WO2005121554A1

WO2005121554A1 - Variable displacement swash plate-type hydraulic rotating machine

Info

Publication number: WO2005121554A1
Application number: PCT/JP2005/009503
Authority: WO
Inventors: Takashi Niidome; Yoshitomo Yabuuchi; Takeshi Kobayashi
Original assignee: Hitachi Construction Machinery Co., Ltd.
Priority date: 2004-06-09
Filing date: 2005-05-18
Publication date: 2005-12-22
Also published as: EP1760313A1; JP2005351140A; US20070180986A1

Abstract

A pair of leg sections (21A, 21B) is provided on a swash plate (21). A main static pressure bearing section (22A) communicating with one supply/discharge path (12A) through an oil guide path (24) is provided on one (21A) of the leg sections, and an auxiliary static pressure bearing section (22C) communicating with the oil guide path (24) is provided on the other leg section (21B). Further, on the other leg section (21B), there is provided the other main static pressure bearing section (22B) communicating with the other supply/discharge path (12B) through an oil guide path (25), and on the one leg section (21A), there is provided the other auxiliary static pressure bearing section (22D) communicating with the oil guide path (25). A separation force is produced between the leg sections (21A, 21B) of the swash plate (21) and a swash plate support body (20) by the main static pressure bearing sections (22A, 22B) and the auxiliary static pressure bearing sections (22C, 22D). The separation force balances with a pressing force of the swash plate (21).

Description

Description Variable displacement swash plate type hydraulic rotating machine Technical field

The present invention can be applied, for example, as a hydraulic pump or hydraulic motor to a work vehicle such as a wheel loader, a wheel-type hydraulic shaft bell, a hydraulic crane or hydraulic hydraulic shovel, or a hydraulic crane. The present invention relates to a variable displacement swash plate type hydraulic rotating machine suitably used. m

Technology

In general, a variable displacement swash plate type hydraulic rotating machine is used as a variable displacement swash plate type hydraulic pump constituting a hydraulic pressure source, for example, in a working vehicle such as a wheel π-dau hydraulic shovel. This variable displacement swash plate type hydraulic rotating machine is also used as a hydraulic motor for turning or hydraulic motor for traveling etc.

A variable displacement swash plate type hydraulic rotary machine of this type according to the prior art includes a cylindrical casing, a rotary shaft rotatably provided on the casing, and a rotary shaft integrally rotating with the rotary shaft. And a plurality of cylinders provided in the casing and having a plurality of cylinders extending in the circumferential direction at intervals, and the cylinders are reciprocably engaged with the cylinders of the cylinders. The plurality of pierced pins, the plurality of shoes mounted on the projecting end side of the respective bistons projecting from the respective cylinders, and the surface side serve as smooth surfaces for slidably guiding the respective sheets. A swash plate whose back side is supported rotatably in the casing

,

Tilting control pressure of the supply and discharge externally provided刖_§ Geshingu The swash plate is roughly constituted by a tilt drive which drives the swash plate to tilt.

In this case, on the back surface side of the swash plate, there are provided a pair of leg portions which are separated from each other with respect to the rotation shaft and which project in a convex curved shape. On the other hand, the casing is provided with a swash plate support portion formed in a concave curved shape corresponding to the pair of leg portions, and the swash plate support portion includes the swash plate via the respective leg portions. It supports to be able to tilt.

Further, the casing is provided with a pair of supply and discharge passages for supplying and discharging pressurized oil in each cylinder of the cylinder block. In addition, a static pressure bearing is provided between each leg of the swash plate and the swash plate support portion (hereinafter referred to as a first prior art).

In the first prior art static pressure bearing, a part of the pressure oil is led from the high pressure side supply / discharge passage of the pair of supply / discharge passages, so that the pressure oil can be used to utilize the pressure oil. The contact surface (between the convex curved surface of the leg portion and the tilt support surface) is kept in a lubricated state while generating a separating force (for example, JP-A-H09-1106). 7 4)).

In addition, as a second prior art, the first hydrostatic bearing and the second hydrostatic bearing which are independent of each other are provided between a pair of legs formed on the swash plate and the swash plate supporting portion, and the casing is Of the pair of supply and discharge passages provided, a variable displacement type diagonal line in which one of the supply and discharge passages is in communication with the first static pressure bearing and the other is in communication with the second static pressure bearing. Plate-type hydraulic rotary machines are also known (see, for example, US Pat. Nos. 6, 0 4 8 and 1 7 6).

As a third prior art, a hydraulic closed loop hydraulic power transmission mechanism (Hydrostatic Transmission or less, There is known a variable displacement swash plate type hydraulic rotating machine used for s τ) and the like. The variable displacement swash plate type hydraulic rotating machine includes a swash plate and a tilting lever for driving the swash plate. Then, in the tilting operation, the swash plate is driven to tilt from the neutral position at the zero tilt angle in the forward direction and the reverse direction, for example, the discharge direction of the pressure oil discharged from the hydraulic pump is reverse to the forward direction. Switch to both sides of the

6 3-2 5 9 1 8 2).

In the first prior art described above, with respect to the hydrostatic bearings provided between the legs of the swash plate and the swash plate support of the casing, one of the supply and discharge passages of the pair of supply and discharge passages is provided. Since the pressure oil is introduced from the piston, the hydraulic reaction force received by the piston from each piston (pressure on the swash plate due to the piston reaction force) and the separation force generated by the static pressure bearing There is a possibility that it may become a lance or lance due to pressure fluctuation on the side.

And in an unbalanced state, the legs of the swash plate are inclined so as to rise above the swash plate support, or the pressure oil introduced into the static pressure bearing is easily leaked to the outside.

As a result, static pressure bearings have a problem that they can not maintain the lubrication between the swash plate legs and the swash plate support in a lubricated state.

Also, for example, in the case of a hydraulic motor, its rotary shaft is rotated in the forward direction and the reverse direction, and each time the rotation direction of the rotary shaft changes, the pair of supply and discharge passages sequentially goes to the high pressure side and the low pressure side. It can be switched. For this reason, in the first prior art, the pressure in the static pressure bearing rapidly changes every time the rotational direction of the rotating shaft changes, and it becomes impossible to maintain the original function as the static pressure shaft.

The third prior art variable displacement swash plate described above In order to use it for HST, etc., the hydraulic pump is configured to drive the swash plate in a forward direction and a reverse direction from a neutral position of zero tilt angle in a single direction. And, since such a variable displacement hydraulic type swash plate type hydraulic pump is switched between the high pressure side and the low pressure side of the pair of supply / discharge passage depending on the tilt direction of the swash plate, the first type The same problem occurs even if M static bearings are used according to the prior art.

On the other hand, in the second related art hydraulic rotary machine, the first hydrostatic bearing and the first hydrostatic bearing which are independent of each other are disposed between the pair of legs and the pair of tilt support surfaces formed on the swash plate support. Two hydrostatic bearings are provided, and one of the pair of water supply and discharge passages is communicated with the first hydrostatic bearing, and the other is communicated with the second hydrostatic bearing. .

For this reason, it is possible to use the hydraulic rotating machine according to the second prior art to a hydraulic motor in which the rotating shaft rotates in the forward direction and the reverse direction, and a variable displacement swash plate type used for HST etc. It is also possible to apply to hydraulic pumps etc.

However, the hydraulic rotating machine according to the second prior art has the left and right sides of the rotation shaft, for example, against the pressing force of the swash plate where the separation force from the first and second static pressure bearings is the reaction force. , Right

It is difficult to balance at (positions on both sides in the radial direction). As a result, there is a possibility that each leg of the swash plate may be inclined or separated so as to be lifted from the swash plate support.

For this reason, even in the second related art hydraulic rotary machine, the pressure oil introduced into the first and second hydrostatic bearings is easily leaked to the outside.

< Then, when the pressure oil leaks, it becomes difficult to keep the space between the legs of the swash plate and the swash plate support in a lubricated state. Disclosure of the invention

The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a good balance between the pressing force of the swash plate by the screw reaction and the separation force by the static pressure bearing. To provide a variable displacement swash plate type hydraulic rotating machine capable of producing stable performance as a static pressure bearing.

Another object of the present invention is to provide a hydraulic motor whose rotary shaft rotates in the forward or reverse direction, or a variable displacement swash plate type hydraulic pump used for HST etc. It is an object of the present invention to provide a variable displacement swash plate type hydraulic rotating machine capable of improving productivity and reducing cost etc. .

(1) In order to solve the problems described above, according to the present invention, there is provided a cylindrical casing provided with a swash plate support on one side and a pair of supply and discharge passages on the other side; A shaft having a rotatable shaft and a plurality of cylinders provided in the casing so as to rotate integrally with the rotating shaft and axially spaced apart in the circumferential direction. □ A plurality of pistons reciprocably fitted to each cylinder of the cylinder block and a protruding end side of each of the pistons projecting from the cylinders are attached. A plurality of shells and a surface side serve as a smooth surface for slidably guiding the respective shells, and a back surface side serves as a pair of leg portions and is rotatably supported on the swash plate support portion.

,

A swash plate to be held, a tilt plate for driving the swash plate to tilt by displacing the swash plate by being provided in the marking and externally supplied with a tilt control pressure, and each of the swash plate Provided between the leg portion and the swash plate support portion and in communication with the supply and discharge passage to contact the two. The present invention is applied to a variable displacement swash plate type hydraulic rotating machine including a hydrostatic bearing that holds a contact surface in a lubricated state and a PL.

And / or And, the feature of the configuration adopted by the present invention is that the static pressure bearing is a first main static pressure bearing portion provided on one leg side of the pair of legs, A second main hydrostatic bearing provided on the other leg of the pair of legs and a second main hydrostatic bearing provided on the other leg apart from the second main hydrostatic bearing.

According to another aspect of the present invention, there is provided an auxiliary static pressure bearing portion according to a first aspect of the present invention, and a second auxiliary static pressure bearing portion provided on the one leg portion side apart from the first main static pressure bearing portion. Ah

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According to the present invention, since it is configured as described above, even when any of the pair of supply and discharge passages becomes high in pressure, the space between each leg of the swash plate and the swash plate support portion. The main static pressure bearing portion and the auxiliary static pressure bearing portion can generate a separation force, and against the hydraulic reaction force (the pressing force of the swash plate due to the piston reaction force) the swash plate receives from each piston, the main static The balance between the pressure bearing and the auxiliary static pressure bearing can be well balanced to provide stable performance as a static pressure bearing.

Therefore, in the variable displacement swash plate type hydraulic rotating machine according to the present invention, a hydraulic rotating machine in which a pair of supply and discharge passages are reversibly switched to high pressure or low pressure (for example, the rotating shaft rotates in forward and reverse directions). The present invention can be easily applied to a hydraulic motor or a variable displacement swash plate type hydraulic pump used for HST etc.). Generality can be improved, productivity can be improved, and costs can be reduced.

(2) Further, according to the present invention, the first main static pressure bearing portion is located at a position close to the combined force application point of the hydraulic reaction force that the swash plate receives from each screw on one side in the radial direction of the rotating shaft. Place in The second main static pressure bearing portion is disposed at a position near the resultant force application point of hydraulic reaction forces received by the swash plate from the respective pistons on the other side in the radial direction of the rotation shaft.

In this manner, the swash plate can be made into the cylinder-bore by placing the first and second main static pressure bearing portions at a position close to the resultant force application point of the hydraulic reaction force received by the swash plate from each screw. It is possible to bring the resultant force acting point of the hydraulic reaction force (piston's reaction force) received from each piston on the rack side closer to the acting point of the separation force of the swash plate by each main static pressure bearing section. Become. As a result, it is possible to reduce the moment acting on the swash plate by the hydraulic reaction force and the separating force (for example, the moment around the axis based on the resultant force application point). As a result, the effective bearing area of the first and second auxiliary static pressure bearing portions can be reduced, and the entire hydraulic rotary machine can be miniaturized, including the swash plate. (3) Further, according to the present invention, the swash plate is provided with a through hole located between the pair of legs and through which the rotary shaft is inserted with a gap, and the first and second main static pressures The bearing portion is disposed at a position closer to the through hole than the first and second auxiliary static pressure bearing portions and has an effective bearing area larger than the first and second auxiliary static pressure bearing portions. It is set as having composition.

Even with this configuration, it is possible to bring the force acting point of the hydraulic reaction force that the swash plate receives from each screw close to the acting point of the swash plate distraction force by each main static pressure bearing portion. . Therefore, the moment acting on the swash plate by the hydraulic reaction force and the separating force can be reduced, and the effective bearing area of the first and second auxiliary static pressure bearing portions can be reduced. The entire hydraulic rotating machine can be miniaturized, including the swash plate.

(4) Further, according to the present invention, in the pair of legs, The first and second slide bearing portions are provided at positions radially separated from the rotation shaft from the first and second main static pressure bearing portions and the first and second auxiliary static pressure bearing portions, respectively. There is.

In this case, even if the balance of the moment acting on the swash plate is changed due to pressure fluctuation on the thread discharge side, the stability of the swash plate by the first and second slide bearings. By providing the first and second slide bearings, the surface pressure between each leg of the swash plate and each tilt support surface of the swash plate support can be secured. It is possible to reduce wear and the like at the contact surface of both, and to improve the reliability and life.

(5) On the other hand, according to the present invention, the first main static pressure bearing portion and the first auxiliary static pressure bearing portion may be formed by

The second main static pressure bearing portion and the second auxiliary static pressure bearing portion are in communication with one of the supply and discharge passages through an oil passage, and the other of the supply and discharge passages is provided with the second main static pressure bearing portion and the second auxiliary static pressure bearing portion. It is configured to communicate with the discharge passage via another oil passage.

As a result, when one of the pair of supply and discharge passages becomes higher in pressure than the other, the one main leg side of the swash plate is connected to the first main static pressure bearing portion. The high pressure hydraulic oil can be introduced, and on the other leg side, the high pressure hydraulic oil can be introduced to the first auxiliary static pressure bearing. In addition, when the other supply / discharge passage is at a higher pressure than the other supply / discharge passage, the high pressure oil is introduced to the second auxiliary static bearing on the leg side of one side of the swash plate. In the other leg side, high pressure oil can be introduced to the second main static pressure bearing. As a result, the main static pressure bearing portion and the auxiliary static pressure bearing portion may be disposed between each leg portion of the swash plate and the swash plate support portion even when any of the supply and discharge passages of the pair of 'suction and discharge passages becomes high pressure. Can generate a separation force, and the swash plate With respect to the hydraulic reaction force received from the engine, the separation force at this time can be well balanced, and stable performance can be exhibited as a static pressure bearing.

(6) Further, according to the present invention, the first main static pressure bearing portion and the first auxiliary static pressure bearing portion have an oil passage in one of the supply and discharge passages of the respective supply and discharge passages. In the middle of the oil passage, there is provided a throttle for adjusting the amount of pressure oil supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion in common. The second main static pressure bearing portion and the second auxiliary static pressure bearing portion communicate with the other supply / discharge passage of the respective supply / discharge passages via another oil passage, In the middle of the oil passage, another throttle is provided to adjust in common the amount of pressure oil supplied to the second main static pressure bearing portion and the second auxiliary static pressure bearing portion.

As described above, the first main static pressure bearing portion and the first auxiliary static pressure bearing portion are provided with a throttle in the middle of the oil passage communicating with the one discharge passage. The amount of pressure oil supplied to the static pressure bearing portion and the first auxiliary static pressure bearing portion is adjusted in common to increase or decrease the separation force of the swash plate by these static pressure bearing portions according to the amount of pressure oil. be able to. In addition, the second main static pressure bearing portion is also provided in the middle of the oil passage which connects the second main static pressure bearing portion and the second auxiliary static pressure bearing portion to the other supply / discharge passage. It is possible to adjust the amount of pressure oil supplied to the second and second auxiliary static pressure bearings in common, and to increase or decrease the separation force of the swash plate by these static pressure bearings according to the amount of pressure oil. .

(7) Further, according to the present invention, the first main static pressure bearing portion and the first auxiliary static pressure bearing portion have an oil passage in one of the supply and discharge passages of the respective supply and discharge passages. To communicate with each other ,

In the middle of the passage, there is provided an individual throttle for adjusting the amount of pressure oil supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion independently of each other. The pressure bearing portion and the second auxiliary static pressure bearing portion are configured to communicate with the other a discharge passage of the respective supply and discharge passages via another oil passage, during the passage of the other oil passage. Another separate throttle is provided to adjust the amount of pressure oil supplied to the second main static pressure bearing and the second auxiliary static pressure bearing independently of each other.

As described above, the first throttle is provided in the middle of the oil passage connecting the first main static pressure bearing portion and the first auxiliary static pressure bearing portion to one of the supply and discharge passages. Main static pressure bearing and

The amount of pressure oil supplied to the auxiliary static pressure bearing portion 1 can be adjusted independently of each other, and the separation force of the swash plate between the main static pressure bearing portion and the auxiliary static pressure bearing portion It can be increased or decreased accordingly. The second main static pressure may also be applied to another individual throttle provided in the middle of the oil passage connecting the second main static pressure bearing portion and the second auxiliary static pressure bearing portion to the other supply / discharge passage. The amount of pressure oil supplied to the bearing portion and the second auxiliary static pressure bearing portion can be adjusted independently of each other, and the separation force of the swash plate between these main static pressure bearing portion and the auxiliary static pressure bearing portion can be It can be increased or decreased according to the amount of pressure oil. As a result, the moment acting on the swash plate can be balanced by the hydraulic reaction force and the separating force from each piston, and the stability of the swash plate can be improved, and as a swash plate type hydraulic rotating machine Can increase the reliability and life of the

(8) Also, according to the present invention, one side of the first main static pressure bearing portion, the first auxiliary static pressure bearing portion and the one supply / discharge passage is the one of the one supply / discharge passage. A common oil passage communicating with the other side extending toward the static pressure bearing portion, and the other side of the common oil passage A branched oil passage is provided which is branched to each other and is separately connected to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion.

One of the two main static pressure bearing portions, the second auxiliary static pressure bearing portion, and the other supply / discharge passage communicate with the other feed / discharge passage, and the other side is directed to the static pressure bearing portion. Another common oil passage that extends and another branch that branches off on the other side of the common oil passage and is separately connected to the main static pressure bearing portion of ^ 2 and the second auxiliary static pressure bearing portion. It is considered to be provided with an oil passage 0

The first main static pressure bearing portion, the first auxiliary static pressure bearing portion, and an i Zt oil passage and a branched oil passage are provided between the first main static pressure bearing portion and the second main static pressure. Since another common oil passage and another branch oil passage are also provided between the bearing, the second auxiliary static pressure bearing and the other supply / discharge passage, each static pressure bearing, for example, is separately provided. Compared to the case of providing separate oil passages, it is possible to reduce the number of oil passages provided in the housing of the hydraulic rotary machine, etc., and realize a small and simple structure. It is possible to improve productivity and reduce costs.

(9) Further, according to the present invention, pressure is supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion from one of the supply and discharge passages in the middle of the common oil passage. A common throttle for adjusting the amount of oil is provided, and in the middle of the branch oil passage, the amounts of pressure oil supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion are mutually independent. The individual throttles to be adjusted are provided respectively. The pressure supplied from the other supply / discharge passage to the second main static pressure bearing and the second auxiliary static pressure bearing in the middle of the other common oil passage. Another common throttle for adjusting the amount of oil is provided, and the amount of pressure oil supplied to the second main static pressure bearing portion and the second auxiliary static pressure bearing portion in the middle of the other branch oil passage Adjust independently of each other The other individual diaphragms are provided.

As described above, the common throttle is provided in the middle of the common oil passage located upstream of each branch oil passage, and the individual throttle is provided in the middle of each branch oil passage. Even if the hole diameter (throttle diameter) of the throttle is made relatively large, the amount of pressure oil supplied to the main static pressure bearing portion and the auxiliary static pressure bearing portion through the common throttle can be adjusted well, and dust etc. It is possible to reduce the possibility of clogging (clogging) of the common throttle due to foreign matter and improve the reliability of the device. Even if a minute gap exists around each static pressure bearing, these may be eliminated. The effect of suppressing the leakage of pressure oil through a gap can be obtained by common throttling, the processability of the entire device can be improved, the productivity can be improved, and the reduction of waste etc. can be achieved o

Further, according to the present invention, the swash plate is configured to be driven to tilt from the neutral position of zero tilt angle in the forward direction and the reverse direction by the tilt actuator. As a result, even if the hydraulic rotary machine according to the present invention is applied to a variable displacement swash plate type hydraulic pump used for HST etc. and this hydraulic pump is connected to a hydraulic circuit using a hydraulic closed circuit, The discharge direction of pressure oil can be reversibly switched and controlled according to the direction of plate tilt (forward direction or reverse direction). And, even when the swash plate is tilted in either the forward direction or the reverse direction, the tilt operation of the swash plate can be stabilized and the space between the swash plate support portion can be maintained in a good lubrication state. . .

(11) Further, according to the present invention, the casing comprises a relief valve having a spool in a control sleeve, and the tilt valve for supplying and discharging the relief valve. The control pressure is controlled in accordance with the command signal from the outside, and the control procedure of the adjustment procedure is followed following the tilting operation of the swash plate. A feedback mechanism for feedback control of the rib is provided, and the feedback mechanism is set to an initial position on the axial side along the rotation axis when the swash plate is in the neutral position. If the swash plate is driven to tilt in the forward or reverse direction, the tilting motion of the swash plate is converted into axial displacement so that the swash plate is displaced from the initial position toward the other side in the axial direction. Of the axial displacement taken out by the converting unit, provided between the converting unit, the converting unit, and the control sleeve of the regu And a displacement transmission unit that transmits to the

When the swash plate is driven to rotate in the forward or reverse direction by the tilt actuator, the control sleeve of the shutter is slid in the same direction as the spool. Feedback control can be performed on the register so as to cause dynamic displacement, and feedback control on the register can be performed even when the swash plate is tilted in either the forward or reverse direction. Can be done smoothly. And, since the refueling valve is constructed by the servo valve having a spring in the control sleeve, the structure of the entire variable displacement hydraulic rotating machine for controlling the inclination of the swash plate is simplified. be able to. Brief description of the drawings

FIG. 1 is a hydraulic circuit diagram for traveling of a wheel type working vehicle provided with a variable displacement swash plate type hydraulic pump according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the hydraulic pump shown in FIG. Fig. 3 is a longitudinal sectional view of the hydraulic pump as viewed in the direction of arrows in Fig. 2.

FIG. 4 is an enlarged sectional view of the hydraulic pump shown in FIG. FIG. 5 is an enlarged sectional view showing the swash plate support and the swash plate in FIG. 4 together with the static pressure bearing portion and the like.

Fig. 6 shows the condition where the swash plate is in the neutral position, as indicated by arrows in Fig.

-It is an expanded sectional view seen from the direction of VI.

Fig. 7 is a cross-sectional view at the same position as in Fig. 6, showing the swash plate in a normal direction.

FIG. 8 is an enlarged perspective view of the swash plate in FIG. Fig. 9 is a rear view of the swash plate of Fig. 8 viewed from the back side. FIG. 10 is a circuit diagram showing a tilt control device for a swash plate according to the first embodiment.

Fig. 1 1 is a front view showing the swash plate in Fig. 10 with a tilting piston.

Fig. 1 2 is a front view showing the swash plate in Fig. 1 1 tilted forward.

Fig. 13 is a front view showing the swash plate in Fig. 11 tilted in the reverse direction.

FIG. 14 is a longitudinal sectional view at the same position as FIG. 3, showing a hydraulic pump according to a second embodiment.

Figure 15 is an enlarged perspective view of the swash plate in Figure 14.

Fig. 16 is a rear view of the swash plate in Fig. 15 viewed from the back side. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the variable displacement swash plate type hydraulic rotating machine according to the embodiment of the present invention is applied to a traveling hydraulic circuit in a wheel type work vehicle such as a wheel loader, for example. Do

Here, FIGS. 1 to 13 are the forms of one embodiment of the present invention. 3 shows a variable displacement swash plate type hydraulic rotating machine according to the embodiment.

In the figure, reference numeral 1 denotes a swash plate type hydraulic pump as a variable displacement swash plate type hydraulic rotary machine, and the hydraulic pump 1 is a case described later.

1 1, rotary shaft 1 3, cylinder block 1 4, multiple cylinders 1 5, piston 1 6, sieve 1 7, valve plate 1 9, swash plate support 20 and swash plate 2 1 etc. It is something that will be

Further, in the hydraulic pump 1, for example, a rotary shaft 13 is rotationally driven by a prime mover 2 such as a diesel engine serving as a drive source, and as shown in FIG. It distributes pressure oil. The hydraulic pump 1 is connected to a hydraulic motor 5 described later via the main pipelines 3 A and 3 B to constitute a so-called hydraulic closed circuit 4.

Reference numeral 5 denotes a traveling hydraulic motor as a hydraulic actuator, and the hydraulic motor 5 is connected to wheels 7 and 7 of a wheeled work vehicle via, for example, a reduction gear 6. And, the hydraulic motor 5 has the pressure oil from the hydraulic pump 1 as the main line 3 A 3

By being supplied and discharged through B, the work vehicle is driven by driving the table 1⁄4 ff1 1 to rotate.

1 1 is a cylindrical casing serving as an outer shell of the hydraulic pump 1, and the casing 1 1 has a cylindrical casing main body 1 1 A as shown in FIGS. 2 to 4 and the casing main body 1 It consists of a fluorocarbon sheeting 1 1 B and a plugging sheet 1 1 C, with both ends of 1 A blocked.

Further, as shown in FIG. 3, an opening 1 1 D and a drain passage 1 1 E are formed on the outer peripheral side of the casing main body 1 1 A, and these opening 1 1 D and the lens passage 1 1 E are , Kashin

* * The main body 1 1 A is always in communication with the inside of the regulator 3 4 valve Hung 3 5 which will be described later. And the casing In the opening 1 ID of the main body 1 1 A, a translation bar 4 4 described later is slidably mounted via a guide member 45 or the like. The inside of the casing 1 1 is a so-called drain chamber and is connected to a tank 4 7 described later.

Here, as shown in FIG. 2 to FIG. 4, a swash plate support 20 described later is provided on the swash plate 2 1 as shown in FIG. 2 to FIG. A pair of supply and discharge passages are provided to the back side 1 1 C, which is provided opposite to the back side and is located on the other side of the casing main body 1 1 A.

2 A 1 2 B is provided, and the supply and discharge passages 1 2 A and 1 2 B are connected to the main pipeline 3 A 3 B shown in FIG.

1 3 is a rotary shaft rotatably provided in the casing 1 1, and the rotary shaft 1 3 is provided with bearings for the front casing 1 1 B and the heating casing 1 1 C respectively. The rotary shaft 13 is rotatably supported by the motor 2 shown in FIG. 1 at the projecting end 13 A side that protrudes in the axial direction from the front bearing 1 1 B.

Reference numeral 14 denotes a cylinder block provided in the casing 1 1 so as to rotate integrally with the rotary shaft 13. The cylinder block 1 4 is spaced apart in the circumferential direction thereof. There are also a plurality of cylinders J 1, 15 1,... Extending in the axial direction.

1 6, 1 6, ... are series • 4 of each series

Each piston 16 is a piston which is slidably inserted in each of the pistons 5. When the swash plate 21, which will be described later, is tilted in the forward direction or in the reverse direction, the pistons 16 may be cylinders. It reciprocates in cylinder 1 5 along with rotation of 1 4 and returns suction and discharge strokes.

1 7, 1 7, ... are provided in each of the pisins 1 In each case, each shoe 1 7 is rocked to one end side (protruding end side) of a screw tongue 16 which protrudes in the axial direction of the rotary shaft 13 from the cylinder 1 5 of the cylinder block 1 4. It is mounted to be movable.

Reference numeral 18 denotes an annular clamp which holds each shoe 17 against the swash plate 21. The clamp 18 is a smooth surface of the swash plate 21 which will be described later as shown in FIG. 3 to FIG. It is intended to compensate for the displacement of each shell 1 7 in an annular path on the smooth surface 2 1 C of the swash plate 2 1 by pressing the shell 1 7 toward 1 C respectively. S.

1 9 is located in the case 1 1

A valve plate provided between 1 C and the cylinder dovetail 14 4 makes sliding contact with the end face of the cylinder block 14 so that the cylinder block 1 4 can be rotated about its axis of rotation 1 3 It is rotatably supported together with Further, as shown in FIGS. 3 and 4, the valve plate 19 is formed with a pair of feeding and discharging ports 1 9 A and 19 B in a bowl shape. And these supply and discharge ports 1 9 A, 1

9 B is the supply and discharge passage of Lyacasing 1 1 C 1 2 A, 1 2

It is in constant communication with B.

Here, the supply and discharge ports 1 9 A and 1 9 B of the valve plate 1 9 intermittently communicate with the cylinders 1 5 when the cylinder block 1 4 rotates. The supply and discharge ports 1 9 A and 1 9 B are provided with hydraulic oil drawn from the side of one supply and discharge passage 1 2 A (or 1 2 B) into each cylinder 1 5 as a piston 1 In addition to pressurizing by 6, it has a function to discharge pressurized oil that has become high pressure in each cylinder 15 from the other supply / discharge passage 12 B (or 12 A).

Reference numeral 20 denotes a swash plate support as a swash plate support, and the swash plate support 20 is located around the rotation shaft 13. It is provided in one sing 1 IB. And, as shown in FIG. 4, the swash plate support 20 has a pair of tilting support surfaces 20 A and 20 B at positions on both the left and right sides sandwiching the rotation shaft 13, for example. It supports 21 so that it can tilt.

And, the tilt support surfaces 20 A and 20 B of the swash plate support 20 are formed in a concave curve corresponding to the legs 21 A and 2 IB of the swash plate 2 1 described later. It guides 21 so that it can tilt (slide) in the directions of arrows A and B around the center of tilt C illustrated in FIG. 6 and FIG. Further, in the swash plate support 20, a part of branched oil passages 24B, 24C25B, 25C described later is bored.

Next, reference numeral 21 denotes a swash plate used in the present embodiment, and the swash plate 21 is provided in the casing 1 1 so as to be able to be tilted via the swash plate support 20. On the back side of the swash plate 2 1 of the bridge, as shown in FIG. 2 to FIG. 7, the left of the swash plate support 20 projects in a convexly curved shape toward the tilting support surfaces 2 OA and 20 B , The right pair of legs 2 1 A, 2 1 B are provided. Then, the legs 2 1 A 2 1 B of the swash plate 2 1 are spaced apart, for example, in the left and right directions with the rotary shaft 1 3 interposed therebetween, and have a concave-curved swash plate support 20 tilt support It is slidably fitted on the surface 20 A 20 B.

On the other hand, as shown in FIG. 2 to FIG. 7, the surface side of the swash plate 21 is a smooth surface 21 which slidably guides each plate 17. As shown in FIG. The swash plate 2 1 is provided with a through hole 21 D extending in the thickness direction. The rotary shaft 13 is inserted between the legs 2 1 A and 2 1 B in the through hole 21 D with a gap.

Here, the legs 2 1 A 2 1 B of the swash plate 2 1 are, as shown in FIG. 6 or FIG. The tilt center C is disposed on the axis O- 0 of the rotation axis 1 3. And, the swash plate 2 1 is shifted from the neutral position of zero tilt angle shown in FIG. 6 and FIG. 1 1 to a positive direction (arrow A direction) and a reverse direction (arrow B direction) as described later. It is driven to tilt using evenings 2 and 3 3. At this time, the capacity (discharge amount of hydraulic oil) of the hydraulic pressure pump 1 is variably controlled according to the tilt angle 0 of the swash plate 2 1.

In addition, the swash plate 21 receives hydraulic reaction force (piston reaction force) from each screw 16 which rotates integrally with the cylinder dovetail 14 around the rotation shaft 13. The combined forces f 1 and f 2 of the hydraulic reaction force are illustrated in FIG. 9 as the action points (hereinafter referred to as combined action points k 1 and k 2) rotate as cylinder block 1 4. It fluctuates to draw the letter “字” as shown. In this case, when the swash plate 2 1 is tilted in the positive direction from the neutral position, it receives a hydraulic reaction force at the position of the resultant force application point kl, and when it is tilted in the reverse direction from the neutral position The hydraulic reaction is received at the point k 2.

Denoted at 2 2 is a hydrostatic bearing provided between the tilt support surfaces 20 A and 20 B of the swash plate support 20 and the legs 21 A and 21 B of the swash plate 2 1. The static pressure bearing 22 is inclined, for example, by the pressure oil being introduced as described later from a pair of supply and discharge passages 12 A and 12 B provided in the rear cover 11 C. While generating a separation force (hydraulic force) between the support surfaces 20 A and 2 08 and the legs 2 1 and 2 1 B, the contact surfaces of both are maintained in a lubricated state.

The hydrostatic bearing 2 2 is provided on the convex curved surface side of one leg 21 A at a position close to the through hole 21 D of the swash plate 2 1 as shown in FIGS. 5, 8 and 9. The first main hydrostatic bearing part 2 2 A, and the other side of the leg 2 1 B in a position close to the through hole 2 1 D The second main static pressure bearing portion 22 B provided on the curved surface side and the second main static pressure bearing portion 22 B are provided on the convex curved surface side of the leg portion 21 B so as to be separated in the radial direction. The second auxiliary static hydrostatic bearing 2 2 provided on the convex curved surface side of the leg 2 1 A at a distance from the first main hydrostatic bearing 2 2 A in the radial direction. It is configured by the auxiliary static pressure bearing 2 2 D.

Further, among the static pressure bearing portions 22A to 22D, the first main static pressure bearing portion 22A and the first auxiliary static pressure bearing portion 22C are provided with oil passages 24 described later. It is connected to one supply / discharge passage 1 2 A via. Further, the second main static pressure bearing portion 22 B and the second auxiliary static pressure bearing portion 22 D are connected to the other supply / discharge passage 12 B via an oil passage 25 which will be described later. It is

In this case, the first and second main hydrostatic bearings 22 A and 22 B are shown by arrows in the directions of arrows A and B along the convexly curved surfaces of the legs 21 A and 2 IB as shown in FIG. The planar shape is an elongated rectangular shape as shown in FIG. The first and second auxiliary static pressure bearings 2 2 C and 2 2 D are the first and second main static pressure bearings 2 2 A with reference to the through hole 21 D of the swash plate 2 1. , 2 2 B is located at the outer side in the left and right direction (radial direction).

The first and second auxiliary static pressure bearings 2 2 C and 2 2 D are also connected to the first and second main static pressure bearings 2 2 along the convexly curved surfaces of the legs 2 IB and 2 1 A. It is formed as a groove extending substantially parallel to A and 22 B (directions of arrows A and B in Fig. 8), and its planar shape is an elongated rectangular shape as shown in Fig. 9. However, the first and second auxiliary static pressure bearings 2 2 C, 2 2 D have groove lengths (ditch lengths in the directions of arrows A and B) and groove widths in the left and right directions. It is smaller than the first and second main static pressure bearings 2 2 A and 2 2 B. That is, in the first main hydrostatic bearing portion 22A, the swash plate 21 receives the hydraulic reaction force received from each screw 1 6 at one radial side (right side in FIG. 9) of the through hole 21D. It is arranged at a position near the resultant action point k 1 and at a distance La from the action point k 1. Also, the second main static pressure bearing portion 2 2 B has a through hole 2

A distance L from the action point k 2 at a position close to the resultant force action point k 2 of the hydraulic reaction force that the swash plate 2 1 receives from each piston 16 on the other side of the radial direction 1 D (left side in FIG. 9). It is placed at the position b.

In the first auxiliary static pressure bearing 22C, the swash plate 21 is a piston on the other side of the through hole 21D in the radial direction (the left side in Fig. 9).

The distance L c from the resultant force action point k 1 of the hydraulic reaction force received from 1 6

It is arranged at the position where (L c> L a). Also, the second auxiliary static pressure bearing 22 D is the hydraulic reaction force that the swash plate 21 receives from each piston 16 at one radial direction side (right side in FIG. 9) of the through hole 21 D. Is located at a distance L d (L d> L b) from the resultant force action point k 2 of

The first and second main static pressure bearings 2 2 A and 2 2 B are shown in FIGS. 5 and 9 as the first and second auxiliary static pressure bearings 2.

The holes are arranged closer to the through holes 21 D than 2 C and 2 2 D. In addition, the effective bearing areas S a and S b of the main static pressure bearing portions 2 2 A and 2 2 B are auxiliary static pressure bearing portions 2 2 C so as to satisfy the relationship according to the following equations (4) and (8). , 22 D is formed larger than the effective axial bearing area S c, S d. The effective bearing areas S a, S b, S c, and S d are equivalent to the pressure receiving areas of the bearing portions 2 2 A, 2 2 B, 2 2 C, and 2 2 D, respectively.

Reference numerals 2 3 A and 2 3 B denote first and second sliding bearings provided on the legs 2 1 A and 2 1 B of the swash plate 2 1, respectively. As shown in Fig.5, Fig.8 and Fig.9, the main bearing for static pressure bearings 2 2 A, 2 2 B and 2 3 A, 2 3 B are located on the left and right sides of the through hole 21 1D. It is located at a position radially away from the through hole 21 D from the auxiliary static pressure bearing 2 2 C, 22 D. That is, as shown in FIG. 8, the slide bearing portions 2 3 A and 2 3 B are formed in a convexly curved shape at positions that become ridges on the left and right sides of the legs 2 1 A and 2 IB. It is

The slide bearing portions 2 3 A and 2 3 B are slidably in contact with the tilt support surfaces 2 OA and 20 B of the swash plate support 20 with a small surface pressure. As a result, the slide bearings 2 3 A and 2 3 B can smoothly rotate the legs 2 1 A and 2 IB of the swash plate 2 1 along the swash plate support 20. It compensates with the static pressure bearing part 2 2A to 2 2D.

Reference numeral 24 denotes an oil introduction passage for guiding pressure oil to the first main static pressure bearing portion 22A of the static pressure bearing 22 and the first auxiliary static pressure bearing portion 22C. As shown in Fig. 4 and Fig. 5, 4 is the supply and discharge passage 1 2

A and 1st main static pressure bearing 2 2 A, 1st auxiliary static pressure bearing

It is provided between 2 2 C and Here, the oil guiding passage 24 is provided in the casing 1 1, the side is in communication with the supply and discharge passage 1 2 A, and the other side is the first main static pressure bearing portion 2 2 A, the first auxiliary static pressure Common oil passage 24 A extending toward the pressure bearing portion 2 2 C, and 2 branch passages 2 4 branched from each other on the other side of the common oil passage 2 4 A

It is composed of B and 24 C. And one branch oil passage 24 B is connected to the first main static pressure bearing portion 22 A, and the other branch oil passage 24 C is connected to the first auxiliary static pressure bearing portion 22 C It is connected.

The branched oil passages 2 4 B and 2 4 C of the oil introduction passage 2 4 are branched from each other toward the swash plate support 20 from the front casing 1 1 B side of the casing 1 1 and extend. ing. And The extension end of the branched oil passage 24 B is opened to the first main static pressure bearing portion 22 A on the tilt support surface 2 OA side of the swash plate support 20. Further, the extension end of the branched oil passage 24 C is opened to the first auxiliary static pressure bearing portion 22 C on the tilt support surface 20 B side of the swash plate support 20.

Reference numeral 2 5 denotes another oil introduction passage for introducing pressure oil to the second main static pressure bearing portion 2 2 B of the static pressure bearing 2 2 and the second auxiliary static pressure bearing portion 2 2 D. As shown in FIG. 4 and FIG. 5, it is provided between the supply / discharge passage 12 B and the second main static pressure bearing portion 22 B and the second auxiliary static pressure bearing portion 22 D. Here, the oil guiding passage 2 5 is provided in the casing 1 1 and one side communicates with the supply and discharge passage 1 2 B, and the other side is the second main static pressure bearing portion 2 2 B, the second auxiliary static pressure bearing It comprises a common oil passage 25A extending toward the part 22D and two branched oil passages 25B and 25C branched from each other on the other side of the common oil passage 25A. There is. And, one branch oil passage 25 B is connected to the second main static pressure bearing 22 B, and the other branch oil passage 25 C is connected to the second auxiliary static pressure bearing 22 D It is done.

And, the branched oil passages 25 B and 25 C of the oil guiding passage 25 are branched from each other toward the inside of the swash plate support 20 from the side of the flowing side 1 1 B of the casing 1 1. It extends. The extension end of the branch oil passage 25 B is opened to the second main static pressure bearing portion 2 2 B on the side of the tilt support surface 2 0 B of the swash plate support 20. Further, the extension end of the branch oil passage 25 C is opened to the second auxiliary static pressure bearing portion 22 D on the tilt support surface 2 OA side of the swash plate support 20.

Reference numeral 2 6 denotes a common throttle provided in the middle of the common oil passage 2 4 A, and 2 7 denotes another common throttle provided in the middle of the common oil passage 2 5 A. One of these common apertures 2 6, 2 7 As shown in Fig. 4 and Fig. 5, the common throttle 2 6 is common to the first main static pressure bearing section 2 2 A and the first auxiliary static pressure bearing section 2 2 C from the supply / discharge passage 12A. The amount of pressure oil to be supplied is adjusted according to the reduction diameter (pore diameter). The other common throttle 2 7 is a pressure oil that is commonly supplied from the supply and discharge passage 12 B to the second main static pressure bearing portion 2 2 B and the second auxiliary static pressure bearing portion 2 2 D. The amount is adjusted according to the diameter of the aperture (hole diameter).

The common throttles 2 6 and 2 7 have throttle diameters larger than the individual throttles 2 8 to 3 1 described later, and supply and discharge passages 12 A and 12 B to the main static pressure bearing portion 2 2 A Roughly adjust the amount of pressure oil supplied to H, 2 2 B and auxiliary static pressure bearings 2 2 C, 2 2 D. As a result, the main static pressure bearings 2 2 A and 2 2 B and the auxiliary static pressure bearings

With 2 2 C and 2 2 D, it is possible to suppress the occurrence of large variations in the amount of pressure oil supplied by means of the common throttles 26, 27.

2 and 2 9 are throttles (hereinafter referred to as individual throttles 2 8 and 2 9) provided in the middle of the branch oil passages 2 4 8 and 2 5 B, respectively

Reference numerals 30 and 31 denote other throttles (hereinafter referred to as individual throttles 30 and 31) provided in the middle of the branch oil passages 24 C and 25 C, respectively. Here, these individual apertures 28 to 31 have smaller aperture diameters than the common apertures 26 and 27. Then, after being roughly adjusted with the common throttle 2 6, 2. 7, the static pressure is supplied to the hydrostatic bearing 2 2 A to 2 2 D via the branched oil passages 2 4 B, 2 5 B, 2 4 C, 2 5 C. The amounts of pressure oil to be added are fine-tuned independently of each other by the individual throttles 2 8 to 3 1.

That is, the individual throttle 2 8 finely adjusts the amount of pressure oil supplied to the first main static pressure bearing portion 2 2 A via the branch oil passage 2 4 B individually The individual throttle 2 9 finely adjusts the amount of pressure oil supplied to the second main static pressure bearing 2 2 B via the branch oil passage 2 5 B individually. Also, the individual throttle 30 finely adjusts the amount of pressure oil supplied to the first auxiliary static pressure bearing portion 2 2 C via the branch oil passage 2 4 C, and the individual throttle 3 1 makes the branch oil passage The amount of pressure oil supplied to the second auxiliary static pressure bearing section 2 2 D via 2 5 C is finely adjusted individually.

Reference numerals 3 2 and 3 3 denote a pair of tilting actuators for driving the swash plate 2 1 to tilt. Here, as shown in Fig. 2, Fig. 3, Fig. 6, Fig. 7 and Fig. 7, one tilting condenser 32 is located radially outward of the cylinder D 14 and The cylinder hole 32 A formed in the main body 1 1 A and the cylinder hole 32 2 A are slidably inserted into the cylinder hole 32 A, and the cylinder hole 3 2

A tilting piston 3 2 C defining a hydraulic pressure chamber 3 2 間に between A and A, and disposed in the hydraulic pressure chamber 3 2 B, the tilting pistine h It consists of a spring 3 2 D and a constant bias toward one side ο

,, ./_

In addition, the other tilting aperture 33 3 also has the cylinder hole 33 A formed in the casing main body 1 1 A in substantially the same manner as the one tilting aperture 31 2 described above, and Hydraulic piston 3 3 A defining a hydraulic chamber 3 3 A in the cylinder hole 3 3 A

It is constituted by 3 C and a spring 3 3 D in which the tilting biston 3 3 C is always biased with the side facing the swash plate 2 1.

Here, each of the tilting arms 3 2 and 3 3 is disposed at a position opposite to each other in the radial direction of the cylinder block 1 4 with respect to the casing main body 1 1 A. The swash plate 21 is driven to tilt in the directions of arrows A and B by pistons 3 2 C and 3 3 C, respectively. That is, as shown in FIG. 3 and FIG. 10, the hydraulic pressure chamber 32 B of the tilting valve 32 is connected to a control line 50 B described later, A tilt control pressure is supplied and discharged from the control line 50 B. The fluid pressure chamber 33 B of the tilting valve 33 is connected to a control line 5 OA described later, and a tilting control pressure is supplied and discharged from the control line 50 A.

Then, when the tilting screw 3 3 C is extended from the inside of the cylinder hole 3 3 A as shown in FIG. 7 by this tilting control pressure, the swash plate 2 1 is shown by an arrow by the tilting piston 3 3 C. It is driven to tilt in the A direction (positive direction). At this time, tilt screw

When 2 2 C is extended from inside the cylinder hole 32 2 C when the cylinder 2 2 C is contracted from inside the cylinder hole 3 2 A, the swash plate 2 1 is inclined screw screw 3 3 2 C arrow

It is driven to tilt in the B direction (reverse direction). In this case, the tilting piston 3 3 C is contracted toward the inside of the cylinder hole 3 3 A.

The reference numeral 3 4 is a regulation tube as a volume control valve that discharges a tilting control pressure to the tilting needle valve 2, 3 3. As shown in Fig. 3, this Regu-yu 1 34 is a casing body.

1 1 A located on the outside of the valve housing 1 5 provided with a valve housing 3 5, a control sleeve 3 6 described later, a spool

It is composed of 3 7, hydraulic piping 3 8 and valve spring 3 9 mag. And, as shown in FIG. 10, the regu- lator tube 3 4 is constituted by a hydraulic servo valve for tilt control having a spool 3 7 in a control sleeve 3 6.

Here, as shown in Fig. 3, the supply and discharge ports 35A, 35B, etc. of the displacement control pressure are provided in the valve housing 35 of the regi-yu 34. As shown in FIG. And, the supply / discharge port 35 A was connected to the discharge side of the pilot pump 46 via the control line 4 8 A described later. The supply / discharge port 35 B is W is connected to the control line 4 8 B described above and the valve housing 3 5 of the regulator 3 4 is provided so as to be liquid-tightly fixed to the outer side surface of the casing 1 1 The

—Bub 6 and sprue 3 7 etc. are arranged so as to extend in parallel with the rotation axis 1 3 (axis O— O shown in FIG. 10)

3 6 is a cylindrical control sleeve slidably inserted into the valve housing 3 5, and the control sleeve 3 6 has a plurality of translation bars 4 4 described later on its outer periphery in the axial direction. The control sleeve 3 6 is integrally connected using a set screw and the like, and the control sleeve 3 6 follows the movement of the translation bar 4 4 (translational movement along the axial direction of the rotation axis 1 3) and the valve 8 kunung It slides in the axial direction (direction of arrow DE in Fig. 6) in 5 5.

Reference numeral 3 7 denotes a spool slidably fitted in the control sleeve 3 6. The spool 3 7 is a control sleeve 3

Slidingly displaces in the axial direction of the valve having 3 5 on the inner side of 6. At the time, the sprue 3 7 selectively supplies 3⁄4 to the 3 1 Α or 5 1 通路 or 1 通路 aisle for the 3 5

2 0 Block it.

Reference numeral 3 8 denotes a hydraulic pilot section located on the axial side of the spool 3 7 and provided in the valve housing 3 5. The hydraulic pilot section 3 8 is opposed to a valve spring 3 9 described later. It has a plunger 3 8 Α for driving the spool 3 7 in the axial direction, and a command pressure is supplied via a command pressure line 5 3 5 described later.

Then, the plunger 38 of the hydraulic pilot section 38 is pressured by using the command pressure from the command pressure line 53 as the pilot pressure, so that the pressure is applied to this pilot pressure. Accordingly, the spool 3 7 is axially displaced in the valve housing 3 5. This As a result, the plunger 3 8 A of the hydraulic pilot section 3 8 changes the regulator 3 4 shown in Fig. 10 from the neutral position (I) to the switching position (11), (III) It is what changes.

Reference numeral 3 9 denotes a valve spring disposed between the other axial side of the spool 3 7 and the valve housing 3 5, and the valve spring 3 9 is a hydraulic pilot portion 3 of the spool 3 7. Always bias toward the 8 side, for example, the regi

It is intended to return to (I).

4 0 follows the tilting movement of the swash plate 2 1

3 Feedback mechanism for feedback control of 4 is shown. This feedback mechanism 40 has the side surface of the swash plate 21 and the regi- tal tube 3 as shown in Figs. 3 to 13.

A conversion unit, which will be described later, provided between the control sleeve 4 and the control sleeve 3 6

It consists of 4 1 and a translation bar 4 4 etc.

4 1 converts the tilting motion of the swash plate 2 1 into axial displacement and removes it

In the changing part, the converting part 4 1 is composed of a cam groove 4 2 and a force follower 4 3 which will be described later. And, converter 4

1 converts the tilting movement of the swash plate 2 1 into axial displacement as described later, and generates translational movement (parallel movement) along the axis O-O of the rotation axis 1 3 in the translational bar 4 4 described later It is

Reference numeral 4 2 denotes a cam groove having a cam surface for converting the tilting movement of the swash plate 2 1 into axial displacement of the cam follower 4 3.

2 is a concave formed by bending in a substantially “V” shape or “U” shape on the side surface of the swash plate 2 1 (the side surface of the other leg 21 B) as shown in FIGS. 3 to 8 It is composed of grooves. In addition, the force groove 4 2 is disposed at a position away from the center C of tilting of the swash plate 2 1. And, the cam groove 4 2 corresponds to the outer diameter of the roller portion 4 3 A so that the roller portion 4 3 A of the force lower 4 3 described later can be slidably (rotated) fitted. Groove width.

Here, as shown in Fig. 10 and Fig. 1 1, when the swash plate 2 1 is in the neutral position with zero tilt angle, the cam groove 4 2 slides on the roller portion 4 3 A of the cam follower 4 3. When the intermediate groove 4 2 A as the neutral position sliding contact portion and the swash plate 2 1 are tilted from the neutral position in the arrow A direction (forward direction), the roller portion 4 3 A is in sliding contact with the neutral position. A reverse direction sliding contact portion in which the roller portion 4 3 A is in sliding contact when the lower inclined groove portion 4 2 B as sliding contact portion and the swash plate 2 1 are tilted in the arrow B direction (reverse direction) from the neutral position. It is composed of the upper inclined groove 4 2 C as an example.

And, among the groove portions 4 2 A 4 2 C of the cam groove 4 2, the middle groove portion 4 2 A is the axis O- O of the rotation axis 13 from the center of rotation C when the swash plate 21 is in the neutral position. The lower inclined groove 4 2 B is disposed at the position of the largest size <spaced apart dimension R a (R a <R) along the center from the position of the intermediate groove 4 2 A to the rotational center C The upper inclined groove portion 4 2 C is formed so as to extend obliquely upward from the intermediate groove portion 4 2 A in a direction approaching the inclination center C from the middle groove portion 4 2 A.

That is, the cam groove 4 2 is an intermediate groove 4 2 on the side surface of the swash plate 2 1.

The lower inclined groove 4 2 B and the upper inclined groove are formed as a concave groove bent in a substantially Γ V shape or “U” shape at the position A.

4 2 C is a shape symmetrical to each other so as to expand downward and upward from the position of the intermediate groove portion 4 2 A based on the axis O-O.

The lower inclined groove portion 4 2 B and the upper inclined groove portion 4 2 C have their tip sides extending to the positions of points G 1 and H 1 described later shown in FIG. 11 and these points G 1 and H 1 are Tilting center of swash plate 2 1

It is disposed at a position separated from C by a dimension R b. of The dimension R b in the case is set to a dimension smaller than the dimension R a from the center of tilt C to the intermediate groove portion 4 2 A (R b less R a <R)

Reference numeral 4 3 denotes a force mousse roll provided in sliding contact with the cam groove 4 2. This cam face 4 3 is integrally formed on one side in the longitudinal direction of a translational bar 4 4 described later as shown in FIG. 3. It has a roller section 43 A that can be rotated (autorotated) along the wall surface (force surface) in the force groove 4 2.

And the cam follower 4 3 is a roller unit 4 3 A is a swash plate

By sliding engagement with the cam groove 4 2 on the 1 1 side, the tilting movement of the swash plate 2 1 is converted into axial displacement as described later, and the axis O-O of the rotating shaft 1 3 is obtained. It generates translational movement (translation) along translational bar 4 4.

In this case, the roller portion 4 3 A of the force lower 4 3 engaged with the cam groove 4 2 on the swash plate 2 1 side is in the initial position shown in FIG. 11 when the swash plate 2 1 is in the neutral position. A line F-which is arranged together with the translational bar 4 4 and which is orthogonal to the axis O-O of the rotation axis 1 3

Located on F. At this time, the D-roller portion 4 3 A of the cam follower 4 3 is retracted along the axis O-O of the rotary shaft 1 3.

(Retracted in the direction of arrow E in Fig. 10).

Also, assuming that the swash plate 2 1 is tilted from the neutral position in the direction of arrow A (positive direction) as shown in FIG. 7 and FIG. 12, the tilt angle 0 of the swash plate 2 1 is an angle When (α α = QL), the roller portion 4 3 of the cam follower 4 3 is a force groove.

4 2 Slide along lower slope groove 4 2 Β and move to the position of point G 1 shown in Fig. 1 2. As a result, the roller portion 4 3 of the force follower 4 3 is translated (translationally moved) to the position of the line G-G together with the translation lever 4 4. It is displaced in the axial direction of axis of rotation 13 by a dimension a with respect to the initial position line F — F.

On the other hand, it is assumed that the swash plate 21 is tilted from the neutral position in the direction of arrow B (reverse direction) as shown in FIG. 13 and the swash plate

If the tilt angle 6> of 2 1 is equal to the angle 0 (Θ = β), the roller portion 4 3 of the force follower 4 3 is the upper side of the force groove 4 2 4 2 C While sliding along the points shown in Figure 1 3

It is moved to the position of HI. As a result, the camber 4 3 mouth part 4 3 A is translated along with the translation bar 4 4 to the position of the line H-H and by the dimension b with respect to the initial position line F-F It is displaced in the axial direction of the rotary shaft 1 3.

The swash plate 2 1 has the same tilt angle in the forward or reverse direction.

When it is tilted with Θ (for example, the angle β, β), the angles α and β corresponding to the tilt angle 0 of the swash plate 2 1 become equal angles (α = / 3) opposite to each other, Axial variation of

,

The dimensions a and b corresponding to the scale are set to the same value (a = b).

Reference numeral 4 4 denotes a translation bar as a translation member that constitutes the displacement transfer part of the feedback mechanism 4 0, and the translation bar 4 4 is an illustration of FIG.

As shown in Fig. 3, it is slidably mounted in the opening 1 1 D of the casing main body 1 1 A via a guide member 4 5 described later, and the axial direction of the rotary shaft 1 3 (the axis shown in FIG. A translational movement along O-O) is performed. And the translation bar 4

4, as shown in FIG. 3, radially extend in the casing 1 1 in the radial direction of the rotating shaft 1 3 and also radially outward with respect to the control sleeve 3 6 and control the side surface of the swash plate 2 1 and control It is disposed between the sleeve 3 and 6

The translational bar 4 4 is provided with a cam follower 4 3 on one side in the longitudinal direction, and is integrated with the cam follower 4 3 A translational movement is given along the axis O-O of the rotation axis 1 3. Further, as shown in FIGS. 3 and 4, the other side of the translational bar 4 4 is a bifurcated fixing portion 4 4 A sandwiching the control sleeve 3 6 from the outside in the radial direction, the fixing portion 4 4 A is fixed to the outer peripheral side of the control sleeve 3 6 by fixing means such as a plurality of fixing screws or rivets.

That is, the translational bar 44 is held fixed at a fixed angle (for example, 90 degrees perpendicular to the control sleeve 3 6). And, the translational valve 4 4 4 is such that the roller portion 4 3 A of the cam follower 4 3 is axially displaced along the axis O-O of the rotation shaft 1 3.

Thus, when the swash plate 2 1 is tilted in the direction of arrow A in FIG. 2, the translation bar 4 4 shown in FIG. 3 and the cam follower 4 3 shown in FIG. A rotating shaft 1

Translate in the axial direction of 3 Then, the parallel movement of the translation bar 4 4 is directly transmitted to the control sleeve 3 6 at the fixed part 4 4 A side of the fixed part 4 4 A, and the control sleeve 3 6 is illustrated.

6 Move in the directions of arrows D and E in 6 along the axis line Ο _ 回転 of rotary shaft 1 3. As a result, the translational bar 4 4 performs feedback control for the regible track 3 4.

4 5 shows the opening 1 1 1 of the casing 1 1 as shown in FIG.

The guide member 4 5, which is a guy F member provided so as to cover the D, movably or slidably supports the lengthwise middle portion of the translation bar 4 4, and the translation bar 4 4 Swinging in the upper or lower direction (for example, circumferential direction of the cylinder jack 14) or vibration by gausse or the like is suppressed. As a result, the guide member 4 5 is in translation, and 4 4 is in rotation.

It compensates for the smooth translation (translational motion) in the 13 axis direction. Reference numeral 4 6 denotes a pilot pump which generates displacement control pressure. The pilot pump 4 6 is driven to rotate together with the hydraulic pump 1 by the prime mover 2 shown in FIG. Figure

The hydraulic oil is drawn from inside the tank 4 7 shown in 3 and the pressure oil for displacement control is discharged into the control pipe 4 8 A.

In this case, the pressure of the pressure oil discharged from the piped pump 46 is maintained at a sufficiently lower pressure than the discharge pressure of the hydraulic pump 1 by the low pressure relief valve 4 9. . The control line 4 8 B is for Reguire 34 3 supply and discharge port 3 5

It is provided between B and a forward / reverse switching valve 5 1 described later.

5 OA and 50 B are other control lines for supplying and discharging the tilt control pressure to the fluid pressure chambers 32 B and 33 B of the tilt ovens 32 and 33, respectively. As shown in Fig. 3 and Fig. 10, A and 50 B are connected to the control line 4 8 through the back and forth switching valve 51 as described later.

It is switched and connected to A and 4 8 B.

5 1 is control line 4 8 A, 4 8 B and control line 5 0 A, 5

It is a forward / reverse switching valve as a direction switching valve provided between 0 B and 10 B. This forward and reverse switching valve 51 has left and right solenoid parts 51 A and 51 B as shown in FIG. 3 and FIG. 10, and for example, a switching lever (not shown) in the driver's cab The operator can manually switch the vehicle from the stop position (a) to the forward position (b) or the reverse position (c).

And, in the state where the forward / reverse switching valve 51 is switched from the stop position (a) to the forward position (b), the operator moves the pilot pedal 5 2 A described later and the pilot pump is operated. The control pressure of 4 6 force, etc. is supplied to the hydraulic pressure chamber 3 3 B of the tilt angle 3 3 through the control line 4 8 A, 5 OA. Also, at this time, from the fluid pressure chamber 32 B of the tilting actuator 32 to the tank 4 7 via the control pipelines 50 B and 4 8 B, etc. Exhausted. Thus, the tilting piston 3 3 C of the tilting actuator 3 3 drives the swash plate 2 1 to tilt in the direction of arrow A in FIG.

,

On the other hand, when the reverse switching valve 51 is switched from the stop position (a) to the reverse position (c), the tilting from the pipe opening pump 46 in response to the depression operation of the traveling pedal 52A. The rolling control pressure is tilted through control lines 4 8 A, 5 0 B.

It is supplied to 3 2 hydraulic pressure chambers 3 2 B. In addition, the hydraulic pressure chamber 33 of the tilting valve 3 3 3 B has a control pipe 5 0 A, 4

The tilt control pressure is tanked via 8 B, regulator 34 and so on.

4 Discharged to the 7 side. As a result, the tilting piston 3 2 C of the tilting gear 3 2 drives the swash plate 2 1 to tilt in the direction of arrow B in FIG. 10.

In this way, the forward / backward switching valve 51 is provided between the register 31 4 and the tilting lever 32 3 3 3 to move forward from the vehicle stop position (a) to the forward position (b) Alternatively, by switching to the reverse drive position (c), the direction of supply and discharge of the tilt control pressure to the tilt actuator 3 2 and 3 3 is switched, and the swash plate 2 1 is switched according to the tilt control pressure. It is driven to tilt from the neutral position in the forward and reverse directions.

5 2 denotes a travel operation valve as a command means provided on the cab side of the wheel type vehicle, and a travel pedal 5 2 A corresponding to an accelerator pedal of the vehicle is attached to the travel operation valve 5 2. It is done. And, the operator of the vehicle is traveling pedal

5 2 When stepping on A, pass the command pressure line 5 3 and send a command to the hydraulic piping section 3 8 of the register 3 4. The pilot pressure is supplied as the issue number, and the traveling speed of the vehicle is variably adjusted as described later.

The traveling hydraulic circuit of the wheel type working vehicle provided with the variable displacement swash plate type hydraulic pump 1 according to the present embodiment has the configuration as described above, and its operation will be described next.

First, stop the forward / reverse switching valve 5 1 shown in Figure 10

In the state of (a), the control lines 5 0 A and 5 0 B are both connected to the control line 4 8, and the tilting angle 3

Since the 2 and 3 3 hydraulic chambers 3 2 B and 3 3 B are kept at the same pressure, the swash plate 2 1 is held at the zero tilt angle neutral position.

Therefore, each piston 16 reciprocates within each cylinder 1 5 of cylinder block 1 4 even if the prime mover 2 rotationally drives the rotary shaft 1 3 and rotates the cylinder head 1 4. The supply and discharge passages 1 2 A and 1 2 B of the hydraulic pump 1 are in the same pressure state, and the pressure through the main lines 3 A and 3 B to the hydraulic motor 5 shown in FIG. 1 does not move. Oil supply and discharge will be suspended

Next, it is assumed that the vehicle operator switches the forward / reverse switching valve 51 from the stop position (a) to the forward position (b). On this occasion, when the Operel club stepped on the running pedestal 52 A, the pressure oil from the pilot pump 46 was inclined through the control pipelines 4 8 A, 5 OA. It is supplied to 3 3 pressure chambers 3 3.

Also, at this time, by the stepping operation of traveling rudder 5 2 A, the hydraulic pressure pipe 5 3 to the regu

□ The mouth pressure is supplied toward the end 3 8. This depends on the valve housing 3 5 of the valve 1 3 4 The spool 37 is slidingly displaced in the axial direction according to the pilot pressure, and the regi- cal valve 34 is switched from the neutral position (I) shown in Fig. 10 to the switching position (II).

For this reason, the control line 4 8 B is connected to the tank 4 7 through the drain chamber in the register 1 34 3 and the casing 1 1, and the tilting line 3 2 3 2 The pressure oil in the fluid pressure chamber 32 B is discharged to the tank 4 7 side through the control pipelines 50 B and 48 B, the regu- lator 34 and so on. As a result, the tilting piston 3 3 C of the tilting lever 3 3 tilts and drives the swash plate 2 1 in the direction of arrow A in FIG. 10.

Then, when the swash plate 21 is tilted in the direction of arrow A, each piston 16 is tilted as the cylinder block 14 rotates integrally with the rotary shaft 13. The reciprocating motion is repeated in each cylinder 1 5 of the cylinder block 1 4 with a stack amount (displacement volume) corresponding to the angle 0. Therefore, for example, the hydraulic pump 1 discharges the pressure oil from the supply / discharge passage 12 A while drawing oil from the supply / discharge passage 12 B into the cylinders 15.

As a result, in the closed hydraulic circuit 4 for traveling shown in FIG. 1, the pressure oil flows in the main pipelines 3 A, 3 B along the direction of arrow A 1, and the hydraulic motor 5 for traveling is It can be driven to rotate by supplying and discharging pressure oil. Then, the rotational output of the hydraulic motor 5 is transmitted to the wheels 7 and 7 of the wheeled working vehicle via the reduction gear 6 and rotationally drives each of the wheels 7, for example, in the forward direction. Can be driven at a speed corresponding to a tilt angle of 0.

On the other hand, it is assumed that the forward / reverse switching valve 51 is switched from the stop position (a) to the reverse position (c). Also at this time, if you depress the traveling pedal 5 2 A and operate it, the Regiyu 1 34 will be shown in Figure 1 It is switched from the neutral position (I) shown in 0 to the switching position (II). Then, the pressure oil from the pilot pump 46 is supplied to the fluid pressure chamber 32 B of the tilting valve 32 through the control line 48 A, 5 OB. In addition, the pressure oil in the hydraulic pressure chamber 3 3 B of the tilting gear 1 3 3 is discharged to the tank 4 7 side via the control pipelines 5 0 A, 4 8 B, the regi Be As a result, the swash plate 21 can be driven to tilt in the direction of arrow B in FIG. 10 by the tilting piston 32 C of the tilting plate 32.

In this case, pressure oil can be circulated along the direction of arrow B1 in the closed hydraulic circuit 4 for traveling shown in FIG. 1, and the hydraulic motor 5 for traveling is rotationally driven in the same direction. Thus, for example, while the rotational output of the hydraulic motor 5 is transmitted to the wheels 7 and 7 of the wheeled working vehicle via the reduction gear 6, for example, a speed corresponding to a tilt angle 0 of the working vehicle in the reverse direction. It can drive and drive.

Here, when the swash plate 2 1 is tilted in the positive direction (direction A) from the neutral position, one of the pair of supply and discharge passages 12 A and 12 B has high pressure. Thus, the swash plate 2 1 receives the resultant force fl of the hydraulic reaction force from each piston 16 at the position of the resultant force application point k 1 shown in FIG.

However, for the first main static pressure bearing portion 2 2 A provided on the leg portion 2 1 A of the swash plate 2 1 and the first auxiliary static pressure bearing portion 2 2 C provided on the leg portion 2 1 B The high pressure oil is led from the supply and discharge passage 1 '2 A through the common oil passage 24' of the oil guiding passage 24 'and the branched oil passage 24' B and 24 C. For this reason, the first main static pressure bearing portion is disposed between the tilt support surfaces 20 A and 20 B of the swash plate support 20 and the legs 2 1 A and 2 1 B of the swash plate 2 1. A separation force fa is generated by the 2 2 A, and a separation force fc is generated by the first auxiliary static pressure bearing portion 2 2 C. Occurs.

Then, as shown in FIG. 5, the first main static pressure bearing portion 22 A is positioned at a distance L a from the resultant force acting point k 1 of the hydraulic reaction force received by the swash plate 21 from each piston 16 as shown in FIG. The first auxiliary static pressure bearing portion 22C is disposed at a position where the distance Lc (Lc> La) from the combined force application point kl.

Therefore, with respect to the resultant force fl of the hydraulic reaction force that the swash plate 2 1 receives from each piston 16, the separation force fa due to the first main static pressure bearing portion 2 2 A and the first auxiliary static pressure bearing The separation force fc of Part 22 C is set to satisfy the following equations (1) to (4). As a result, the resultant force fl of the hydraulic reaction force is balanced with the separating forces fa and fc, and the tilt support surfaces 20 0 A and 20 B of the swash plate support 20 and the legs 2 of the swash plate 2 1 The contact surface between 1 A and 2 1 B can be maintained in a lubricated state.

That is, the separation force fa due to the first main static pressure bearing 22 A and the separation force fc due to the first auxiliary static pressure bearing 22 C are, for example, swash plates tilted in the positive direction from the neutral position. It is set so that the following relationship is satisfied for the resultant force fl of the hydraulic reaction force received from each of the pistons 21 by 2 1. .

f 1 = f a + f c (1)

Further, the resultant force f 1 received by the swash plate 2 1 at this time is expressed by the following equation from the relationship between the pressure P due to the hydraulic reaction force and the pressure receiving area S 1.

f 1 = S 1 X P (2)

And assuming that the same pressure P acts on the first main static pressure bearing 22 A and the first auxiliary static pressure bearing 22 C, the main static pressure bearing 22 A is Since the auxiliary bearing 2 2 C has an effective bearing area S a and an effective bearing area S c (S c <S a), the following equations (1) and (2) are obtained. Seki The person in charge will be guided.

S 1 = S a + S c (3)

Further, the separation force fa (effective bearing area S a) due to the first main static pressure bearing portion 22 A acts on the position from the combined force application point k 1 to the distance L a, and the first auxiliary static pressure The separation force fc (effective bearing area S c) due to the bearing portion 2 2 C acts on a position where the distance L c is from the combined force application point kl. For this reason, the moments of the separation forces f a and f c with respect to the combined working point k l are set to satisfy the following relationship.

L aX S a = L cX S c (4)

As a result, against the resultant force fl of the hydraulic pressure reaction force that the swash plate 2 1 receives from each piston 16, the separation force fa of the main static pressure bearing portion 2 2 A and the auxiliary static pressure bearing portion 2 2 C The balance force with the separation force fc of the swash plate 2 1 can be balanced, and the legs 2 1 A and 2 1 B of the swash plate 2 1 are lifted from the tilt support surfaces 2 OA and 20 B of the swash plate support 20. As a result, it is possible to prevent tilting and separation.

As a result, the pressure oil introduced into the hydrostatic bearing 2 2 A, 2 2 C can be prevented from leaking to the outside, and the legs 2 1 A, 2 1 B of the swash plate 2 1 and the swash plate support 2 Lubrication can be maintained between 0 and the tilt bearing surfaces 2 0 A and 2 0 B. And, the tilting movement of the swash plate 21 can be stabilized, and the tilting drive force by the tilting actuators 32 and 33 can be reduced.

On the other hand, when the swash plate 2 1 is tilted in the reverse direction (direction B) from the neutral position, the swash plate 2 1 is located at the position of the resultant force application point k 2 shown in FIG. It receives the resultant force f 2 of the hydraulic reaction force from. Then, with respect to the resultant force f 2 at this time, the separation force f b and the second auxiliary static pressure by the second main static pressure bearing portion 2 2 B. The separation force fd due to bearing 2 2 D is set to satisfy the following relationship.

f 2 = f b + f d (5)

Further, the resultant force f 2 received by the swash plate 2 1 at this time is expressed by the following equation from the relationship between the pressure P due to the hydraulic reaction force and the pressure receiving area S 2.

f 2 = S 2 X P (6)

And assuming that the same pressure P acts on the second main static pressure bearing 22 B and the second auxiliary static pressure bearing 22 D, the main static pressure bearing 22 B is Since the auxiliary static pressure bearing portion 2 2 D has an effective bearing area S b and an effective bearing area S d (S d <S b), the following relationship is derived from the above equation (5) .

S 2 = S b + S d (7)

In addition, the separation force fb (effective bearing area S b) due to the second main static pressure bearing portion 2 2 B acts at a distance L b from the force application point k 2, and the second auxiliary static pressure The separation force fd (effective bearing area S d) due to the pressure bearing portion 2 2 D acts on a position at a distance L d from the combined force application point k 2. For this reason, the moments of the separation forces f b and f d with respect to the combined working point k 2 are set so as to satisfy the following relationship.

L bx S b = L dx S d (8)

As a result, with respect to the resultant force f 2 of the hydraulic pressure reaction force that the swash plate 2 1 receives from each piston 16, the separation force f b of the main 'static pressure bearing portion 2 2 B and the auxiliary static pressure bearing portion 2 2D can be balanced with the separation force fd, and the legs 2 1 A and 2 1 B of the swash plate 2 1 float from the tilt support surfaces 2 OA and 2 OB of the swash plate support 20. Can be prevented from tilting or separating. As a result, even when the swash plate 21 is tilted in the reverse direction from the neutral position, the pressure oil introduced into the static pressure bearing portions 2 2 B and 2 2 D can be prevented from leaking to the outside, and The legs of the board 2 1 2 1 A

2 1 B and the tilt support surface 2 0 A 2 0 B of the swash plate support 2 0 can be maintained in a lubricated state, and the tilt operation of the swash plate 2 1 is stabilized, and the tilt motion can be maintained. The tilting drive force by 3 2 and 3 3 can also be reduced.

However, the traveling speed of the vehicle when the vehicle moves forward or backward is determined by the discharge amount (flow rate) of the pressure oil from the hydraulic pump 1, and this discharge amount is determined according to the tilt angle 斜 of the swash plate 21. It is increased and decreased. And, unless feedback control is performed on the capacity control valve, Reg. 3 4 according to the tilt angle 0 of the swash plate 2 1, the tilt angle 6 of the swash plate 2 1> (ie, It is difficult to control the running speed of the vehicle stably only by stepping on the running pedal 5 2 A

Therefore, in the present embodiment, the feedback mechanism 40 is provided between the control slip 36 of the control panel 34 and the side surface of the swash plate 21. This feedback mechanism When the swash plate 2 1 is driven to tilt in either the positive direction or the reverse direction from the neutral position at a tilt angle of 0, the regulation action of the swash plate 2 1 is performed. Let's follow

-E3 34 is configured to perform feedback control.

And this fid-no, 'cucking mechanism 40 is formed on the side surface of the swash plate 2 1 (the side surface of the leg 21 B) and is approximately' V 'based on the axis 0-0 of the rotation shaft 13 A cam groove 4 2 having a U-shaped curved groove or a U U-shaped concave groove, and a roller portion 4 3 A in sliding contact with the cam groove 4 2 The cam follower 4 3 converted into and extracted, and the axial displacement of the rotating shaft 1 3 due to the axial displacement taken out by the cam follower 4 3 It consists of a translation bar 4 4 which translates in the direction of arrow. And, this translational valve 4 4 is configured to transmit the axial displacement due to the force transfer force 3 3 3 to the fixing portion 4 4 A on the tip side to the control slide 3 6

In this case, when the swash plate 21 is in the neutral position as shown in FIG. 1 1, the cam groove 4 2 on the swash plate 2 1 side extends from the center of rotation to the axis O— O of the rotation shaft 13. An intermediate groove portion 4 2 A disposed at the position of the dimension R a (R a <R) which is most widely separated, and an oblique downward direction toward the tilting center C from the position of the intermediate groove portion 4 2 A And an upper inclined groove 4 2 C extending obliquely from the middle groove 4 2 A toward the inclination center C. There is. And, the entire cam groove 42 is formed on the side surface of the swash plate 2 1 as a concave groove bent in a substantially "V" shape or "U" shape at the position of the intermediate groove portion 42A.

In addition, the fixed part 4 4 A of the translation bar 4 4 and the control sleeve 3

Since 6 is held, for example, in a vertically fixed state, the roller portion 4 3 A of the force follower 4 3 moves in the direction orthogonal to the axis O-O of the rotation shaft 1 3 (misalignment) The structure is regulated so that only axial displacement along the axis O-O is permitted.

The roller portion 4 3 A of the cam follower 4 3 is disposed at a position where the swash plate 2 1 is in sliding contact with the intermediate groove portion 4 2 A when the swash plate 2 1 is in the neutral position of zero tilt angle. And, when the swash plate 2 1 is tilted in the direction of arrow A (positive direction) from the neutral position, the roller portion 4 3 A slides along the lower side inclined groove portion 4 2 B, When the plate 21 is tilted from the neutral position in the direction of arrow B (reverse direction), it slides along the upper inclined groove portion 4 2 C. Therefore, when the swash plate 2 1 is tilted from the neutral position in the direction of arrow A (positive direction) as shown in FIG. 12 and the tilt angle 0 is the angle α (a = a), the cam follower 4 3 mouth part 4 3 A is slid to the position of point G 1 along the lower inclined groove 4 2 B of the cam groove 4 2, and the translation bar 4 4 is cam fo

Position of line G — G shown in Figure 1 2 together with 3 3

(Translational movement)

And the line G 1 G passing through the point G 1 at is from C to the dimension R b. On the other hand, when the swash plate 2 1 is in the neutral position, the translation block 4 4 is disposed at the initial position along the line F-F, and the line F-F at this time is the center of tilt of the swash plate 2 1 From C to dimension R a. According to this, 4 4 is the initial position line F _ F from line G — G position Axis 1

The amount of axial displacement when displaced in the axial direction of 3

It can be determined as the dimension a by the equation (9).

a = R a-R b (9)

On the other hand, the swash plate 2 1 is tilted from the neutral position in the direction of arrow B (reverse direction) as shown in FIG. 13, and the tilt angle が is the angle β

When (Θ = β), the cam groove 4 3 has a rib 4 3 and the cam groove 4 2 has a point along the upper inclined groove 4 2 C of the cam groove 4 2.

It is slid to the H 1 position, and the translation bar 4

It can be translated to the position of line H-H shown in Fig. 13 together with 4 3.

And also for the line H 1 H that passes through the point H 1 in this case, since the parallel bar 4 4 is at the initial position line F − F from the tilting center C to the position R b from the tilting center C The amount of axial displacement when displacing in the axial direction of the rotary shaft 13 up to the position of the line H 1 H can be determined as the dimension b by the following equation (10). b = R a-R b (1 0)

As shown in the figure, the roller portion 4 3 A of the cam shaft D 3 3 sliding contact with the force groove 4 2 on the swash plate 2 1 side has the swash plate 2 1 with the cam groove

When tilting forward or backward with 2, swash plate

The tilting movement of 2 1 can be taken out by converting it into a translation along the axis O-O of the rotation axis 1 3, an axial displacement of 14 4 (for example, a displacement of a dimension a b). And, the translational bar 4 4 can transmit the axial displacement at the same time to the control sleeve 3 6 as the same axial displacement by means of the fixed part 4 4 A.

Therefore, according to the present embodiment, even when the variable displacement swash plate type hydraulic pump 1 is connected to the hydraulic motor 5 using the hydraulic pressure closed circuit 4 illustrated in FIG. The swash plate 2 1 can be tilted from the neutral position in the forward and reverse directions, respectively, to control the discharge amount (flow rate) of the pressure oil in both directions, and the swash plate 2 1 can be used during forward or reverse travel of the vehicle. Speed control can be performed smoothly according to the tilt angle of the motor.

In addition, the regu- lator valve 34, which functions as a displacement control valve, can be configured by a hydraulic servo valve of a simple structure having a spool 3 7 in the control sleeve 3 6. As a result, the tilt control device consisting of the tilt control valves 32 and 33, the regulator 34 and the feedback mechanism 40 can simplify the whole structure. The number of parts can be reduced to improve the workability at the time of assembly, etc.

In addition, since the forward and reverse switching valve 51 is provided between the regulator 34 and the tilting actuator 32 and 33, the tilting control including the regulation 34 is performed as follows. The entire structure is simplified compared to the prior art, and productivity is improved. It is possible to reduce costs etc. In addition, the tilt control device of the hydraulic pump 1 is not limited to the hydraulic closed circuit 4 illustrated in FIG. 1, and even if it is applied to a so-called hydraulic open circuit, pressure oil is supplied to the hydraulic motor such as hydraulic motor. can do . Therefore, the tilt control device of hydraulic pump 1 can be applied to both hydraulic closed circuit and open circuit, and it can improve versatility, improve productivity, reduce cost and so on. It is possible to

Also, in the present embodiment, the tilt support surfaces 20 A and 20 B of the swash plate support 20 and the legs 2 1 A and 21 of the swash plate 2 1.

A hydrostatic bearing 2 2 (hydrostatic bearing 2 2 A 2 2 D) is provided between B and B, and the hydrostatic bearing 2 2 A 2 2 D is provided with a pair of supply and discharge passages 1 2 A, 1 2 B force is used to guide the high pressure hydraulic oil. Therefore, the tilt support surface 20 0 2 0 B and the legs

A separation force (for example, separation force fafb, fc, fd in FIG. 5) is generated by the static pressure bearing part 2 2 A 2 2 D between 2 1 A and 2 1 B, and the tilt support surface 2 0 A, 2 0 B and leg

The contact surface between 2 1 A and 2 1 B can be maintained in a lubricated state

As a result, the separation force fa, fc (separation force fbfd) due to the main static pressure bearing portion 2 2 A 2 2 B (auxiliary static pressure shaft receiving portion 2 2 C 2 2 D) is obtained for each swash plate 21 The static pressure bearing 22 composed of the static pressure bearing portion 2 2 A 2 2 D can be maintained in a well-balanced state with respect to the resultant force f 1 (the resultant force f 2) of the hydraulic reaction force received from 16. And stable bearing performance can be exhibited.

As a result, the application of the present invention is limited to the variable displacement swash plate type hydraulic pump 1 used for HST etc. <For example, a hydraulic motor etc. in which the rotation shaft rotates in the forward or reverse direction The present invention can be easily applied to a hydraulic rotary machine or the like in which a pair of supply and discharge passages are reversibly switched to high and low pressure, so that the versatility as a hydraulic rotary machine can be enhanced and productivity can be improved. Cost reduction can be achieved.

Also, as shown in FIG. 5, the first and second main static pressure bearing portions 22 A and 22 B are received by the swash plate 21 from the respective pistons 16. , K 2 are placed close to the position. For this reason, it is possible to bring the resultant force acting point k l, k 2 close to the acting point of the separating force f a, f b by the main static pressure bearing portions 2 2 A, 2 2 B.

Then, by bringing the resultant point of action kl, k 2 close to the point of action of the separation force fa, fb, a moment acting on the swash plate 2 1 (for example, the reference point kl, k 2 is referred to As a result, the first and second auxiliary static pressure bearing units 2 2 C 2 2 D can reduce their effective bearing areas S c and S d. It is possible to reduce the size of the entire hydraulic pump 1 including the swash plate 2 1.

In addition, the leg portions 21A and 21B of the swash plate 21 are separated from the rotary shaft 13 in the radial direction from the auxiliary static pressure bearing portions 22D and 22C, respectively. The second slide bearing 2 3 A 2 3 B is provided. For this reason, the first and second sliding bearings 2 3 A,

2 3 B is the stability of the swash plate 2 1 even when the lance plate or the lance changes due to pressure fluctuation on the supply / discharge passage 1 2 A, 12 B side, etc. In addition, the first and second slide bearings 2 3 A 2 3 B slide with a small surface pressure on the tilt support surfaces 2 OA and 20 B of the swash plate support 20. As a result, the sliding bearing parts 2 3 A, 2 3 B are in contact with the leg parts 2 1 A, 2 1 of the swash plate 2 1. B and tilt support surface 2 swash plate support 2 0 OA,

The contact pressure can be reduced, and wear and the like on the contact surface between the two can be suppressed, and reliability and life can be improved.

On the other hand, between the first main static bearing 2 2 A, the first auxiliary static pressure bearing 2 2 C and one of the supply and discharge passages 12 A, a common oil path 24 A and a branch oil are provided. Routes 2 4 B and 2 4 C are provided. Also, another common oil path 25 A and a branch are provided between the second main static pressure bearing 22 B and the second auxiliary static pressure bearing 22 D and the other supply / discharge passage 12 B. Oil passages 2 5 B and 2 5 C are provided and common oil passages 2 4 A and 25 A in the middle are a common throttle

It is assumed that 2 6 and 2 7 are provided.

Therefore, even if the hole diameter (diaphragm diameter) of the common throttles 2 6 and 2 7 is formed relatively large, the auxiliary static pressure bearing portions 2 2 A and 2 2 B and the auxiliary The amount of pressure oil supplied to the hydrostatic bearing 2 2 C, 2 2 D can be well adjusted, and there is a possibility that the common throttle 2 6, 2 7 may be blocked (heavy clogging) by foreign matter such as dust and the like. To improve the reliability of the equipment.

Also, in the case where micro clearances exist around hydrostatic bearing 2 2 A to 2 2 D, the effect of suppressing leakage of pressure oil through these clearances by means of common throttles 2 6 and 2 7 is As a result, the processability of the entire apparatus can be improved, productivity can be improved, and cost reduction can be achieved.

In addition, separate throttles 2, 8, 29 and 3 0 3 1 independent of each other are provided in the middle of each branched oil passage 2 4 B, 2 4 C, 2 5 B and 2 5 C, respectively. For this reason, the individual throttles 2, 2 9, 3 0 3 1 are pressure oil to be supplied to the main static pressure bearing portions 2 2 A and 2 2 B and the auxiliary static pressure bearing portions 2 2 C and 2 2 D. The amounts can be adjusted independently of one another, and the separation force fa, fb, fc, fd of the swash plate 2 1 by these static pressure bearing portions 2 2 A to 2 2 D These can be easily increased or decreased according to the amount of pressure oil flowing through the individual throttles 2 8 to 3 1.

Therefore, the resultant force f l, f 2 of the hydraulic pressure reaction force that the swash plate 2 1 receives from each piston 16 and the static pressure bearing portions 2 2 A, 2 2 B,

According to the separation forces fa, fb, fc and fd by 2 C and 22 D, the balance of the moment acting on the swash plate 21 can be enhanced, and the tilt operability of the swash plate 2 1 The stability can be improved, and the reliability and life of the swash plate type hydraulic pump 1 can be improved.

Next, FIGS. 14 to 16 show a second embodiment of the present invention. A feature of the present embodiment is that the main static pressure bearing portion and the auxiliary static pressure bearing portion provided on the leg portion of the swash plate are mutually separated in the circumferential direction along the convex curved surface of the leg portion; It consists of a configuration in which an oil passage for introducing pressure oil to the receiving part is bored inside the swash plate. In this embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

In the figure, reference numeral 61 denotes a variable displacement swash plate type hydraulic pump employed in the present embodiment, and the hydraulic pump 61 is substantially the same as the hydraulic pump 1 described in the first embodiment. , Rotary shaft 1 3, Cylinder block 1 4, Multiple cylinders 1 5, Pistons 1 6, Screws 1 7, Valve plates 1 9, Swash plate supports 20 and Swash plates 2 1 etc. It is composed of

6 2 is a static pressure bearing employed in the present embodiment, and the static pressure bearing 6 2 is a tilt support surface 2 OA, 20 B of the swash plate support 20 and a leg portion 2 of the swash plate 2 1 It is provided between 1 A and 2 1 B. Here, in the hydrostatic bearing 6 2, pressure oil is led from the pair of supply and discharge passages 12 A and 12 B in substantially the same manner as the hydrostatic bearing 2 2 described in the first embodiment. According to the tilt support surface 20 A separation force (hydraulic force) is generated between A and 20 B and the legs 21 A and 2 IB, and the contact surface between the two is maintained in a lubricated state.

However, as shown in Fig. 15 and Fig. 16 in this case, the hydrostatic bearing 6 2 is located on the convex curved surface side of one leg 21 A at a position close to the through hole 21 D of the swash plate 21 The first main static pressure bearing part 6 2 A which is also formed, and the other leg 2 1 at a position close to the through hole 2 1 D

A second main static pressure bearing portion 6 2 B provided on the convex curved surface side of B and a leg spaced from the second main static pressure bearing portion 6 2 B in the circumferential direction of the leg portion 2 1 B Two first auxiliary static pressure bearing portions 6 2 C, 6 2 C and a first main static pressure bearing portion 6 2 A to a leg portion 2 1 B provided on the convex curved surface side of the portion 21 B. Spaced apart in the circumferential direction of the legs

2 second auxiliary static pressure bearing portions 6 2 D and 6 2 D provided on the convex curved surface side of 21 A,

The first and second main static pressure bearings 6 2 A and 6 2 B are shown by arrows in the directions A and B along the convexly curved surfaces of the legs 2 1 A and 2 1 B as shown in FIG. The planar shape is rectangular as shown in FIG. 16. Also, the first auxiliary static pressure bearing portions 6 2 C and 6 2 C are formed from the both sides of the second main static pressure bearing portion 6 2 B along the convex curved surface of the leg portion 2 1 B in the circumferential direction. They are disposed so as to be sandwiched, and are formed as oval-shaped concave grooves which thinly extend in the left and right directions on the convex curved surface of the legs 21 B.

In addition, the second auxiliary static pressure bearing portions 6 2 D and 6 2 D sandwich the first main static pressure bearing portion 6 2 A from both sides in the circumferential direction along the convexly curved surface of the leg portion 2 1 A As shown, each is formed as an oval-shaped concave groove which thins in the left and right directions on the convex curved surface of the leg 21A.

Also, the first of these hydrostatic bearings 62 A to 62 D Main static pressure bearing portion 6 2 A and the first auxiliary static pressure bearing portion 6 2 C,

What is 6 2 C? One water supply and discharge passage via the oil guiding passage 6 4 described later

It is connected to 1 2 A. Also, the second main static pressure bearing 6

2 B and the second auxiliary static pressure bearing portion 6 2 D, 6 2 D are connected to the other water supply and discharge passage 1 2 B via an oil passage 6 5 described later.

And, the first main static pressure bearing portion 62 A is a hydraulic pressure that the swash plate 21 receives each piston 1 6 on one side in the radial direction of the through hole 21 D (right side in FIG. 16). It is placed at a position close to the resultant force action point k 1 of the reaction force. Also, the second main static pressure bearing portion 6 2 B is a swash plate 2 on the other side (left side in FIG. 1 6) of the through hole 2 1 D in the radial direction.

Reaction force acting point k of hydraulic reaction force that 1 receives from each screw 1 6

It is located near 2 \.

Even in the present embodiment, the main static pressure bearing portion 6 2 A,

6 2 B, the effective bearing area of the auxiliary static pressure bearing portion 6 2 C, 6 2 D is the main static pressure bearing portion 2 2 A, 2 described in the first embodiment.

2 B, It is set to the area almost the same as the auxiliary static pressure bearings 2 2 C and 2 2 D

Reference numerals 6 3 A and 6 3 B denote first and second slide bearings provided on the legs 2 1 A and 2 1 B of the swash plate 2 1, and the first and second slide bearings 6 3A and 6 3 B are configured substantially the same as the slide bearing portions 2 3 A and 2 3 B described in the first embodiment.

6 4 is an oil passage for introducing pressure oil to the static pressure bearing portion 6 2 A, 6 2 C of the static pressure bearing 6 2, and 6 5 is a static pressure bearing portion 6 2 B, 6 2 of the static pressure bearing 6 2 The other oil introduction channel which leads pressure oil to D is shown. As shown in Fig. 1 4 to Fig. 1 6, static electricity bearings 6 2 A to 6 2 D are connected to a pair of water supply and discharge passages 1.

2 A and 1 2 B are connected to each other, and one of the oil passages 64 is one of the supply and discharge passages 12 A and the main static pressure bearing portion 62. A, It is provided between the auxiliary static pressure bearing portion 6 2 C. The other oil guiding passage 65 is provided between the other water supply and discharge passage 12 B, the main static pressure bearing portion 62 B, and the auxiliary static pressure bearing portion 62 D.

Here, one oil passage 64 is in communication with the supply / discharge passage 12 A on the side, and the first oil passage 64 A extends on the other side to the first main static pressure bearing portion 62 A (Fig. 1 4) and 2nd oil passage 6 4 B 3rd oil passage 6 4 C and the second oil passage drilled in the swash plate 2 1

4 oil passages 6 4 D 6 4 D and these second oil passages 6 4 B, third oil passages 6 4 C and fourth oil passages 6 4 D, 64 D is the first main hydrostatic bearing 6

2 A is linked to the first auxiliary static pressure bearing portion 6 2 C 6 2 C.

In this case, the second oil passage 64 B is opened in the first main static pressure bearing portion 62 A at one side as shown in Figs. 15 and 16, and the other side is the third. The fourth oil passage 6 4 D through the oil passage 6 4 C

It is in communication with the 4 D side and the 4th oil passage 6 4

The D 64 D is branched in a “V” shape, and its tip end side is opened to the first auxiliary static pressure bearing portion 6 2 C 6 2 C.

In addition, as shown in Fig.14 and Fig.16, the other oil passage 65 is in fluid communication with the supply and discharge passage 12B on the side and the other side is directed to the second main static pressure bearing portion 62B. The first oil passage 65 A which has been extended, and the second oil passage 65 B which is bored in the swash plate 2 1, the third oil passage

It consists of 6 5 C and the 4th oil passage 6 5 D, 6 5 D. And these second oil passages 65 B third oil passages 65 C and fourth oil passages 65 D, 65 D are auxiliary static pressure bearings for the second main static pressure bearing portion 62 B. It communicates with parts 6 2 D and 6 2 D. In this case, one side of the second oil passage 65 B opens into the second main static pressure bearing portion 62 B as shown in FIGS. 15 and 16, and the other side is the third one. It is in communication with one side of the fourth oil passage 65 D, 65 D via an oil passage 65 C. And, the fourth oil passages 6 5 D, 6 5 D are branched in a “V” shape, and the tip end side is opened to the second auxiliary static pressure bearing portion 6 2 D, 6 2 D ing.

6 6 is a diaphragm provided in the middle of the first oil passage 6 4 A, 6

7 shows another throttle provided in the middle of the first oil passage 65A. One of these apertures 6, 6 7 6

6 is to adjust the amount of pressure oil supplied from the supply and discharge passage 12 A to the first main static pressure bearing 6 2 A as shown in FIG. 14 in accordance with the diameter of the throttle (hole diameter). . Also, the other aperture 6

7 adjusts the amount of pressure oil supplied from the supply and discharge passage 12 B to the second main static pressure bearing portion 6 2 B in accordance with the diameter of the throttle (hole diameter).

In this case α one throttle 6 6 is the first main static pressure bearing 6

The amount of pressure oil supplied to 2A and the first auxiliary static pressure bearing portion 6 2 C 6 2 C is adjusted in common. The other throttle 6 7 is used to adjust the amount of pressure oil supplied to the second main static pressure bearing portion 62 B and the second auxiliary static pressure bearing portion 6 2 D, 6 2 D in common. is there.

Thus, even in the present embodiment configured as described above, it is possible to stabilize the tilt and movement of the swash plate 21 and to obtain substantially the same effect as that of the first embodiment. However, in the present embodiment, the oil passage in the swash plate 2 1

6 4 A 6 4 D, oil passages 6 5 B to 6 5 D are provided, so casing 1 1 and swash plate support 2

Simplified the pipeline structure of the first oil passage 6 4 A, 65 A provided at 0 Can improve the workability at the time of production, processing, etc.

., ■ / 1

In the first embodiment, the legs 2 of the swash plate 2 1 are used.

The case where main static pressure bearings 2 2 A and 2 2 B and auxiliary static pressure bearings 2 2 C 2 2 D are provided in 1 A and 2 1 B has been described by way of example α. However, the present invention is not limited to this, and the first and second main static pressure bearing portions and the first and second auxiliary static pressure bearing portions may be used, for example, the tilt bearing surface 2 0 A 2 of the swash plate support 20. It may be provided at 0 B

In addition, the first and second main static pressure shaft portions and the first and second auxiliary static pressure bearing portions are the tilt support surface 20 0 A, of the swash plate support 20.

It may be configured to be provided over both of 20 B and the legs 21 A and 21 B of the swash plate 21. And this point is the same as in the second embodiment.

Also, in the first embodiment, the feedback unit of feedback mechanism 40 that performs feedback control of the regu- lation track 34 by following the tilting operation of the swash plate 21 in the first embodiment. The force groove 4

The case where it is configured by 2 and the cam follower 4 3 has been described as an example. However, the present invention is not limited to this, and the conversion unit of the feedback mechanism may be configured using a mechanism other than the feedback mechanism.

In each of the embodiments, the travel control valve 52 is used as an external command means, and a pilot pressure corresponding to the amount of stepping operation of the travel pedal 52 A is used as a command signal. The case of supply to the regulator was described as an example. However, the present invention is not limited to this.

3 4 hydraulic piping section 3 8 is composed of electromagnetic proportional solenoid H etc. From the external command means, an electric signal corresponding to the amount of stepping operation of the traveling pedal 5 2 A is used as the command signal. Output It may be configured to

In each of the above-described embodiments, the case where the variable displacement swash plate type hydraulic pressure pumps 1 and 6 1 are applied to a traveling hydraulic circuit in a wheeled work vehicle such as a wheel loader is described as an example. did. However, the present invention is applicable not only to the hydraulic circuit for traveling but also to a hydraulic closed circuit for various applications such as a hydraulic circuit for turning, for example.

Further, in each of the above-described embodiments, the case where the variable displacement swash plate type hydraulic fluid rotating machine is applied to the swash plate type hydraulic pump 1 or 6 1 has been described as an example. However, the application object of the present invention is not limited to the variable displacement swash plate type hydraulic pump, and may be applied to, for example, a variable displacement swash plate type hydraulic motor and the like.

Further, the working vehicle to which the present invention is applied is not limited to the wheel loader. For example, a working vehicle called a wheel hydraulic shovel, a wheel hydraulic crane, a bulldozer, or a lift truck It can also be applied to work vehicles such as crawler hydraulic hydraulic shovels.

Claims

1. A cylindrical casing provided with a swash plate support on one side and a pair of supply and discharge passages on the other side, a rotary shaft rotatably provided on the casing, and an integral body with the rotary shaft The cylinder has a plurality of cylinders which are provided in the casing so as to rotate in the circumferential direction and which are axially spaced apart in the circumferential direction.

A plurality of pistons reciprocably fitted to each cylinder of the cylinder block, and a plurality of pistons mounted on the side of the projecting end of each of the pistons projecting from each of the cylinders. The surface side is a smooth surface for slidably guiding each of the shells, and the back side is a pair of leg portions.

A swash plate capable of being supported; a tilt control system for driving the swash plate by driving the swash plate by being provided and discharged from an outer part of the casing; and the swash plate A variable displacement swash plate type fluid pressure provided between each leg of the swash plate and the swash plate supporting portion and having a hydrostatic bearing communicating with the supply and discharge passage to keep the contact surfaces of the two in a lubricated state In the rotating machine,

The static pressure bearing includes a first main static pressure bearing portion provided on one leg side of the pair of legs and a second main static pressure bearing portion provided on the other leg side of the pair of legs. A main static pressure bearing portion, a first auxiliary static pressure bearing portion separated from the second main static pressure bearing portion and provided on the other leg side, and the first main static pressure bearing portion What is claimed is: 1. A variable displacement swash plate type hydraulic rotating machine characterized by comprising: a second auxiliary static pressure bearing portion provided on the side of the one leg portion apart from the second leg.

2. The first main static pressure bearing portion is disposed at a position close to the combined force action point of the hydraulic reaction force received by the swash plate from each screw at one side in the radial direction of the rotation shaft, and The main hydrostatic bearing of 2 is The variable displacement swash plate type liquid according to claim 1, wherein the swash plate is disposed at a position near the resultant force application point of the hydraulic reaction force received from each screw on the other side in the radial direction of the rotary shaft. Pressure rotary machine.

3. The swash plate is provided with a through hole located between a pair of legs and through which the rotary shaft is inserted with a gap, and the first and second main hydrostatic bearings include the first, second and third main static pressure bearings. The second invention is characterized in that it is disposed at a position closer to the hole than the auxiliary static pressure bearing section 2 and has an effective bearing area larger than that of the first and second auxiliary static bearing sections. Variable displacement swash plate type liquid pressure rotation 記載 3⁄4 ο described in 1

4 • The pair of legs has the first and second main static pressure bearing portions and the first and second auxiliary static pressure bearing portions at positions radially away from the rotation axis. 1 A variable displacement swash plate type hydraulic rotating machine according to SH claim 1 which is configured to have a second slide bearing portion.

5 • The first main static pressure bearing portion and the first auxiliary static pressure bearing portion are connected to each other through one oil supply / discharge passage of each of the supply / discharge passages.

,

The second main static pressure bearing portion and the second auxiliary static pressure bearing portion are in fluid communication with each other through the other oil supply and discharge passages of the respective port discharge passages. The variable displacement swash plate type hydraulic rotating machine according to claim 1, which is configured to communicate with each other.

6. The first main static pressure bearing portion and the first auxiliary static pressure bearing portion are connected to each other through an oil passage in one of the supply and discharge passages.

In the middle of the oil passage, the amount of pressure oil supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion is adjusted in common. The second main static pressure bearing portion and the second auxiliary static pressure bearing portion communicate with each other through the other supply and discharge passages of the respective supply and discharge passages through the other oil passage. In the middle of the other oil passage, the second main static pressure bearing portion and the second The variable displacement swash plate type hydraulic rotating machine according to claim 1, wherein another throttle is provided to commonly adjust the amount of pressure oil supplied to the auxiliary static pressure bearing portion of the second embodiment.

7. The first main static pressure bearing portion and the first auxiliary static pressure bearing portion communicate with one of the supply and discharge passages through the oil passage, the oil passage In the middle of this section, separate throttles are provided to adjust the amount of pressure oil supplied to the first main static pressure bearing section and the first auxiliary static pressure bearing section independently of each other. The main static pressure bearing portion and the second auxiliary static pressure bearing portion communicate with the other of the supply and discharge passages through the other oil passage, and the other oil passage In the middle of the above, another individual throttle is provided to independently adjust the amount of pressure oil supplied to the main static pressure bearing section of the HU eye 2 and the second auxiliary static pressure bearing section. A variable displacement swash plate type hydraulic rotating machine according to claim 1.

8. Between the first main static pressure bearing portion, the first auxiliary static pressure bearing portion and the one supply / discharge passage, one side communicates with the one supply / discharge passage and the other side is each static pressure A common oil passage extending toward the bearing, and a branch branched to each other on the other side of the common oil passage and separately connected to the first main static pressure bearing and the first auxiliary static pressure bearing. An oil passage is provided, and one side communicates with the other supply / discharge passage between the second main static pressure bearing portion, the second auxiliary static pressure bearing portion and the other supply / discharge passage, and the other side is The other common oil passage extending toward each of the static pressure bearing portions, and the second main static pressure bearing portion and the second auxiliary static pressure bearing portion which are branched from each other on the other side of the common oil passage. The variable displacement swash plate type hydraulic rotating machine according to claim 1, wherein another branch oil passage is provided, which is separately connected to the face of the vehicle.

9. In the middle of the common oil passage, from the one supply / discharge passage to the first main static pressure bearing portion and the second auxiliary static pressure bearing portion A common throttle for adjusting the amount of pressure oil supplied is provided, and the amounts of pressure oil supplied to the first main static pressure bearing portion and the first auxiliary static pressure bearing portion are independent of each other in the middle of the branch oil passage. Separate throttles are provided, and are supplied to the second main static pressure bearing portion and the second auxiliary static pressure bearing portion from the other supply / discharge passage in the middle of the other common oil passage. Another common throttle for adjusting the pressure oil amount is provided, and the pressure oil amount supplied to the second main static pressure bearing portion and the second auxiliary static pressure bearing portion in the middle of the other branch oil passage. The variable displacement swash plate type hydraulic rotating machine according to claim 10, wherein other individual throttling means are provided to adjust each independently of each other.

1 0. The variable displacement type according to claim 1, wherein the swash plate is configured to be driven to tilt from the neutral position at a tilt angle of zero to a positive direction and a reverse direction according to the tilting angle. Swash plate type hydraulic rotating machine

1 1. The casing consists of a relief valve with a spring in the control sleeve and controls the displacement control pressure supplied to and discharged from the displacement electrode according to an external command signal. Providing a feedback mechanism for feedback control of the control sleeve of the regi- tal track following the tilting movement of the swash plate;

The feedback mechanism

When the swash plate is in the neutral position, it is at the initial position on one side in the axial direction along the rotation axis. When the swash plate is driven in a forward direction or a reverse direction A converting unit for converting the tilting movement of the swash plate into axial displacement so as to displace toward the other side;

An axial displacement provided between the converting portion and the control sleeve of the regu 10. The variable displacement swash plate type hydraulic rotating machine according to claim 9, which is constituted by a displacement transmitting unit for transmitting to a control slip in the evening.