ROTOR FOR VANE PUMP AND MOTOR

Abstract

 57 A rotor (10) for a vane pump and motor comprises a hollow rotor body (12), end plates (13, 14) welded to both end surfaces thereof, and a rotating shaft (11) secured to the end plates. If required, a heat pipe working fluid could be sealed within the rotating shaft (11) or the rotor body (12). The rotor (10) provided with the rotor body (12), the rotating shaft (11) and the end plates (13,14) is made of a composite material prepared by mixing whiskers into a matrix metal, and has a sufficiently high strength even if the wall thicknesses are further reduced, so that it is possible to obtain an extremely light-weight rotot.

Description

TECHNICAL FIELD:

[0001] The invention relates to a hollow rotor for use in vane-type pumps and rotors.

BACKGROUND ART:

[0002] Vane-type pumps and motors are widely used in most industries and conventionally provided with such relatively heavy solid rotors as disclosed in Tokkyo Kokai Koho (Japanese Published Unexamined Patent Application) No. 5E 5988. It is always required to reduce the weight of a pump. Recently, the pump for use in vehicles has been desired to be less in weight for saving energy. The pump can not be less in weight without substituting a heavy solid rotor for a hollow light rotor. However, it is a problem how to efficiently make a hollow rotor. It is also preferable that a hollow rotor is as thin as possible and that rotor elements, such as a rotor body, a rotor shaft, and side plates, are made of light metal such as aluminum and the like. This needs to solve another problem that a thin rotor body or light metal shaft is too fragile to be practically used. In the case of oil free type vane pumps in which temperature highly rises, a heat pipe is desirably built in a rotor for cooling the inside of the pump.

[0003] To solve the problems as described above, it is an object-of the invention to provide an improved hollow rotor that is less in weight.

[0004] It is another object of the invention to provide an improved hollow rotor of the type having a thin and strong wall.

[0005] It is a further object of the invention to provide an improved hollow rotor of the type having its elements made of light metal.

DISCLOSURE OF THE INVENTION:

[0006] The invention consists in a rotor comprising a hollow body, both end plates welded to the opposite end faces of the rotor body, and at least a rotary shaft fixed to one of the both end plates. The hollow body and the rotary shaft are preferably made of a base metal reinforced by whiskers. The base metal may be either ferrous or non-ferrous material. The whisker may be of inorganic material, such as silicon carbide, carbon and glass, that has a softening or melting temperature higher than the base metal.

[0007] The hollow body or rotary shaft can be made of the composite material as described above by a casting method. Whiskers are so compacted to have at least about 50% void and then set in a mold. Then, molten base metal is poured into the mold to infiltrate the void in the whiskers and form a complete hollow body reinforced by whiskers or superhigh strength fibers having an extremely high specific intensity, thereby the body being able to have a very thin and light wall as compared with the conventional one.

[0008] A heat-pipe can be built in the rotor in a manner that working liqid is confined in a blind hole which is formed in the rotary shaft and tapered toward a pulley on the rotary shaft. The blind hole is sealed by a plug mounted on the center of the end plate. Otherwise, the liquid can be confined within the full inside of the rotor.

[0009] The advantages offered by the invention are that the hollow rotor has a simple construction in which a hollow body is welded to the both end plates and that it is less in weight and easy in mass-production. Another advantage is that heat-pipes is easily built in the rotor for cooling the inside.

BRIEF DESCRIPTION OF DRAWINGS:

[0010] 

FIGS. 1 and 2 are exploded and partially cutaway perspective views of the rotor of the invention;

FIG. 3 is a view, similar to FIG. 2, of another embodiment equipped with a heat-pipe;

FIG. 4 is a view, similar to FIG. 3, of a further embodiment;

FIG. 5 is a partly enlarged section of the rotor;

FIG. 6 is a view, similar to FIG. 5, of still embodiment;

FIG. 7 is a schematic longitudinal section of the rotary shaft and the end plate which are manufactured as one body by casting;

FIG. 8 is a section of a preform to be forged into the rotary shaft and the end plate as one body; and

FIG. 9 is a section of the rotary sh:ft and the end plate which have been forged as one body.

BEST MODE FOR CARRYING OUT THE INVENTION:

[0011] The rotor of the invention is described below with reference to drawings which illustrate preferred embodiments. Referring now to FIGS. and 2, the rotor 10 has a hollow rotor body 12 shaped by means of extrusion, press-working or the like, the both end plates 13, 14 which are separately fabricated by press-working, casting or forging and then bonded to the opposite faces of the hollow rotor body by welding, preferably by resistance welding. The rotary shaft 11 and the end plate 14 can be fabricated as one body by a single process of forging, which might need more cost than the aforementioned press-working and welding process. The hollow rotor 10 is light and has its elements, such as hollow rotor body 12, rotary shaft 11 and end plates 13, 14, which can easily be manufactured and assembled by welding, thereby being suitable for mass-production at a low cost.

[0012] Inpreference, the rotor body 12 is provided with at least a reinforcement plate 16 which is similar in shape to the hollow section of the hollow body and fixed to the inner surface of the body 12 as seen in FIG. 2. The reinforced body works well under severe conditions in. which the rotor body 12 of FIG. 1 would have the vane groove warped to prevent the vane from smoothly moving out of the vane groove.

[0013] As seen in FIG. 3, the rotary shaft 11 is formed with a blind hole 2 tapering toward the pulley-mounting end, prior to having the opposite end welded to the end plate 14. The blind hole 2 has a threaded inlet 3 opened to the inside of the rotor body 12. The blind hole 2 is filled with heat-pipe working liquid and then sealed up with the intervention of a sealing member 4 and a plug 5 which is screwed in the inlet 3. Thus, the rotary shaft 11 serves as a heat pipe; one end fixed to the end plate 14 as a heat absorption part and the other pulley-mounting end as a heat discharge part.-Heat inside the rotor is transferred through the end plate 14 to the heat absorption part in which the working liquid is caused to evaporate. The working liquid vapor passes through the center of the blind hole 2 to the heat discharge part in which it gives the heat through the pulley-mounting end to the open air to liquidize and return to the heat absorption part along the conical periphery of the blind hole 2. The heat-pipe action carries out quick heat exchange and allows efficient discharge of inside heat, so that the temperature in the rotor 10.never rises over a tolerable limit.

[0014] As seen FIG. 4, the rotor body 12 as well as the rotary shaft 11 can contain the working liquid and serve as the heat absorption part of a heat pipe for more rapid cooling of the rotor 10. The blind hole 2 is similarly formed in one-side rotary shaft 11 as shown in FIG. 3. The inlet 3 is formed in the opposite side rotary shaft 15 fixed to the other end plate 13. After the rotor body 12 and the rotary shaft 11 have been filled with the working liquid, the plug 5 is screwed into the inlet 3 in the rotary shaft 15. In the case of a cantilever type rotor with a single rotary shaft, the inlet may be provided in the center of the flat end plate which is centrally concaved. The plug can be wel- d to the inlet.

[0015] As seen in FIG. 5, the rotor body 12 may be made of a composite _materail of a base light metal M, such as aluminum, aluminum alloy, magnesium alloy or the like, and whiskers F of inorganic substance, such as silicon carbide, carbon, glass or the like. The whiskers F arc so compacted to have at least about 50% void and then set in a mold in which the body is to be casted. Molten base light metal M is poured into the mold to infiltrate the void in the compacted whiskers and shape the rotor body 12 consisting of a composite material. The rotor body 12 can have a thin, light, and strong wall made of a light metal M reinforced by fibrous superhigh strength whiskers F and the weight remarkably reduced as compared with the usual. The casted body is welded to a separately fabricated end plate with a rotary shaft to produce a complete rotor.

[0016] The hollow body of aluminum or aluminum alloy can have its outer periphery partly or fully treated by anodic oxidation. In particular, the vane groove is preferable to be oxidized for smooth sliding of the vane.

[0017] The rotor body 12 can be manufactured by forging. The whiskers F are so compacted to have at least about 50% void and then set in a mold in which the body is to be made. Molten base light metal M is poured into the mold to infiltrate the void in the compacted whiskers to produce a preform of a composite material. The preform is shaped into a hollow rotor body 12 in which the whiskers F aline along grain flow lines in the base metal M as shpwn in FIG. 6. Therefore, the forged rotor 12 has an extremely high specific intensity.

[0018] As seen in FIG. 7, the both end plates 13, 14 with the respective rotary shafts 11, 15 can also be made of a composite material consisting of a base ferrous or non-ferrous metal M, such as steel, aluminum, aluminum alloy, and magnesium alloy, and whiskers F of inorganic substance, such as silicon carbide, carbon, and glass. The whiskers F are so compacted by press-working to have at least about 50X void and then set in a mold in which a rotary shaft integral with an end plate is to be casted. Molten base metal M is poured into the mold to infiltrate the void in the compacted whiskers to form rotary shaft 11 or 15 with the respective end plate 13 or 14 consisting of a composite material. The rotary shaft 11 or 15 with rotary shaft 13 or 14 can have a thin, light and strong structure made of a metal M reinforced by fibrous superhigh strength whiskers F and the weight remarkably reduced as compared with the usual. The rotary shaft 11, 15 with the respective end-plates 13, 14 are welded to the separately fabricated rotor body to produce a complete rotor.

[0019] The end plate integral with the rotary shaft of a composite material can also be manufactured by forging. The whiskers are so compacted to have at least about 50% void and then set in a mold into which molten base metal is poured. Thw molten base metal M infiltrates the void in the compacted whiskers F to produce a preform consisting of a composite material, as shown in FIG. 8. The preform is shaped into the rotary shaft 11 or 13 with the end plate 13 or 14 in which the whiskers F aline along grain flow lines in the base metal M as shown in FIG. 9. Therefore, the forged rotary shafts 11, 15 with the respective end plates 13, 14 have an extremely high specific intensity.

INDUSTRIAL APPLICABILITY:

[0020] The inventive rotor for use in vane pumps and motors is less in weight because of being hollow. It is especially suitable to a vane pump applicable as a supercharger for an a mobile engine and a compressor for air cooler.

Claims

1. A rotor for a vane pump and motor comprising a hollow rotor body (12), both end plates (13, 14) welded to the both end faces of said hollow rotor body, and a rotary shaft (11) fixed to said end plate.

2. The rotor of claim 1, wherein said rotary shaft (11) is integrally shaped with said end plate (14).

3. The rotor of calim 1, wherein said rotary shaft (11) is welded to said end plate (14).

4. The rotor of claim 1, wherein said rotor body (12) is reinforced by at least a reinforcement plate (16) which is similar in shape to the hollow section of said hollow rotor body and fixed to the inner surface of said hollow rotor body.

5. The rotor of claim 1, wherein said rotor body (12) is made of a composite material comprising a base metal (M) and whiskers (F).

6. The rotor of claim 5, wherein said base metal (M) is either aluminum or aluminum alloy to form the outer periphery of said rotor body (12) treated by anodic oxidation.

7. The rotor of claim 1, wherein said rotary shaft (11, 15) is made of a composite material of a base metal (M) reinforced by whiskers (F).

8. The rotor of claim 7, wherein said end plate (13, 14) is made of a composite material of a base metal (M) reinforced by whiskers (F).

9. The rotor of claim 7, wherein said composite material is forged to have said whiskers alined along grain flow lines.

10. A rotor for a vane pump and motor comprising a rotor body (12), both end plates (13, 14) welded to the both end faces of said rotor body, and a rotary shaft (11) fixed to at least one of said end plates and formed with a blind hole (2) tapering toward the pulley-mounting of said rotary shaft, and heat-pipe working liquid sealed in said blind hole.

11. The rotor of claim 10, wherein said working liquid is sealed within said blind hole in said rotary shaft (11) by a sealing member (4) and a plug which is fitted in an inlet of said blind hole.

12. The rotor of claim 10, wherein an inlet is formed in said rotary shaft (15) fixed to said end plate (13) opposite to said rotary shaft (11), said inlet is closed by a plug to seal said working liquid within the inside of said rotor body (12) and said rotary shaft (11).

Drawing