JPH0241359Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a vane type air pump that is mainly used as a secondary air introduction device or a supercharger for a vehicle internal combustion engine.

[Prior art]

An example of a vane type air pump is shown in FIGS. 3 and 4. In the drawing, a cylindrical chamber 2 is formed in a casing 1, a rotor 3 is provided in this cylindrical chamber 2 with its rotational axis eccentric to the axis of the cylindrical chamber 2, and this rotor 3 is attached to the casing. It is rotatably supported on the end wall of 1 via a bearing. A vane 12 extends through a long hole 10 formed in the rotor and rotates via a bearing 17 on a vane shaft 9 that is fixed at one end to the casing 1 and extends inside the rotor 3 concentrically with the cylindrical chamber 2. The long hole 10 of the rotor 3 is provided with a pair of seal members 11, one of which is resiliently supported by a spring member 16, and this seal member 11 abuts against the side surface of the vane 12 to maintain airtightness. I am getting . A suction chamber 14 and a discharge chamber 15, which are partitioned by a land portion 13, are open in the cylindrical chamber 2, and when the rotor 3 rotates and the vanes 12 rotate accordingly, a pumping action is performed. It is something. A rotor 3 is attached to the end wall 5 of this casing 1.
A communication hole 18 is formed to communicate the interior with the atmosphere, and this communication hole 18 releases the air inside the rotor 3 to the atmosphere, cools the bearing 17 that supports the vane 12, and improves the durability of the bearing 17. Improving.

[Problem that the invention attempts to solve]

In this type of pump, forming the communication hole 18 in the casing end wall 5 reduces pump efficiency because gas compressed during pump rotation leaks into the rotor 3 and is exposed to the atmosphere. There was a drawback. This phenomenon has a large effect especially in the low-speed rotation range because the flow rate is small, and has become a major problem.

The present invention was devised in view of these points, and aims to improve the durability of a vane-type air pump by cooling the bearing that supports the vane, and at the same time prevent a decrease in pump efficiency.

[Means for solving problems]

The present invention will be explained with reference to FIGS. 1 and 2, which correspond to embodiments. In the present invention, a rotor 3 is provided with its rotational axis eccentric to the axis of a cylindrical chamber 2 formed in a casing 1, and a vane shaft 9 is placed inside the rotor 3 concentrically with the cylindrical chamber 2. and on the vane shaft 9,
Vanes 12 extending through the long holes 10 of the rotor 3
The seal member 11 provided in the long hole 10 of the rotor 3 is brought into contact with the side surface of the vane 12, and the rotor 3 is supported rotatably on the end wall 5 of the casing 1.
In a vane type air pump in which a communication hole 18 is formed so that the inside communicates with the atmosphere, the communication hole 18
A temperature-sensitive release valve 19 that opens when the temperature exceeds a predetermined temperature is provided.

[Effect]

As mentioned above, the temperature of the bearing 17 does not rise in the low speed rotation range of the vane type air pump, and the inside of the rotor 3 is at a low temperature, and the temperature-sensitive release valve 19 is closed as shown in FIG. When air leaks into the rotor 3, the internal pressure increases, and the amount of air leaking into the rotor 3 immediately decreases, preventing a drop in pump efficiency. In the high speed range of the pump, the temperature of the bearing 17 rises significantly, so the inside of the rotor 3 also becomes high temperature, and the temperature-sensitive release valve 19 becomes open as shown in FIG. , to prevent the life of the bearing 17 from decreasing. In this case, since the rotation speed is high enough to obtain a sufficient flow rate, a decrease in pump efficiency does not pose a problem in use.

〔Example〕

1 and 2 show an embodiment of the present invention. In the drawings, a bimetal is fixed to the communicating hole 18 of the end wall 5 of the casing with screws 20 to form a temperature-sensitive open valve 19. The state shown in Fig. 1 is the rotor 3.
The inside of the rotor 3 is at low speed, and the temperature-sensitive release valve 19 is closed, so that the inside of the rotor 3 is isolated from the atmosphere.
In our experiments, when the diameter of the communication hole 18 is 5 mm, the pump efficiency decreases by about 10% when the communication hole 18 is left open compared to when the temperature-sensitive release valve 19 is closed. Therefore, in a low rotation range where the inside of the rotor 3 is at a low temperature, a decrease in pump efficiency is prevented. Then, in a high rotation range where the bearing 17 supporting the vane becomes high temperature, the temperature-sensitive release valve 19 is opened to the rotor 3.
The bearing 17 becomes open due to the internal temperature, and the gas leaking into the rotor 3 is released to the atmosphere to cool the bearing 17, thereby improving durability. At this time, the temperature-sensitive release valve 19 does not suddenly become open;
Since the opening degree is appropriate depending on the internal temperature of the rotor 3, the pump efficiency does not drop suddenly during pump rotation.

In this embodiment, a bimetal was used as the temperature-sensitive release valve 19, but a shape memory alloy or the like may also be used.
It is also possible to provide a temperature-sensitive release valve inside the communication hole 18.

[Effect of idea]

Since the present invention is as described above, by cooling the bearings that support the vanes in a vane type air pump, the durability of the pump can be improved and a decrease in pump efficiency can be prevented. This has the effect of significantly improving pump efficiency in the low rotation range where the temperature is low.

[Brief explanation of the drawing]

Figures 1 and 2 are Figure 3B showing an embodiment of the present invention.
FIG. 1 shows the temperature-sensitive release valve in a closed state, and FIG. 2 shows the temperature-sensitive release valve in an open state. Figure 3 is a longitudinal sectional view showing an example of a vane type air pump, and Figure 4 is Figure 3A-A.
It is a sectional view along a line. Explanation of symbols, 1...Casing, 2...Cylindrical chamber, 3...Rotor, 5...End wall of casing, 9
... Vane shaft, 10 ... Long hole, 11 ... Seal member, 12 ... Vane, 16 ... Spring member, 18 ...
...Communication hole, 19...Temperature-sensitive release valve.

Claims (1)

[Scope of utility model registration request] A rotor 3 is provided with its rotation axis eccentric to the axis of a cylindrical chamber 2 formed in a casing 1,
A vane shaft 9 is disposed in the rotor 3 concentrically with the cylindrical chamber 2, and a vane 12 extending through the elongated hole 10 of the rotor 3 is rotatably supported on the vane shaft 9.
A vane type in which a seal member 11 provided in a long hole 10 of the rotor 3 is brought into contact with the side surface of the vane 12, and a communication hole 18 is formed in the end wall 5 of the casing 1 so that the inside of the rotor 3 communicates with the atmosphere. A vane type air pump characterized in that the communication hole 18 is provided with a temperature-sensitive release valve 19 that opens at a predetermined temperature or higher.