JPH0615868B2 - Rolling piston type rotary machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rolling piston type rotary machine, for example, a negative pressure source used in a diesel engine vehicle,
Alternatively, it is effective when used as a negative pressure pump as a negative pressure source that supplies negative pressure to the brake booster.

(Prior Art) In a conventional rolling piston type rotary machine, as shown in FIG. 8, an intake port 9'and a discharge port 10 'are provided on both sides with a vane 4' interposed therebetween. 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 via the lower side of the rotor 3'in the figure. When the rotor 3'rotates at a high speed, the check valve 8'may not be able to follow the rotation, and the discharge port 10 'may not be fully closed, resulting in the check valve 8'.
And, backflow of the atmosphere occurs in the suction chamber 9'a through the discharge port 10 '. As a result, there are problems that noise is generated, driving torque is increased, and the degree of vacuum is deteriorated.

(Problems to be Solved by the Invention) 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, as described above.

(Means for Solving Problems) In order to solve the above problems, the present invention provides a cylinder having a cylindrical inner peripheral surface, and an axial center of the cylinder so as to roll along the inner peripheral surface of the cylinder. With respect to the rotor arranged in the cylinder with a predetermined eccentricity, and a space between the cylinder and the rotor while slidingly contacting the outer peripheral surface of the rotor and reciprocating in the direction perpendicular to the axis of the rotor. A vane that is partitioned and formed into a suction chamber and a discharge chamber, a vane chamber that is formed in the cylinder and that houses the vane, a suction port that sucks fluid into the suction chamber, a space between the upper and lower ends of the vane, and the vane. A discharge passage that is formed between the discharge chamber and a wall of the chamber, and that communicates between the vane chamber and the discharge chamber to guide the fluid in the discharge chamber into the vane chamber; and discharges the fluid in the discharge chamber to the outside. To do the above The opening area is formed in a predetermined shape at a position where it does not overlap with the discharge passage, and the opening area is increased or decreased by the upper end wall portion of the vane according to the reciprocating movement of the vane. And a discharge port in which the increase and change are gradually performed.

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

In FIGS. 1 and 2, the main shaft 2 is axially supported by the front housing 6 and the rear housing 7 via ball bearings 17. A balancer 13 for smoothing the rotation of the main shaft 2 is provided in the center of the main shaft 2, and both sides of the balancer 13 are eccentric by a predetermined amount from the shaft center.
4 are formed. The cylindrical rotor 3 is axially supported by 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 eccentric by a predetermined amount. Further, side plates 5a and 5b are arranged between the front housing 6 and the rear housing 7 on the side surface of the rotor 3, and the casing 1 and the side plates 5a and 5b form a cylinder.

A vane chamber 11 opening in the axial direction is formed in the casing 1, and a plate-shaped vane 4 is inserted into the vane chamber 11. A spring receiving hole 4a is formed in the vane 4, and a spring 12 is arranged between the spring receiving hole 4a and the floor surface of the vane chamber. The vane 4 is always in contact with the outer peripheral surface of the rotor 3 by the biasing force of the spring 12,
When the rotor 3 moves eccentrically in the cylinder, this rotor 3
The vane 4 reciprocates in the vane chamber 11 with the movement of the. 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 has a suction port 9 for introducing air into the suction chamber 9a.
Is formed, and a substantially circular discharge port 10 for discharging the air in the discharge chamber 10a is provided in the vane chamber 11 so as to open. Further, a check valve 8 is provided at the discharge port 10 by a valve receiver 19 to allow only air flowing from the discharge port 10 to the outside to pass through. The side plate 5
The pins a and 5b are positioned on the front housing 6 and the rear housing 7 by pins 16, and the front housing 6, the casing 1, and the rear housing 7 are fastened to each other by bolts 18.

FIG. 3 is a perspective view of the vane 4. As can be seen from this figure, the vane 4 has a plate-like shape, and a discharge passage 41 for communicating the discharge chamber 10a with the vane chamber 11 is formed on the surface thereof. The discharge passage 41 has a groove shape as shown in FIG. 3 and has a shape in which the upper and lower end portions of the vane 4 are open, and as understood from FIG.
It is formed at a position where 0 does not polymerize.

The discharge port 10 is fully opened when the vane 4 projects the maximum from the vane chamber 11, and the vane 4 is opened by the vane chamber 11.
As it is stored inside, as shown in FIGS. 1 and 2, the upper end wall portion of the vane 4 is gradually closed to reduce the opening area.

Next, the material of each component will be described. The casing 1 and the eccentric rotor 3 are, for example, iron coated with Teflon, iron coated with plasma spraying of molybdenum, alumina, or the like, carbon fiber, SiC, Si ₃
Aluminum composite material mixed with N ₄ whiskers (F
(RM) or the like, which is made of a material having a coefficient of thermal expansion equivalent to that of the ball bearing 15. The vane 4 is a resin-impregnated sintered carbon, the side plate 5 is a metal-impregnated sintered carbon, or iron is molybdenum,
It consists of plasma sprayed alumina or the like.

Next, the operation of this embodiment will be described.

The eccentric shaft 14 eccentrically rotates around the main shaft 2 in accordance with the rotation of the main shaft 2 driven by a prime mover (not shown). At this time,
Since the eccentric rotor is rotatably supported by the eccentric shaft 14 via the ball bearing 15, the eccentric rotor has a second bearing inside the casing 1.
A rotary swing motion is performed in the direction of arrow R in the figure. At this time, the vanes 4 are moved by the urging force of the compression springs 12 into the eccentric rotor 3
It abuts the outer peripheral portion of the vane chamber and reciprocates in the vane chamber 11 as the eccentric rotor 3 rotates and swings. As a result, the suction chamber 9
The discharge chamber 10a and the discharge chamber 10a are repeatedly expanded and contracted to perform a pumping action. That is, with the rotation of the main shaft 2, the suction chamber 9a
The air in the vacuum tank (not shown) of the brake booster is sucked into the suction chamber 9a through the suction port 9 until the value becomes maximum. Thereafter, the sucked air is discharged to the atmosphere through the discharge port 10 due to the reduction of the discharge chamber 10a.

Here, the discharge port 10 opening in the vane chamber 11 follows the reciprocating motion of the vane 4, and the opening area of the discharge port 10 changes corresponding to the rotation angle of the main shaft 2 as shown in FIG. That is, as shown in FIG. 4, in the vicinity of the rotation angle of 0 ° (the rotor 3 is at the lowest position in FIG. 2), the volume change rate of the discharge chamber 10a is maximum (at the maximum discharge flow rate), and The aperture ratio is 100%. After that, the aperture ratio gradually decreases, and the aperture ratio of the discharge port 10 becomes almost 0 near the rotation angle of 180 ° (the rotor 3 is at the highest position in FIG. 2).
The decrease in the opening area of the discharge port 10 at the end of this discharging step is due to the change in the volume change rate of the discharge chamber 10a, that is, the change in the discharge flow rate, as shown in FIG. At that time, it does not become exhaust resistance.

Then, the rotor 3 further rotates, the next discharge process starts, and the vane 4 is rotated by the rotation of the rotor 3 due to both actions of the biasing force of the spring 12 and the discharge pressure in the vane chamber 11.
Begins to drop. Due to the lowering of the vanes 4, the vane chamber 1
As shown in FIG. 4, the opening area of the discharge port 10 opening at 1 gradually starts to increase. That is, the discharge port 10 and the discharge chamber 10
The area of the communication port of “a” gradually expands, and the discharge port 1
The backflow corresponding to the pressure difference from 0 to the discharge chamber 10a gradually changes, and the instantaneous backflow is prevented from occurring. Therefore, even if the response of the check valve 8 is delayed, the atmosphere does not flow back from the discharge port 10 into the suction chamber 9a. Also, noise and drive torque are reduced as shown in FIG.

According to the present embodiment described above, since the vane 4 existing at the highest position of the eccentric rotor 3 is provided with the discharge passage 41, the casing 1'in front of the highest position of the eccentric rotor 3'as in the conventional case. Outlet 1 on the inner surface of
As compared with the pump provided with 0 ', since the fluid can be discharged through the discharge passage 41 until the volume of the discharge chamber 10a is reduced to the maximum, the volumetric efficiency can be improved.

Further, in this embodiment, since the discharge chamber 10a and the vane chamber 11 above the vane 4 are conducted to introduce pressure, a pressing force corresponding to the discharge pressure can be applied to the vane 4, so the spring 12 is It is not necessary to increase the size of the spring 12 to increase the urging force of the spring 12 itself, and the physique of the spring 12 can be reduced.

Although the discharge passage 41 is provided in the vane 4 in this embodiment,
As shown in the figure, the wall of the vane chamber 11, that is, the casing 1
A groove may be provided on the inner circumference of the discharge passage 101 between the wall portion and the upper and lower ends of the vane 4, or the discharge passages 101 and 41 may be provided on both sides of the casing 1 and the vane 4. The same effect can be obtained.

Further, in the present invention, the discharge port 10 is penetrated from the vane chamber 11 through the casing 1, but the same effect can be obtained by providing the discharge port 10 on both side plates or one side plate 5a, 5b of the casing 1 as shown in FIG. Obtainable. Also,
The shape of the ejection port 10 is not limited to a substantially circular shape as long as the shape of the opening area gradually increases when the opening area increases.

Although the check valve has an umbrella shape, it may be a poppet or a reed valve.

Although the casing 1, the side plate 5, the front housing 6 and the rear housing 7 are integrally fixed, they may be fixed to each other.

Although the drive source is the prime mover, it may be driven by a rotation transmitting means such as a pulley.

Although the eccentric rotor 3 is supported by the eccentric shaft 14 via the ball bearing 15, it may be supported by a needle bearing or a bush having a self-lubricating property.

(Effect of the Invention) According to the present invention, although the discharge port for discharging the fluid in the discharge chamber to the outside is opened in the vane chamber in a predetermined shape in the relationship between the vane and the discharge passage, the discharge port is overlapped with the discharge passage. Set to open at the position that does not overlap (does not overlap),
Moreover, since the opening area of the discharge port is increased or decreased by the upper end wall portion of the vane according to the reciprocating movement of the vane,
The rapid communication between the discharge port and the discharge chamber via the discharge passage is suppressed, so that the backflow into the discharge chamber becomes small little by little and the instantaneous backflow is prevented.

Therefore, the noise due to the backflow and the driving torque of the vane are reduced.

Further, since the discharge passage is formed between the upper and lower ends of the vane and the wall of the vane chamber, the discharge passage is always open to the vane chamber and is left behind in the discharge chamber due to some backflow. Even if the fluid is present, it can flow into the vane chamber through the discharge passage, the vane chamber can be used as a damper, and the pressure increase in the discharge chamber can be suppressed.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of the first embodiment, and FIG. 2 is II- of FIG.
II sectional view, FIG. 3 is a perspective view of the vane, FIG. 4 is a view for showing the operation, FIG. 5 is a view showing the effect of the embodiment, FIG. 6 is a partial perspective view showing the other embodiment, FIG. 7 is a longitudinal sectional view showing another embodiment, and FIG. 8 is a transverse sectional view showing a conventional example. 3 ... Rotor, 4 ... Vane, 9 ... Suction port, 9a ...
Suction chamber, 10 ... Discharge port, 10a ... Discharge chamber, 11 ...
Vane chamber, 41 ... Discharge passage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Hattori, 1-1, Showa-cho, Kariya city, Aichi prefecture, Nihondenso Co., Ltd. (56) References

Claims (1)

[Claims] 1. A cylinder having a cylindrical inner peripheral surface, and a rotor arranged in the cylinder with a predetermined eccentric amount with respect to the axial center of the cylinder so as to roll along the inner peripheral surface of the cylinder. A vane that is in sliding contact with the outer peripheral surface of the rotor and reciprocates in a direction perpendicular to the axis of the rotor to partition and form a space between the cylinder and the rotor into an intake chamber and a discharge chamber; A vane chamber that is formed and accommodates the vane, an intake port that sucks fluid into the intake chamber, an upper end and a lower end portion of the vane, and a wall portion of the vane chamber, and the vane chamber and the A discharge passage that communicates with the discharge chamber and guides the fluid in the discharge chamber into the vane chamber, and a discharge passage that discharges the fluid in the discharge chamber to the outside does not overlap with the discharge passage in a predetermined shape in the vane chamber. At the position And a discharge port whose opening area is increased or decreased by the upper end wall portion of the vane according to the reciprocating movement of the vane, and the increasing change is gradually performed in the initial stage of the increase of the opening area. Characteristic rolling piston type rotating machine.