JPH0726216Y2 - Trochoid type hydraulic system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a trochoidal hydraulic device, and more specifically,
The present invention relates to a trochoid type hydraulic device such as a trochoid pump or a motor that uses a trochoid curve in the shape of a rotor.

[Conventional technology]

A trochoid type hydraulic device utilizing a trochoid curve in a rotor shape has been conventionally known, and is used, for example, as a lightweight motor of an all-hydraulic power steering device. Such a trochoid pump or a lightweight motor has a stator having a plurality of arcuate tooth portions formed at equal intervals in the circumferential direction and a tooth tip that is one less than the number of tooth portions of the stator. A rotor having a tooth profile, and rotating the rotor while meshing the arc-shaped tooth portion of the stator and the trochoid tooth profile of the rotor inside the stator, thereby each arc-shaped tooth portion of the stator and the tooth profile of the rotor. The pressure oil is sucked and discharged by utilizing the fact that the volume of the space defined by each tooth tip changes.

Here, regarding the conventional trochoid type hydraulic device, the third to fifth aspects will be explained.
Description will be given with reference to the drawings. FIG. 3 shows an all-hydraulic power steering system using a trochoid type hydraulic system as a metering motor. Inside the casing (11), a cylindrical outer valve member (13) constituting a control valve (12) is provided. ) Is rotatably supported, and an inner valve member (14) is rotatably supported in the outer valve member (13). Double valve member (1
3) and (14) are pins (1) that are connected to the outer valve member (13) by penetrating through an elongated hole formed in the inner valve member (14) in the circumferential direction.
5) are connected to each other so as to be rotatable within a predetermined angle range, and both valve members (13) and (14) are normally held by springs in an intermediate position within a range in which they can mutually rotate, that is, a neutral position. ing. The inner valve member (14) is interlocked with the steering handle (16), and the outer valve member (13) is connected to the rotor (19) of the metering motor (18) via the pin (15) and the drive shaft (17). They are connected so as to rotate integrally.

The configuration of the control valve (12) is well known and will not be described, but the fluid circuit is switched by the operation of the control valve (12) to measure the pressure oil from the oil pump (20) to the metering motor (18). ). Then, the metering motor (18) measures the amount of oil corresponding to the operation amount of the steering handle (16), supplies the oil amount to the power cylinder (21), and operates the power cylinder (21). The steered wheels are turned in accordance with the measured amount of oil, that is, the amount of operation of the steering wheel (16).

Here, the structure of the above-mentioned metering motor (18) will be described in detail. As shown in FIG. 4, the stator (22) has seven arcuate tooth portions (23) formed at equal intervals in the circumferential direction. And a recess (24) formed between these tooth portions (23). On the other hand, the rotor (19) has six tooth tips (25), which is one less than the number of arcuate tooth portions (23) of the stator (22).
And a concave surface portion (26) formed between these tooth tips (25), and the tooth profile of this rotor (19) is constituted by a trochoidal curve.

If the gap between the rotor (19) and the stator (22) is zero, smooth rotation cannot be performed, and therefore the shape of the rotor (19) or the stator (22) is deformed and the two are not deformed. By forming a slight gap between them, smooth rotation is made possible and measures are taken to prevent foreign matter from entering. Furthermore, as shown in FIG. 5, the rotor (19), the side plate (27) and the end plate (2
The required clearances (C ₁ ) and (C ₂ ) are formed between the _two (8) to make the rotation of the rotor (19) smoother. However, if the clearances (C ₁ ) and (C ₂ ) are too large, the pressure chamber (A), which is the high-pressure side space, moves from the pressure chamber (A) to the drive shaft (17).
A continuous space (arrow in FIG. 5) to the space (B) (low pressure side space) on the side of the spline connection between the rotor (19) and the rotor (19) is formed, which causes the error in the amount of rotation of the rotor (19). The continuous space was a cause of internal leakage of oil from the high pressure side pressure chamber (A) to the low pressure side pressure chamber (B). Therefore, in particular, the amount of leakage is kept to a minimum and the rotor (19)
Clearance (C ₁ ), (C ₂ ) so as not to impair the smooth rotation of
Was set.

That is, the stator (22) includes the side plate (27) and the end plate (28) arranged at the end of the casing (11).
The rotor (19) and the spacer (31) are fitted in a space formed between the rotor (19) and the spacer (31). The end of the drive shaft (17) is inserted inside the rotor (19), and the rotor (19) and the drive shaft (17) are spline-connected. Also the above spacer (31)
Is attached to the rotor (19) and the drive shaft (1
It is a support member that supports the end face of 7) and is fitted to prevent it from coming off, and is adapted to move along with the eccentric rotation of the rotor (19). Furthermore, the three members of the side plate (27), the stator (22), and the end plate (28) are integrally fixed to the casing (11) by bolts (29) penetrating the respective mounting holes (third part). See figure). Mounting holes (30) and bolts (29) for the stator (22)
As shown in FIG. 4, each tooth portion (2
It is provided near the outer circumference of 3). Further, the side plate (27) is provided with communication holes (40) corresponding to the recesses (24) of the stator (22), and the stator (2
Each pressure chamber (A) defined by the arcuate tooth portion (23) of 2) and the tooth tip (25) of the rotor (19) is connected to the casing (11).
It is adapted to communicate with the control valve (12) through an internal passage.

When the rotor (19) rotates, for example, in the direction of the arrow (D) in FIG. 4 during the operation of the metering motor (18) having the above-described configuration, the volume of each pressure chamber (A) increases or decreases, and both suction and discharge are performed. Do the process. However, at this time, since the clearances (C ₁ ) and (C ₂ ) are formed between the rotor (19) and the side plate (27) and between the rotor (19) and the end plate (28), There was a drawback in that the rotation of (19) was misaligned due to internal leakage of oil and the like, and an error occurred in the rotation angle of the rotor (19) even when the handle was operated. Moreover, a slight internal leakage phenomenon of oil from the pressure chamber (A) to the space (B) on the spline connecting portion side via the clearances (C ₁ ) and (C ₂ ) cannot be avoided. Furthermore, since the drive shaft (17) is inclined and connected to the axial center of the stator (22), the rotor (19) is inclined within the clearances (C ₁ ) and (C ₂ ) and the rotor (19 During the rotation of (19), the inside of the weighing motor (18) might be damaged. Therefore, in the trochoid type hydraulic device applied to the all-hydraulic power steering device, if an error or the like occurs in the rotation of the rotor as described above, particularly in the locked state, that is, the steering handle is cut to the hopper position, or the axle. Even when the vehicle is locked due to an obstacle, the steering system is not mechanically connected, so the steering wheel rotates and the driver cannot feel the lock, which gives the driver a sense of anxiety. It was

Therefore, as a conventional technique, there has been proposed one in which a spacer is attached to a rotor to support a drive shaft, and the spacer maintains liquid tightness on the high-pressure side and the low-pressure side. That is, as shown in FIG. 6, this product has a recess (19a) formed on the end face of the rotor (19) on the end plate (28) side, and a sealing mechanism such as an O-ring is formed in the recess (19a). By fitting the spacer (31) with the interposition of (1), the oil tightness between the pressure chamber (A) and the space (B) is maintained, and the rotor (19) is kept by the hydraulic pressure of the pressure chamber (A). Together with the spacer (31) are pressed and urged against the side plate (27). As a result, the pressure chamber (A)
To prevent the internal leakage of oil into the space (B) through the clearances (C ₁ ) and (C ₂ ) as shown in Fig. 5 and to prevent the excessive displacement of the rotor (19). ing.

[Problems to be solved by the invention]

However, in such a structure, the rotor (19) together with the spacer (31) is urged by the side plate (27) due to the oil pressure difference between the space (B) and the pressure chamber (A). However, if this pressing force becomes larger than necessary, the rotor (19) will be affected by the frictional force of the contact surface between the side plate (27) and rotor (19).
Becomes difficult to rotate normally. In this state, even if the control valve (12) is turned off by rotating the steering handle (16) and the handle (16) is kept stationary at the predetermined rotation angle, the rotor (19 ) Does not rotate according to the amount of handle operation. Then, although the rotor (19) is stationary, the pressure oil supplied from the oil pump (20) to the metering motor (18) causes the gap between the rotor (19) and the stator (22) to go to the high pressure side. The pressure chamber (A) leaks to the low pressure side pressure chamber (B), and the leaked oil is sent to the power cylinder (21),
This causes a problem that the power cylinder (21) is activated and the steering wheel is naturally disconnected.

The present invention has been made to solve such problems, and it is possible to adjust the internal leakage of oil in the rotor part and
An object of the present invention is to obtain a trochoidal hydraulic device that can prevent natural breakage of steering wheels and that does not damage the inside of the metering motor by the rotor.

[Means for solving problems]

In the trochoid type hydraulic device according to the present invention, a stator is formed with a plurality of arc-shaped tooth portions at equal intervals in the circumferential direction, and a rotor having a trochoid tooth shape that rotates while meshing with the arc-shaped tooth portions of the stator is used as the stator. The stator is sandwiched by a pair of plates disposed inside the rotor and forming a required clearance with the rotor, the end of the drive shaft and the rotor are connected in the rotor, and the drive shaft is supported. And a spacer for maintaining liquid tightness between the high pressure side and the low pressure side is attached to the rotor, and the space defined by the arcuate tooth portion of the stator and the tooth profile of the rotor,
In a trochoidal hydraulic device that sucks and discharges pressure oil due to a volume change accompanying the rotation of a rotor, a communication hole is formed in the spacer to connect the high pressure side and the low pressure side.

[Action]

According to the present invention, the pressure oil moves in the communication hole formed in the spacer that maintains the liquid tightness between the high pressure side and the low pressure side, so that the pressing biasing force of the rotor against the side plate is reduced, The frictional force between the plate and the rotor is reduced, which causes the rotor to rotate smoothly.

〔Example〕

The present invention will be described below based on an embodiment shown in FIGS. 1 (a) to 1 (c). FIG. 1 (a) is equivalent to FIG. 6, and the rotor (19) is spline-connected to a drive shaft (not shown), and the end plate (28) side end surface has a recess (19a) having a diameter larger than the diameter of the spline connecting portion. ) Is formed, and a spacer (31) for maintaining liquid tightness between the high pressure side pressure chamber (A) and the low pressure side space (B) is fitted in the recess (19a). A step portion (31a) is cut at the end of the peripheral surface of the spacer (31) on the side of the recess (19a), and an O-ring (1) is attached to the step portion (31a). And weighing motor (18)
As for the spacer (31) and the rotor (19) assembled in the recess (19a), one end face of the rotor (19) contacts the side plate (27), and the outer end face of the spacer (31) is the end plate. It is designed to come into contact with (28). On this occasion,
The mounted O-ring (1) is pressed and deformed by the inner peripheral surface of the recess (19a) and slightly protrudes from the inner end surface of the spacer (31), whereby the rotor (19) and the spacer (31) are separated from each other by the side plate (27). , The spacers (31) are mounted between the end plates (28) so that a gap (δ) is formed between the inner end surface of the spacer (31) and the bottom surface of the recess (19a).
Is molded (see FIG. 1 (b)). Further, the spacer (31) is formed with a communication hole (50) for communicating the pressure chamber (A) on the high pressure side with the space (B) on the low pressure side. The communication hole (50) An inner diameter of 0.1 to 0.3 mm is preferable. As shown in FIG. 1 (b), the communication hole (50) in this embodiment has a small diameter hole (51) on the high pressure side and a slightly larger diameter hole (52) on the low pressure side. This is because pressure oil can easily pass through the hole (50).

Therefore, when the metering motor (18) having the above-described configuration operates, the oil tightness of each pressure chamber (A) that has become high pressure is maintained by the O-ring (1), and the clearance space becomes high pressure and the rotor (19). , The spacer (31) is pressed and biased toward the side plate (27). Then, as shown in FIG. 1 (c), the spacer (31) is inserted into the recess (19a) by a size corresponding to the gap (δ) formed by the O-ring (1). 31) The outer end surface forms a gap (δ) with the inner surface of the end plate (29), and the rotor (19) and the spacer (31) are elastically contacted with the side plate (27). However, since the communication hole (50) is formed in the spacer (31), a predetermined amount of oil moves from the high pressure side to the low pressure side through the communication hole (50), and the side wall The pressing force of the rotor (19) on the surface of the plate (27) is relaxed. Therefore, the rotor (1
The frictional force acting between the side plate (27) and the side plate (27) becomes small, and the rotation of the rotor (19) is not restricted by this frictional force. For this reason, as described in the above-mentioned prior art, when the steering handle (16) is rotated to turn off the control valve (12) and the handle (16) remains stationary at a predetermined rotation angle, The pressure of the oil supplied from the oil pump (20) to the pressure chamber (A) of the metering motor (18) in accordance with the handle operation amount causes the rotor (19) to rotate smoothly. Therefore, the supplied pressure oil does not leak from the high pressure side pressure chamber (A) to the low pressure side pressure chamber (B) in the gap between the rotor (19) and the stator (22), and the steering wheel is naturally disconnected. That phenomenon does not occur.

Further, in the above-described embodiment, since the pressure chamber (A) of the metering motor (18) can be kept oil-tight, the rotor (1
9) It is possible to prevent internal leakage of oil from the clearance (C) formed on the end surface. Furthermore, as a result of keeping the pressure chamber (A) oil-tight, the rotor (19) and the spacer (3
The side plate (27) of 1) is pressed and urged by an appropriate force to prevent displacement of the rotor (19) due to rotation, and rotation of the rotor (19) due to inclination of the rotor (19). It is possible to prevent irregularities, prevent damage to the inside of the rotor (19) and the plates (27), (28), and improve steering characteristics of the steering wheel.

2 (a) and 2 (b) show a second embodiment of the present invention. The difference from the first embodiment is that the back surface of the spacer (31), that is, the surface on the end plate (28) side. Protruding part (31b)
Is formed. With this configuration, the spacer (31) and the end plate (28) are not in close contact with each other and a gap is always maintained therebetween, so that oil is easily introduced into the communication hole (50). Therefore, the transition from the state shown in FIG. 1 (b) to the state shown in FIG. 1 (c) becomes smooth, and the operation of the weighing motor (18) is stabilized.

If the spacer itself is molded with an elastic material such as plastic, when the spacer is pressed against the rotor recess by the hydraulic pressure of each pressure chamber, the spacer expands its diameter to change the spacer outer peripheral surface and the recess inner peripheral surface. Closely attached,
The pressure chambers are sealed so that the oil tightness of each pressure chamber is maintained, and the same effect as that of each of the above embodiments is expected.

By the way, in the above description, the case where only one communication hole (50) is formed in the spacer (31) is shown, but a plurality of communication holes (50) may be provided, and the hole (50) may be formed on the high pressure side and the low pressure side. Any shape may be used as long as they are communicated with each other.

[Effect of device]

As described above, the present invention has the structure in which the communication hole is formed in the spacer that holds the liquid tightness between the high pressure side and the low pressure side. Therefore, the biasing force of the rotor against the side plate is relaxed and the plate is closed. The frictional force between the rotor and the rotor is reduced, and the rotation of the rotor is smoothed. This has the effect of preventing the steering wheel from naturally breaking.

[Brief description of drawings]

1 (a) to 1 (c) are views showing an embodiment of a trochoid type hydraulic device according to the present invention, and FIG. 1 (a) is a cross-sectional view of a main part,
(A) and (c) of FIG.
2 (a) and 2 (b) are side cross-sectional views and a front view of essential parts showing another embodiment, and FIG. 3 is a vertical cross-sectional view showing an all-hydraulic power steering system to which a conventional trochoid type hydraulic device is applied. 4 and 5 are sectional views of the trochoidal hydraulic system taken along the line IV-IV in FIG. 3, FIG. 5 is a sectional view showing an essential part of FIG. 4, and FIG.
It is sectional drawing equivalent to FIG. 5 which shows what improved the apparatus shown in FIG. (17) …… Drive shaft (19) …… Rotor (22) …… Stator (23) …… Arc tooth (27), (28) …… Plate (31) …… Spacer (50) …… Communication Holes (C), (C ₁ ), (C ₂ ) ... Clearance In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. A stator having a plurality of arcuate tooth portions formed at equal intervals in a circumferential direction, a rotor having a trochoidal tooth profile that rotates while meshing with the arcuate tooth portions in the stator, and the stator. A pair of plates which sandwich the rotor from both sides and have a required clearance with the rotor, a drive shaft connected in a hole formed in the shaft core of the rotor, and the drive which is attached to the rotor. A spacer for preventing the shaft from coming off, and sucking pressure oil by a volume change accompanying the rotation of the rotor in a space defined by the arcuate tooth portion of the stator and the tooth profile of the rotor.
In the trochoidal hydraulic device for discharging, a recess having a diameter larger than this hole is formed around the hole of the shaft core portion of the rotor end face, and a spacer is fitted in the recess by interposing a seal mechanism. A trochoidal hydraulic device characterized in that the spacer is provided with a communication hole for communicating the high pressure side and the low pressure side while keeping the high pressure side and the low pressure side liquid-tight.