JPH0320552Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a trochoidal hydraulic system, and more specifically, to a trochoidal hydraulic system such as a trochoidal pump or a motor that uses a trochoidal curve in the shape of its rotor. be.

[Conventional technology]

A trochoidal hydraulic system that uses a trochoidal curve in its rotor shape has been known for a long time, and is used, for example, as a metering motor for a fully hydraulic power steering system. Such a trochoid pump or motor is composed of a stator having a plurality of arc-shaped teeth provided at equal intervals in the circumferential direction, and a rotor having one tooth tip less than the number of teeth of the stator. This method takes advantage of the fact that by rotating the rotor while meshing inside the stator, the volume of the space defined by each tooth of the stator and each tooth tip of the rotor changes.

Here, a conventional trochoid type hydraulic system will be explained. Fig. 2 shows a fully hydraulic power steering system using a trochoid type hydraulic system as a metering motor, in which a cylindrical outer valve member 13 constituting a control valve 12 is rotatably mounted on a shaft within a casing 11. An inner valve member 14 is rotatably supported within the outer valve member 13 . Both valve members 13 and 14 are connected to each other so that they can rotate within a predetermined angular range by a pin 15 that passes through a circumferential dark blue elongated hole bored in the inner valve member 14 and is connected to the outer valve member 13. And both valve members 13, 14
are normally held by a spring 10 at an intermediate position within their mutually rotatable range, that is, at a neutral position.
The inner valve member 14 is interlocked with a steering handle 16, and the outer valve member 13 is connected via the pin 15 and drive shaft 17 to a rotor 19 of a metering motor 18 so as to rotate integrally therewith.

The configuration of the control valve 12 is well known and will not be described here, but the operation of the control valve 12 switches the fluid circuit to supply pressure oil from the oil pump 20 to the metering motor 18. Then, this metering motor 18 measures the amount of oil according to the amount of operation of the steering handle 16, and transfers the amount of oil to the power cylinder 2.
1, and by the operation of this power cylinder 21, the measured amount of oil, that is, the steering handle 16
The steering wheel is turned in accordance with the amount of operation.

Here, to explain in detail the configuration of the metering motor 18, as shown in FIG.
has seven arcuate tooth portions 23 arranged at equal intervals in the circumferential direction and a recess portion 24 formed between each of these tooth portions 23. On the other hand, the rotor 19 has six tooth tips 2, one less than the number of arcuate teeth 23 of the stator 22.
5 and a concave surface portion 26 formed between these tooth tips 25, and the tooth profile shape of this rotor 19 is constituted by a trochoid curve.

These rotor 19 and stator 22 are connected to a side plate 2 disposed on the control valve 12 side.
7 and an end plate 28 covering the outside, both plates 27, 28 and the stator 2
2 are integrally connected by bolts 29. The rotor 19 is normally rotated smoothly between the plates 27 and 28.
A slight gap is formed between the end surfaces of both plates 27 and 28 on the rotor 19 side.

In such a conventional trochoidal hydraulic system, during operation, the rotor 1 is
In order to prevent oil leakage to the low pressure part B in the rotor 9, a seal member 30 is fitted into an annular groove 19a formed on the end plate 28 side of the rotor 19.

[Problem that the invention attempts to solve]

As mentioned above, in the conventional trochoid type hydraulic system, a small gap is formed between the rotor 19 and the side plate 27 and end plate 28 that sandwich it, so that the rotor 19 can rotate smoothly. During operation, oil leaks from the high pressure chamber A to the low pressure section B within the rotor 19 through these gaps. Therefore, in order to prevent this, the seal member 30 is provided on the end plate 28 side of the rotor 19 as described above. Part 3
0 prevents oil leakage, and at the same time, high pressure from within the blocked pressure chamber A acts on the side surface of the rotor 19 on the outer peripheral side of the seal member 30. Therefore, due to the high pressure acting on the side surface of the rotor 19 on the end plate 28 side, the rotor 19 is moved toward the side plate 28.
As a result, oil leakage from between the rotor 19 and the side plate 27 is effectively prevented along with the end plate 28 side of the rotor 19 having the seal member 30.
However, the rotor 19 is
There are cases where the force of pressing the rotor 19 to the side is too large, and in this case, there is a drawback that smooth rotation of the rotor 19 is hindered.

The present invention was devised to eliminate the above-mentioned drawbacks, and is a trochoid that prevents oil leakage and enables smooth rotation of the rotor 19 by adjusting the force pressing the rotor 19 against the side plate 27 to an appropriate value. type hydraulic system.

[Means for solving problems]

The trochoidal hydraulic system according to the present invention has a sealing member between one plate and a rotor that rotates within a stator that is fixed between two plates, and a sealing member is provided on the outer circumferential side of the rotor. A through hole communicating with both sides is formed.

[Effect]

In the trochoidal hydraulic system according to the present invention, the high pressure chamber and the low pressure inside the rotor are sealed off by the seal member, and the area of the portion of the rotor on the outer peripheral side than the seal member on which the high pressure in the pressure chamber acts is By reducing the force, the force pressing the rotor can be adjusted to an appropriate value.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.
FIG. 1 is a longitudinal cross-sectional view of a trochoidal hydraulic system according to an embodiment of the present invention taken at the same position as in FIG. 3, and the same parts as in FIG. 3 are given the same reference numerals.

The shape of the teeth 23 in the stator 22 and the shape of the tooth profile consisting of the tooth tip 25 and the concave surface 26 on the outer peripheral surface of the rotor 19 are the same as those of the conventional device, and the rotor 1
9 rotates in the stator 22 with similar meshing, and the hydraulic pump ( (not shown) sucks in and discharges pressurized oil discharged from the pump.

Further, in the rotor 19 according to the present embodiment, a through hole 31 is formed in each of the six tooth tips 25 so that the two side surfaces communicate with each other. As described above, the force F that presses the rotor 19 toward the side plate 27 disposed on the control valve 12 side is determined by the area S on the side surface of the rotor 19 on the outer peripheral side of the seal member 30 and the pressure P in the pressure chamber A. (Equation 1), F=S×P... (1) By providing the through hole 31, the above area S can be reduced, and therefore the value of F becomes smaller, allowing smooth rotation of the rotor 19. When the operating pressure of the trochoid type hydraulic system is low, the value of F is also small, so there is no problem with the operation of the rotor 19. However, as a countermeasure when using it at high pressure, a through hole is provided in the rotor 19 as in this embodiment. 31 is particularly effective. However, if the value of F is too small, leakage between the rotor 19 and the side plate 27 will increase, so it is necessary to set the area S according to the working pressure and set the value of F to an appropriate value. be. It should be noted that the through holes 31 need only be formed on the outer peripheral side of the sealing member 30, that is, on the surface on which the high pressure in the pressure chamber A acts, and it goes without saying that the number, position, shape, etc. thereof can be selected as appropriate. Nor.

Reducing the area S means that the sealing member 3
It is also possible by enlarging the diameter of 0, but
Since the friction of the seal member 30 made of a material such as rubber is not preferable, the smaller the diameter of the seal member 30, the better, and the area S is reduced by providing the through hole 31.

The rotor 19 can be manufactured by various methods such as precision casting, sintering, etc. in addition to machining.

Note that oil grooves 19b may be formed on the surface of the rotor 19 on the side plate 27 side to further improve lubricity (see FIG. 4).

[Effect of idea]

As described above, according to the present invention, oil leakage from the high pressure side to the low pressure side of the trochoid type hydraulic system is prevented, and the force that presses the rotor toward the side plate is adjusted to an appropriate value to smoothly operate the rotor. It can be rotated to

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a trochoidal hydraulic system according to an embodiment of the present invention, and FIG. 2 is a partially sectional side view showing a conventional trochoidal hydraulic system applied to a fully hydraulic power steering system. Figure 3 is - of Figure 2.
FIG. 4 is a cross-sectional view taken along a line showing a main part of a modified example of the present invention. 19: Rotor, 20: Hydraulic pump, 22: Stator, 23: Arc-shaped tooth portion of stator, 25, 2
6: Rotor tooth profile, 27: Side plate, 2
8: End plate, 30: Seal member, 31:
Through hole, A: pressure chamber, B: low pressure part.

Claims (1)

[Scope of utility model registration request] A stator having a plurality of arcuate teeth formed at equal intervals in the circumferential direction, a rotor consisting of a trochoidal tooth profile that rotates within the stator while meshing with the arcuate teeth, and disposed on both sides of the stator and the rotor. The pressure discharged from the hydraulic pump due to the volume variation accompanying the rotation of the rotor in each pressure chamber defined by the arc-shaped teeth of the stator and the teeth of the rotor. In a trochoid type hydraulic system that sucks and discharges oil, a sealing member is provided between the rotor and one plate to seal off the pressure chamber and the low pressure section inside the rotor, and the sealing member is lower than the sealing member of the rotor. On the outer circumference side,
A trochoid type hydraulic device characterized by having a through hole communicating between both sides.