EP1614900A2

EP1614900A2 - Rotor of a vacuum vane pump

Info

Publication number: EP1614900A2
Application number: EP04021482A
Authority: EP
Inventors: Hyun-Cheol Lee; Kyeong-Hyeong Lee
Original assignee: Valeo Electrical Systems Korea Ltd
Current assignee: Valeo Electrical Systems Korea Ltd
Priority date: 2004-07-06
Filing date: 2004-09-09
Publication date: 2006-01-11
Also published as: CN1719037A; KR100605377B1; JP2006022799A; KR20060003988A

Abstract

The present invention relates to a pump rotor of a vacuum pump for a vehicle capable of decreasing a friction force between a pump housing and a pump vane, and a pump rotor and enhancing durability in such a manner that a lubricant supply structure of a pump rotor is enhanced. In a vacuum pump that includes a shaft, a pump rotor that has a shaft hole, a plurality of vanes that are assembled to a vane sliding groove of the pump rotor, and a pump housing, there is provided a pump rotor comprising a concave groove part that is formed in a lateral surface of the pump rotor and is not connected with the vane sliding groove but is connected with the shaft hole for thereby forming an oil storing part therein.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pump rotor of a vacuum pump for a vehicle, and in particular to a pump rotor of a vacuum pump for a vehicle capable of decreasing a friction force between a pump housing and a pump vane, and a pump rotor and enhancing durability in such a manner that a lubricant supply structure of a pump rotor is enhanced.

2. Description of the Background Art

Generally, a vacuum suction force is used in a vehicle for multiple purposes. The vacuum suction force is generated in such a manner that a vacuum pump directly connected with a driving force shaft of an engine or a vacuum pump connected with an alternator is driven. Figure 1 is a view illustrating the construction of a vacuum pump 20 that is additionally installed at a vehicle alternator 10.
As shown therein, a pump rotor 21 is engaged to a shaft 12 of an alternator 10 that receives a driving force from an engine through a pulley 11. A vane 22 is assembled to the pump rotor 21. The above elements are rotated in a pump housing 23 for thereby generating a vacuum suction force.
As the revolution of the vacuum pump 20 is increased, a friction occurs between the pump rotor 21 and the vane 22, and the pump housing 23. The friction generates heat, so that a contacting portion is worn out. Therefore, the durability of the pump is decreased.
In order to decrease the friction of each element and the heat generated by the friction, a lubricant is supplied into the interior. In a conventional lubricant supply structure, the lubricant is directly supplied to a sliding portion between the vane 22 and the pump rotor 21.
However, according to the conventional direct oil supply method, when the pump rotor 21 is rotated at a high speed, the lubricant supplied to the friction portion is easily moved due to a centrifugal force and the flow of the vacuum, so that it is impossible to effectively decrease the friction and heat generation.
In order to overcome the above problems, when the supply amount of lubricant is increased, noise is increased, and a shearing force applied to the vane is increased.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to overcome the problems encountered in the conventional art.
It is another object of the present invention to provide a pump rotor of a vacuum pump for a vehicle capable of effectively supplying lubricant to a vane sliding portion and each portion in the interior of a vacuum pump by improving a structure of a pump rotor.
It is further another object of the present invention to provide a pump rotor of a vacuum pump for a vehicle capable of automatically continuously supplying lubricant based on an inter-operation between a centrifugal force of a pump rotor and an inertia force of lubricant in such a manner that a lubricant storing part is formed in a lateral surface of a pump rotor, and lubricant is stored in the storing part.
To achieve the above objects, in a vacuum pump that includes a shaft for receiving a rotational force, a pump rotor that has a shaft hole for receiving an end of the shaft therein, a plurality of vanes that are assembled to a sliding groove of the pump rotor, and a pump housing in which each end of the vanes contacts with an inner surface of the pump housing and is rotated, there is provided a pump rotor of a vacuum pump for a vehicle, comprising a concave groove part that is formed in a lateral surface of the pump rotor and is not connected with a vane sliding groove but is connected with the shaft hole for thereby forming an oil storing part therein.
The concave groove part of the oil storing part is provided in multiple numbers between the vane sliding grooves, wherein the oil storing parts are connected with each other through a communicating part.
The concave groove part is slanted at a certain angle θ with respect to a certain radial direction extension line L1 which initiates from a center of the pump rotor and passes through the concave groove part, and the concave groove part of the oil storing part is slanted in a polygonal shape for thereby achieving a smooth flow of oil.
An oil movement hole is formed between the vane sliding groove and the shaft hole irrespective of the presence of the communicating part.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein;

Figure is a cross sectional view illustrating a vacuum pump attached to a vehicle alternator;
Figure 2 is a perspective view illustrating a pump rotor according to the present invention;
Figure 3 is a perspective view illustrating a pump rotor according to another embodiment of the present invention;
Figure 4 is an enlarged view illustrating an oil storing part according to the present invention; and
Figure 5 is a perspective view illustrating the construction according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The construction and operation of the present invention will be described with reference to the accompanying drawings.
Figure 2 is a perspective view illustrating a pump rotor according to the present invention, and Figure 3 is a perspective view illustrating a pump rotor according to another embodiment of the present invention.
As shown in Figure 1, the vacuum pump 20 includes a shaft 12 that receives a rotational force at a lateral side of an alternator (engine), a pump rotor 21 that is engaged to an end portion of the shaft 12 and has a shaft hole 21 b for receiving a shaft therein, a plurality of vanes 22 that are formed on a circumferential surface of the pump rotor 21 in a radial shape, and a pump housing 23 that has an inner diameter determined in such a manner that the ends of the vanes 22 are rotated in a state contacting with the inner surface of the pump housing 23 when the pump rotor 21 is rotated.
In the present invention, the pump rotor 21 has an oil storing part 30 capable of storing lubricant in a lateral surface of the pump rotor 21.
The oil storing part 30 includes a plurality of concave groove parts 31 that are connected with the shaft hole 21 b of the center and are not connected with a vane sliding groove 21 a formed in a surrounding portion of the concave groove parts 31, and a communicating part 32 connecting the concave groove parts 31.
The concave groove parts 31 and the communicating part 32 have the maximum distances d2 and d1 from the center of the shaft hole. The maximum distance d2 of the concave groove part 31 is larger than the maximum distance d1 of the communicating part 32 for thereby enhancing the storing capacity of lubricant.
As shown in Figure 4, the concave groove part 31 is formed in a polygonal shape that is slanted at a certain angle θ with respect to a certain radial direction extension line L1 which initiates from a center of the pump rotor 21 and passes through the concave groove part 31. Therefore, lubricant is supplied by the small amount during the operation.
At this time, the polygonal shape means a structure having at least three sides such as a triangle shape, a rectangular shape or a diamond shape. For example, in the case of the triangle shape, it is needed that at least the slanted direction of the apex should be at a certain angle θ with respect to a certain radial direction extension line L1 which initiates from a center of the pump rotor 21 and passes through the concave groove part 31.
The above construction may be determined based on that the supply direction of the lubricant is guided in the directions of the ends of the vanes or is guided in the inward directions of the vanes.
The pump rotor 21 according to the present invention is rotated by receiving a rotational force from the shaft 12 in the interior of the pump housing 23. The vanes 22 assembled to the sliding groove 21 a are rotated, contacting with the inner diameter of the pump housing 23 for thereby generating a vacuum suction force.
At this time, the both lateral surfaces of the pump rotor 21 contact with the inner surfaces of the both sides of the pump housing 23 during the rotation. An oil storing part 30 including a concave groove part 31 and a communicating part 32 is formed at a lateral side of the pump rotor 21, so that the lubricant stored in the oil storing part 30 is supplied by the small amount.
In details, when the centrifugal force of the pump rotor 21 is larger that the stop inertia force based on cohesion of the lubricant, the lubricant is supplied by the small amount for thereby performing lubrication operation. As the speed of the rotation is increased, the centrifugal force gets increased, so that more lubricant is supplied. As the rotation speed is decreased, and the centrifugal force is decreased, less lubricant is supplied for thereby achieving a proper supply amount of lubricant.
In particular, as shown in Figure 4, since the concave groove part 31 of the oil storing part 30 is slanted at a certain angle θ with respect to a certain radial direction extension line L1, the supply direction of the lubricant is fixed to a certain direction, and it is possible to prevent over lubricant from being supplied at one time.
Since an oil movement groove 33 is formed between a vane sliding groove 21 a and a shaft hole 21 b irrespective of the presence of the communicating part 32, so that oil supplied to one vane among multiple vanes flows to another vane through the oil movement groove 33 for thereby enhancing lubricant effects.
As described above, in the present invention, there is provided an oil storing part in the lateral side of the pump rotor closely contacting with an inner side of the pump housing wherein the oil storing part includes a concave groove part and a communicating part, and the lubricant stored therein is automatically continuously supplied based on a centrifugal force of the pump rotor and an inertia force of the lubricant for thereby achieving a long time supply of the lubricant.
In addition, since the lubricant stored in the oil storing part does not easily move into the interior of the housing, it is possible to uniformly supply lubricant to the vane sliding parts and each portion of the interior of the vacuum pump. Furthermore, the anti-abrasion property of the pump rotor is enhanced, and heating and noise are prevented. The life span of the pump could be extended.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

A vacuum pump that includes a shaft for receiving a rotational force, a pump rotor that has a shaft hole for receiving an end of the shaft therein, a plurality of vanes that are assembled to a vane sliding groove of the pump rotor, and a pump housing in which each end of the vanes contacts with an inner surface of the pump housing and is rotated, a pump rotor of a vacuum pump for a vehicle, comprising:
a concave groove part that is formed in a lateral surface of the pump rotor and is not connected with the vane sliding groove but is connected with the shaft hole for thereby forming an oil storing part therein, wherein said concave groove part is formed in a shape that is slanted at a certain angle θ with respect to a certain radial direction extension line L1 which initiates from a center of the pump rotor and passes through the concave groove part.
The rotor of claim 1, wherein said concave groove part of the oil storing part is provided in multiple numbers between the vane sliding grooves.
The rotor of claim 2, wherein said concave groove part of the oil storing part is provided in multiple numbers between the vane sliding grooves in such a manner that the oil storing parts are connected with each other through a communicating part.
The rotor of claim 3, wherein in said concave groove part of the oil storing part, the maximum distance d2 from the center of the shaft hole to the concave groove part is larger than the maximum distance d1 from the center of the shaft hole to the communicating part for thereby enhancing a storing capacity of a lubricant.
The rotor of claim 1, wherein in said pump rotor, an oil movement groove is formed between the vane sliding groove and the shaft hole irrespective of the presence of the communicating part.