JPS58128477A - Hydraulic rotary machine - Google Patents

Abstract

PURPOSE:To reduce flow path resistance of fluid and improve mechanical efficiency by forming large diameter recesses in opposite ends of cylinders provided in a cylinder block of a hydraulic rotary machine used for a swash plate type hydraulic pump or the like. CONSTITUTION:Opposite ends of cylinders 22 provided in a cylinder block 21 are formed with large diameter recesses 23. And auxiliary piston portions 25 provided projectingly on a pressure plate 24 for pressing a valve plate 8 are fitted into said recesses 23. Thus, the diameter D of the auxiliary piston portion 25 can be made properly larger than the diameter d of the cylinder 22 so that groove width B of intake and exhaust ports 14, 15 provided in the valve plate 8 can be made large to reduce the flow path resistance of fluid flowing in the intake and exhaust ports 14, 15 and auxiliary cylinder 26 for improving machine efficiency and self-absorbing ability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic rotary machine used as a hydraulic pump or motor for a swash plate overflow, a slant lees house, etc.

FIGS. 1 and 2 show a swash plate type hydraulic bong f as a conventional hydraulic rotary machine.

In the figure, 1 is a casing, 2 is a rotating shaft provided within the casing 1 and supported by a bearing 3, and 4 is a cylinder member fixed to the rotating shaft 2 by means such as press fitting. The cylinder block 4 has a plurality of cylinders 15, 5... bored in its axial direction, and each cylinder 5
Inside is a piston 6 whose one end is supported by a swash plate (not shown).
are slidably inserted into each piston 6, and each piston 6 is connected to a rotating shaft 20.
It is caused to reciprocate by rotation.

Reference numeral 7 denotes a pressing plate as a valve plate pressure me mechanism which rotates together with the cylinder block 4. The pressing plate 7 has a sliding surface 7At whose one end is opened and is brought into sliding contact with the valve plate 8, and an auxiliary piston at the other end. 9.9#... are formed, and each auxiliary piston part 9 is fitted into each cylinder 5 of the cylinder block 4. Furthermore, communication passages 10 are bored in the axial direction of the skeleton auxiliary piston portion 9, and each communication passage 10 has an opening on the sliding surface 7AVCH of the pressing plate 7. Further, a spring seat 11 is provided in the middle of each communication path 10, and a spring 12 is stretched between the spring seat 11 and the end surface of the piston 6.

Next, the valve plate 8 has a sliding surface 8A on one side that contacts the sliding surface 7A of the pressing plate 7 W1, and the other side is fixed to the casing 1 by a pin 13. And the valve plate 8 has suction &-?
14 and discharge/-) 15 are drilled 9, and the suction/- port 14. The discharge ports 15 are always delayed to the iron man passage 16 and the discharge passage 17 bored in the casing 1, respectively, and are intermittently communicated with the communication passage 10 bored in the suppression plate 7 (second (see figure).

In addition, in the figure, 18.18. . . . is a sealing member provided between the auxiliary piston portion 9 and the cylinder 5.

The conventional swash plate hydraulic pressure switch has the above-described configuration, and when the rotating shaft 2 is rotated by a driving means (not shown) such as an engine, the cylinder block 4 rotates together with the suppressing plate 7. . For this reason, the cylinder block 4
The piston 6 is mounted on a swash plate that is inclined with respect to the zero rotation axis.
reciprocates within the cylinder 5, and the communication passage 10 that communicates with the cylinder 5 is intermittently connected to the suction port 14 or the discharge port of the valve plate 8. Since it communicates with 15, the 471 action is performed.

When the bonder is driven under a high load, the pressure inside the discharge port 14 becomes high. Therefore, a separating force is generated in the pressing plate 7 that tends to separate the pressing plate 7 from the valve plate 8. In response to this opening force, a pressing force is applied to the suppression plate 7 against the valve plate 8 by the spring force of the spring 12 and the fluid pressure acting on the end face of the auxiliary piston part 9 in the cylinder 5. By designing the pressing force to be larger than the above-mentioned separating force, the sliding surface 7A of the pressing plate 7
This prevents fluid from leaking between the valve plate 8 and the sliding surface 8A of the valve plate 8. Here, the groove width of suction/exhaust port 14°15 is b
When the diameter of the cylinder 5 is d, the above-mentioned separating force is determined by the groove width, and the pressing force is determined by the diameter d. Therefore, by making the groove width bt of the suction/discharge port 14, 15 as small as possible relative to the diameter d of the cylinder 15, the pressing force can be increased and excessive leakage of fluid can be prevented.

However, the prior art bonders described above have a number of drawbacks. First of all, the diameter of the communication passage 10 is limited by the groove width of the shedding 4-toe 14,15. Therefore, if the groove width b'f is made smaller, the flow resistance of the communicating passage 10 increases, pressure loss increases, and a large precious load is applied to the bonder, which reduces its mechanical efficiency. There was a drawback that the self-priming ability also decreased. Second, the high-pressure oil in the communication passage 10 does not flow into the discharge passage 17 even during the pump discharge stroke, and the volume of the communication passage 100 out of the compression due to the bulk modulus of the fluid is However, there is also the drawback that the volumetric efficiency of the bonder is reduced due to the apparent amount of leakage. Thirdly, since the auxiliary piston part 9 protrudes into the cylinder 5, the piston 6 has to be inserted into the piston 60 in order to avoid contact with the auxiliary piston part 9 at its top dead center position.
The stroke S is limited. Therefore, in order to make the piston 60 stroke sufficiently large, it is necessary to lengthen the cylinder axle 4 in the axial direction, which has the disadvantage of increasing the volume of the entire device. .

The present invention is an attempt to improve the above-mentioned nine drawbacks of the conventional technology, and its first purpose is to form a recess with a larger diameter than the cough cylinder at the end of the cylinder block at a position corresponding to the cylinder, and to form a recess in the suppression plate. By fitting the auxiliary piston formed in the recess into the recess and increasing the outer diameter of the auxiliary piston that determines the pressing force of the suppression plate against the valve plate, the load on the pump is reduced and mechanical efficiency is improved. It is an object of the present invention to provide a hydraulic rotary machine which has a good self-priming ability.

A second object of the present invention is to make it possible for the piston to enter the auxiliary cylinder by boring an auxiliary cylinder with a diameter larger than the diameter of the piston in the suppression plate, thereby reducing the dead volume and reducing the auxiliary piston/part. An object of the present invention is to provide a hydraulic rotary machine in which the piston stroke is not restricted by the piston stroke.Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 3 and 4.

In this figure, the same components as in FIGS. 1 and 2 are given the same reference numerals, and their explanations will be omitted. A recess 23 having a larger diameter than each cylinder 22 is formed in the cylinder protrusion 21 at a position corresponding to the end of each cylinder 22. On the other hand, a nine auxiliary piston part 25 protruding from the pressing plate 24 is fitted into the recess 23.The auxiliary piston part 25 is inserted into the pressing plate 24 through the auxiliary male piston part 25, which is larger than the diameter of the piston 60. Auxiliary cylinder with pore size /26
is drilled. The auxiliary cylinder 26 is opened in a sliding surface 24A of the press plate 24 that slides on the valve plate 8, and is intermittently communicated with the suction/exhaust port 14 or 15 provided on the valve plate 8. Therefore, the auxiliary cylinder 26 not only has the function of the communication ayu 10 in the prior art described above, but also has the function of the piston 6.
Since the cylinder 2 is prevented from entering the auxiliary cylinder 26 at its top dead center position, the cylinder 2
In the figure, 27 indicates a step 2A formed on the rotating shaft 2 and a step 24B of the pressing plate 24.
A nine disc spring disposed between the disc spring 27 presses the pressing plate 24 against the valve plate 8, and fluid pressure acts between the end face of the auxiliary piston 25 and the bottom wall of the recess 23 of the cylinder block 210. A gap δ is formed. 28 is a sealing member provided between the auxiliary piston portion 25 and the recessed portion 23.

The hydraulic rotating machine according to the present invention has the above-mentioned configuration,
In the case of a swash plate type hydraulic pump, there is no particular difference in its function as a pump from that in the prior art described above. However, since the pressing plate 24H is fitted into the recess 23 which has a larger diameter than the cylinder 22, the diameter of the auxiliary piston part 25, which determines the pressing force against the valve plate 8 by the pressing plate 24 together with the disc spring 27, is reduced. The diameter of the cylinder 220 can be increased as appropriate without being restricted by the diameter d.

Therefore, as the diameter of the auxiliary piston portion 25 is increased, the pressure receiving area formed on the end surface 25A of the auxiliary piston portion 25 increases dramatically, and a large pressing force can be obtained. Seismic amplitude B of the intake and exhaust ports 14 and 15 to be installed
Even if the separation force increases by increasing the thickness of the
4A can be prevented from leaking from between.

In this way, by increasing the groove width B of the intake/discharge port 14.15, the diameter of the auxiliary cylinder 26 can also be increased, so the flow resistance to the auxiliary cylinder 26 is significantly reduced, reducing pressure loss. can be done, tllyf
It is possible to increase the mechanical efficiency of the pump, improve the self-priming ability, and prevent the occurrence of capitation.

Next, since the diameter of the auxiliary cylinder 6 is larger than the diameter of the piston 6, the piston 6 can plunge into the auxiliary cylinder 26. Therefore, the lower stroke of the piston 6 can be set near its top dead center position, which opens to the intake/exhaust port 1415 in the auxiliary cylinder 26, without being restricted by the auxiliary piston 25. The stroke 111 of the piston 60 can be increased, and most of the fluid compressed in the cylinder 22 can be discharged into the discharge port 15. Although we have described the case where such a hydraulic rotary machine is used as a swash plate type hydraulic bonder, it can also be used as a hydraulic tanabata, and it can also be used as a pump or motor for other types of pumps and motors such as slant shaft temperature. Of course you can.

As described in detail above, according to the hydraulic rotating machine according to the present invention, firstly, the cylinder I bored in the cylinder pro
A recess with a diameter larger than that of each cylinder is formed at a position corresponding to the cylinder, and the auxiliary piston part protruding from the suppression plate is fitted into the recess, so that the flow path connecting the cylinder and the suction/exhaust port is Since the vibration amplitude can be increased, pressure loss due to flow path resistance can be reduced, and the mechanical efficiency of hydraulic rotating machines can be improved, as well as improved self-priming ability when used as a pump. can be achieved.

Second, an auxiliary cylinder with a diameter larger than the diameter of the piston that slides inside the cylinder is bored in the press plate, and the piston can be pushed into the auxiliary cylinder. By significantly reducing the amount of
By improving the volumetric efficiency of the hydraulic rotary machine, the volumetric efficiency can be extremely improved, especially during high pressure operation. Also,
Since the top dead center of the piston can be set near the opening to the suction/exhaust port in the auxiliary cylinder, the stroke of the piston can be increased, and the hydraulic rotating machine can be shortened in its axial direction. The entire device can be turned into a shed.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal sectional view of a hydraulic rotating machine according to the prior art, FIG. 2 is a sectional view taken in the direction indicated by the ■-■ arrow in FIG. 1, and FIG. 3 is a partial vertical sectional view of a hydraulic rotating machine according to the present invention. Figure 1 Figure 4 is Figure 3 w
-rt arrow shows the direction of the arrow. 2... Rotating shaft, 6... Piston, 8... Valve plate, 2
DESCRIPTION OF SYMBOLS 1... Cylinder/foy holder, 22... Cylinder, 23... Recessed part 124... Pressing plate, 25... Auxiliary piston part, 26... Auxiliary cylinder. Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 111 A cylinder fixed to the rotating shaft/
A plurality of cylinders are bored in the cylinder block with a distance rJPh in the axial direction, a piston is provided in each cylinder so as to be able to reciprocate, and a pressing plate is provided at the end of the cylinder block. Installation, the pressure plate is brought into sliding contact with the valve plate, resulting in hydraulic rotation +! In i, a concave portion having a diameter larger than that of each cylinder is formed at the end of the cylinder /f a at a position corresponding to the cylinder I, and the suppressing plate has an auxiliary piston portion that fits in each of the concave portions. 1, and an auxiliary cylinder is formed in the auxiliary piston portion to communicate between the cylinder and the intake/exhaust/-1 formed in the valve plate.
-Features hydraulic rotation. (2) A rotary shaft and a cylinder block fixed to the rotary shaft are connected to each other, and a plurality of cylinders are bored in the cylinder block at intervals in the axial direction. In a hydraulic rotating machine in which a piston is provided to be reciprocally movable, a press plate is attached to an end of the cylinder block, and the press plate is slidably abutted on a valve plate, the end sK of the cylinder block is forming a recess with a larger diameter than each cylinder at a position corresponding to the cylinder, forming an auxiliary piston part in the suppressing plate to fit into each recess, and drilling an auxiliary cylinder communicating with the cylinder; A hydraulic rotating machine characterized in that the diameter of the auxiliary cylinder is larger than the diameter of the piston.