JPH1054342A - Swash plate pump - Google Patents

Abstract

(57) Abstract: A plurality of plungers are coaxially coupled to a rotating shaft supported on a casing via first and second bearings, and each of the plungers is slidably fitted to the cylinder body. In a swash plate type pump in which a cylinder body is rotatably slidably contacted with a valve plate attached to an inner surface of a casing on the side opposite to the swash plate and opposite to the swash plate, downsizing in the axial direction of the rotary shaft And improve the service life. A cylinder body has a second bearing portion.
An annular concave portion 31 facing the side is formed between the rotary shaft 12 and the rotary shaft 12, and is coupled to the rotary shaft 12, and the second bearing 33 and a part of the bearing housing 21 a provided in the casing 11 to support the second bearing 33. Is inserted into the annular concave portion 31 such that the axial middle position of the second bearing 33 corresponds to the close contact surface of the cylinder body 13 and the valve plate 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type pump, and more particularly, to a swash plate type pump having a first bearing portion supported on a casing via a first bearing at one end and supported on the casing via a second bearing. A cylinder body is coaxially coupled to a rotating shaft having a second bearing portion at the other end, and a number of plungers slidably fitted into a number of cylinder holes provided in the cylinder body in an annular arrangement, respectively. Abutting against a swash plate arranged at an angle to the axis of the rotating shaft,
The present invention relates to a swash plate type pump in which a cylinder body is rotatably slidably attached to a valve plate attached to an inner surface of a casing on a side opposite to the swash plate.

[0002]

2. Description of the Related Art Conventionally, such a swash plate type pump is already known, for example, from Japanese Utility Model Laid-Open No. 5-52266.

[0003]

The above-mentioned conventional swash plate type pump is constructed as shown in FIG. 8, and has an adjusting rod 66 provided in a casing 65 so as to be able to adjust the axial advance / retreat position, and a spring. Holder 6 to which a spring force of 67 is applied
8 are engaged and abutted on a swash plate 69 sandwiched between the plungers 70 and 8 and having a determined inclination angle, and a cylinder body 71 for slidably fitting the plungers 70. A rotating shaft 72 rotatably supported by the casing 65 and coaxially penetrating the cylinder body 71 is connected by a spline 73.

One end of the rotating shaft 72 protrudes from one end of the casing 65, and a first bearing 74 is provided between the casing 65 and a first bearing portion 72a provided near one end of the rotating shaft 72. The second end of the other end of the rotating shaft 72.
A second bearing 75 is provided between the bearing 72 b and the casing 65. That is, the rotating shaft 72 is
5 is supported at both ends by the second bearing portion 72.
b is relatively large, the size of the swash plate type pump is relatively large along the axial direction of the rotary shaft 72, and the rotary shaft 72 and the cylinder body 7
Since the distance from the first joint to the second bearing 75 is relatively long, the moment acting on the second bearing 75 is relatively large, and the load on the second bearing 74 is relatively large. May be reduced in durability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a swash plate type pump which can be downsized along the axial direction of a rotating shaft and has an improved life.

[0006]

According to the present invention, there is provided, in accordance with the present invention, a first bearing portion which is supported on a casing via a first bearing at one end and a second bearing is provided on the casing. A cylinder body is coaxially coupled to a rotation shaft having a second bearing portion at the other end supported via
A large number of plungers, each of which is slidably fitted in a large number of cylinder holes provided in the cylinder body in an annular arrangement, abut on a swash plate which is arranged obliquely with respect to the axis of the rotating shaft. In a swash plate type pump in which a cylinder body is rotatably slidably attached to a valve plate attached to an inner surface of a casing on a side opposite to the swash plate, the cylinder body has an annular recess facing a second bearing portion side as a rotation shaft. And a part of a bearing housing provided on the casing for supporting the second bearing and the second bearing.
The axially intermediate position of the bearing is inserted into the annular recess so as to correspond to the close contact surface between the cylinder body and the valve plate. Therefore, the projecting amount of the second bearing portion from the cylinder body can be made relatively short to reduce the size of the entire swash plate pump, and the length from the connection between the rotary shaft and the cylinder body to the second bearing can be increased. Is relatively short so that
The moment acting on the bearing can be made relatively small, and the life can be improved by reducing the load on the second bearing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on an embodiment in which the present invention shown in the accompanying drawings is applied to a variable displacement swash plate pump.

1 to 7 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a variable displacement type swash plate type pump, and is a sectional view taken along line 1-1 of FIG. 2, and FIG. FIG. 3 is an enlarged longitudinal sectional view of the casing main body along line 3-3 in FIG. 2, FIG. 4 is a cross-sectional view of the casing main body along line 4-4 in FIG. 3, FIG. 6 is a longitudinal sectional view of the rotating shaft and the cylinder body, FIG. 6 is a side view of the swash plate holder, and FIG. 7 is a view taken in the direction of arrow 7 in FIG.

First, in FIG. 1, this variable displacement swash plate type pump is used, for example, in a lubrication and hydraulic control system for a transmission, etc., and has a casing 11 and a rotating shaft rotatably supported by the casing 11. 12, a cylinder body 13 that rotates together with the rotating shaft 12, and a large number of cylinder holes 14 provided in an annular array in the cylinder body 13 so as to surround the axis of rotation. , A swash plate 16 for engaging and abutting one end of each plunger 15, and a swash plate 16 for holding the swash plate 16 at an angle with respect to the axis of the rotary shaft 12. It has a swash plate holder 17 to be supported, and a valve plate 18 attached to the casing 11 by closely contacting the cylinder body 13 so as to be able to rotate and slide.

Referring to FIGS. 2, 3 and 4 together,
The casing 11 is formed by mutually connecting a casing main body 20 and a flat cover plate 21. The casing main body 20 includes a cylindrical portion 20a, an end wall portion 20b connected to one end of the cylindrical portion 20a, and a flange portion 20c connected to the other end of the cylindrical portion 20a and extending outward.
Rectangular windows 22, 22 are provided on both sides of the cylindrical portion 20a and the end wall portion 20b. A circular recess 23 coaxial with the cylindrical portion 20a is provided on the inner surface of the central portion of the end wall portion 20b, and the inner end is opened at the center of the concave portion 23 and the outer end is opened at the outer surface of the end wall portion 20b. A through hole 24 to be formed is provided at the center of the end wall 20b so as to be coaxial with the recess 23.

A support plate 20d extending upward is integrally formed on the upper end of one end of the cylindrical portion 20a.
a thick supporting portion 20e thicker than the flange portion 20b and extending above the supporting plate portion 20d.
Are integrally and continuously provided so as to face the support plate portion 20d at intervals. On both sides of the upper part of the cylindrical portion 20a, connecting portions 20f and 20g connecting between the supporting plate portion 20d and the thick supporting portion 20e are provided.
d, the thick supporting portion 20e and the two connecting portions 20f and 20g form an operating hole 25 having a square cross section having an inner end opened in the cylindrical portion 20a and an outer end opened to the outside. Further, on both lower sides of the cylindrical portion 20a, a cylindrical portion 20 is provided.
The bosses 20h and 20i extending from one end to the other end of “a” are provided. The support plate 20d, the thick support 20e, and the connecting portion 20f, the support plate 20d, and the thick support 20e are provided.
The connecting portion 20g and the boss portions 20h and 20i are provided with through holes 26, respectively.

The cover plate 21 is screwed with fastening bolts 27 which are inserted into the respective insertion holes 26.
By these fastening bolts 27...
The cover plate 21 is coupled to the casing main body 20 so as to close the opening at the other end of the cylindrical portion 20a. Moreover, the other end of the sleeve 28 having one end fitted to a specific plurality of the insertion holes 26 is fitted to the cover plate 21, and the fastening bolt 27 penetrates the sleeve 28 to cover the cover plate 21. 21.

A plurality of holes 29... Corresponding to each other are provided in the flange portion 20 c of the casing main body 20 and the cover plate 21, and bolts (not shown) inserted into the holes 29. ) By casing 1
1 is fixedly supported by a fixed support (not shown).

Referring also to FIG. 5, the rotating shaft 12 has a first bearing portion 12a at one end thereof and a second bearing portion 12b at the other end. On the other hand, the cylinder body 13 has a ring shape surrounding the rotary shaft 12 coaxially.
An annular concave portion 30 facing one end of the rotary shaft 12 and an annular concave portion 31 facing the other end of the rotary shaft 12 are formed between the rotary shaft 12 and the rotary shaft 12. You.

The rotary shaft 12 is rotatably supported by a casing 11 as shown in FIG. That is, one end of the rotating shaft 12 is connected to the end wall portion 20 of the casing main body 20.
b, projecting outward through the through hole 24 of the end wall portion 20.
The first bearing portion 12a is rotatably supported by a ball bearing 32 as a first bearing in which the outer ring is fitted into the concave portion 23 of b. Further, a cylindrically extending bearing housing 21a extending inward is provided integrally with the inner surface of the central portion of the cover plate 21, and a ball bearing 33 as a second bearing in which an outer ring is fitted to the bearing housing 21a. , The second bearing portion 12b is rotatably supported. In addition, a part of the bearing housing 21a and a part of the ball bearing 33 are made to protrude into the annular concave portion 31, and a substantially center position along the axial direction of the ball bearing 33, that is, a substantially center position along the axial direction of the second bearing portion 12b. Is the cylinder body 1
3 and a position corresponding to the close contact surface of the valve plate 18.

The end wall 20b of the casing body 20
A spline 34 is provided on the outer surface of one end of the rotating shaft 12 protruding from
And a sprocket 35 is coupled thereto. Power from a power source (not shown) is input to the rotary shaft 12 via the sprocket 35.

The cylinder holes 14 are formed in the cylinder body 13
Are provided in the cylinder body 13 in an annular arrangement surrounding the rotary shaft 12 so as to be open to one end surface of the cylinder body 13. Ports 36.. Thus, it is provided on the cylinder body 13.

Each of the plungers 15 is formed in a closed-end cylindrical shape with one end closed at a hemispherical shape.
6 and the pump chambers 37.
3 and slidably fitted in the respective cylinder holes 14... Between the cylinder body 13 and the respective plungers 15, one end of each of the plungers 15 projects from the cylinder body 13. , Which exert a spring force to urge the spring 38, are provided.

On the inner surface of the cover plate 21, an annular valve plate 18 coaxially surrounding the rotary shaft 12 is fitted with both ends of a plurality of split pins 39 to the valve plate 18 and the cover plate 21, respectively. The other end surface of the cylinder body 13 is rotatably slidably contacted with the valve plate 18. The valve plate 18 has a discharge path (not shown) communicating via a port 36 to a pump chamber 37 of the plunger 15 in the discharge stroke, and a port 36 to the pump chamber 37 of the plunger 15 in the suction stroke. And a suction passage (not shown) that communicates with the pump body 37. As the cylinder body 13 rotates together with the rotating shaft 12, the liquid is sucked into the pump chambers 37 and the liquid from the pump chambers 37. Discharge is switched by the valve plate 18.

The swash plate 16 is formed in a ring shape surrounding the rotary shaft 12, and one end of each of the plungers 15 is engaged with and brought into contact with the surface of the swash plate 16 on the cylinder body 13 side. Are provided, respectively.

6 and 7, a swash plate holder 17 is provided.
Is provided with a cylindrical portion 17a protruding into the swash plate 16, and a flange portion 17b extending radially outward from one end of the cylindrical portion 17a and facing the swash plate 16. A needle bearing 42 is provided between the portions 17a, and a needle bearing 43 is provided between the swash plate 16 and the flange 17b.

The swash plate holder 17 has a trunnion shaft 17 projecting on both sides in a semicircular cross-section centered on a virtual trunnion axis O orthogonal to the axis of the rotating shaft 12.
The trunnion shafts 17c, 17c are attached to receiving seats 44, 44 provided on the inner surface of the end wall 20b of the casing main body 20 of the casing 11, and the trunnion shafts 17c, 17c around the trunnion axis O. Each is fitted so as to be rotatable. By changing the rotation position of the swash plate holder 17 around the trunnion axis O, the inclination angle of the swash plate 16 changes, and each plunger 15.
Stroke, that is, the discharge amount of the swash plate pump
Will change in accordance with the inclination angle of.

An extension 17d extending toward the operation hole 25 of the casing 11 is connected to the flange 17b of the swash plate holder 17. The connection arm 45 has a tip operably housed in the operation hole 25. Is connected to the distal end of the extension 17d by a pair of rivets 46,46. The connecting arm 45 has a forked portion 45a at the tip end thereof.
Engagement holes 47, 47 are provided in 5a.

An adjusting rod 49 having an axis parallel to the rotating shaft 12 is supported by the support plate portion 20d and the thick support portion 20e of the casing 11 so as to be movable in the axial direction. Are arranged so as to straddle the adjusting rod 49, and both ends of a pin 48 that penetrates the adjusting rod 49 along one diameter line thereof have engagement holes 47,
47 is inserted and engaged. Therefore, the connecting arm 45, that is, the swash plate holder 1 is moved in accordance with the axial movement of the adjusting rod 49.
7 and the swash plate 16 swing about the trunnion axis O, so that the inclination angle of the swash plate 16 is changed.

The fork 45a of the connecting arm 45
The engagement holes 47 are formed as long holes so that the connecting arm 45 can swing in accordance with the axial movement of the adjustment rod 49.

The support plate 20d is provided with a support hole 51 into which one end of the adjustment rod 49 is slidably fitted.
The thick support portion 20e has a support hole 52 into which the other end of the adjustment rod 49 is slidably fitted, a slide hole 53 having a diameter larger than the support hole 52, and a A mounting hole 54 having a large diameter is provided coaxially with a step formed therebetween. A piston 55 is slidably fitted in the sliding hole 53, and one end of the piston 55 is
An annular hydraulic chamber 56 is formed between the outer surface of the adjusting rod 49 and the inner surface of the sliding hole 53 so as to face one end of the piston 55. A retaining ring 57 is fitted on the inner surface of the mounting hole 54 to restrict the moving end of the piston 55 in the direction of increasing the volume of the hydraulic chamber 56 by contacting the other end of the piston 55.

The cover plate 21 is provided with a screw hole 58 corresponding to the mounting hole 54, and an adjusting member 59 is screwed into the screw hole 58 so as to be able to advance and retreat, and is contacted with the adjusting member 59. A nut 60 that is in contact is screwed, and a spring 61 that biases the piston 55 in a direction to reduce the volume of the hydraulic chamber 56 is provided between the adjustment member 59 and the piston 55. A passage 62 communicating with the hydraulic chamber 56 is provided in the thick supporting portion 20e.
Is provided. A hydraulic pressure source (not shown) is connected to the passage 62, and the adjusted hydraulic pressure from the hydraulic pressure source acts on the passage 62, that is, the hydraulic pressure chamber 56.

The position of the piston 55 and the adjusting rod 49, that is, the inclination angle of the swash plate 16, balances the spring force acting on the piston 55 from the spring 61 and the force acting on the piston 55 by the hydraulic pressure in the hydraulic chamber 56. The inclination angle of the swash plate 16 is determined by adjusting the advancing / retreating position of the adjusting member 59 and adjusting the hydraulic pressure acting on the hydraulic pressure chamber 56.

By the way, the lubricating oil is supplied into the casing 11. The windows 22, 22 are provided on both sides of the cylindrical portion 20 a of the casing main body 20 of the casing 11, so that the lubricating oil is stored in the casing 11. The oil level L of the lubricating oil is located in the lower part of the casing 11 as shown by the chain line in FIG. 1, and only the lower parts of the cylinder body 13 and the swash plate 16 are immersed in the lubricating oil.
The resistance caused by the cylinder body 13 stirring the lubricating oil is relatively small, and the efficiency of the swash plate pump is improved accordingly.

Next, the operation of this embodiment will be described. Since the rotary shaft 12 and the cylinder body 13 are integrally formed without a seam, there is no play between the rotary shaft 12 and the cylinder body 13. Therefore, it is possible to prevent at least the generation of vibration and noise due to the rattling between the rotating shaft 12 and the cylinder body 13.

One end of the rotating shaft 12 is
Of the rotating shaft 12 is supported by a ball bearing 32 on one end, that is, an end wall portion 20b.
Of the rotary shaft 12 is formed between the cylinder body 13 and the rotary shaft 12 so as to form an annular concave portion 31 facing the other end of the rotary shaft 12. The ball bearing 33 and a part of the bearing housing 21a provided in the casing 11 to support the ball bearing 33 are protruded into an annular concave portion 31, and are located at an axially intermediate position of the ball bearing 33, in this embodiment, a ball. A substantially central position in the axial direction of the bearing 33 corresponds to a close contact surface between the cylinder body 13 and the valve plate 18. Therefore, the amount of protrusion of the other end of the rotating shaft 12, that is, the second bearing portion 12b from the cylinder body 13 can be made relatively short, which can contribute to downsizing of the entire swash plate pump. Further, it is possible to reduce the length from the connection between the rotating shaft 12 and the cylinder body 13 to the ball bearing 33, and the swash plate 16
Thus, the reaction force moment acting on the ball bearing 33 based on the reaction force acting on the cylinder body 13 via the plunger 15 can be made relatively small, so that the life of the ball bearing 33 can be improved by reducing the load. it can.

Further, since the adjusting rod 49 for operating the swash plate holder 17 and the swash plate 16 has both ends supported by the casing 11, the connecting arm 45 connected to the swash plate holder 17 and the adjusting rod 49 are connected. The connection point, that is, the position of the pin 48 is stabilized, and the inclination angle of the swash plate 16 can be stably maintained. On the other hand, in the conventional device shown in FIG. 8, a swash plate 69 is provided between an adjustment rod 66 that is cantilevered in a casing 65 and a holder 68 in which a spring 67 is interposed between the adjustment rod 66 and the casing 65. Because of the configuration in which the swash plate 16 is held, the holding position of the adjustment rod 66 and the holder 68 is unstable, and the inclination angle holding of the swash plate 16 is unstable.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the sprocket 35 is used to input power to the rotary shaft 12. However, the sprocket 35 is not limited to the sprocket 35 but may be of another type. Although the example in which the adjusting rod 49 is provided continuously is shown, the adjusting rod 49 may be driven in the axial direction by a solenoid or an electric motor. Further, the cylinder body 13 does not have to be formed integrally with the rotating shaft 12 and may be spline-coupled.

[0035]

As described above, according to the present invention, the second bearing and the casing for supporting the second bearing are partially projected into the annular recess formed between the cylinder body and the rotary shaft. By disposing the bearing housing provided on the inner surface, the amount of protrusion of the second bearing portion from the cylinder body can be made relatively short, and downsizing of the swash plate pump along the axial direction of the rotating shaft can be achieved. Thus, the length from the connecting portion between the rotating shaft and the cylinder body to the second bearing is made relatively short, the moment acting on the second bearing is made relatively small, and the life of the second bearing is improved by reducing the load on the second bearing. it can.

[Brief description of the drawings]

1 is a longitudinal sectional view of a variable displacement swash plate type pump, and is a sectional view taken along line 1-1 of FIG. 2;

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

FIG. 3 is an enlarged vertical sectional view of a casing main body taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view of the casing main body taken along line 4-4 in FIG. 3;

FIG. 5 is a longitudinal sectional view of a rotating shaft and a cylinder body.

FIG. 6 is a side view of the swash plate holder.

FIG. 7 is a view taken in the direction of arrow 7 in FIG. 6;

FIG. 8 is a longitudinal sectional view of a conventional variable displacement swash plate type pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Casing 12 ... Rotating shaft 12a ... 1st bearing part 12b ... 2nd bearing part 13 ... Cylinder body 14 ... Cylinder hole 15 ... Plunger 16 ... Swash plate Reference Signs List 17 swash plate holder 18 valve plate 21a bearing housing 31 annular recess 32 ball bearing as first bearing 33 ball bearing as second bearing

Claims (1)

[Claims] 1. A first bearing (32) on a casing (11).
A first bearing portion (12a) supported at one end by a second bearing (3) is provided on the casing (11).
A cylinder body (13) is coaxially coupled to a rotation shaft (12) having a second bearing portion (12b) at the other end supported via 3), and is provided on the cylinder body (13) in an annular arrangement. A plurality of plungers (15) which are slidably fitted in a plurality of cylinder holes (14), respectively, are provided with a swash plate (1) which is arranged to be inclined with respect to the axis of the rotating shaft (12).
6) and a cylinder plate (13) is rotatably slidably attached to a valve plate (18) attached to the inner surface of the casing (11) on the side opposite to the swash plate (16). In the pump, the cylinder body (13) has an annular concave portion (31) facing the second bearing portion (12b) side and a rotating shaft (12).
And a bearing housing (21a) coupled to the rotating shaft (12) and provided in the casing (11) to support the second bearing (33) and the second bearing (33).
Of the second bearing (33) is inserted into the annular recess (31) so that the axial middle position of the second bearing (33) corresponds to the close contact surface of the cylinder body (13) and the valve plate (18). And swash plate pump.