JPH041345Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention is an axial piston machine, in detail,
a cylinder block having a main shaft, a plurality of pistons that are spline-coupled to the spline portion of the main shaft and rotate together with the main shaft; a swash plate having a contact surface with which the heads of the pistons come into contact; The present invention relates to an axial piston machine including a spring that presses the head of the machine and a pin that transmits the pressing force of the spring to the head.

(Prior Art) A conventional axial piston machine is disclosed in, for example, Japanese Utility Model Application Publication No. 56-169479, and as shown in FIG. A cylinder block D having a plurality of pistons C connected together and rotating together with the main shaft A; a swash plate F having a contact surface E where the heads of the pistons C come into contact; and the contact surface portion of the swash plate F. E is provided with a spring G that presses the head of the piston C, and a pin H that transmits the pressing force of the spring G to the head, and the pin H is connected to the spline joint of the cylinder block D. The spline groove was inserted into an insertion hole I provided closer to the outer periphery than the spline groove.

(Problem to be solved by the invention) However, since the spline joint requires strength, a certain width (thickness) is required between the insertion hole I and the spline groove, and , the position of the insertion hole I is a certain width closer to the outer periphery than the spline joint, and there is also a need for a certain width (thickness) between the insertion hole I and the outer periphery of the cylinder block D. The problem was that the diameter of the cylinder block D became large, and as a result, the entire machine became large. Also, in order to make the entire machine smaller, there is a plan to form a space in the spline part of the cylinder block D and arrange the pin H in the space, but specifically, a holder is required. There was a problem with poor assembly workability.

The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to provide an axial piston machine that does not require increasing the diameter of the cylinder block and allows the entire machine to be made compact. It is in.

(Means for solving the problem) In order to achieve the above object, the present invention
A concave portion 42 in which at least one concave strip is missing is provided in the spline portion 41 of the spline portion 41 .
Spline portion 5 of cylinder block 5 connected to
1 is embedded with at least one groove to form a protrusion 52 that fits into the recess 42, and the piston 5 provided on the cylinder block 5 is attached to the protrusion 52.
a to the contact surface portion 7a of the swash plate 7.
An insertion hole 53 for the pin 14 for transmitting the pressing force of the spring 13 is formed.

(Function) Therefore, in the protruding portion 52, the pin 1
By forming the insertion hole 53 of No. 4, the strength of the spline joint can be sufficiently compensated while the pin No.
4 can be inserted and supported, and therefore the cylinder block 5 can be made smaller, thereby making it possible to make the entire machine smaller.

(Example) What is shown in the drawing is an axial piston machine using a cradle-type swash plate, and as shown in FIGS. 2 and 3, it consists of a first housing 1a and a second housing 1b. A main shaft 4 is pivotally supported on a machine body 1 through a front bearing 2 and a rear bearing 3, and a cylinder block 5 having a plurality of pistons 5a is supported on the main shaft 4 by spline connection. One side of the block 5, that is, the front side, has a contact surface part 7a on the front surface with which the head of the piston 5a contacts via the shoe 6, and a horizontal cylindrical receiver constituting a cradle type support structure on the back surface. A swash plate 7 having a surface 7b is disposed, and this swash plate 7 is supported on a horizontal cylindrical receiving surface 8a of a holder 8 fixed to the machine main body 1 so as to be able to change the horizontal inclination angle. , a control pressure acting surface 9a is provided at an outer position of the swash plate 7.
A servo piston 9 is provided which is operated under the control of a pressure compensator valve 10, and the servo piston 9 and the swash plate 7 are connected by a servo arm 12 via a slider block 11 and are interlocked. , by the operation of the servo piston 9, the swash plate 7
The horizontal inclination angle of the pump is controlled, the discharge amount of the pump is adjusted, and the rotation speed of the motor is adjusted.

In the above configuration, as shown in FIG. 1, the spline portion 41 of the main shaft 4 is provided with a concave portion 42 in which at least one groove is missing, and the spline portion 51 of the cylinder block 5 coupled to the spline portion 41 is provided with a concave portion 42 in which at least one groove is missing. At least one groove is embedded to form a protrusion 52 that fits into the recess 42, and the head of the piston 5a provided on the cylinder block 5 is attached to the swash plate via the shoe 6. An insertion hole 53 is formed for the pin 14 for transmitting the pressing force of the spring 13 to be pressed against the contact surface 7a of the spring 7.

One end of the spring 13 is engaged with a spring receiver 15 attached to the inner periphery of the cylinder block 5, pushing the pin 14 toward the swash plate 7, and the tip of the pin 14 is connected to the swash plate 7.
The shoe 6 is pressed into contact with the swash plate 7 through the shoe pressing member 16, and the head of the piston 5a is pressed against the swash plate 7 via the shoe 6. It is in contact with the contact surface portion 7a.

With the above configuration, as shown in FIG. 1, the insertion hole 53 for the pin 14 is formed in the protrusion 52 formed on the spline portion 51 of the cylinder block 5, so the cylinder block 5 can be made large. The insertion hole 53 can be formed with sufficient wall thickness on the inner and outer circumferential surfaces of the cylinder block 5 without causing any problems.Therefore, the cylinder block 5 can be made compact, and Therefore, it is possible to downsize the entire machine.

Incidentally, the present invention is not limited to the cradle type shown in the above embodiment, and the angle control structure of the swash plate 7 is not limited to the structure of the embodiment.

Further, in FIG. 1, the protruding portion 52 is formed by embedding one groove of the spline portion 51, but it may be formed by embedding two grooves.

(Effect of the invention) As described above, the present invention provides a concave portion 4 in which at least one concave strip is missing from the spline portion 41 of the main shaft 4.
2, and at least one groove is embedded in the spline portion 51 of the cylinder block 5 that is coupled to the spline portion 41 to form a protrusion 52 that fits into the concave portion 42. An insertion hole 5 for a pin 14 for transmitting the pressing force of a spring 13 that presses the head of a piston 5a provided on the block 5 against the contact surface portion 7a of the swath plate 7.
3, the cylinder block 5 can be made compact, thereby making it possible to make the entire machine compact.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the main parts of an embodiment of the present invention.
FIG. 2 is a side sectional view of the entire machine, FIG. 3 is a horizontal sectional view of the upper part of the entire machine, and FIG. 4 is a diagram illustrating a conventional example. 4...Main shaft, 41...Spline section, 42...
Recessed part, 5... Cylinder block, 5a... Piston, 51... Spline part, 52... Projection part,
53...Insertion hole, 7...Swash plate, 7
a... Contact surface portion, 13... Spring, 14...
pin.

Claims (1)

[Scope of utility model registration request] a cylinder block 5 having a main shaft 4 and a number of pistons 5a splined to a spline portion 41 of the main shaft 4 and rotating together with the main shaft 4;
A contact surface portion 7a with which the head of the piston 5a comes into contact
A swash plate 7 having a swash plate 7, a spring 13 that presses the head of the piston 5a against the contact surface 7a of the swash plate 7, and a pin 14 that transmits the pressing force of the spring 13 to the head. In the axial piston machine, the spline section 41 of the main shaft 4 has at least one protrusion removed to form a concave section 42, and the spline section 51 of the cylinder block 5 coupled to the spline section 41, An axial piston machine characterized in that a protrusion 52 is formed by embedding at least one groove so that the protrusion 52 can be fitted into the recess 42, and an insertion hole 53 through which the pin 14 is inserted is formed in the protrusion 52. .