JPS6299691A - Rolling piston type rotary machine - Google Patents

Abstract

PURPOSE:To prevent noise and driving torque from increasing by decreasing the communicated sectional area of a communicating path between a discharge chamber and a vane chamber into nothing when all the vanes have been received in the vane chamber, to prevent discharged fluid from flowing backward into a suction port through the discharge chamber. CONSTITUTION:A plane on the side of a discharge chamber 10a for a vane 4 is provided with two communicating grooves 20 extending from one end plane 41 to the other end plane 42, and a communicating path 22 formed by the communicating grooves 20 and the inner wall plane of a vane chamber 11 causes the discharge chamber 10a to communicate with the vane chamber 11. Thus, until a rotor 3 reaches its lowest position from its highest one in a drawing, the communicated area of the communicating path 22 increases with its revolution, and on the other hand until it reaches its highest position from its lowest one, the above mentioned area decreases with its revolution, and becomes practically zero when the rotor 3 arrives at the highest position. Consequently, it becomes possible to prevent discharge fluid from flowing backward from a discharge port to a suction port 9 through the discharge chamber 10a, thus an increase in noise and driving torque can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rolling piston type rotating machine, and is used as a negative pressure source used in, for example, a diesel engine vehicle or a negative pressure source that supplies negative pressure to a brake booster. It is effective when used as a negative pressure pump.

[Conventional technology]

In a conventional rolling piston rotary machine, as shown in FIG. 8, an inlet 9' and an outlet 10' are provided on both sides with a vane 4' in between. In this case, when the rotor 3' is at the uppermost position in the figure as shown in FIG. 8, the suction port 9' and the discharge port 10' communicate with each other through the lower side of the rotor 3' in the figure. When the rotor 3' rotates at high speed, the check valve 8' may not be able to follow the rotation, and the discharge port 10' may not be closed sufficiently, causing the check valve 8'
A backflow of the discharge fluid occurs into the suction chamber 9'a through the discharge port 10'. As a result, there were problems such as generation of noise, increase in driving torque, and deterioration of the degree of vacuum.

[Problem that the invention seeks to solve]

As described above, the present invention solves the problem of communication between the discharge port and the suction port due to the inability of the discharge check valve to follow the flow.

[Means for solving problems]

In order to solve the above problems, the present invention takes the following measures. That is, a cylinder having a cylindrical inner peripheral surface,
a rotor disposed within the cylinder that performs revolution movement while slidingly contacting the cylindrical inner circumferential surface;
A plate-shaped vane that reciprocates in a direction perpendicular to the axis of the rotor and divides the space formed by the cylinder and the rotor into a suction chamber and a discharge chamber, and a plate-shaped vane formed in the cylinder to accommodate the vane. a vane chamber, a suction port that opens toward the suction chamber for sucking fluid into the suction chamber, and a discharge port that opens toward the vane chamber for discharging the fluid in the discharge chamber. A communication groove is formed in a surface of the vane on the discharge chamber side, and the discharge chamber and the vane chamber are communicated with each other by a communication path formed by the communication groove and an inner wall surface of the vane chamber. , as the vanes are stored in the vane chamber, the communication cross-sectional area of the communication path gradually decreases, and at least when all the vanes are stored in the vane chamber, the communication cross-sectional area of the communication path becomes substantially zero. This is a rolling piston rotating machine that is characterized by:

〔Example〕

Next, an embodiment in which the present invention is used as a vacuum pump for a brake booster will be described.

1 and 2, the main shaft 2 is supported via a ball bearing 17 by a front housing 6 and a rear housing 7G. A balancer 13 is provided at the center of the main shaft 2 to smooth the rotation of the main shaft 2, and on both sides of the balancer 13 are eccentric shafts 1 that are eccentric by a predetermined amount from the shaft center.
4 is formed. A cylindrical rotor 3 is supported on the eccentric shaft 14 via a ball bearing 15. A casing 1 having a cylindrical inner surface 1a is sandwiched between the front housing 6 and the rear housing 7, and the center of the cylindrical inner surface 1a and the center of the rotor 3 are offset by a predetermined amount. Further, on the side surface of the rotor 3, a side plate 5a is provided between each of the front housing 6 and the rear housing 7.

5b is arranged, and the casing 1, side plates 5a, 5
b forms a cylinder.

A vane chamber 11 that opens in the axial direction is formed in the cane I, and a plate-shaped vane 4 is inserted into the vane chamber 11. In this vane company 4, a spring receiver is formed with a hole 4a, and a spring 12 is disposed between the hole 4a and the bottom surface of the vane chamber. The vane 4 is always in contact with the outer peripheral surface of the rotor 3 due to the biasing force of the spring 12.
When the rotor 3 moves eccentrically inside the cylinder, this rotor 3
As the vane 4 moves, the vane 4 reciprocates within the vane chamber 11. Further, the vane 4 divides a cylinder chamber formed by the inner surface of the cylinder and the outer peripheral surface of the rotor 3 into a suction chamber 9a and a discharge chamber 10a. The casing 1 is formed with a suction port 9 for guiding air into the suction chamber 9a, and a discharge port 10 for discharging air in the discharge chamber 10a is provided to open into the vane chamber 11. . In addition, a check valve 8 is provided at the discharge port 10 to allow only the air directed to the outside from the discharge port 10 to pass through the valve receiver 1.
9. The side plates 5a and 5b are positioned on the front housing 6 and the rear housing 7 by means of pins 16, and the front housing 6,
The casing 1° and the rear housing 7 are fastened to each other by bolts 18.

Next, the shape of the vane 4 will be explained based on FIG. 3.

This vane 4 is made of a plate-like member, and is
One end surface 41 in sliding contact with the outer circumferential surface of is in the shape of an arc,
A hole 4a is bored in the other end surface 42 of the spring receiver. Further, one end surface 4 is provided on the surface facing the discharge chamber 10a.
Two communication grooves 20 extending from the first side toward the other end surface 42 side
(having groove length L) is formed. The communication groove 20 is formed at a predetermined distance H from one end surface 41 of the vane 4, and is formed from the one end surface 41 side to the other end surface 42.
The groove depth gradually becomes deeper toward the side, and the other end surface 42
It is open at .

The vane 4 is housed in the vane chamber 11 so as to fit into the vane chamber 11, and the discharge chamber 10a and the vane chamber 1 are connected to each other.
Connect with 1. A communication path 22 is formed by the communication groove 20 and the inner wall of the vane chamber 11.

Next, we will discuss the materials of each component. The casing 1 and the eccentric rotor 3 are made of a material having a coefficient of thermal expansion equivalent to that of the ball bearing 15, such as steel coated with Teflon, or an aluminum composite material (FRM) containing carbon fiber, SiC, 5izN4 Swisscar, etc. . The vane 4 is made of resin-impregnated sintered carbon, and the side plate 5 is made of metal-impregnated sintered carbon.

Next, the operation of this embodiment will be explained.

The eccentric shaft 14 eccentrically rotates around the main shaft 2 as the main shaft 2 is rotated by a prime mover (not shown). At this time,
Since the rotor 3 is rotatably supported on the eccentric shaft 14 via a ball bearing 15, a second
Carry out a movement in the direction of the arrow R in the figure. At this time, the vane 4 comes into contact with the outer periphery of the eccentric rotor 3 due to the pressing force of the compressor coil nose 12, and the rotational oscillation movement of the eccentric rotor 3 causes the reciprocation within the vane chamber 11. Do exercise. From this point on, the suction chamber 9a and the discharge chamber tOa are enlarged.
Repeat contraction and pump action. That is, as the main shaft 2 rotates, air in, for example, a vacuum tank (not shown) of a brake booster is sucked into the suction chamber 9a through the suction port 9 until the suction chamber 9a reaches its maximum capacity.

Thereafter, the inhaled air is transferred to the communication path 22 due to the contraction of the discharge chamber 10a. It is discharged into the atmosphere from the discharge port 10 via the vane chamber 11.

Here, the communication area of the communication path 22 formed by the communication groove 20 and the inner wall of the vane chamber 11 is increased or decreased depending on the amount of protrusion of the vane 4 from the vane chamber 11. That is, when the vane 4 is completely housed in the vane chamber 11,
The part of the vane 4 having the predetermined distance H or the vane chamber 11
The communication path 22 is cut off from the discharge chamber 10a. Thereafter, when the vane 4 protrudes by a predetermined distance IH, the communication passage 22 begins to open into the discharge chamber 10a, and as the vane 4 further protrudes, the communication area of the communication passage 22 increases by the depth of the communication groove 20. It continues to increase. The communication area becomes maximum when the vane 4 protrudes the most. Conversely, when the vane 4 retreats into the vane chamber 11, the communication area of the communication path 22 gradually decreases.

In other words, from the time when the rotor 3 is located at the uppermost position in FIG. The communication area of the communication passage 22 decreases as the rotor 3 revolves from the position to the uppermost position. When the capacity of the discharge chamber 10a becomes zero, that is, when the rotor 3 reaches the uppermost position, the communication area of the communication passage 22 becomes substantially zero, and the communication area between the vane chamber 11 where the discharge port 10 opens and the discharge chamber 10a
is blocked. Incidentally, when the amount of protrusion of the vane 4 is within the predetermined distance H, the communication area of the communication passage 22 is kept substantially zero, so that the distance of the rotor 3 corresponding to this predetermined distance H is The revolution angle is α.

Then, when the rotor 3 is located within a range of ±α° from the uppermost position angle of the rotor 3, the communication path 22 is blocked.

FIG. 4 shows the communication area S of the communication passage 22 and the discharge chamber 1 with respect to the revolution angle of the rotor 3, that is, the rotation angle θ of the eccentric shaft 14.
It shows the volume change rate dV/dθ of 0a. The rotation angle θ is O when the rotor 3 is located at the lowest position as shown in FIG.

The angle when the rotor 3 is located at the highest position is 180°. As can be seen from this figure, as the volume change rate dV/dθ of the discharge chamber 10a decreases, the communication area S of the communication path also decreases, and the rotation angle θ becomes 180°.
In the vicinity, S=0.

Incidentally, the communication groove 20 formed in the vane 4 may be formed starting from one end 41 of the vane 4 and opening at the other end 42, as shown in FIG. If the communication groove 20 is formed in this way, the communication path 22 will be closed only when the rotor 3 is located at the uppermost position and the vane 4 is completely housed in the vane chamber 11. Therefore, the fluid can be discharged through the communication passage 22 until the volume of the discharge chamber 10a is reduced to the maximum extent, and the volumetric efficiency of the entire pump can be improved.

Furthermore, the communication groove 20 may have a shape as shown in FIGS. 6 and 7. In the one shown in FIG. 6, the width of the communication groove 20 gradually widens from one end 41 toward the other end 42. As shown in FIG. As the vane 4 protrudes from the vane chamber 11, the communication area of the communication path 22 increases by an amount corresponding to the width of the communication groove 20.

In the one shown in FIG. 7, the longest groove 20a has the longest groove length.
, the shortest groove 20c with the shortest groove length, and this longest groove 2Q
intermediate groove 20b having a length intermediate between a and the shortest length 120c
Two of each were formed on the vane 4. As the vane 4 protrudes from the vane chamber 11, first the longest groove 20a opens into the discharge chamber 10a, then the middle groove m20b opens, and finally the shortest groove 20c opens. Therefore, in the communication groove 20 made up of grooves having three different lengths, the communication area increases stepwise as the vane 4 protrudes.

In the embodiment described above, the discharge chamber 10a and the vane chamber at the upper part of the vane 4 are communicated with each other by the communication groove, and discharge pressure is introduced into the upper part of the vane 4. Therefore, the pressing against the roller 3 according to the discharge pressure is performed by a force. can be given to the vane 4. Therefore, the biasing force of the compression coil spring 12 can be small, and the size of the compression coil spring 12 can be reduced.

〔Effect of the invention〕

As explained above, when the rolling piston rotating machine of the present invention is used, when all the vanes are housed in the vane chamber, the communication path connecting the discharge chamber and the discharge port is cut off, so that the discharge fluid can be discharged. The problem of backflow from the outlet via the discharge chamber to the suction port cannot occur. Therefore, it is possible to prevent problems such as noise, increase in driving torque, and deterioration of the effectiveness of the rotating machine due to backflow to the fluid.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the embodiment, Fig. 2 is a cross-sectional view, Fig. 3 is a perspective view showing the vane, Fig. 4 is a view showing the operation, Fig. 5, Fig. 6, and Fig. 7 are Perspective view showing a modified example of the vane, No. 8
The figure is a cross-sectional view of a conventional example. DESCRIPTION OF SYMBOLS 1... Casing, 3... Rotor, 4... Vane, 9... Suction port, 9a... Suction chamber, 10... Discharge port, 10a... Discharge chamber, 11... Vane chamber, 20・
...Communication groove, 22...Communication path.

Claims (1)

[Claims] A cylinder having a cylindrical inner circumferential surface, a rotor disposed within the cylinder that revolves while sliding on the cylindrical inner circumferential surface, and a rotor that slides on the outer circumferential surface of the rotor and reciprocates in a direction perpendicular to the axis of the rotor. a plate-shaped vane that divides the space formed by the cylinder and the rotor into a suction chamber and a discharge chamber; a vane chamber formed in the cylinder to accommodate the vane; and a vane chamber formed in the cylinder to accommodate the vane; a suction port that opens toward the suction chamber to suck in fluid; and a discharge port that opens toward the vane chamber to discharge fluid in the discharge chamber; A communication groove is formed in the surface, and the discharge chamber and the vane chamber communicate with each other through a communication path formed by the communication groove and the inner wall surface of the vane chamber, and the vane is housed in the vane chamber. A rolling piston characterized in that the communication cross-sectional area of the communication passage gradually decreases as the vane is moved, and the communication cross-section area of the communication passage becomes substantially zero at least when all the vanes are housed in the vane chamber. rotary machine.