JP2624015B2 - Constant velocity joint and axial piston pump / motor device using the joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint suitable for connecting rotating shafts of machines to each other and an axial piston pump / motor apparatus using the joint.

[0002]

2. Description of the Related Art As described in Japanese Patent Application Laid-Open No. 63-308220, a conventional universal joint has a pair of drive pins arranged with a guide pin interposed between opposed drive shafts, and one end of the drive pin is connected to the drive shaft. It is provided so as to be slidable in the axial direction, and is rotatable and movable in the radial direction with the other end being a ball head.

[0003] Further, a device utilizing a universal joint is disclosed in
As described in JP-A-63-309785, torque transmission between a cylinder block and a piston support concentrically arranged on the axis of a drive shaft is performed by a pair of drive pins buried diagonally on an end face of the cylinder block, and It is movable on the pin,
In addition, it is supported in a drive groove provided in the piston support, and the inside of the drive groove is configured to be moved by a spherical bearing movable in a radial direction.

[0004] Japanese Patent Application Laid-Open No. 63-13921 discloses a universal joint having a drive pin and a center guide pin.

[0005]

The first and second prior arts are configured so as to absorb a difference in pitch diameter of a drive pin which is displaced in accordance with a change in the inclination angle of a drive shaft (joint shaft). However, the speed changes twice per rotation,
There was a problem that rotation could not always be transmitted at a constant speed.

In the universal joint described later, the tilt angle of the drive shaft cannot be made large. Since torque is transmitted using the wall surface of the drive pin insertion hole, there are problems such as large mechanical loss.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a constant velocity joint capable of transmitting rotation at a constant speed even when the inclination angle of a drive shaft changes, with a simplified structure.

Another object of the present invention is to provide an axial piston pump / motor device which can drive a cylinder barrel or a drive shaft at a constant speed even if the inclination angle of a piston support which changes according to the rotation of the drive shaft changes. It is in.

[0009]

In order to achieve the above object, a drive pin is provided between a drive shaft and a driven shaft to mechanically connect both members. A pair of drive shafts having cylindrical holes formed at regular intervals on the same circumference facing both members and extending parallel to the axis, and a compression spring in a cylindrical hole of one of the drive shafts. A driving pin having a spherical head formed at one end of the cylindrical portion and inserted into the other cylindrical hole via a compression spring; and a shaft at the center portion. This is achieved by providing a stopper that prevents movement in the direction.

Another object of the present invention is to provide a cylinder barrel housed in a housing and rotating integrally with a drive shaft, a tilt plate fixed to a side surface of the housing and receiving a piston support, and one end of which is the same circle as the cylinder barrel. On the circumference, each is rotatable and axially movable, and the other end of the ball head is freely held on the end face of the piston support, and on the concentric circle on the inner diameter side of the piston of the cylinder barrel, respectively. This is achieved by a plurality of drive pins rotatably held on the end face of the piston support so as to be rotatable and movable in the axial direction and the other end of the spherical head movable in the axial direction.

[0011]

The one end of the drive pin of this constant velocity joint rotates and slides along a concentric fixed trajectory while rotating on the cylinder hole of the drive shaft or the driven shaft. The other end of the ball head is rotated by a driven shaft or a cylinder hole (ball receiving hole) of the drive shaft. Therefore, the pins maintain a linear sliding motion in accordance with the rotation of the respective drive shafts or driven shafts, and the other end ball head keeps the drive center floating on the concentric circle of the driven shaft or drive shaft. Will be retained.

Thus, since the respective pistons are driven concentrically, a constant velocity joint is possible, and no mechanical vibration is caused.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 show a constant velocity joint used in an axial piston pump / motor device to be described later. The input shaft (drive unit) 1 and the output shaft (measured) are mechanically connected to a separately installed drive means. The drive section 2 is formed by cold forging or cutting. The input shaft 1 is formed with four cylinder holes 3 which are open on one side in parallel with the shaft and are evenly divided by milling or the like. On the other hand, the output shaft 2 is formed in the same manner, and the cylinder hole 4 is similarly formed at the same position on the surface facing the cylinder hole 3.

One end of the drive pin 5 is inserted into the cylinder hole 3 via a compression spring 6, and the other end of the ball head 7
Are arranged at the open ends of the cylinder bores 4 of the output shaft 2 via compression valleys 8, respectively. Here, the compression of the compression springs 8 and 6 is almost uniform (the spring 8 on the output shaft side may be slightly weaker) and is balanced so that the driving pin 5 is always supported at the center in a floating state.

The spring seat 9 is formed in a ring shape, and the compression spring 8 is arranged on the ball head 7 of the driving pin and the inner peripheral portion of the cylinder hole so as not to hinder the movement of the interruption ball head. However, if the relationship with the spring shape or the ball head is appropriate, this can be abolished.

In the above configuration, the drive pins 5 are preferably arranged evenly on concentric circles as shown in FIG. 2. However, the number of drive pins only needs to be three or more. What is necessary is just to oppose so that it may balance. The size of the ball head 7 is determined in accordance with the required strength, and quenching, surface treatment such as titanium coating, or an appropriate material is selected as necessary together with the piston.

As shown in FIG. 1, the input shaft 1 and the output shaft 2 are arranged at a predetermined tilt angle θ, and when the input shaft 1 is rotated, the drive pins cause the compression springs 6, 8 to correspond to the tilt position. The range from the maximum compression to the minimum compression is alternately and gradually changed, and the rotational driving force is transmitted to the output shaft 2. At this time, since the compression springs 6 and 8 always have a strength that balances the compression pressure, the drive pin 5 moves in the axial direction and is always positioned at the center of the drive unit in a floating state.
The ball head 7 always moves correctly on a concentric trajectory to realize a true constant velocity joint.

Although the embodiment mainly describes the one having a compression spring, the spring on the ball head side has a cylindrical hole whose axial movement of the ball head when the tilt angle is 5 ° or more. Is not always necessary because it regulates

In the above-described embodiment, four drive pins 5 are arranged concentrically. However, the number of drive pins may be three or more. Is preferable because of good stress balance.

Next, an embodiment using the above-described constant velocity joint will be described with reference to FIGS.

First, FIGS. 3 and 4 show an oblique-axis type piston pump device. In the drawings, an enclosure 21 has a side cover 22 having a suction hole 22a and a discharge port 22b, and is airtightly connected to the side cover 22. And a cup-shaped housing 23. A cylinder pin 24 is vertically implanted in the center of the side cover 22 toward the inner space, and a cylinder barrel 26 is rotatably mounted on the cylinder pin 24 via a valve plate 25. The cylinder barrel 26 is formed of a cylindrical body, and the cylinder bore 2 communicates with the suction hole 22a or the discharge port 22b via the barrel plate 25 at equal intervals on the same circumference.
6a are formed in an even number (eight). A plurality (four) of cylinder insertion holes 26b are formed at equal intervals on the concentric circle of the cylinder pin 24 at the center. A drive shaft 27 integrally formed with a piston support 27a is rotatably held on a tilting plate 29 via a needle bearing 28, and the tilting plate 30 contacts a hemisphere 32 of the housing 23 via a hemisphere 31. ing.

Reference numeral 33 denotes a piston inserted into the cylinder bore 26a, which is rotatably disposed via a seal ring 34, and the other end ball head 33a is rotatably disposed on the piston support 27a. Is held.

Numeral 37 denotes a drive pin arranged on a concentric circle on the inner diameter side of the piston 33, and a compression spring 38
Into the drive pin insertion hole 39 through the
a is inserted and arranged via a compression spring 39A in a ball receiving hole 27b formed in the end face of the piston support 27a.

The drive pin insertion hole 39 and the ball receiving hole 27b form oil passages 40 and 41 at the rear, respectively.
Improves lubrication capacity.

In the above configuration, when the drive shaft 27 is rotated, the rotational force is transmitted to the cylinder barrel 26 via the piston support 27a and the drive pin 37, and is rotated synchronously. On the other hand, the drive pin 37 and the piston 33 begin to slide in the axial direction as the piston support 27a is tilted as the piston support 27a is inclined.
The suction-discharge action is performed via 5.

In the above operation, the piston support 27a
The difference between the pitch circle of the cylinder hole 26a and the pitch circle of the ball head 33a caused when the tilt angle θ of the
Is absorbed by free movement. On the other hand, the drive pin 37
Is absorbed by sliding in the axial direction, and the drive shaft 2
7 to the cylinder barrel 26 smoothly.

The pump device of this embodiment is of a so-called variable displacement type, and the piston stroke is arbitrarily changed by moving the drive shaft 27 to the left and right, thereby changing the discharge displacement.

In FIG. 3, the stopper 21 is positioned at a maximum of 22 °.
a is provided to lock one end of the tilting plate 30.

According to the present embodiment, despite the fact that the drive pin 37 makes an elliptical motion, the ball head moves in the axial direction, so that the ball is smoothly rotated without exerting an excessive force, and mechanical vibration is reduced. Is done.

Further, since the drive pin is separate from the displacement piston, a high-output pump device can be provided at low cost without unnecessarily increasing the size of the device.

Next, a swash plate type piston pump device for gas pressure according to a third embodiment will be described with reference to FIGS.

The drive shaft 50 has one end supported by the side cover 51 via a bearing 52 and the other end supported by a housing 53 via a bearing 54.

A cylinder barrel 55 similar to that shown in FIG. 3 is arranged and fixed to one end of the drive shaft 50 via a valve plate 56. A plurality of pistons 57 inserted into the cylinder hole 55a are mounted on a piston support 58 concentrically supported at the center of the drive shaft 50 by a ball head 5 thereof.
7a is connected and held. Note that the holding structure is the same as that of the third embodiment, and a description thereof will be omitted.

As shown in FIG. 6, the drive pin 59 is disposed on a concentric circle on the inner diameter side of the piston 57, and the piston is inserted into the drive pin insertion hole 55b via the compression spring 60.
The other end ball head 59a is inserted and arranged in a ball receiving hole 58b formed in the end face of the piston support 58.

The tilting plate 62 located on the back side of the piston support 58 is a cylindrical body having a tapered surface.
2a is fitted to the stepped surface 53a of the housing 53, is positioned using the positioning pin 61, and is fixed by a pin (not shown) or the like. In this type of pump device, when the drive shaft 50 is driven, the cylinder barrel 55 rotates synchronously,
The piston support 58 is driven to rotate. Therefore, the piston reciprocates by the rotation to generate a discharge pressure.

At this time, when the cylinder barrel 55 is rotated, the driving pin 59 transmits a rotational driving force to the piston support 58, but the driving pin 59 slides according to the rotation angle, and the ball head is concentric. Transmit the driving force.

Therefore, the piston portion which determines the performance can be rotated synchronously without giving any external force.

It is preferable that several types of tilting plates 62 having different tilt angles are prepared and arbitrarily selected according to the discharge capacity.

According to this embodiment, a low-noise, small-sized gas pressure pump can be easily and inexpensively provided.

FIG. 7 shows another embodiment of the constant velocity joint. The ball head 7 of the drive pin is inserted into the cylinder hole 4 via the slipper 10, and the slipper 10 receives the compression spring 8. I have. Note that the slipper 10 is C-shaped or half-split, and is inserted into a cylinder hole after being assembled in a ball head in advance.

By doing so, the slidability of the ball head is improved, and the spring can also be used, so that the movement becomes smooth.

FIGS. 8 and 9 show a state in which a hydraulic pressure is applied instead of the compression spring 6. As shown in FIG. 9, liquid (oil) is connected to the cylinder hole by a passage 11 crossing the bottom of the cylinder hole 3.
12 is enclosed. In this case, it is necessary to provide an O-ring 13 in the piston portion so that the liquid does not leak.

Accordingly, a constant-velocity joint having good compression balance between the drive pins, easier absorption of mechanical vibration, and low noise can be obtained.

FIG. 10 shows a type in which a compression spring 6 is provided.
Cylinder hole 3 for smooth sliding of piston
The bearing metal 14 is press-fitted into the piston, and the piston portion is supported via the metal 14.

Therefore, the sliding of the piston portion is good,
Mechanical loss is small, and it is also effective in reducing noise.

Each of the above embodiments is effective in the case where the distance between the drive shaft and the driven shaft is maintained at a constant interval. FIG.
13 to 13 are effective for a constant velocity joint of a type in which a load is applied in a direction facing each other. A pair of drive shafts 101 and 102 have cylinder holes 103 and 104, and a drive pin 105 provided with a ball head 107 is arranged via compression springs 106 and 108 and a seat 109, as in the previous embodiment. It is.

The main difference is that the driven shaft 102 is provided with a hemispherical projection 110 at the center thereof, and a stopper pin 112 is provided at the center of the driving shaft 101 opposed thereto via a compression spring 111. I have.

In the above description, the projection 110 is
It may be formed integrally with 2 or may be separately supplied later. The stopper pin 112 is connected to the drive shaft 10.
When 1 is a synthetic resin body, a metal body is preferably embedded, but when the drive shaft is a metal body, it is more effective to integrally mold the drive shaft.
Further, the compression spring 111 is optionally used as needed.

As described above, in this embodiment, since the stopper for preventing the movement in the axial direction is provided at the center between the two drive shafts,
A joint that can take a large tilt angle can be obtained. The stopper is preferably hemispherical, and the axial load is applied to the center, so that the balance is good and a constant velocity joint can be easily and reliably obtained.

Generally, the enclosure including the first embodiment is formed of a metal body such as an aluminum material. However, in order to further reduce the weight, the main object can be achieved by using a plastic material. Further, it goes without saying that the main purpose can be achieved even if the driving side is replaced with the long driving side in the above-described embodiment.

[0052]

The constant velocity joint of the present invention can absorb the distortion stress caused by the rotational movement of the drive pin by the forward and backward movement of the drive pin, so that even if the inclination angle of the drive shaft changes, the constant velocity joint can rotate. By providing the stopper at the center, the axial load is applied to the center, and a well-balanced constant velocity joint can be easily provided.

Since the constant velocity joint can surely transmit the rotational force synchronously, there is no backlash between parts, low vibration and low vibration.
There is an effect that a low-noise piston pump / motor device can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a constant velocity joint according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a semi-longitudinal sectional view of an oblique-axis piston pump / motor device.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a half longitudinal sectional view of a swash plate type piston pump / motor device.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a sectional view showing another embodiment of a main part of the constant velocity joint.

FIG. 8 is a sectional view showing another embodiment of a main part of the constant velocity joint.

FIG. 9 is a sectional view showing another embodiment of a main part of the constant velocity joint.

FIG. 10 is a sectional view showing another embodiment of a main part of the constant velocity joint.

FIG. 11 is a partial semi-longitudinal sectional view of a constant velocity joint showing still another embodiment.

FIG. 12 is a side view of the drive shaft of FIG.

FIG. 13 is a side view of the driven shaft of FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive part, 2 ... Driven shaft, 3, 4 ... Cylinder hole, 5 ...
Driving pins, 6, 8 compression spring, 7 ball head.

Claims (8)

(57) [Claims] 1. A universal joint comprising a drive pin disposed between a drive section and a driven section and mechanically connecting both members, wherein the pair of drive sections are arranged concentrically, And a constant velocity joint having one end slidable and the other end connected by a plurality of drive pins arranged so as to perform ball movement and slide movement, and further having a stopper at a central portion for preventing axial movement. . 2. The stopper according to claim 1, wherein the stopper has a hemispherical shape and is formed on one of the driving portions, and is rotatably opposed to a stopper pin located on the opposite side. 3. The stopper pin according to claim 2, wherein the stopper pin is slidably disposed via a compression spring. 4. The stopper pin according to claim 2, wherein the stopper pin is in spherical contact with the stopper. 5. A cylinder barrel rotated in synchronization with rotation of a drive shaft rotated with a predetermined tilt angle, or a drive shaft rotated with a predetermined tilt angle in synchronization with rotation of a cylinder barrel. An axial piston pump / motor device comprising a plurality of piston devices disposed between a shaft and the cylinder barrel and reciprocating, and a drive pin, wherein the piston device has one end of a piston on the same circumference of the cylinder barrel. Each of the cylinder barrels is rotatably movable in the axial direction, the other end of the ball head is freely held on the end face of the piston support, and a plurality of drive pins are placed on a concentric circle on the inner diameter side of the piston of the cylinder barrel. , Each of which is rotatably movable in the axial direction, and the other end spherical head is rotatably held in the axial direction on the end face of the piston support. Axial piston pump motor device characterized. 6. An axial piston pump according to claim 5, wherein one end of the drive pin is disposed in a drive pin insertion hole of the cylinder barrel via a compression spring.
Motor device. 7. The axial piston pump / motor device according to claim 5, wherein the drive shaft is disposed on an inner surface of the housing via a tilting plate. 8. housed in a housing cylinder barrel that rotates integrally with the drive shaft, is fixed to the side surface of the housing, the tilting plate receives the piston support, the piston reciprocating disposed between the piston support and the cylinder barrel An axial piston pump / motor device comprising: a piston device, wherein one end of a piston is rotatably and axially movable on the same circumference of a cylinder barrel, and the other end is a spherical head. Part is freely held on the end face of the piston support, and a plurality of drive pins are rotatably and axially movable on a concentric circle on the inner diameter side of the piston of the cylinder barrel, and the other end is a spherical head. An axial piston pump characterized in that the piston support is rotatably held on an end face of the piston support so as to be movable in an axial direction.
Motor device.