JPH0821366A - Axial piston type pump - Google Patents

Abstract

PURPOSE:To reduce the noise level by suppressing the relative vibration between a housing and an end cover. CONSTITUTION:A casing 20 is formed by a housing 21 one end of which is opened, and an end cover 22 to close an opening of the housing. In addition, a rotary shaft 1a inserted in the casing and an axial piston 32 which is reciprocated in the direction of the rotary shaft as the rotary shaft is driven to compress the fluid are provided. The end cover 22 is fixed to the housing by bolts 4a, 4a... so as to suppress the relative vibration of the end cover 22 relative to the housing in the direction of the rotary shaft and the relative vibration in the radial direction relative to the housing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial piston type pump, and more particularly to a vibration reduction measure.

[0002]

2. Description of the Related Art Generally, in an axial piston type pump, a rotary shaft is inserted into a casing and the rotary shaft rotates inside the casing, as disclosed in Japanese Patent Laid-Open No. 3-264778. There is a cylinder block that rotates in accordance with the above, and a swash plate that is inclined with respect to the cylinder block. The cylinder block is formed by inserting a piston into the cylinder so that the piston can reciprocally slide. The piston rotates with the rotation of the rotating shaft and reciprocates by a swash plate to compress the fluid flowing into the cylinder. And is discharged.

[0003]

In the above-mentioned axial piston type pump, suppression of noise, that is, vibration is desired. However, conventionally, it cannot be said that sufficient research has been conducted on the vibration of the axial piston type pump, and the present situation is that appropriate reduction means have not been provided, and the suppression of vibration is insufficient. There was a problem. That is, as the conventional vibration reducing means, a means for suppressing the vibration generated when the high-pressure fluid is discharged and a means for suppressing the vibration generated between the casing and the pedestal supporting the casing are proposed. However, there is a demand for the appearance of a completely new vibration suppressing means for realizing low noise.

The present invention has been made in view of the above point, and aims to reduce noise by a completely new vibration suppressing means.

[0005]

In order to achieve the above object, the means taken by the present invention is to suppress relative vibration between the housing and the cover. That is, when the inventors of the present application first study the cause of noise generation, as a result of measuring the overall vibration of the casing at a larger number of points than in the conventional case, it is assumed that the conventional casing vibrates as a whole. Although it was considered, it was discovered that the housing and the cover that make up the casing vibrate in different modes, and it was clarified that noise was generated due to the difference in the vibration mode between the housing and the cover. From this point, the present invention has been completed.

Specifically, as shown in FIG. 1, in the means implemented by the invention according to claim 1, first, one end is opened to open.
A casing (20) including a housing (21) formed with (2c) and a cover (22) closing the opening (2c) of the housing (21) is provided. Furthermore, the casing (20)
A rotary shaft (1a) inserted into the housing (21) and a cover (22) is rotatably supported by the cover (22). Moreover,
The rotary shaft (1a) is housed in the casing (20).
It is intended for an axial piston type pump provided with an axial piston (32) that reciprocates in a direction parallel to the rotation axis (1a) in accordance with the rotation of to compress a fluid. In addition, a fastening means (40) for fixing the cover (22) to the housing (21) is provided so as to suppress relative vibration of the cover (22) with respect to the housing (21) in the rotation axis direction. The means taken by the invention according to claim 2 is intended for the axial piston type pump similar to the invention according to claim 1, and suppresses the relative vibration of the cover (22) with respect to the housing (21) in the radial direction. Thus, a fastening means (40) for fixing the cover (22) to the housing (21) is provided. Further, in the invention of claim 1 or 2, the means taken by the invention of claim 3 is such that the fastening means (40) presses the mating surface of the cover (22) and the housing (21). Cover (22) housing (21)
Is constituted by a screw member (4a, 4a, ...) Tightening in the direction of the rotation axis, and the fastening means (40) is attached to the housing (21) of the cover (22). An arc surface (4b) which is formed on at least two opposite sides of the mating surface, and an intermediate side portion between the corner portions swells from the corner portion, and a cover (22).
To the housing (21) in the direction of the rotation axis.
4a, ...). Further, in the invention of claim 1 or 2, the fastening means (40) is the housing (2) of the cover (22).
A joint cylinder (4c) that is formed so as to project toward the mating surface side with respect to 1) and the opening side end of the housing (21) is press-fitted so that the outer peripheral side surface of the housing (21) is in contact, and a cover (22). And a screw member (4a, 4a, ...) for fastening the housing to the housing (21). The means of the invention according to claim 6 is such that the fastening means (40) is the opening end of the housing (21). And the outward flange (4e) formed on the housing, and the flange of the housing (21) formed on the mating surface side of the housing (21) of the cover (22).
The outward flange (4f) that contacts (4e) and the above housing (2f
It is composed of screw members (4a, 4a, ...) For joining the flange (4e) of 1) and the flange (4f) of the cover (22). Further, in the invention of claim 6 described above, the means taken by the invention of claim 7 is that the fastening means (40) is the housing (2
While the holding member (4h) for holding the flange (4e) of 1) and the flange (4f) of the cover (22) is provided, the screw members (4a, 4a, ...) Are provided.
Is the flange (4e) of the housing (21) together with the holding member (4h).
And the flange (4f) of the cover (22) are joined together. In the invention of claim 1 or 2, the means taken by the invention of claim 8 is the fastening means (4
0) is the uneven portion (4i) formed on the mating surface of the cover (22) with respect to the housing (21) and the uneven portion (4i) of the cover (22) formed on the opening side end surface of the housing (21). Uneven parts that mesh
(4j) and screw members (4a, 4a, ...) Tightening the cover (22) to the housing (21) in the rotation axis direction.

In the means taken by the invention according to claim 9, as shown in FIG. 15, first, a housing (21) having an opening (2f) formed at one end and an opening (21) of the housing (21). 2f)
And a cover (23) for closing the
0) is provided. Further, there is provided a rotating shaft (1a) which is inserted into the casing (20) and is rotatably supported by the housing (21) and the cover (23). Furthermore, an axial piston (32) is provided that is housed in the casing (20) and that reciprocates in the direction parallel to the rotary shaft (1a) in parallel with the rotation of the rotary shaft (1a) to compress the fluid. The target is an existing axial piston type pump. Then, on the opening side of the housing (21), an end wall (2b) having the opening (2f) is formed in the central portion. In addition, the housing (21) is configured to be attached and supported by the end wall (2b).

[0008]

With the above construction, in the inventions according to claims 1 and 2, first, when the rotary shaft (1a) is rotationally driven, the axial piston (32) reciprocates in the rotary shaft direction to suck the fluid, It will be compressed and discharged. During this compression operation, the housing (21) and the cover (22) are connected to each other by the fastening means (4
Since it is fixed by (0), the relative vibration of the housing (21) and the cover (22) in the rotational axis direction and the radial direction is suppressed, and the generation of noise is suppressed. Specifically, according to the invention of claim 3, since the housing (21) and the cover (22) are fixed by the screw members (4a, 4a, ...), the housing (21) and the cover (22) are fixed. 22) Relative vibration in the rotation axis direction and radial direction with respect to 22) is suppressed, and generation of noise is suppressed. According to the invention of claim 4, the arcuate surface (4b) covers the cover (22) with the housing (21) by the screw members (4a, 4a, ...).
When it is tightened, it becomes flat and each side of the cover (22) is evenly pressed against the housing (21) over almost the entire area. As a result, mainly relative vibration in the direction of the rotation axis in the direction in which the cover (22) moves away from the housing (21) is suppressed. Further, according to the invention of claim 5, the opening-side end of the housing (21) is press-fitted into the joining cylinder (4c) in a state close to a clearance fit so that the cover (22) can be removed, Screw member (4a, 4a,…)
The cover (22) is fastened to the housing (21) by the above.
As a result, the vibration in which the opening side end of the housing (21) bulges outward and the relative vibration in the twisting direction between the housing (21) and the cover (22) are mainly suppressed. Further, according to the invention of claim 6, the flange (4e) formed on the housing (21).
And the flange (4f) formed on the cover (22).
a, 4a,…). Particularly, according to the invention of claim 7, the flange (4e) of the housing (21) and the flange (4f) of the cover (22) are press-fitted into the holding member (4h) so that both flanges (4e, 4f) are formed. It is sandwiched by the sandwiching member (4h). As a result, the vibration that the cover (22) is separated from the housing (21), the vibration that the opening end of the housing (21) bulges, and the torsional vibration between the cover (22) and the housing (21) are suppressed. To be done. According to the invention of claim 8, the cover is provided by the screw members (4a, 4a, ...) in a state where the uneven portion (4i) of the cover (22) and the uneven portion (4j) of the housing (21) are engaged with each other. The (22) and the housing (21) are tightened. As a result, the vibration in which the opening side end of the housing (21) bulges outward and the relative vibration in the twisting direction between the housing (21) and the cover (22) are mainly suppressed. According to the invention of claim 9, the housing is
The cover (23) closes the opening (2f) formed in the center of the end wall (2b) of (21). As a result, the housing (2
1) can be directly attached to a support such as a stand, so cover
The entire casing (20) including (23) is fixed to a support base that is much more rigid than the casing (20), and vibration of the casing (20) itself is suppressed.

[0009]

Therefore, according to the first aspect of the present invention,
The cover (2) for the housing (21) is secured by the fastening means (40).
Since relative vibration in the direction of the rotation axis of (2) is suppressed, the cover (2
It is possible to suppress the noise generated by the vibration that 2) separates from the housing (21), and to reduce the noise. Particularly, according to the invention of claim 3, the screw member (4
a, 4a, ...) suppresses relative vibration of the cover (22) in the rotational axis direction, and according to the invention of claim 4, the arc surface (4b)
And the screw members (4a, 4a, ...) Suppress relative vibration of the cover (22) in the direction of the rotation axis, and according to the inventions according to claims 6 and 7, the flange (4e, 4f) and the screw member (4a). , 4a,…),
Furthermore, relative vibration of the cover (22) in the rotational axis direction is suppressed by the holding member (4h), and according to the invention of claim 9, since the housing (21) is directly attached to a support base such as a pedestal, Vibration of the casing (20) itself including the cover (23) is suppressed by a support base that is much stiffer than the casing (20).

Further, according to the second aspect of the invention, the relative vibration in the radial direction between the housing (21) and the cover (22) is suppressed by the fastening means (40), so that the opening side of the housing (21) is Vibrations that cause the ends to bulge outwards and the housing (21) and cover
It is possible to suppress the noise generated by the relative vibration in the twisting direction with respect to (22), and to reduce the noise. In particular,
According to the invention of claim 5, relative vibration in the radial direction between the housing (21) and the cover (22) is suppressed by the joining cylinder (4c), and according to the inventions of claims 6 and 7, the flange ( 4e,
4f), the screw members (4a, 4a, ...), and the sandwiching member (4h) suppress relative radial vibrations. According to the invention of claim 8, the concave-convex portions (4i, 4j) form the housing ( The relative vibration in the radial direction between the cover 21 and the cover 21 is suppressed, and according to the invention of claim 9, the housing 21 is directly attached to a support stand such as a pedestal. Including casing
The vibration of (20) itself is suppressed by a supporting base that is much stiffer than the casing (20).

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. -Example 1-FIG. 1 shows a swash plate type axial piston type pump (10), in which the rotary shaft (1a) is inserted into a casing (20). Together with the cylinder block kit (3
0) and a swash plate (11). The casing (20) includes a housing (21) and an end cover (22). The housing (21) has a bottom wall (2b) at one end (left end in FIG. 1) of a side wall (2a). It is integrally molded and is shown in Figure 1.
One end, which is the right end side, is opened and an opening (2c) is formed to form a bottomed box. In the axial piston type pump (10), the shaft side (left end in FIG. 1) from which the rotary shaft (1a) projects is called the front side, and the opposite pump side (right end in FIG. 1) is called the end side. Above End Cover (22)
Is formed in a substantially flat plate shape that closes the opening (2c) of the housing (21), and a mating surface (2d) with the housing (21) is formed as a flat surface. One end of the rotating shaft (1a) is an end cover
(22) is rotatably supported, the other end penetrates the bottom wall (2b) of the housing (21) and is led out to the outside, and the housing
It is rotatably supported by (21). Although not shown, the rotary shaft (1a) has a motor connected to the outer end thereof. The swash plate (11) is installed on the bottom wall (2b) in the housing (21) through the holder (12), and a bias piston is provided between the swash plate (11) and the end cover (22). (13) and a control piston (14) are provided to hold the swash plate (11) at a predetermined tilt angle. The cylinder block kit (30) is connected to the rotary shaft (1a) and
An axial piston (32) is housed in (31) so as to be capable of reciprocating in a direction parallel to the rotary shaft (1a). The cylinder block kit (30) is in close contact with the end cover (22) via the valve plate (15), while the axial piston
For example, nine (32) are provided, one end (left end) of which is a swash plate (1).
It is in sliding contact with 1). Then, the axial piston (3
2) reciprocates along with the rotation of the rotary shaft (1a), and although not shown, while sucking fluid into the cylinder (31) through the inflow passage of the end cover (22), it compresses high pressure fluid. It is configured to discharge from the outflow passage.

On the other hand, as shown in FIGS. 2 and 3, the end cover (22) is fixed to the housing (21) by the fastening means (40) which is a feature of the present invention. The fastening means (4
(0) is composed of bolts (4a, 4a, ...), which are eight screw members, and each of the bolts (4a, 4a, ...) has two screws on the periphery of each side of the end cover (22). It is provided for. The bolts (4a, 4a, ...) Extend in the rotation axis direction,
The tip is screwed to the end face of the side wall (2a) of the housing (21) on the opening side to fix the end cover (22) to the housing (21). The eight bolts (4a, 4a, ...) Above are the casing (2
The internal pressure of (0), that is, the tightening force that opposes the fluid pressure generated by the compression operation of the axial piston (32) is set, and at the same time, as a feature of the present invention, the end cover ( 22) Relative vibration in the rotating shaft direction and end cover for the housing (21)
It is set so as to have a tightening force that suppresses relative vibration of (22) in the radial direction.

Then, the reason why the relative vibration between the housing (21) and the end cover (22) is suppressed by the fastening means (40) will be explained. Conventionally, the noise of the axial piston type pump (10) has been considered as the casing (20) vibrating integrally, that is, regarding the individual vibration of the housing (21) and the end cover (22), It was not considered at all. Regarding the vibration of the casing (20), the inventors of the present application measured the vibration of the surface of the casing (20) at a large number of points, which is considerably more than in the conventional case. As a result, it was found that the casing (20) was conventionally considered to vibrate integrally, but the end cover (22) and the housing (21) were vibrating in different modes. Specifically, the following relative vibrations occur. When the end cover (22) is vibrating relative to the housing (21) in the rotation axis direction, the end cover (2
2) may vibrate away from the housing (21). The opening-side end of the side wall (2a) of the housing (21) may bulge outward, causing radial vibration such as shaking of the skirt with respect to the end cover (22). The housing (21) and the end cover (22) may be twisted relative to each other to cause radial vibration. From the above measurement results, the housing (21) and end cover (2
The relative vibration with respect to 2) is suppressed by the fastening means (40).

Next, considering the noise, first, the force for separating the housing (21) and the end cover (22) is the fluid pressure of the cylinder (31). Therefore, the fluctuation component of this fluid pressure is the actual component. It becomes a vibration. For example, the rotation speed is 1,800 rpm,
With nine axial pistons (32) of equal pitch, a vibration force with a fundamental frequency of 270 Hz is generated. So 9
The exciting force of the axial piston (32) of the book fluctuates as shown in FIG. 4 with respect to the order based on the fundamental frequency. On the other hand, the calculation result of the transfer function between the vibration force applied to the housing (21) with the end cover (22) fixed and the vibration response of the housing (21) is as shown in FIG.
In FIG. 5, the solid line A1 is the case where eight bolts (4a, 4a, ...) Are used as in this embodiment, and the one-dot chain line B1 is four bolts (4a, 4a ,. ) Is used.
Next, the vibration amplitude of the housing (21) is calculated from the vibration force of FIG. 4 and the transfer function of FIG. In FIG. 6, the solid line A2 is 8 as in this embodiment.
This is the case where four bolts (4a, 4a, ...) Are used and the chain line B2 uses four bolts (4a, 4a, ...) As in the conventional case. And up to the 13th (3,510Hz) 8 bolts (4a,
Vibration will be reduced when 4a, ...) are used. Particularly, in the pump (10) of this type, the problem of vibration and noise is 3,000 Hz or less, so that the vibration level is lower than in the conventional case, and the noise is suppressed.

-Compression Operation of First Embodiment- Next, the compression operation of the axial piston type pump (10) will be described. First, when the rotary shaft (1a) is rotationally driven, the cylinder block kit (30) rotates together with the rotary shaft (1a). And the axial piston (32) is
It will move back and forth with 1). By the reciprocating movement of the axial piston (32), the fluid is sucked into the cylinder, compressed and discharged. At the time of this compression operation, the housing (21) and the end cover (22) are fixed by the eight bolts (4a, 4a, ...), so that the housing (21) and the end cover (22) rotate. The relative vibrations in the axial direction and the radial direction are suppressed, and the generation of noise is suppressed.

-Effect of Fastening Means (40) in First Embodiment-As described above, the housing (2) is made by the fastening means (40).
Since the relative vibration between 1) and the end cover (22) is suppressed, the end cover (22) may move away from the housing (21) and the opening side end of the housing (21) may expand. It is possible to reliably control the generated vibration and the torsional vibration between the end cover (22) and the housing (21). As a result,
Noise during compression operation can be suppressed, and low noise can be achieved.

Embodiment 2 In this embodiment, as shown in FIGS. 7 and 8, the fastening means (40) is used.
Is constituted by the circular arc surface (4b) of the end cover (22) and the bolts (4a, 4a, ...) As four screw members. The arcuate surface (4b) contacts the opening-side end surface of the housing (21).
It is formed on the side. That is, in FIG. 7, each side of the end cover (22) is formed as an arc surface (4b) in which an intermediate side portion between the corners bulges toward the housing (21) from the corner. The four bolts (4a, 4a, ...) Are provided at the four corners of the end cover (22) and are screwed into the housing (21) in the rotational axis direction. Moreover,
The arcuate surface (4b) is configured to be flat when the end cover (22) is fastened to the housing (21) with four bolts (4a, 4a, ...). That is, the bolt (4a,
4a,…) When tightened, the arc surface (4b) becomes flat, and each side of the end cover (22) covers the housing (21) over almost the entire area.
It is designed to be evenly pressed against. As mentioned above,
According to the present embodiment, since the arc surface (4b) is formed on the end cover (22), each side of the end cover (22) is pressed against the housing (21) evenly over the entire surface. Therefore, relative vibration between the housing (21) and the end cover (22) can be suppressed. In particular, relative vibration mainly in the direction of the rotation axis in the direction in which the end cover (22) separates from the housing (21) can be reliably suppressed. As a result, noise during the compression operation can be suppressed, and low noise can be achieved.
In this embodiment, the four sides of the end cover (22) are formed in an arc shape, but the facing two sides may be formed in an arc shape, for example, an arc shape curved only in the vertical direction in FIG. May be

Embodiment 3 In this embodiment, as shown in FIGS. 9 and 10, the fastening means (4
0) is composed of a joining cylinder (4c) and a plurality of bolts (4a, 4a, ...). The joining cylinder (4c) is fitted with an end cover (2
2) is formed on the mating surface side of the housing (21),
The opening side end of the housing (21) is press-fitted so that the outer peripheral side surface on the opening side of the housing (21) contacts. Further, the joint cylinder (4c) is configured such that the housing (21) is press-fitted in such a manner that the end cover (22) can be removed so that the end cover (22) is close to a clearance fit, and the bolt holes (4d, 4d, ... ) Is formed. The above bolts (4a, 4a, ...) are joined cylinders (4c)
A screw member is screwed from the side surface of the end cover (2) in a direction orthogonal to the rotation axis (1a) to tighten the end cover (22) to the housing (21). As described above, according to the present embodiment, since the opening side end of the housing (21) is press-fitted into the end cover (22), the housing (21) and the end cover (22) are relatively opposed to each other. Vibration can be suppressed. In particular, it is possible to reliably suppress the vibration in which the opening side end of the housing (21) bulges outward and the relative vibration in the torsional direction between the housing (21) and the end cover (22). As a result, noise during the compression operation can be suppressed, and low noise can be achieved. In this embodiment, the bolts (4a, 4a, ...) Are screwed in the direction orthogonal to the rotary shaft (1a), but as shown by the alternate long and short dash line in FIGS. Alternatively, as in the second embodiment, the bolts (4a, 4a, ...) May be screwed into the housing (21) from the outer end surface of the end cover (22) in the rotation axis direction. When the bolts (4a, 4a, ...) Are screwed in the rotation axis direction in this way, relative vibration of the housing (21) and the end cover (22) in the rotation axis direction can be reliably suppressed. .

Embodiment 4 In this embodiment, as shown in FIGS. 11 and 12, fastening means is used.
The (40) is composed of the outward flanges (4e, 4f) of the housing (21) and the end cover (22) and a plurality of bolts (4a, 4a, ...). The outward flange (4e) of the housing (21) is formed on four sides at the opening-side end of the housing (21) and has bolt holes (4g, 4g, ...).
The outward flange (4f) of the end cover (22) is formed on four sides of the end cover (22) on the mating surface side with respect to the housing (21), and is formed on the flange (4e) of the housing (21). Bolt holes (4g, 4g,…) configured to contact
Are formed. Further, the fastening means (40) is a holding member.
(4h), and the holding member (4h) is formed in a U-shaped cross section so as to hold the flange (4e) of the housing (21) and the flange (4f) of the end cover (22). The sandwiching member (4h) is configured such that the flanges (4e, 4f) are press-fitted in a state in which the end cover (22) is removable and approximates a clearance fit. Above bolts (4a, 4
10 bolts (4a, 4a, ...) Of the (a, ...) Together with the holding member (4h) by the nut (not shown), the flange (4e) of the housing (21) and the flange (4e) of the end cover (22). Four
It constitutes a screw member that joins f) with the rotation axis direction.
Further, the other bolts (4a, 4a, ...) Are provided so as to be screwed onto the side wall (2a) of the housing (21) in the rotation axis direction from the outer end surface of the end cover (22). As described above, according to this embodiment, the flanges (4f, 4e) formed on the end cover (22) and the housing (21) are fixed by the bolts (4a, 4a, ...). In addition, vibration that the end cover (22) is separated from the housing (21), vibration that the opening side end of the housing (21) bulges, and torsional vibration between the end cover (22) and the housing (21) It can be regulated with certainty. As a result, noise during the compression operation can be suppressed, and low noise can be achieved. In this embodiment, the holding member (4h) is provided, but the holding member
(4h) may be omitted, and both flanges (4e, 4f) of the housing (21) and the end cover (22) may be directly tightened with bolts (4a, 4a, ...) And nuts.

Embodiment 5 In this embodiment, as shown in FIGS. 13 and 14, the fastening means.
(40) is an uneven portion of the housing (21) and the end cover (22)
(4i, 4j) and a plurality of bolts (4a, 4a, ...). The concavo-convex portion (4i) of the end cover (22) is formed on four sides of the end cover (22) on the mating surface side with respect to the housing (21). The concavo-convex portion (4j) of the housing (21) is formed on the opening-side end surface of the housing (21),
The end cover (22) is configured to mesh with the uneven portion (4i). The bolts (4a, 4a,…) above are the end covers.
A screw member is screwed into the housing (21) from the outer end face of the (22) in the direction of the rotation axis. As described above, according to the present embodiment, the end cover (22) and the housing (21) are provided with the concave and convex portions (4i, 4j) which mesh with each other, and
Relative vibration between the (21) and the end cover (22) can be suppressed. Especially, the vibration that the opening-side end of the housing (21) bulges outward or the housing (21) and the end cover (2
It is possible to reliably suppress relative vibration in the twisting direction with 2). As a result, noise during the compression operation can be suppressed, and low noise can be achieved.

-Embodiment 6-In this embodiment, as shown in FIGS.
The opening (2f) of (21) is formed on the right front side in FIG. That is, the above housing (21)
Is the upper wall (2) corresponding to the end cover (22) of Examples 1 to 5.
e) is continuously formed integrally with the side wall (2a), and the opening side of the housing (21) that is the front side has an opening at the center.
A bottom wall (2b), which is an end wall having (2f), is formed continuously with the side wall (2a), and an opening (2f) is formed in the center of the bottom wall (2b). The opening (2f) is formed so that the holder (12) can be inserted therein. The front cover (23) closing the opening (2f) is fixed to the housing (21) by bolts (4a, 4a, ...). Further, the housing (21) has a mounting hole (2g) formed in the bottom wall (2b), and although not shown, the mounting hole (2g) is configured to be mounted and supported on the motor support base. There is. As described above, according to this embodiment, the bottom wall (2b) of the housing (21) is
Since the opening (2f) is formed only in the center of the housing and the front cover (23) is provided in the opening (2f), the fluid pressure by the axial piston (32) is received by the entire housing (21). It will be. Since the housing (21) is directly attached to the support base, the casing (2) including the cover (23) is
The whole of 0) is fixed to a supporting base that is much stiffer than the casing (20), and vibration of the casing (20) itself is suppressed. That is, the front cover is fixed to the support base and the housing is fixed to the front cover in the past, but in the present embodiment, the housing (21) is directly fixed to the support base and the casing (20) itself. Since the vibration of the housing (21) is suppressed, the relative vibration of the housing (21) and the front cover (23) is suppressed. As a result, noise during the compression operation can be suppressed, and low noise can be achieved.

-Other Modifications-In this embodiment, the swash plate type axial piston type pump (10) has been described, but the present invention can be applied to a swash shaft type axial piston type pump and the like. Good. The concavo-convex portions (4i, 4j) in the fifth embodiment may be formed by conical or pyramidal recesses and protrusions, and the protrusions may be press-fitted into the recesses. In addition, Examples 1, 2, 3
Although 5 and 5 have been described as applied to the end cover (22), it goes without saying that they may be applied to the front cover.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an axial piston type pump.

FIG. 2 is an exploded perspective view of the casing of the first embodiment.

FIG. 3 is a top view of the casing of the first embodiment.

FIG. 4 is a characteristic diagram of excitation force with respect to rotation speed.

FIG. 5 is a characteristic diagram of a transfer function of a housing.

FIG. 6 is a characteristic diagram of vibration amplitude with respect to rotation speed.

FIG. 7 is an exploded perspective view of a casing of the second embodiment.

FIG. 8 is a top view of the casing of the second embodiment.

FIG. 9 is an exploded perspective view of a casing according to a third embodiment.

FIG. 10 is a side view of the casing of the third embodiment.

FIG. 11 is an exploded perspective view of a casing according to a fourth embodiment.

FIG. 12 is a top view of the casing according to the fourth embodiment.

FIG. 13 is an exploded perspective view of a casing according to a fifth embodiment.

FIG. 14 is a top view of the casing of the fifth embodiment.

FIG. 15 is a vertical sectional view of an axial piston type pump according to a sixth embodiment.

FIG. 16 is an exploded perspective view of a casing according to a sixth embodiment.

FIG. 17 is a bottom view of the casing according to the seventh embodiment.

[Explanation of symbols]

 10 Axial piston type pump 1a Rotating shaft 11 Swash plate 20 Casing 21 Housing 22 End cover 23 Front cover 2c, 2f Opening 30 Cylinder block kit 32 Axial piston 40 Fastening means 4a Bolt (screw member) 4b Arc surface 4c Joining cylinder 4e, 4f Flange 4h Clamping member 4i, 4j Uneven part

Claims (9)

[Claims] 1. A casing (20) comprising a housing (21) having one end opened to form an opening (2c) and a cover (22) closing the opening (2c) of the housing (21). A rotary shaft (1a) inserted into the casing (20) and rotatably supported by a housing (21) and a cover (22); and a rotary shaft (1a) housed in the casing (20). )
An axial piston type pump provided with an axial piston (32) that reciprocates in a direction parallel to the rotating shaft (1a) in accordance with the rotation of the compressor to compress a fluid, the cover (22) for the housing (21). The cover (22) so as to suppress the relative vibration of the housing in the direction of the rotation axis.
An axial piston type pump characterized by comprising a fastening means (40) for fixing to (1). 2. A casing (20) comprising a housing (21) having one end opened to form an opening (2c) and a cover (22) closing the opening (2c) of the housing (21). A rotary shaft (1a) inserted into the casing (20) and rotatably supported by a housing (21) and a cover (22); and a rotary shaft (1a) housed in the casing (20). )
An axial piston type pump provided with an axial piston (32) that reciprocates in a direction parallel to the rotating shaft (1a) in accordance with the rotation of the compressor to compress a fluid, the cover (22) for the housing (21). An axial piston type pump characterized by comprising a fastening means (40) for fixing the cover (22) to the housing (21) so as to suppress radial relative vibration of the pump. 3. The axial piston pump according to claim 1 or 2, wherein the fastening means (40) houses the cover (22) so that the mating surfaces of the cover (22) and the housing (21) are in pressure contact with each other. An axial piston type pump characterized in that it comprises a screw member (4a, 4a, ...) Tightened in the rotational axis direction at (21). 4. The axial piston type pump according to claim 1 or 2, wherein the fastening means (40) is formed on at least two opposite sides of a mating surface of the cover (22) with respect to the housing (21), and between the corners. The intermediate side of the arcuate surface (4b) bulges from the corner and the screw members (4a, 4a, ...) that fasten the cover (22) to the housing (21) in the rotation axis direction. A characteristic axial piston type pump. 5. The axial piston type pump according to claim 1 or 2, wherein the fastening means (40) is formed so as to project toward the mating surface side of the cover (22) with respect to the housing (21), and the opening side of the housing (21). Joining cylinder in which the opening side end of the housing (21) is press-fitted so that the outer peripheral side surface of the housing contacts.
(4c) and the screw members (4a, 4a) that fasten the cover (22) to the housing (21).
A, ...), and an axial piston type pump. 6. The axial piston pump according to claim 1 or 2, wherein the fastening means (40) is an outward flange formed at the open end of the housing (21).
(4e), an outward flange (4f) formed on the mating surface side of the cover (22) with respect to the housing (21) and in contact with the flange (4e) of the housing (21), and the flange (4e of the housing (21). ) And a flange (4f) of the cover (22), and a screw member (4a, 4a, ...) For joining the axial piston pump. 7. The axial piston pump according to claim 6, wherein the fastening means (40) sandwiches the flange (4e) of the housing (21) and the flange (4f) of the cover (22). ), The screw members (4a, 4a, ...) are configured to join the flange (4e) of the housing (21) and the flange (4f) of the cover (22) together with the holding member (4h). Axial piston type pump characterized by 8. The axial piston pump according to claim 1 or 2, wherein the fastening means (40) includes a concavo-convex portion (4i) formed on a mating surface of the cover (22) with respect to the housing (21), and a housing ( A cover (22) is formed on the end face on the opening side of 21).
And a screw member (4a, 4a, ...) for fastening the cover (22) to the housing (21) in the rotation axis direction. Axial piston type pump. 9. A housing (21) having an opening (2f) formed at one end thereof, and a cover for closing the opening (2f) of the housing (21).
A casing (20) constituted by (23), a rotary shaft (1a) inserted into the casing (20) and rotatably supported by the housing (21) and the cover (23), and the casing ( 20) It is housed in the rotary shaft (1a)
Is an axial piston type pump provided with an axial piston (32) that reciprocates in the direction parallel to the rotation axis (1a) with the rotation of and compresses a fluid, wherein the opening side of the housing (21) is The above opening (2f) in the center
An axial piston type pump characterized in that an end wall (2b) having the above is formed, and the housing (21) is configured to be attached and supported by the end wall (2b).