JP2600544Y2 - Swash plate pump stopper - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a variable displacement type swash plate pump, and more particularly, to an improvement of a stopper which abuts on a swash plate and regulates its inclination within a certain range.

[0002]

2. Description of the Related Art A variable displacement swash plate pump is provided with a stopper for preventing the swash plate from being displaced beyond a preset maximum and minimum tilt angle.

[0003] Such a stopper is constituted by, for example, a projection formed on the pump body or a pin engaged with the pump body. When these stoppers come into contact with the swash plate, the swash plate is prevented from further tilting. It is supposed to.

[0004]

[Problems of the Invention] By the way, a moment due to hydraulic pressure acts on the swash plate, and when the swash plate in contact with the stopper separates from the stopper, the fluctuation of the moment causes the swash plate to vibrate and hit the stopper. Thus, there is a problem that vibration is transmitted to the pump body via the stopper, and as a result, noise is generated.

In order to prevent the vibration that causes noise from being transmitted to the pump body via the stopper, the stopper may be made of a resin having an anti-vibration function. However, since a large load acts on the contact portion between the stopper and the swash plate, there is a problem that the stopper made of resin is severely worn, and the required durability cannot be satisfied.

The present invention has been made to solve the above problems, and has as its object to provide a stopper for a swash plate having a vibration absorbing function and durability.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a stopper of a swash plate pump which contacts a tilting swash plate to restrict further tilting of the swash plate is fitted into a hole formed in the pump body. And a cylindrical metal cover with a bottom protruding toward the swash plate and a spherical surface formed on the contact surface of the metal cover with the swash plate
A resin vibration isolating member housed inside the metal cover, one end of which is in contact with the bottom surface of the hole, and the other end of which is in contact with the inner surface of the metal cover ; and a through hole formed in the center of the resin vibration isolating member. When,
A clearance was provided between the bottom surface of the hole of the pump body and the open end of the metal cover .

[0008]

[0009]

The vibration of the swash plate is absorbed by the vibration isolator made of resin, and the transmission of the vibration to the pump body is prevented. Further, the metal cover prevents the resin vibration isolator from directly contacting the swash plate, thereby preventing the resin vibration isolator from being worn due to the direct contact with the swash plate.

Further, when the resin vibration damping member is worn by a certain amount , the open end of the metal cover comes into direct contact with the pump body, thereby suppressing the further inclination of the swash plate, and functioning as a stopper. maintain. Also, resin vibration isolator
Formed by a through hole at the center of the
High vibration damping effect of the vibration isolator.

[0011]

1 and 2 show an embodiment of the present invention.

In the swash plate pump shown in FIG. 1, reference numeral 1 denotes a pump body, and a rotary shaft 2 penetrates a central portion. Inside the pump body 1, a cylinder block 3 fixed to the outer periphery of the rotating shaft 2 is housed.

A plurality of cylinders 4 are formed in the cylinder block 3 in parallel with the rotating shaft 2, and a piston 5 is slidably inserted inside the cylinder 4. The base end of the piston 5 slides on the swash plate 7 via the shoe 6.

A push pin 16 urged by springs 9 and 10 abuts one end of the swash plate 7. A push rod 17 projecting from the pump body 1 in the axial direction abuts on the end of the swash plate 7 on the opposite side of the rotary shaft 2 from the push pin 16. The push rod 17 presses the swash plate 7 in the axial direction with a pressure corresponding to the discharge pressure of the pump.

On the other hand, the pump body 1 has a push pin 1
Stoppers 11 and 12 for supporting the swash plate 7 in the opposite direction to the push rod 6 and the push rod 17 are attached.

The stoppers 11 and 12 have the same structure, and are arranged symmetrically with respect to the rotation shaft 2.

As shown in FIG. 2, the stopper 11 (12) comprises a vibration isolating member 13 made of resin and a cover 14 made of metal. The anti-vibration member 13 is a member made of a columnar resin having a through hole formed in the center, and the cover 14 is a metal bottomed cylindrical member fitted to the outer periphery of the anti-vibration member 13. Cover 14
Is fitted inside the hole 15 formed in the pump body 1 with the vibration isolating member 13 fitted inside, and its bottom projects toward the swash plate 7. The bottom of the cover 14 is formed in a spherical shape as shown in the figure.

Both end surfaces of the vibration isolating member 13 are in contact with the bottom surface of the hole 15 and the bottom surface of the cover 14, respectively. The dimension of the cover 14 in the axial direction is set so that a predetermined clearance δ is secured between the opening end of the cover 14 and the bottom surface of the hole 15.

Next, the operation will be described.

FIG. 1 shows a state in which the swash plate 7 is supported at the largest tilt angle.

Here, the shoe 6, the push pin 16 and the push rod 17 press the swash plate 7 in the axial direction, and press the swash plate 7 against the stopper 11 in an inclined state.

When the discharge pressure of the pump increases according to the load, the pressing force exerted on the swash plate 7 by the push rod 12 and the shoe 6 increases, and the swash plate 7 is displaced in a direction to decrease the tilt angle.

When the discharge pressure reaches a maximum, the pressing force also reaches a maximum, and the swash plate 7 comes into contact with the stopper 12 as shown by a chain line in the figure.

In this manner, the maximum tilt angle of the swash plate 7 is defined by the stopper 11 and the minimum tilt angle is defined by the stopper 12.

When the swash plate 7 separates from the stopper 11 or 12, the swash plate 7 slightly vibrates, and
This vibration is transmitted to (12). This vibration is caused by cover 1
4 and further propagates to the vibration isolating member 13, but is greatly attenuated inside the vibration isolating member 13, so that it is hardly transmitted to the pump body 1, so that noise due to the vibration of the swash plate 7 hardly occurs.

Further, the vibration isolating member 13 made of resin does not directly contact the swash plate 7 and thus has good durability. Further, even if the vibration isolating member 13 is worn by a certain amount, the gap between the cover 14 and the body 1 is reduced. Is moved by the clearance δ of
Thereafter, since the open end of the metal cover 14 directly contacts the pump body 1, no further movement of the stopper 11 (12) occurs, and no excessive tilting of the swash plate 7 occurs.

[0027]

The present invention as described above, according to the invention] is fitted to the hole portion formed in the pump body, a bottom and a bottomed cylindrical metal cover which projects toward the swash plate, the swash plate of the metal cover Contact with
It is stored inside the spherical surface formed on the surface and the metal cover,
The bottom surface of one end the hole, and the resin vibration isolating member the other end is <br/> contact with the inner surface of the metal cover, forms the center of the resin damping member
And a clearance provided between the bottom surface of the hole of the pump body and the open end of the metal cover .
Thus, the vibration of the swash plate transmitted to the pump body can be greatly attenuated on the way by the resin vibration isolator. In addition, since the resin vibration isolator does not directly contact the swash plate, the durability is good.Moreover, when the resin vibration isolator is worn by a certain amount, the open end of the metal cover directly contacts the pump body. The problem that the swash plate is excessively tilted can also be prevented. Also, resin vibration isolator
With a metal cover and the wall of the hole,
The structure is not exposed to the inside of the
Debris falls into the pump chamber even if the vibration member is damaged
No damage to other parts. Also, the tree
A through hole is formed at the center of the vibration isolator made of resin,
The damping effect of the vibration member is enhanced.

Therefore, it is possible to improve the vibration absorption of the stopper of the swash plate while maintaining the durability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a swash plate pump according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a stopper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump body 7 Swash plate 11, 12 Stopper 13 Anti-vibration member 14 Cover

Claims (1)

(57) [Scope of request for utility model registration] 1. A stopper for a swash plate pump which abuts on a tilting swash plate and restricts further tilting of the swash plate. The stopper is fitted into a hole formed in the pump body, and the bottom portion is directed toward the swash plate. Cylindrical metal cover with a bottom and a swash plate of the metal cover
And a spherical surface formed on an abutting surface thereof, and housed inside a metal cover, one end of which is on the bottom surface of the hole, and the other end of which is made of a metal cover.
Between the resin vibration isolator and the resin vibration isolator
The through hole formed in the center and the clearance provided between the bottom of the hole of the pump body and the open end of the metal cover
Swash plate stopper pump, characterized in that it includes.