JPH08232832A - Radial plunger pump - Google Patents

Abstract

PURPOSE: To reduce a manufacturing cost by reducing number of check valves to be arranged on a discharge side. CONSTITUTION: An intake chamber 8 is formed outside an eccentric cam 3. A plurality of spiral cylinder holes 2 are formed axially by two pairs of lines A and B. A plunger 4 is formed in each cylinder hole 2, which plunger 4 reciprocates by means of the eccentric cam 3. The cylinder holes 2 of the lines A, B are formed at the same positions in a circumferential direction. The cylinder holes 2 of the lines A, B at the same positions in the circumferential direction are communicated with a discharge chamber 6 through one check valve 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial plunger pump having a plurality of pump mechanism sections arranged along the axial direction.

[0002]

2. Description of the Related Art As a radial plunger pump, a plurality of cylinder holes are radially formed inside a casing,
There is one in which a plunger is housed in each of the cylinder holes so that the plunger can move forward and backward, and the plunger is sequentially moved forward and backward by an eccentric cam that rotates by driving. In this pump, the working liquid is sucked into the cylinder hole when the plunger is projected, and is discharged to the discharge chamber through the check valve when the plunger is retracted.

In such a plunger pump,
If a large discharge flow rate is to be obtained, the diameter of the device becomes large due to an increase in the number of plungers installed and the volume thereof, which is not suitable for use in a limited space such as a vehicle.
Therefore, as a radial plunger pump suitable for use in such an application, those shown in FIGS. 3 and 4, for example, have been conventionally devised.

This radial plunger pump is provided with two sets of rows A and B of cylinder holes 2 in which a plurality of cylinder holes 2 are radially formed in a casing 1, and eccentric cams are provided in the cylinder holes 2 of each row A and B. A plunger 4 that moves forward and backward by the pressing of 3 is housed, and each cylinder hole 2 is connected to a discharge chamber 6 via a check valve 5. Then, in this pump, when the eccentric cam 3 rotates integrally with the drive shaft 7, the plungers 4 of both rows A and B sequentially move forward and backward according to the profile of the cam 3 to move from the suction chamber 8 to each cylinder hole 2. The sucked hydraulic fluid is discharged into the discharge chamber 6 through the corresponding check valves 5. In the case of this pump, since the cylinder holes 2 are provided in a plurality of rows in the axial direction,
Although the number of plungers 4 is large and a sufficient discharge flow rate can be obtained, the diameter of the device can be kept extremely small.

Incidentally, this similar technique is disclosed in, for example, Japanese Patent Laid-Open No.
It is disclosed in Japanese Patent No. 286886.

[0006]

However, in the case of the conventional radial plunger pump described above, as shown in FIG. 4, the arrangement of the cylinder holes 2 in each row A and B is displaced in the circumferential direction, and all the plungers 4 are arranged. Since the timings of suction and discharge are different, it is necessary to provide the check valves 5 so as to correspond to the cylinder holes 2 of each row A and B in a one-to-one correspondence. Therefore, the number of parts is increased and the manufacturing cost is increased, which is a problem.

Therefore, the present invention is intended to provide a radial plunger pump capable of reducing the manufacturing cost by reducing the number of check valves arranged on the discharge side.

[0008]

As a means for solving the above-mentioned problems, the present invention provides a suction chamber in the outer region of an eccentric cam which is driven and rotated, and a plurality of cylinder holes are radially provided on a peripheral wall of the suction chamber. A plurality of rows of cylinder holes are formed along the axial direction, and the cylinder holes of each row accommodate the plungers that move forward and backward by the eccentric cam. In a radial plunger pump that discharges the entered hydraulic fluid into the discharge chamber via a check valve when the plunger retracts, the cylinder holes of each row are arranged at the same position in the circumferential direction, and the cylinder holes of each row at the same position in the circumferential direction are arranged. The cylinder holes were communicated with each other, and these cylinder holes were communicated with the discharge chamber via one check valve.

[0009]

Since the cylinder holes in each row are arranged at the same position in the circumferential direction, suction and discharge are performed at the same timing in the cylinder holes in each row. The hydraulic fluid discharged from the cylinder holes of each row at the same timing is discharged to the discharge chamber through one check.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described with reference to FIGS. The same parts as those of the conventional one shown in FIGS. 3 and 4 are designated by the same reference numerals.

In the drawings, 1 is a casing,
Reference numeral 7 is a drive shaft supported by the casing 1 via bearings 10 and 11, and reference numeral 3 is an eccentric cam integrally attached to the drive shaft 7.

A suction chamber 8 having a circular cross section which communicates with a suction passage (not shown) is provided at a substantially central portion of the casing 1, and the eccentric cam 3 is rotatably accommodated in the suction chamber 8. There is. Further, on the peripheral wall of the suction chamber 8, two rows A and B of cylinder holes 2 each having a plurality of cylinder holes 2 formed radially are provided along the axial direction. A plunger 4 having a suction hole 12 on its side surface is housed in each cylinder hole 2 so as to be able to move forward and backward. This plunger 4 has a spring 13 housed in the cylinder bore 2.
Is urged inward in the radial direction, and its tip end surface is always in contact with the outer peripheral surface of the eccentric cam 3. still,
Reference numeral 14 is a plug that forms the bottom wall of each cylinder hole 2, and 15 is a retainer that supports one end of the spring 13.

The cylinder holes 2 of the row A and the cylinder holes 2 of the row B are arranged at the same position in the circumferential direction, and the plunger 4 in each cylinder hole 2 is sucked and discharged at the same timing by the pressing of the eccentric cam 3. Is supposed to do. Also,
Each cylinder hole 2 at the same position in the circumferential direction has a passage 16 between them.
Are in communication with each other, and these cylinder holes 2
The set of No. 2 communicates with the discharge chamber 6 via one check valve 5.

Since this radial plunger pump is constructed as described above, when the drive shaft 7 rotates, the eccentric cam 3 sequentially presses the plungers 4 in both rows A and B to move the plungers 4 forward and backward. Then, each plunger 4 sucks the working fluid into the cylinder hole 2 from the suction hole 12 during the projecting operation and discharges the working fluid during the retracting operation. At this time, suction and discharge are performed at the same timing in the cylinder holes 2 aligned in the axial direction of both rows A and B, and the hydraulic oil discharged from both cylinder holes 2 is discharged through the common check valve 5 into the discharge chamber. Exhaled by 6.

In the case of this radial plunger pump, since the check valves 5 corresponding to each cylinder hole 2 can be shared by both rows A and B, the number of check valves 5 installed can be reduced and the manufacturing cost can be reduced. it can.

The embodiment of the present invention is not limited to that described above, and for example, the number of rows of the cylinder holes 2 may be increased to two or more. In such a case, the discharge flow rate can be increased by increasing the number of plungers without increasing the outer diameter of the device.

[0017]

As described above, according to the present invention, the cylinder holes of each row are arranged at the same position in the circumferential direction, the cylinder holes of each row at the same position in the circumferential direction are communicated with each other, and these cylinders are also connected. Compared to the conventional one, the holes are connected to the discharge chamber through one check valve, and the hydraulic fluid discharged from the cylinder holes in each row at the same timing is discharged to the discharge chamber through a common check valve. Thus, the number of check valves to be installed is reduced, and the manufacturing cost can be surely reduced accordingly.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a side view showing the same embodiment.

FIG. 3 is a vertical sectional view showing a conventional technique.

FIG. 4 is a side view showing the same technique.

[Explanation of symbols]

 2 ... Cylinder hole, 3 ... Eccentric cam, 4 ... Plunger, 5 ... Check valve, 6 ... Discharge chamber, A, B ... Row of cylinder holes.

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Claims (1)

[Claims] 1. A suction chamber is provided in an outer region of an eccentric cam that is driven to rotate, and a plurality of rows of cylinder holes radially formed with a plurality of cylinder holes are provided on a peripheral wall of the suction chamber along with an axial direction. Plungers that move back and forth by the eccentric cams are housed in the cylinder holes in each row, and the working fluid sucked from the suction chamber into each cylinder hole when the plunger projects is discharged into the discharge chamber through the check valve when the plunger retracts. In the radial plunger pump, the cylinder holes of each row are arranged at the same position in the circumferential direction, and the cylinder holes of each row at the same position in the circumferential direction are communicated with each other, and these cylinder holes are connected to one check valve. The radial plunger pump is characterized in that it is communicated with the discharge chamber through the radial plunger pump.