JPH0144909B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a vane pump in which a side plate that comes into sliding contact with the side surface of a rotor provided with vanes is made of a sintered product.

<Prior Art> Generally, a side plate of a vane pump is provided with a suction port, a discharge port, etc., and has a complicated shape that is extremely difficult to manufacture by machining. For this reason, a side plate of a sintered product is used, which uses powder metallurgy to put metal powder into a mold, press-form it, and heat and sinter it to create the final product shape.

By the way, in such a press forming process, the metal powder filled in the mold is strongly pressed by the upper mold and the lower mold, so the sintering density differs depending on the wall thickness, and the sintering occurs in the thicker parts. It was found that the density was low and the strength was also getting weaker.

Especially as a problem when the vane pump rotates at high speed,
Cavitation corrosion may occur in the grooves provided at the end of the discharge port of the side plate. In the conventional product, the wall thickness of the same part is almost equal to the side plate thickness and belongs to the thick category, so this is thought to be because the sintered density is smaller than other parts and the strength is low.

<Objective of the Invention> Therefore, an object of the present invention is to provide a vane pump that increases the sintering density of the whisker groove portions where cavitation corrosion is likely to occur, improves mechanical strength, and does not cause cavitation corrosion.

<Structure of the Invention> In the present invention, a groove is actively provided on the back side of the groove portion where cavitation corrosion is likely to occur, thereby reducing the wall thickness and increasing the sintering density.

<Examples> Examples of the present invention will be described below based on the drawings. In FIG. 1, reference numeral 10 indicates a pump housing, and the pump housing 10 has a hollow chamber formed therein, the open end of which is closed with an end cover 11. Inside the hollow chamber of the pump housing 10 there is a cam ring 12 and side plates 1 on both sides of the cam ring 12.
3 and 14 are accommodated. A rotor 15 is rotatably housed within the cam ring 12, and the rotor 15 is splined to a rotating shaft 16 rotatably supported on the pump housing 10. Rotor 1
A vane groove 18 (FIG. 2) is formed on the circumference of the vane 5 to accommodate a plurality of vanes 17 slidably in the radial direction. A plurality of pump chambers partitioned by vanes 17 are formed between the cam ring 12 and the rotor 15, and the pump chamber for the distension stroke is connected to the suction passage 20 via the suction port 19, and the pump chamber for the compression stroke is connected to the suction passage 20 through the suction port 19. The pump chamber forming the pump chamber is connected to a discharge passage 22 via a discharge port 21.

Of the side plates 13 and 14 that are in sliding contact with both side surfaces of the rotor 15, the side plate 13 on the rotating shaft 16 side is connected from one side corresponding to the pump discharge area as shown in FIGS. 3 and 4. A discharge port 21 consisting of an arc-shaped elongated hole passing through the other side is formed, and a whisker groove 30 is formed at one end of the discharge port 21 on the sliding surface side with the rotor 15, as shown in FIG. ing. As shown in FIG. 4, a recess 31 is formed on the back side of the hair groove 30 in the direction in which the discharge port 21 extends. With this, the beard groove 3
The thickness of the area where the 0 is formed is significantly smaller than other areas. By providing such a recess 31,
During press forming using the sintering method, the whisker groove 30
Since the sintered density and strength of the formation area are increased, durability against cavitation corrosion is improved.

<Effects> As described above, according to the present invention, by partially changing the formation of the side plate formed by powder metallurgy and reducing the thickness of the side plate in particular, the thickness of the grooved portion is reduced, thereby preventing cavitation corrosion in that portion. It has the effect of increasing durability.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view of a vane pump, FIG. 2 is a cross-sectional view taken along the line - in FIG. 1, FIG. 3 is a view taken along the line - in FIG. 5 is a cross-sectional view taken along the line ``-'' in FIG. 4. DESCRIPTION OF SYMBOLS 10... Pump housing, 12... Cam ring, 13, 14... Side plate, 21... Discharge port, 30... Beard groove, 31... Recessed part.

Claims (1)

[Claims] 1. A vane pump comprising a rotor that holds a plurality of vanes slidably in a radial direction and is rotatably housed in a cam ring, and a side plate that is in sliding contact with a side surface of the rotor, wherein the side plate is a sintered product. A vane pump characterized in that a concave portion is formed on the back side of the whisker groove formed at the end of the discharge port, and the wall thickness of this portion is reduced to increase the sintering density.