump space 200B (2) via the communication path 292, Then, after flowing into the gear housing chamber 200 </ b> A through the oil passage 293, it can be discharged to the outside through the discharge port 294.
Accordingly, the oil introduced through the introduction port 291 becomes the first hydraulic pump main body 300a in the first pump space 200B (1) and the second hydraulic pump main body 300b in the second pump space 200B (2). Both of the first and second hydraulic pumps are cooled and then discharged to the outside through the gear housing chamber 200A to prevent the stored oil from staying over the entire area of the housing 200. The cooling efficiency of the main bodies 300a and 300b can be improved.

  In the present embodiment, as shown in FIGS. 3, 4, and 6, the partition wall 202 is between the plate member 360 and the first pump space 200 </ b> B (1) and the second pump wall 200 </ b> B. A groove that opens outward is formed at the free end so as to form a communication passage 292 that communicates with the pump space 200 </ b> B (2) so that oil can flow freely.

Preferably, as shown in FIG. 6, the partition wall 202 may be configured such that at least a part of a free end thereof is in contact with the plate member 360.
In this way, by configuring at least a part of the free end of the partition wall 202 to contact the plate member 360, the plate member 360 can be stably connected to the housing body 230, Thereby, the leakage of the hydraulic fluid from between the plate member 360 and the first and second hydraulic pump bodies 300a and 300b can be effectively prevented or reduced.

In the present embodiment, a groove is formed at the free end of the partition wall 202 so that the communication path 292 is formed between the partition wall 202 and the plate member 360. Instead of or in addition to the groove, the partition wall 202 can be provided with a through hole.
In addition, a groove is provided in a portion of the plate member 360 that faces the partition wall 202, and oil can flow between the first pump space 200B (1) and the second pump space 202B (2) through the groove. It is also possible to do.

Here, the hydraulic circuit of the pump device 100 according to the present embodiment will be described.
As shown in FIGS. 2, 4, and 7, the plate member 360 includes a pair of first hydraulic oil passages 410a that constitute a part of the pair of first operation lines 400a, and the pair of first operations. A first bypass oil passage 430a communicating between the oil passages 410a, wherein a first bypass oil passage 430a in which a bypass valve 435 communicating and blocking the first bypass oil passage 430a is inserted; A pair of second hydraulic oil passages 410b forming part of the second hydraulic oil line 400b, and a second bypass oil passage 430b communicating between the pair of second hydraulic oil passages 410b, the second bypass oil A second bypass oil passage 430b in which a bypass valve 435 for communicating / blocking the passage 430b is inserted is provided.

Further, as shown in FIG. 2, the plate member 360 has a common charge oil passage 421 having one end opened on the outer surface to form a charge port 420 </ b> P, and a branch charge communicated with the common charge oil passage 421. The oil passage 422 is provided with a branch charge oil passage 422 extending across the pair of first hydraulic fluid passages 410a and the pair of second hydraulic fluid passages 410b.
Note that check valves 425 are inserted in communication portions between the pair of first hydraulic oil passages 410a and the pair of second hydraulic oil passages 410b and the branch charge oil passage 422, respectively.

The check valve 425 allows inflow of pressure oil from the branch charge oil passage 422 to each of the pair of first hydraulic oil passages 410a and the pair of second hydraulic oil passages 410b, and performs a flow in the opposite direction. Provided to prevent.
In the present embodiment, the check valve 425 has a relief valve function (see FIG. 2) that operates when the corresponding hydraulic fluid passages 410a and 410b have an abnormally high pressure.

The pair of first hydraulic oil passages 410a are formed substantially in parallel with the corresponding first pump shaft 310a interposed therebetween.
Specifically, each of the pair of first hydraulic oil passages 410a has a pair of first hydraulic oil ports 411a with one end opening on one outer surface (the upper surface in the present embodiment) of the plate member 360. (See FIG. 3), the other end is open to the outer surface (the lower surface in the present embodiment) of the other side of the plate member 360, and the substantially central portion is in the first hydraulic pump main body 300a. It forms a fluidly connected kidney port.
The other end openings of the pair of first hydraulic oil passages 410a are sealed through the check valve 425 (see FIG. 7).

Similarly, the pair of second hydraulic oil passages 410b are also formed substantially in parallel with the corresponding second pump shaft 310b interposed therebetween.
Specifically, each of the pair of second hydraulic oil passages 410b has one end opened to an outer surface (upper surface in the present embodiment) on one side of the plate member 360, and a pair of second hydraulic oil ports 411b. The other end of the plate member 360 is open on the other outer surface (the lower surface in the present embodiment), and the substantially central portion is fluidly connected to the second hydraulic pump main body 300b. Forming a port.
The other end openings of the pair of second hydraulic oil passages 410 b are sealed via the check valve 425.

Furthermore, as shown in FIG.
Of the pair of first hydraulic oil passages 410a, a first flushing oil passage 440a that communicates a reverse high-pressure side first hydraulic oil passage 410a (R) that is low in pressure when traveling forward and an oil reservoir (internal space of the common housing 200). A reverse high-pressure side second hydraulic fluid passage 410b (R) that has a low pressure during forward movement among the first flushing fluid passage 440a in which the first flushing valve 445a is inserted and the pair of second hydraulic fluid passages 410b. ) And the oil sump, and a second flushing oil passage 440b in which a second flushing valve 445b is inserted is formed.

The first and second flushing valves 445a and 445b are a high pressure hydraulic fluid passage 410a (F) at the time of forward advancement that becomes a high pressure during forward movement of the pair of first hydraulic fluid passages 410a and the pair of second hydraulic fluid passages 410b, The hydraulic pressure of 410b (F) is configured to operate as a pilot pressure. When the hydraulic pressure in the forward high pressure side hydraulic oil passages 410a (F) and 410b (F) exceeds a predetermined pressure, the reverse pressure high pressure side operation is performed. The oil passages 410a (R) and 410b (R) are configured to return the oil to the oil sump through a throttle.
By providing such a configuration, the common charge oil passage 421 and the branch charge oil passage 422 are connected to the low-pressure side hydraulic fluid passages of the pair of first hydraulic fluid passages 410a and the pair of second hydraulic fluid passages 410b. A flushing action that promotes the replenishment of the hydraulic oil is achieved, thereby effectively preventing an increase in the temperature of the hydraulic oil in the pair of first hydraulic oil lines 400a and the pair of second hydraulic oil lines 400b.

  As shown in FIG. 2, the plate member 360 further includes either one of the pair of first hydraulic oil lines 400a or the pair of second hydraulic oil lines 400b when the charge pump main body 510 described later is stopped. A self-priming oil passage 450 for self-priming oil from the oil reservoir (internal space of the housing 200) to the hydraulic oil line having the negative pressure when any one of them becomes negative; A check valve 455 that allows oil flow to the negative pressure line in the pair of first hydraulic oil lines 400a or the negative pressure line in the pair of second hydraulic oil lines 400b and prevents reverse flow. It has been.

That is, for example, when the engine 40 is stopped in the HST neutral state and the work vehicle is stopped on a slope or the like, a rotational force is applied to the motor shaft operatively connected to the drive wheels 50, and the hydraulic motor units 10 and 20 are pumped. To try.
At this time, if the pair of first hydraulic oil lines 400a and the pair of second hydraulic oil lines 400b are filled with hydraulic oil, a brake force is applied to the hydraulic motor units 10 and 20 by the hydraulic oil. On the other hand, due to the pumping action of the hydraulic motor units 10 and 20, one of the pair of first hydraulic oil lines 400a and one of the pair of second hydraulic oil lines 400b become high pressure, and the high pressure side operation is performed. Hydraulic oil may leak from the oil line.
When such a hydraulic fluid leak occurs, the pair of first hydraulic fluid lines 400a and the pair of second hydraulic fluid lines 400b respectively circulate oil from the negative pressure hydraulic fluid line to the high pressure hydraulic fluid line. Occurring and hydraulic fluid leakage from the high-pressure hydraulic fluid line is promoted. Finally, there is no hydraulic oil in the pair of first hydraulic oil lines 400a and the pair of second hydraulic oil lines 400b, the drive wheels 50 begin to rotate freely, and the vehicle begins to descend on the slope ( Freewheel phenomenon).

In this regard, in the pump device according to the present embodiment, either one of the pair of first hydraulic oil lines 400a or one of the pair of second hydraulic oil lines 400b is caused by the self-priming oil passage 450. When a negative pressure is reached, oil is supplied from the oil reservoir (in the illustrated embodiment, the internal space of the common housing 200) to the hydraulic oil line having the negative pressure.
Therefore, the free wheel phenomenon can be effectively prevented.

Further, as shown in FIGS. 2, 4 and 5, the pump device 100 according to the present embodiment includes one of the first and second pump shafts 310a and 310b (this embodiment Is provided with a charge pump unit 500 driven by a second pump shaft 310b).
Specifically, the charge pump unit 500 includes a charge pump main body 510 driven by the second pump shaft 310b, and a charge pump case 520 connected to the plate member 360 so as to surround the charge pump main body 510. It has.

As shown in FIGS. 4 and 5, in the present embodiment, the second pump shaft 310b has a transmission direction downstream end opposite to the transmission direction upstream end supporting the second transmission gear 282b. The plate member 360 is extended outward.
The charge pump body 510 is driven by an outwardly extending portion of the second pump shaft 310b.

As shown in FIG. 4, the charge pump case 520 has a shape substantially equal to the size of the plate member 360, and one end surface of the charge pump case 520 is an outer surface of the plate member 360 (the first housing member in the plate member 360). The plate member 360 is detachably connected to the plate member 360 in a polymerized state on the surface opposite to the surface 240.
The other end surface of the charge pump case 520 opposite to the one end surface is a mounting surface of an auxiliary pump unit 800 (hereinafter referred to as an auxiliary pump unit mounting surface 800a) corresponding to the second pump shaft 310b. ), And a region corresponding to the first pump shaft 310a constitutes a mounting surface of the line filter 530 described below (hereinafter referred to as a line filter mounting surface 530a).

The charge pump case 520 is formed with the following oil passages including an intake / exhaust oil passage for the charge pump main body 510.
That is, as shown in FIGS. 2, 3, 5, 6, and 7, the charge pump case 520 includes
A suction oil passage 480 having one end opened to the outer surface (the upper surface in the present embodiment) to form a suction port 480in and the other end communicated with the suction port of the auxiliary pump main body 510; Unfiltered discharge oil 481 opened in the line filter mounting surface 530a so that the other end can communicate with the discharge port of the auxiliary pump main body 510 and the other end communicate with the inlet port 530in of the line filter 530, and one end thereof A filtered discharge oil passage 482 opened in the line filter mounting surface 530a so as to communicate with the outlet port 530out of the line filter 530, and a resistance valve 475 whose primary side is communicated with the filtered discharge oil passage 482; One end portion communicates with the secondary side of the resistance valve 475 and the other end portion communicates with the charge port 420P so as to contact the plate member 360. A charge discharge oil passage 483 that is open on the contact surface, a charge relief valve 540 that is inserted in the charge discharge oil passage 483, and a first PTO oil passage 491 that has one end communicating with the filtered discharge oil passage 482. The PTO solenoid valve 556 whose primary side is communicated with the first PTO oil passage 491, one end portion is communicated with the secondary side of the PTO solenoid valve 556, and the other end portion is opened on the contact surface with the plate member 360. The second PTO oil passage 492 is communicated with the internal space of the common housing 200 through an oil passage having one end connected to the drain port of the PTO solenoid valve 556 and the other end formed in the plate member 360. The first PTO drain oil passage 556a and the accumulator 558 inserted in the second PTO oil passage 492 are provided.

  The suction port 480in is fluidly connected to an external tank 90 containing a strainer 486 via an external pipe 485 (see FIGS. 1 and 2).

  The charge discharge oil passage 483, together with the common charge oil passage 421 and the branch charge oil passage 422 provided in the plate member 360, from the charge pump main body 510 to the pair of first hydraulic oil passages 410a and the pair of pairs. A charge line for supplying hydraulic oil to the second hydraulic oil passage 410b is formed.

The first and second PTO oil passages 491 and 492 constitute part of a PTO line 490 (see FIG. 2) for supplying hydraulic oil from the charge pump main body 510 to the PTO clutch mechanism 600A.
That is, in the present embodiment, the PTO line 490 is formed in the plate member 360 in addition to the first and second PTO oil passages 491 and 492, as shown in FIGS. The third PTO oil passage 493, the fourth PTO oil passage 494 formed in the first housing member 240, the first end wall portion 241 of the first housing member 240, and the second end wall of the second housing member 250. An internal pipe 499 extending between the portions 251, a fifth PTO oil passage 495 formed in the second housing member 250, and a rotary provided at a contact portion between the second end wall portion 251 and the PTO shaft 610. A joint 498 and a PTO axial hole 615 drilled in the PTO shaft 610 are included.

As shown in FIG. 6, the third PTO oil passage 493 opens to the contact surface with the charge pump case 520 so that one end thereof communicates with the other end of the second PTO oil passage 492, and the other An end portion is opened in a contact surface with the first housing member 240.
As shown in FIG. 6, the fourth PTO oil passage 494 opens to the contact surface with the plate member 360 so that one end thereof communicates with the other end of the third PTO oil passage 493, and the other end The portion is opened to the gear housing chamber 200A.
As shown in FIGS. 6 and 8, the fifth PTO oil passage 495 has one end opened to the gear housing chamber 200A and the other end opened to the inner peripheral surface of the bearing hole that supports the PTO shaft 610. Has been.

Further, as shown in FIG. 6, the internal pipe 99 is arranged in the gear housing chamber 200A so as to communicate the other end portion of the fourth PTO oil passage 494 and one end portion of the fifth PTO oil passage 495. It is installed.
Of course, the other end portion of the fourth PTO oil passage 494 is opened to the joint surface with the second housing member 250, and one end portion of the fifth PTO oil passage 495 is connected to the first housing member 240. It is possible to make the internal pipe 499 unnecessary by opening the joint surface.

  As shown in FIG. 5, the PTO axial hole 615 has one end communicating with the fifth PTO oil passage 495 through the rotary joint 498 and the other end being the pushing member of the PTO clutch mechanism 600A. It opens toward 650.

  As shown in FIG. 2, the PTO line 490 is arranged on the downstream side of the PTO electromagnetic valve 556, the accumulator 558 arranged on the downstream side of the PTO electromagnetic valve 556, and the PTO electromagnetic valve 556. A PTO relief valve 557 is inserted.

  As shown in FIG. 6, the second end wall portion 251 is formed with a leak oil passage 497 for returning leak oil in the rotary joint 498 into the gear housing chamber 200A, and the air intake port. 910 uses the leak oil passage 497 to communicate the outside with the gear housing chamber 200A.

In the pump apparatus 100, the unfiltered discharge oil passage 481 and the filtered discharge oil passage 482 are further provided in the charge pump case 520 when the line filter 530 is clogged, as shown in FIGS. A filter bypass valve 470 for bypassing between the two is incorporated.
By providing such a filter bypass valve 470, it is possible to prevent running out of oil on the downstream side of the line filter 530 when the line filter 530 is clogged.

  Furthermore, as shown in FIGS. 1 and 2, the pump device 100 according to the present embodiment includes one of the first and second pump shafts 310a and 310b (in the present embodiment, The auxiliary pump unit 800 is operatively driven by the second pump shaft 310b).

The auxiliary pump unit 800 is provided for supplying hydraulic oil to a working machine or the like provided in the working vehicle.
In the present embodiment, as shown in FIGS. 1, 2 and 5, the auxiliary pump unit 800 is provided in a double-acting hydraulic cylinder 75 used for raising and lowering the working machine 70 (for example, the mower device). On the other hand, hydraulic oil is supplied.
After the return oil from the working machine is cooled by the oil cooler 855, the pump accommodating chamber 200B (in the present embodiment, the first pump space 200B (1 )).

As shown in FIGS. 2 and 5, the auxiliary pump unit 800 includes an auxiliary pump body 810 and an auxiliary pump case 820.
The auxiliary pump body 810 can take various forms, but in the present embodiment, the auxiliary pump main body 810 is a high-pressure type that engages with an external gear.
Specifically, as shown in FIG. 5, the auxiliary pump body 810 includes an auxiliary pump drive shaft 811 operatively connected to the second pump shaft 310b, and an auxiliary pump disposed substantially parallel to the auxiliary pump drive shaft 811. A pump driven shaft (not shown) and the auxiliary pump drive shaft 811 and a pair of pump gears 813 supported by the auxiliary pump driven shaft so as to mesh with each other are provided.

  The auxiliary pump case 820 is detachably connected to the auxiliary pump unit mounting surface 800a, supports the auxiliary pump drive shaft 811 and the auxiliary pump driven shaft, and surrounds the pair of pump gears 813. ing.

  As shown in FIG. 5, the auxiliary pump case 820 has a suction port with one end opening on the outer surface to form a suction port 821 and the other end communicating with one side of the meshing point of the pair of pump gears 813. An oil passage and a discharge oil passage having one end communicating with the other side of the meshing point of the pair of pump gears 813 and the other end opening on the outer surface to form a discharge port 822 are provided.

In the present embodiment, as shown in FIGS. 1, 2, and 8, the suction port 821 is fluidly connected to the external tank 90 via an external pipe 830.
The discharge port 822 is fluidly connected via an external pipe 840 to a valve unit 850 in which a work machine relief valve 851 and a switching valve 852 are incorporated.
The return oil from the valve unit 850 is introduced into the housing 200 from the introduction port 291 of the housing 200 via the external pipe 880a in which the oil cooler 855 is inserted. Thus, the first and second hydraulic pump bodies 300a and 300b accommodated in the housing 200 are actively cooled.
Reference numeral 860 in FIGS. 1 and 2 is a pipe that fluidly connects the valve unit 850 and the double-acting hydraulic cylinder 75 in the working machine 70.

Embodiment 2
Hereinafter, another embodiment of the pump device according to the present invention will be described with reference to the accompanying drawings.
FIG. 11 shows a rear view of the pump device 100B according to the present embodiment.

The pump apparatus 100B according to the present embodiment is the same as the pump apparatus 100 according to the first embodiment except that the air intake mechanism 900 is changed to an air intake mechanism 900B.
Accordingly, only the air intake mechanism 900B will be described below.
In FIG. 11, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The air intake mechanism 900B includes the air intake port 910 and a tubular member 920B having a base end connected to the air intake port 910.
The distal end of the tubular member 920B is connected to the air layer 95 of the external tank 90.

Such a pump device 100B has the following effects in addition to the effects of the first embodiment.
That is, in the present embodiment, the air intake mechanism 900B is configured to take in air in the sealed circuit.
Therefore, the stored oil in the housing 200 does not leak to the outside, and the foreign matter does not enter the housing 200 when air is sucked without the filter 990.

Embodiment 3
Hereinafter, still another embodiment of the pump device according to the present invention will be described with reference to the accompanying drawings.
FIG. 12 shows a longitudinal side view of the pump device 100C according to the present embodiment.
In the figure, the same members as those in the first or second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In each of the first and second embodiments, the first and second hydraulic pump bodies 300a and 300b are arranged in parallel. However, as shown in FIG. The first and second hydraulic pump bodies 300a and 300b are tandem types arranged in series.

  Specifically, the pump device 100C includes a housing 200C, the first and second hydraulic pump bodies 300a and 300b, the first and second pump shafts 310a and 310b, and cradle type first and second output adjustments. Members 350Ca and 350Cb and a gear train 280C are provided.

  As shown in FIG. 12, the housing 200C has a base housing 240C that defines the gear housing chamber 200A and the PTO chamber 200C, and the bases of the first and second pump shafts 310a and 310b. A first pump housing 250C and a second pump housing 260C connected to one side and the other side of the housing 240C, and a first pump housing 250C connected to the first pump housing 250C so as to define the first pump space 200B (1). One plate member 360C and a second plate member 370C connected to the second pump housing 260C so as to define the second pump space 200B (2) are provided.

  The gear train 280 </ b> C includes the input gear 281 that cannot be rotated relative to the input shaft 210, a transmission gear 282 </ b> C that meshes with the input gear 281, and the PTO gear 283.

  In the present embodiment, the first and second pump shafts 310a, 310b are supported by the housing 200C so as to be coaxial with each other, and the first and second pump shafts 310a, 310b, The transmission gear 282C is supported at the opposite end of 310b so as not to be relatively rotatable.

The pump apparatus 100C according to the present embodiment includes a charge pump unit 500C instead of the charge pump unit 500, and the auxiliary pump unit 800 is omitted.
The charge pump unit 500C is configured to be driven by the end of the input shaft 210 opposite to the input end.

  In the tandem pump device 100C, first and second inlets 291 for introducing oil from the outside into the first pump storage chamber 200B (1) and the second pump storage chamber 200B (2), respectively. Second introduction ports 291a and 291b are provided, and the oil in the first and second pump storage chambers 200B (1) and 200B (2) flows into the gear storage chamber 200A as the oil passage 293, respectively. First and second oil passages 293a and 293b are provided.

Of course, in the present embodiment, either the air intake mechanism 900 or the air intake mechanism 900B can be adopted as desired or necessary.
Also in such a tandem pump device 100C, the same effect as in the first and second embodiments can be obtained.

  In each of the above embodiments, the case where a plurality of hydraulic pump bodies are provided has been described as an example. However, the present invention is not limited to such a form, and of course, a single hydraulic pump body is provided. It is also applied when it has.

FIG. 1 is a schematic side view of a working vehicle to which a pump device according to an embodiment of the present invention is applied. FIG. 2 is a hydraulic circuit diagram of the working vehicle shown in FIG. FIG. 3 is a plan view of the pump device shown in FIGS. 1 and 2. 4 is a cross-sectional plan view of the pump device shown in FIG. FIG. 5 is a sectional view of the pump device taken along line VV in FIG. 6 is a cross-sectional view of the pump device taken along line VI-VI in FIG. FIG. 7 is a sectional view of the pump device taken along line VII-VII in FIG. FIG. 8 is a rear view of the pump device shown in FIGS. FIG. 9 is an enlarged cross-sectional view of the distal end of the tubular member in the pump device. FIG. 10 is a partial rear view of a modification of the pump device. FIG. 11 is a rear view of a pump device according to another embodiment of the present invention. FIG. 12 is a longitudinal side view of a pump device according to still another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Work vehicle 90 External tank 95 Air layer 100,100B, 100C Pump apparatus 200 Housing 200A Gear accommodation chamber 200B Pump accommodation chamber 200B (1) One side of pump accommodation chamber (first pump space)
200B (2) The other side of the pump storage chamber (second pump space)
201 partition wall 202 partition wall 280 gear train 281 input gear 282a first transmission gear 282b second transmission gear 283 PTO gear 291 introduction port 291a first introduction port 291b second introduction port 292 communication passage 293 oil passage 293a first oil passage 293b first 2 oil passage 294 discharge port 295 second discharge port 300a, 300b first hydraulic pump body, second hydraulic pump body 310a, 310b first pump shaft, second pump shaft 350a, 350b first trunnion type movable swash plate, second Trunnion type movable swash plate 600A PTO clutch mechanism 610 PTO shaft 900, 900B Air intake mechanism 910 Air intake port 920, 920B Tubular member 960 One-way valve 990 Filter

Claims (12)

A housing in which an oil-storable internal space is partitioned into a pump housing chamber and a gear housing chamber by a partition wall, a hydraulic pump body housed in the pump housing chamber, and a gear train housed in the gear housing chamber A pump device,
The housing has an inlet for introducing oil from the outside into the pump housing chamber;
An oil passage for flowing oil in the pump housing chamber into the gear housing chamber;
A pump device comprising a discharge port for taking out oil in the gear housing chamber to the outside. A housing in which an internal space in which oil can be stored is partitioned by a partition wall into a pump storage chamber and a gear storage chamber, and a housing that is supported by the housing so as to extend through the partition wall into the pump storage chamber and the gear storage chamber. First and second pump shafts; first and second hydraulic pump bodies supported by the first and second pump shafts so as to be located in the pump housing chamber; and a gear train housed in the gear housing chamber; A pump device comprising:
The housing has an inlet for introducing oil from the outside into the pump housing chamber;
An oil passage for flowing oil in the pump housing chamber into the gear housing chamber;
A pump device comprising a discharge port for taking out oil in the gear housing chamber to the outside. The housing has a partition wall that partitions the pump housing chamber into a first pump space and a second pump space through which oil can flow.
The introduction port is provided in one of the first and second pump spaces,
The pump device according to claim 2, wherein the oil passage is provided in the other of the first and second pump spaces. The pump storage chamber includes a first pump storage chamber and a second pump storage chamber respectively disposed on one side and the other side in the axial direction of the first and second pump shafts across the gear storage chamber,
The inlet includes first and second inlets for introducing oil from outside into the first pump housing chamber and the second pump housing chamber, respectively.
The pump device according to claim 2, wherein the oil passage includes first and second oil passages for allowing oil in the first and second pump housing chambers to flow into the gear housing chamber, respectively. A PTO shaft supported by the housing;
A PTO clutch mechanism for engaging / interrupting power transmission from the gear train to the PTO shaft,
The pump device according to any one of claims 1 to 4, wherein the housing has a PTO storage chamber communicated with the gear storage chamber.   The oil passage is provided at a position where the inflow of oil from the pump housing chamber to the gear housing chamber is performed using a pump action by at least one gear constituting the gear train. The pump device according to any one of claims 1 to 5.   An air intake mechanism for taking air into the gear housing chamber, wherein the air take-in mechanism is configured to suck air into the gear housing chamber using a pump action of at least one gear constituting the gear train. The pump device according to any one of claims 1 to 6, further comprising:   The said air intake mechanism is comprised so that the pump action by the gear located in the lowest part may be utilized in the installation state of this pump apparatus among the gears which comprise the said gear train. The pump device described in 1. The air intake mechanism has an air intake port provided in the housing so as to allow communication between the gear housing chamber and the outside, and a tubular member having a base end connected to the air intake port. And
The tubular member has a portion higher than an oil level of a reserve tank fluidly connected to the discharge port on the basis of a rotation stop state of the one gear. The pump device described in 1. The air intake mechanism has an air intake port provided in the housing so as to allow communication between the gear housing chamber and the outside, and a tubular member having a base end connected to the air intake port. And
The pump device according to claim 7 or 8, wherein a distal end portion of the tubular member is connected to an air layer of a reserve tank fluidly connected to the discharge port.   The air intake mechanism includes an air intake port provided in the housing so as to allow communication between the gear storage chamber and the outside, and intake of air into the gear storage chamber via the air intake port The pump device according to claim 7, further comprising a one-way valve that allows oil to flow out of the gear housing chamber through the air intake port. The pump device according to any one of claims 7 to 11, wherein the air intake mechanism includes a filter that prevents foreign matter from being sucked into the gear housing chamber from the outside.

Images