JPH0811954B2 - Hydraulic engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a piston type hydraulic engine that can be used as a motor or a pump.

[Prior Art] The piston type hydraulic engine that has been widely used has
Due to mechanical friction and leakage of high-pressure liquid, there has been a problem of energy loss and wear of sliding parts, which shortens equipment life.

To improve this, there is a hydraulic engine described in JP-B-51-22644. This includes an eccentric shaft having an eccentric portion, a cylinder block that engages with the eccentric portion and radially forms a plurality of cylinders, and a piston that fits into each cylinder of the cylinder block and has a flat outer end surface. ,
A piston cap having a flat surface on which the outer end surface of the piston is in close contact, and an inflow passage and an outflow passage for the fluid that respectively open into recesses formed on both sides of the eccentric portion through the inside of the eccentric shaft, The pressure pocket provided on the outer end surface of the piston and the inner end of the piston are in fluid communication with each other, and the piston has a degree of freedom with respect to the cylinder block by fitting in a part of the piston. As described above, the hydraulic engine is provided with the restraint means that does not rotate. A high-pressure liquid column is formed radially on one side of the eccentric portion of the eccentric shaft, and the axial pressure is directly obtained by this liquid pressure, and the cylinder block and hollow piston for forming the liquid column are The static pressure balance is maintained almost completely.

[Problems to be Solved by the Invention] The improved hydraulic engine has excellent longevity and high performance in which problems due to wear of main parts are unlikely to occur, but the flow path of the rotating output shaft is improved. On the other hand, since a distributor for supplying and discharging the fluid is required, there is a problem that a leakage loss and a torque loss occur at this portion and an external dimension becomes large. In order to solve this problem, it is considered that the casing containing the eccentric shaft is housed in a separately formed outer case, and the casing side is rotated without rotating the eccentric shaft. However, there is a problem in that the manufacturing cost is increased due to the increase in weight and the weight.

[Means for Solving Problems] In order to solve the above problems, the present invention has the following configuration. That is, in the device described in JP-B-51-22644, the piston cap having a flat surface to which the outer end surface of the piston is closely attached is formed in a casing shape including a cylinder block, and the output shaft protruding to the outside is formed. The eccentric cover is formed integrally with the cap, a bearing is provided on the outer peripheral portion of the piston cap to hold the outer ring side of the main body case, and covers the rear end opening of the casing-shaped piston cap. The cover is integrally formed with the shaft, and the cover is provided with a fluid inlet / outlet communicating with the inflow passage and the outflow passage.

[Operation] The fluid supplied from the inlet provided in the cover is
The fluid is discharged to one of the recesses partitioned by the eccentric shaft, and the fluid in the other recess is discharged to the outside through the outflow passage. As a result, a rotational moment is generated between the eccentric shaft and the cylinder block, and the casing-shaped piston cap including the cylinder block is rotated together with the output / input shaft. Since fluid is supplied and discharged through an eccentric shaft that does not rotate, no special distributor is required.

[Examples] Examples described in the drawings will be described below.
In this hydraulic engine 1, a casing-shaped piston cap 3 is housed in a main body case 2, and a cylinder block 5 is provided inside thereof.

The cylinder block 5 is provided with a shaft chamber 6 having a circular cross-section in the center thereof with a slight eccentricity, and generally an odd number (five in the illustrated example) of radial cylinders 7 are radially formed around the shaft chamber 6. . Each cylinder has a piston 8
Are fitted. The piston 8 is provided with a piston ring 11 in order to prevent leakage of the fitting portion with the cylinder.
The contact length between the piston and the cylinder is smaller than its diameter in order to increase the degree of contact between the piston 8 and the piston cap 3.

A recess 13 that engages with the pin 12 is formed in the cylinder block 5, and the rotation of the cylinder block 5 is restricted. The pins 12 and the recesses 13 serve as restraint means for restraining the rotation of the cylinder block.

The outer end surface of the piston 8 has an inner flat surface of the piston cap 3 through a pressure pocket 15 which forms a hydrostatic bearing.
It is in contact with 3a. The pressure pocket 15 communicates with the inner end surface of the piston 8 by a through hole 16.

An eccentric shaft 20 having an eccentric portion 19 is rotatably fitted in the shaft chamber 6 of the cylinder block 5, so that the eccentric portion 19 forms concave portions 21, 21 'on both sides of the shaft chamber 6. It is partitioned. The eccentric shaft 20 is formed integrally with a cover 23 that covers the rear opening of the piston cap 3 formed in a casing shape, and the core part has flow paths 25, 25 communicating with an inlet / outlet port formed in the cover. 'Is provided. These two flow paths communicate with the flow paths 26, 26 'opening in the recesses 21, 21' at the eccentric portion, respectively. In addition, cover 2
The bolt 3 is fixed to the rear end surface of the main body case 2 by a bolt 28.

A bearing 30 is provided on the outer periphery of the piston cap 3,
The outer ring 31 of the bearing is fitted in the body case 2. An output / input shaft 35 is integrally projectingly provided on the front surface of the piston cap 3, and the input / output shaft 35 is provided in the front shaft hole 36 of the body case 2.
It is supported by a bearing 37 fitted in. A seal material 39 is provided at the opening of the shaft hole 36.

The hydraulic engine 1 can be used as both a hydraulic motor and a hydraulic pump, and its operation will be described below taking the case of operating as a hydraulic motor as an example. If a working fluid such as pressure oil is now introduced into the port 25a, the working fluid is guided through the flow passages 25 and 26 to the recess 21 formed on the side of the eccentric portion 19, and further to the cylinder block 5-5. It flows into A and B of the individual cylinders 7.

On the other hand, the working fluid filled in the cylinders D and E passes from the other recess 21 'through the flow passage 26' and the flow passage 25 'to the port 25a'.
Is discharged from the outside. At this time, the volumes of the cylinders A and B increase, and the volumes of the cylinders D and E decrease, and as a result, the cylinder block 5 rotates counterclockwise together with the piston cap 3 into which it is fitted, Rotate 35. Since the structure of the hydraulic engine 1 is symmetrical, the output / input shaft 35 rotates in the opposite direction by reversing the inlet and outlet ports of the working fluid. By rotating the input / output shaft 35 with another drive device, this device can be used as a pump.

Fig. 4 shows the basic configuration of this hydraulic motor.
The high-pressure oil introduced from the port provided at the end of the eccentric shaft 20 which is a fixed shaft enters the radial oil passage of the cylinder block through the distribution valve composed of the eccentric part 19 and the shaft chamber 6, and the piston Reach the edge. The high-pressure oil (H) column in the high-pressure section formed between the piston P (8 in FIG. 3) and the cylinder block M (5 in FIG. 3) directly finishes the eccentric shaft and the inner peripheral surface into a pentagonal shape. It works in cooperation with the piston cap S (3 in FIG. 1) that is set to generate torque. The piston cap S and the cylinder block M are constrained in a state in which their pentagonal surfaces are kept parallel by a constraining means constituted by a pin 12 provided on the cylinder block and a recess 13 provided on the piston cap side. . On the other hand, the eccentric shaft 20 is fixed, and the two chamfered portions of the eccentric portion 19 and the distribution valve portion formed by the cylinder block 5 also advance in phase with the rotation of the cylinder block 5 that rotates in synchronization with the piston cap 3. .

In this way, the high-pressure section area moves sequentially with the inflow and discharge of oil, and continuously generates torque. In this hydraulic engine, the piston and the cylinder block B can be perfectly statically balanced, and they do not participate in the force transmission by mechanical contact.

[Effects of the Invention] As described above, the hydraulic engine according to the present invention is
Since no force is transmitted by mechanical contact,
Solving various problems such as wear and friction of main parts, especially torque loss at start-up, slip stick at extremely low speed, etc., a hydraulic engine with extremely long life and high performance can be obtained.

Further, as compared with the same type as the conventional one, there is no distributor, so that there is a great advantage that no fluid / mechanical loss occurs in this part. Further, it is structurally compact, and in particular, the dimension in the longitudinal direction can be shortened to be thin, and the number of required parts can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a sectional view showing an internal structure of a piston cap, and FIG. 1 ... hydraulic engine, 2 ... main body case 3 ... piston cap, 5 ... cylinder block 7 ... cylinder, 8 ... piston 19 ... eccentric part, 20 ... eccentric shaft, 35 ... input / output shaft

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F04B 1/04 1/047 1/053 1/107 1/113

Claims (1)

[Claims] 1. An eccentric shaft (20) having an eccentric part (19), and a shaft chamber (6) engaging with the eccentric part at a central portion, and a plurality of cylinders (7) being radially arranged from the shaft chamber. A formed cylinder block (5), a piston (8) in which each cylinder of the cylinder block fits and has a flat outer end surface, a piston cap (3) having a flat surface to which the outer end surface of the piston closely contacts, Flow paths (25) and (2) for inflow and outflow that pass through the inside of the eccentric shaft (20) and open in recesses (21) and (21 ') formed on both sides of the eccentric portion (19), respectively.
5 '), the pressure pocket (15) provided on the outer end surface of the piston (8) is in fluid communication with the inner end of the piston, and the cylinder block (5) rotates more than a certain rotation angle. Restraint means (12),
In a hydraulic engine provided with (13), the piston cap (3) is formed in a casing shape containing the cylinder block (5), and the output / input shaft (35) protruding to the outside is formed as the piston cap. The piston cap is integrally formed, and a bearing (30) is provided on the outer peripheral portion of the piston cap to hold the outer ring (31) side of the body case (2). A cover (23) for covering the end opening is formed integrally with the eccentric shaft (20), and the flow paths (25), (2) are formed in the cover.
A hydraulic engine characterized by being provided with a fluid inlet / outlet communicating with 5 ').