JPH04228924A - Constant velocity joint and axial piston pump motor device using the joint - Google Patents

Abstract

PURPOSE:To obtain a constant velocity joint capable of transmitting shaft rotation at constant velocity, regardless of shaft inclination, and an axial piston pump motor device capable of transmitting driving force at constant velocity. CONSTITUTION:A pair of drive sections 1 and 2 are concentrically arranged, and coupled to each other with a plurality of drive pins 5 having one freely slidable end and the other end so laid as to be capable of spherical and slide motion, thereby constituting a constant velocity joint. According to the construction, strain stress resulting from the irregular motion of the drive pins 5 can be absorbed by the back and forth motion thereof, thereby enabling the transmission of drive shaft rotation at constant velocity, regardless of a change in the inclination angle of a drive shaft.

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, and an axial piston pump/motor device using the joint.

0002

[Prior art] The conventional universal joint is disclosed in Japanese Patent Application Laid-Open No. 63-3082.
As described in No. 20, a pair of drive pins are arranged with a guide pin sandwiched between opposing drive shafts, one end of the drive pin is provided so as to be slidable in the axial direction, and the other end is provided with a spherical head. It has a structure that allows it to rotate freely and move in the radial direction.

[0003] Furthermore, as described in Japanese Patent Laid-Open No. 63-309785, a device using a universal joint transmits torque between a cylinder block and a piston support arranged concentrically on the axis of a drive shaft. A pair of drive pins embedded diagonally on the end face of the cylinder block, and a spherical bearing that is movable on the drive pins, supported in a drive groove provided in the piston support, and movable in the radial direction within the drive groove. The system is configured to perform the following steps.

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

[0005]

[Problems to be Solved by the Invention] The first and second prior art techniques are configured to absorb the difference in pitch diameter of the drive pin that is displaced in response to changes in the inclination angle of the drive shaft (joint shaft). However, there are two speed changes per revolution,
There was a problem that rotation could not necessarily be transmitted at a constant speed.

[0006] With the universal joint described later, it is not possible to obtain a large tilting angle of the drive shaft. 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 An object of the present invention is to provide a constant velocity joint that can transmit rotation at a constant velocity even if the inclination angle of the drive shaft changes, with a simple structure.

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

[0009]

[Means for Solving the Problems] In order to achieve the above object, a drive pin is disposed between the drive section and the driven section to mechanically connect the two members. Then, on the same circumference on the facing side of the pair of driving parts between both members, each is rotatable, one end is movable only in the axial direction, and the other end in the same direction is a spherical head. This is achieved by arranging at least three or more drive pins.

Furthermore, in order to achieve the other object mentioned above, a drive pin is provided between the drive shaft and the driven shaft to mechanically connect the two members. Then, the pair of drive shafts have cylindrical holes formed on the same circumference of each facing member at equal intervals and extending parallel to the axis, and a compression spring is installed in the cylindrical hole of one of the drive shafts. This is achieved by a cylindrical part inserted through the cylindrical part and a drive pin formed at one end of the cylindrical part and having a ball head inserted into the other cylindrical hole via a compression spring.

[0011]Furthermore, the other object is to provide a cylinder barrel which is housed in a housing and rotates together with a drive shaft;
A tilting plate fixed to the side surface of the housing and receiving the piston support, one end of which is rotatable and movable in the axial direction on the same circumference of the cylinder barrel, and the other end of which is a ball head of the piston support. A piston freely held on an end surface, and a piston support, each of which is rotatable and movable in the axial direction on a concentric circle on the inner diameter side of the piston of the cylinder barrel, and the ball head of the other end is movable in the axial direction. This is achieved by a plurality of drive pins rotatably held on the end face of the.

0012

[Operation] One end of the drive pin of this constant velocity joint rotates and slides along a fixed concentric locus while rotating in the cylinder hole of the drive shaft or driven shaft. The ball head at the other end rotates in the cylinder hole (ball receiving hole) of the driven shaft or drive shaft. Therefore, the pin maintains a linear sliding motion in accordance with the rotation of each driving shaft or driven shaft, and the ball head at the other end keeps the driving center floating on the concentric circle of the driven shaft or driving shaft. Retained.

[0013] As a result, each piston is driven concentrically, so a constant velocity joint is possible and there is no mechanical vibration.

[0014]

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
The explanation will be based on.

The input shaft (driving section) 1 and output shaft (driven section) 2, which are mechanically connected to a separately installed drive means, are formed by cold forging, cutting, or the like. In the input shaft 1, four cylinder holes 3, one of which is open parallel to the shaft, are formed concentrically and equally spaced by milling or the like. On the other hand, the output shaft 2 is also molded in the same manner, and a 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 is connected to a ball head 7.
are likewise arranged at the open end of the cylinder hole 4 of the output shaft 2 via compression valves 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 the balance is maintained so that the drive pin 5 is always supported in a floating state at the center.

The spring seat 9 has a ring shape, and a compression spring 8 is arranged between the ball head 7 of the driving pin and the inner circumference of the cylinder hole so as not to hinder the movement of the cutting ball head. However, if the shape of the spring or the relationship with the ball head is appropriate, it may be omitted.

In the above structure, the drive pins 5 are preferably arranged concentrically and evenly spaced as shown in FIG. It is sufficient if they are placed facing each other so as to be balanced. Further, the size of the ball head 7 is determined according to the required strength, and along with the piston part, surface treatments such as hardening and titanium coating or appropriate materials are selected as necessary.

As shown in FIG. 1, the input shaft 1 and the output shaft 2 are arranged with a predetermined tilt angle θ, and when the input shaft 1 is rotated, the drive pin releases the compression springs 6 and 8 according to the tilt position. The rotational driving force is transmitted to the output shaft 2 by alternating and gradually changing the range from maximum compression to minimum compression. At this time, since the compression pressures of the compression springs 6 and 8 are always balanced, the drive pin 5 moves in the axial direction and is always located in a floating state at the center of the drive unit.
The ball head 7 always moves correctly on a concentric trajectory to realize a true constant velocity joint.

[0020] In the embodiments, explanations are mainly given on those having a compression spring, but if the spring on the ball head side has a tilt angle of 5° or more, the cylindrical hole will move in the axial direction of the ball head. It is not necessarily necessary as it regulates the

In the above embodiment, four drive pins 5 are arranged concentrically, but the number of drive pins may be three or more, and in the case of an odd number arrangement, they may be arranged at equal pitches. is preferable because it has a good stress balance.

FIG. 7 shows another embodiment, in which the ball head 7 of the drive pin is inserted into the cylinder bore 4 via a slipper 10, which receives the compression spring 8. Incidentally, the cylinder 10 is used in a C-shape or in half, and is inserted into the cylinder hole after being assembled into the ball head in advance.

[0023] By doing so, the slideability of the ball head is improved, and since it can also be used as a spring seat, the movement becomes smooth.

8 and 9 show a system in which hydraulic pressure is applied instead of the compression spring 6, and as shown in FIG.
12 is enclosed. In this case, it is necessary to provide an O-ring 13 in the piston portion to prevent liquid from leaking.

[0025] Therefore, a constant velocity joint with good compression balance between the drive pins, which absorbs mechanical vibrations more easily, and has low noise can be obtained.

FIG. 10 shows a type in which a compression spring 6 is provided.
Cylinder hole 3 to make the piston slide smoothly
A bearing metal 14 is press-fitted into the piston, and the piston portion is supported through the bearing metal 14.

[0027] Therefore, the piston part slides well,
This results in less mechanical loss and is also effective in reducing noise.

Next, an embodiment using the constant velocity joint described above will be explained based on FIGS. 3 to 6.

First, FIGS. 3 and 4 show an oblique shaft type piston pump device. In the figures, an enclosure 21 is airtightly connected to a side cover 22 having a suction hole 22a and a discharge port 22b. It is composed of a cup-shaped housing 23. A cylinder pin 24 is installed vertically 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 made of a cylindrical body, and the suction holes 2 are arranged at equal intervals on the same circumference through the barrel plate 25.
2a or the cylinder hole 26 communicating with the discharge port 22b
An even number (8) of a is formed. A plurality of (four) cylinder insertion holes 26b are formed at equal intervals on the concentric circle of the cylinder pin 24 in the center. A drive shaft 27 integrally formed with a piston support 27a is rotatably held by a tilting plate 29 via a needle bearing 28, and the tilting plate 30 is connected to the housing 2 via a hemispherical surface 31.
It is in contact with the hemispherical surface 32 of No. 3.

A piston 33 is inserted into the cylinder bore 26a and is rotatably arranged via a seal ring 34, and the ball head 33a at the other end is rotatably arranged on the piston support 27a, and is secured by a retaining plate 36. Retained.

Reference numeral 37 denotes a drive pin arranged concentrically on the inner diameter side of the piston 33, which connects the piston to the compression spring 38.
into the drive pin insertion hole 39 through the ball head 37 at the other end.
A is inserted into a ball receiving hole 27b formed in the end surface of the piston support 27a via a compression spring 39A.

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

In the above configuration, when the drive shaft 27 is rotated, rotational force is transmitted to the cylinder barrel 26 via the piston support 27a and the drive pin 37, and the cylinder barrel 26 is rotated synchronously. On the other hand, since the piston support 27 is inclined, the drive pin 37 and the piston 33 begin to slide in the axial direction as they rotate, and the piston 33 moves toward the valve plate 25.
The inhalation-exhalation action is performed through the

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 spherical head 33a that occurs when the tilt angle θ of the piston 33 changes
is absorbed through free movement. On the other hand, the drive pin 37
is absorbed by sliding in the axial direction, and the drive shaft 2
The driving force is smoothly transmitted from 7 to the cylinder barrel 26.

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

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

According to this embodiment, even though the drive pin 37 moves in an elliptical manner, the ball head moves in the axial direction, so it rotates smoothly without applying any unreasonable force, and mechanical vibrations are reduced. be done.

Furthermore, since the drive pin is separate from the displacement piston, a high-output pump device can be provided at low cost without making the device larger than necessary.

Next, a gas pressure swash plate type piston pump device according to a third embodiment will be explained with reference to FIGS. 5 and 6.

The drive shaft 50 has one end supported by a 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. The plurality of pistons 57 inserted into the cylinder holes 55a are supported by their spherical heads 58 on a piston support 58 that is concentrically supported in the center of the drive shaft 50.
7a is connected and held. Note that the holding structure is the same as that of the third embodiment and will therefore be omitted.

59 is the piston 57 as shown in FIG.
The piston part is inserted into the drive pin insertion hole 55b via the compression spring 60, and the other end ball head 59a is formed in the end surface of the piston support 58. 58b.

The tilting plate 62 located on the back side of the piston support 58 is a cylindrical body with a tapered surface, and has a hollow portion 6.
2a is fitted onto the stepped surface 53a of the housing 53, positioned using the positioning pin 61, and then fixed with 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 rotation causes the piston to reciprocate and generate discharge pressure.

At this time, when the cylinder barrel 55 is rotated, the drive pin 59 transmits rotational driving force to the piston support 58, but the drive pin 59 slides depending on the rotation angle, and the ball head is placed on a concentric circle. Transmits driving force.

[0045] Therefore, the piston parts, which affect the performance, can rotate synchronously without applying any external force.

It is preferable that several kinds of tilting plates 62 with different angles of inclination 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 provided at low cost.

[0048] All of the above embodiments were effective for those in which the distance between the driving shaft and the driven shaft was maintained at a constant distance. Fig
11 to 13 are effective for constant velocity joints of the type in which loads are applied in directions facing each other. A pair of drive shafts 101,1
02 has cylinder holes 103 and 104, and a ball head 107.
This is the same as in the previous embodiment in that a drive pin 105 with a drive pin 105 is disposed via compression springs 106, 108 and a seat 109.

The main difference is that the driven shaft 102 has a hemispherical protrusion 110 at its center, and the driving shaft 101 facing the protrusion has a stopper pin 112 at its center via a compression spring 111. There is.

In the above, the protrusion 110 is connected to the driven shaft 10.
It may be molded as an integral part with 2, or a separate part may be added later. Further, the stopper pin 112 is connected to the drive shaft 10.
If 1 is a synthetic resin body, it is better to embed a metal body, but if the drive shaft is a metal body, it is more effective to mold it integrally. Furthermore, the compression spring 111 may be used as desired.

In this way, in this embodiment, a stopper is provided at the center between both drive shafts to prevent movement in the axial direction.
It is possible to create a joint that allows a large tilting angle. The stopper is preferably hemispherical, and since the axial load is applied to the center, it is well balanced and a constant velocity joint can be easily and reliably obtained.

Generally, the enclosure, including the first embodiment, is formed of a metal material such as aluminum, but in order to further reduce the weight, the main purpose can also be achieved by using a plastic material. Furthermore, it goes without saying that in the embodiments described above, the main objective can be achieved even if the drive side is replaced with a permanent drive side.

[0053]

[Effects of the Invention] According to the present invention, the strain stress caused by the variable-speed rotational movement of the drive pin can be absorbed by moving the drive pin back and forth, so even if the inclination angle of the drive shaft changes, the rotation can be maintained at a constant speed. It has a communicable effect.

Furthermore, since the rotational force can be reliably transmitted in synchronization, there is no rattling between the parts, and a product with low vibration and low noise can be realized with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of a constant velocity joint showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

FIG. 3 is a half-longitudinal cross-sectional view of the oblique shaft type piston pump/motor device.

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

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

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

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

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

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

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

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

FIG. 12 is a side view of the drive shaft of FIG. 11;

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

[Explanation of symbols]

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

Claims (20)

[Claims] 1. A universal joint in which a driving pin is disposed between a driving part and a driven part to mechanically connect the two members, wherein the pair of driving parts are arranged concentrically, A constant velocity joint that is connected by a plurality of drive pins arranged so that one end can freely slide and the other end can make spherical and sliding movements. 2. The constant velocity joint according to claim 1, wherein at least three drive pins are arranged in the cylindrical hole (bore) via compression means. 3. The constant velocity joint according to claim 1, wherein the drive side of the drive pin is a cylindrical body and is inserted into the cylindrical hole via compression means. 4. The constant velocity joint according to claim 2, wherein the compression means is a compression spring. 5. The constant velocity joint according to claim 2, wherein the compression means is a liquid sealed in a cylindrical hole, and the adjacent cylindrical holes are connected to each other via a conductive path. 6. The constant velocity joint according to claim 3, wherein the cylindrical body of the drive pin is disposed in the cylindrical hole via a bearing. 7. A constant velocity joint according to claim 3, wherein the ball head of the drive pin is disposed in the cylindrical hole via compression means. 8. The constant velocity joint according to claim 7, wherein the compression means is a compression spring. 9. The constant velocity joint according to claim 8, wherein the compression spring is in contact with the ball head via a slipper or a spring seat. 10. A universal joint in which a drive pin is disposed between a drive shaft and a driven shaft to mechanically connect the two members,
The pair of drive shafts each have cylindrical holes extending equally spaced on the same circumference and parallel to the axis, and the drive shaft is inserted into the cylindrical hole of one of the drive shafts via a compression spring. 1. A constant velocity joint comprising a cylindrical body part and a drive pin formed at one end of the cylindrical body part and having a spherical head inserted into the other cylindrical hole via a compression spring. 11. The constant velocity joint according to claim 10, wherein the driving center of the ball head is maintained in a floating state. 12. The constant velocity joint according to claim 11, wherein the drive pins are arranged in a balanced manner on the same circumference. 13. A universal joint in which a driving pin is disposed between a driving part and a driven part to mechanically connect the two members,
The pair of drive parts are arranged concentrically and connected by a plurality of drive pins arranged so that one end can freely slide and the other end can make spherical and sliding movements, and further have an axial direction in the center. A constant velocity joint that is equipped with a stopper that prevents movement. (14) In the thirteenth aspect, the stopper has a hemispherical shape and is formed on one side of the driving portion, and is rotatably opposed to the stopper pin located on the opposite side. (15) In the fourteenth aspect, the stopper pin is arranged to be slidable via a compression spring. (16) In the fourteenth aspect, the stopper pin is in spherical contact with the stopper. 17. A cylinder barrel that is rotated in synchronization with the rotation of a drive shaft that is rotated with a predetermined tilt angle, or a drive shaft that is rotated with a predetermined tilt angle in synchronization with the rotation of the cylinder barrel; An axial piston pump/motor device comprising a plurality of piston devices arranged between a shaft and the cylinder barrel and reciprocating, and a drive pin, the piston device having one end of the piston positioned on the same circumference of the cylinder barrel. Each of the pins is rotatable and movable in the axial direction, the ball head at the other end is freely held on the end surface of the piston support, and a plurality of driving pins are arranged 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 of the spherical head is movable in the axial direction and is rotatably held on the end surface of the piston support. 18. The axial piston pump motor device according to claim 17, wherein one end of the drive pin is disposed in the drive pin insertion hole of the cylinder barrel via a compression spring. 19. The axial piston pump motor device according to claim 17, wherein the drive shaft is disposed on the inner surface of the housing via a tilting plate. 20. A cylinder barrel housed in a housing and rotating together with the drive shaft; a tilting plate fixed to a side surface of the housing to receive a piston support; a piston disposed between the piston support and the cylinder barrel and reciprocating. An axial piston pump/motor device comprising a device, the piston device having one end of the piston on the same circumference of the cylinder barrel, each rotatable and movable in the axial direction, and the other end having a spherical head. At the same time, a plurality of drive pins are each rotatably movable in the axial direction on a concentric circle on the inner diameter side of the piston of the cylinder barrel, and a ball head at the other end is held on the end face of the piston support. An axial piston pump/motor device, wherein the axial piston pump/motor device is rotatably held on an end face of the piston support so as to be movable in the axial direction.