JPH0244072Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a two-blade hydraulic vane pump.
In particular, two vanes are inserted into and out of each vane groove that is tilted in the opposite direction to the rotation direction of the rotor, and an oil passage is provided on the surfaces of the vanes that face each other from the bottom to the tip of the vane. The two-blade type hydraulic system has an arcuate groove formed on the side plate to guide the suction pressure at the bottom of the vane groove in the suction region, and an arcuate groove to guide the discharge pressure at the bottom of the vane groove in the discharge region and the intermediate region. Regarding vane pumps.

[Prior art]

As one type of hydraulic vane pump, there is a conventional hydraulic vane pump shown in FIGS. 1 to 7. 1st
The hydraulic vane pump shown in the figure has a pump body 1
1, cam ring 12, rotor 13, side plate 14,
The main components are a cover (not shown) that is assembled to the pump body 11, and vanes 15 and 16 that are inserted as a pair into and out of each vane groove 13a provided in the rotor 13, and each vane The groove 13a is shown by an arrow and is formed so as to be inclined in a direction opposite to the rotational direction (clockwise) of the rotor 13.
In addition, in the same hydraulic vane pump, the a region is the discharge region, the b region is the intermediate region transitioning from the discharge region to the suction region, the c region is the suction region, and the d region is the transition from the suction region to the discharge region. In the intermediate region, the side plate 14 has a vane groove 13a in the suction region.
An arcuate groove 1 that guides suction pressure to the bottom of the vane groove 13 and discharge pressure to the bottom of the vane groove 13a in the discharge region and intermediate region.
4a and 14b are provided, respectively.

The vanes 15 and 16 used in the hydraulic vane pump have the same shape, and as shown in FIGS. 2 and 3, the vanes 15 and 16 have surfaces facing each other. Two oil grooves S reaching from the bottom to the tip are bored, and when inserted into each vane groove 13a, an oil passage A is formed (Figs. 4 to 7). figure).

In a hydraulic vane pump having such a configuration, a
Both vanes 15 and 16 are projected as shown in FIG. 4 by the centrifugal force caused by rotation and the discharge pressure P applied to the bottom of the vane groove 13a. That is, in this case, the rotating side vane 15 is connected to both vanes 1
Discharge pressure P also applied to oil path A between 5 and 16
Although the blade tries to come into close contact with the rotation side side wall 13a1 of the vane groove 13a by being pressed by The vane 16 on the opposite side is pressed by the discharge pressure P and the frictional force F applied to the oil passage A, and comes into close contact with the opposite side wall 13a2 of the vane groove 13a.

In addition, when the bottom of the vane groove 13a in the area b starts to communicate with the suction arc groove 14a, the vane groove 1
Since the pressure in the bottom of 3a drops rapidly, the vane 16 whose tip is receiving the discharge pressure P at that time
As shown in the figure, it moves toward the bottom of the vane groove 13a and leaves the cam ring 12 under the force in the direction of the arrow. At this time, since suction pressure is acting on a part of the tip of the vane 15 (on the right side in the figure), the vane 15 does not move to the bottom of the vane groove 13a, and the vane 15 does not move to the bottom of the vane groove 13a, but further by the amount that the vane 16 moves due to the frictional force F. This prevents the vane 16 from tilting and then popping out.

Furthermore, in region c, suction pressure is acting on the entire tips and bottoms of both vanes 15 and 16, and the vane 16 is tilted as described above.
Because it does not receive enough force to push back and pop out,
The state formed in FIG. 5 continues as shown in FIG. 6.

[Problem that the invention attempts to solve]

By the way, in the above-described hydraulic vane pump, when the bottom of the vane groove 13a in region d, especially, begins to communicate with the discharge arcuate groove 14b, the discharge pressure acts on the bottom of the vane 16, causing the vane 16 to move into the vane groove 13a.
Although it tries to fly out along the wall surface, its movement is blocked by the inclined vane 15. Therefore, the vane 16 moves away from the cam ring 12, and the pressure oil in the bottom of the vane groove 13a flows to the suction side through the oil passage A and the gap between the tip of the vane 16 and the cam ring 12. Therefore, the pressure in the bottom of the vane groove 13a decreases instantaneously, and the vane 15, which is receiving discharge pressure at a part of its tip, receives a force in the direction of the arrow as shown in FIG. 13a moves toward the bottom and leaves the cam ring 12. As a result, pressure oil escapes from the discharge side to the suction side as shown by the arrow, causing pressure vibrations and abnormal noise. This phenomenon occurs when the discharge pressure is low and the rotor 1
3 occurs when the number of revolutions is low. Note that since discharge pressure is immediately applied to the bottom of the vane groove 13a and the pressure increases, both vanes 15 and 16
will fly out due to the centrifugal force acting on it, as shown in Figure 4.

The operation of both vanes 15 and 16 was confirmed by synchronizing the rotational speed of the rotor 13 and the flash period of the stroboscope in a pump whose cover (not shown) was made of transparent acrylic resin.

[Means for solving problems]

The present invention has been made to address the above-mentioned problems, and in the above-mentioned two-blade hydraulic vane pump, a recess is formed at the bottom of the rear surface of each vane on the opposite side of the rotation direction in each vane groove. The vane and the side wall of the vane groove form an oil pocket that opens toward the bottom of the vane groove.

[Functions and effects of the idea]

In the present invention, while moving from the state shown in FIG. 6 to the state shown in FIG. As it flows through the gap to the suction side, a portion of the pressure oil flows into the oil pocket, pushing the bottom of the vane up from the side wall of the vane groove and tilting it along the vane 15. Therefore, the vane is less likely to be hindered from popping out by the vane 15,
It pops out due to the discharge pressure acting on the bottom and comes into contact with the cam ring 12, thereby blocking the flow of pressure oil in the bottom of the vane groove 13a toward the discharge side. Therefore, pressure drop in the bottom of the vane groove 13a is prevented, and the vane 1
5 can also be prevented from moving away from the cam ring 12. As a result, it is possible to prevent pressure oil from escaping from the discharge side to the suction side, and it is possible to prevent pressure vibration from occurring.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 8 to 11. Figures 8 to 10 show a vane 17 used in place of the vane 16 described above, and the vane 17 has two oil grooves S drilled in its front surface, similar to the vane 16, and its rear bottom. A recess 17a is formed in. The recess 17a is formed by cutting the bottom part of the back surface of the vane 17 with a cutter having a predetermined width W, and is formed in a substantially wedge shape that becomes deeper toward the bottom part. Also vane 17
If a hydraulic vane pump is constructed by inserting the vane 15 into and out of each vane groove 13a so as to be removable into each vane groove 13a, as shown in FIG.
An oil pocket B is formed that opens toward the bottom of 3a.

In such a hydraulic vane pump, a, b,
Although each vane 15, 17 moves in the region c as in the conventional hydraulic vane pump, in the region d, especially when the bottom of the vane groove 13a begins to communicate with the discharge arcuate groove 14b, the following operation is obtained.
That is, the bottom of the vane groove 13a is the discharge arc groove 14.
When the pressure oil in the bottom of the vane groove 13a communicates with the vane groove 13a flows to the suction side through the oil passage A formed between both vanes 15 and 17 and the gap between the tip of the vane 17 and the cam ring 12, the pressure oil flows to the suction side. A part of the oil flows into the oil pocket B, pushes up the bottom of the vane 17 from the side wall 13a2 of the vane groove 13a, and removes the vane 15.
Tilt it to follow. For this reason, the vane 1
7 is less obstructed from popping out by the vane 15, and pops out due to the discharge pressure P acting on the bottom and comes into contact with the cam ring 12, thereby blocking the flow of pressure oil in the bottom of the vane groove 13a to the suction side. do. Therefore, pressure drop in the bottom of the vane groove 13a is prevented, and movement of the vane 15 away from the cam ring 12 can also be prevented. As a result, it is possible to prevent pressure oil from escaping from the discharge side to the suction side, and it is possible to prevent pressure vibration from occurring.

In addition, as an experimental result that supports the above-mentioned effect, when the discharge pressure is 100 to 140 Kgf/ ^cm2, the rotor 1
Even if the rotation speed of rotor 13 was lowered to 600 rpm, no pressure vibrations would occur, but when the discharge pressure was 10 to 100 Kgf/cm ² , pressure vibrations would occur if the rotation speed of rotor 13 was lowered to 1200 rpm or less.Minimum rotation speed of 800 rpm specification In the two-blade hydraulic vane pump, each vane on the opposite side to the rotation direction is the vane 1.
7 was adopted and operated at a rotation speed of the rotor 13 of 600 rpm, an experimental result was obtained that no pressure vibration occurred even when the discharge pressure was approximately zero.

In the above embodiment, the shape of the recess formed at the bottom of the back surface of each vane 17 is approximately wedge-shaped, but the recess is an oil pocket that opens toward the bottom of the vane groove 13a by the side wall 13a2 of the vane groove 13a. 13 and is not limited to the shape of the above embodiment.

[Brief explanation of drawings]

Figure 1 is a side view showing an example of a two-blade hydraulic vane pump to which the present invention is applied, Figure 2 is a side view of each vane shown in Figure 1, Figure 3 is a front view of the same, and Figure 4 is a side view of each vane shown in Figure 1. 7 are enlarged explanatory diagrams of the hydraulic vane pump shown in FIG. 1, FIG. 8 is a side view of the vane according to the present invention, and FIG. 9 is a rear view of the same.
FIG. 10 is a front view of the same, and FIG. 11 is an enlarged explanatory view of the operation of the present invention. Explanation of symbols, 13... Rotor, 13a... Vane groove, 14... Side plate, 14a, 14b... Arc groove, 15, 17... Vane, 17a... Recess, A
...Oil passage, B...Oil pocket, S...Oil groove,
a...Discharge area, b, d...Intermediate area, c...Suction area.

Claims (1)

[Scope of utility model registration request] Two vanes are removably inserted into each vane groove provided in the rotor at an angle opposite to the rotational direction,
The surfaces of the vanes facing each other are formed with oil passages reaching from the bottom to the tip of the vane, and the suction pressure is applied to the bottom of the vane groove in the suction area, while the oil passage is applied to the bottom of the vane groove in the discharge area and intermediate area. In this two-blade hydraulic vane pump, each side plate is provided with an arcuate groove for guiding discharge pressure, and a recess is formed at the bottom of the rear surface of each vane on the side opposite to the rotational direction within each vane groove. A two-blade hydraulic vane pump characterized in that an oil pocket that opens toward the bottom of the vane groove is formed by the side wall of the vane groove and the side wall of the vane groove.