US2520087A - Vane type pump - Google Patents

Description

2, 1950 w. F. HELMRICH 2,520,087

VANE TYPE PUMP,

Filed May 29, 1948 IN V EN TOR. M'lll'am F/klmrich manna/44 6%- Patented Aug. 22, 1950 VANE TYPE PUMP William F. Helmrich, Royal Oak, Mich, assignor to Ex-Cell-O Corporation, Detroit, Miclu, a corporation of Michigan Application May 29, 1948, Serial No. 29,982 3 Claims. (cl. 103138) The present invention pertains generally to rotary pumps and more specifically to an improved vane type pump.

One of the objects of the invention is to provide a pump of the foregoing type which will be particularly well suited for smooth operation at high speed.

Another object is to provide a vane type pump of simple, compact form and which will lend itself readily to economical construction.

Other objects and advantages will become apparent as the following detailed description proceeds, taken in connection with the accompanying drawings, wherein:

Figure 1 is a longitudinal sectional view taken axially through an illustrative pump embodying the invention.

Fig. 2 is a transverse sectional view through the pump of Fig. 1, taken in the plane of the line 22.

Figs. 3 and 4 are detail views showing in plan and elevation respectively a novel spring guide utilized in the pump of Fig. 1.

Fig. 5 is a transverse sectional view through the guide of Fig. 4, taken in the plane of the line 5-5.

While the invention is susceptible of various modifications and alternative constructions, a preferred embodiment has been shown in the drawings and will be described below in considerable detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Upon more specific reference to the drawings, it will be observed that the invention has been there exemplified in the form of an illustrative pump Ill. The latter will, of course, be recognized as a vane type pump by those skilled in the art. The pump I0 is organized within a casing ll comprising in this instance a barrel l2 which, together with a pair of end plates l4, l5, defines a pump chamber ll. Mounted eccentrlcally with respect to the chamber l6 and enclosed within the latter is a generally cylindrical rotor H which is unitary with a shaft I8 journaled in the end plates I4, II. The rotor H is formed with a plurality of circumferentially spaced, diametrically opposed slots !9 of appropriate size'to receive a corresponding plurality of radially slidable vanes 20. The latter are adapted to coact with the inner periphery of the barrel i2 so as to pump 2 fluid into the casing via suitable inlet passages and exhaust it from thecasing via suitable outlet passages. These passages have not been fully indicated in the drawing since the present invention does not concern the casing details per se.

To insure even wear between the radially slidable vanes 20 and the internal surfaces against which these vanes bear, diametrically opposed ones of such vanes are connected in pairs by means of appropriate guide means. This is accomplished in the present instance by interposing a single guide member 2| between each pair of diametrically opposed vanes. To accommodate the member 2l, each of the vanes 2&9 is formed with a centrally located, relatively deep radial bore 22 which is properly proportioned to receive the adjacent end portion of the guide member 25 with what is known in the art as a neat fit. In other words, there is just suiilcient difference between the diameters of the member 2! and the bore 22 to permit the former to slide comfortably within the latter.

In order to render the pump l0 more compact and in addition to simplify its construction, provision is made for mounting the guide members 2! in substantially coplanar relation within the rotor W. This is achieved preferably by reducing the thickness of the central portion of each guide member 25 without sacrificing its strength. Turning once more to Figs. 3 to 5 inclusive, it will be noted that the guide members 2| for the illustrative pump it are of identical construction, being fashioned from pieces of round stock having flattened central portions 24 which in the present instance are of generally rectangular shape. The thickness of the flattened portions 24 is slightly less than the radius of the end portions of the member 2| to provide clearance between these members when they are assembled into a pump as shown in Figs. 1 and 2'. The lateral dimension of each flattened portion 24 is substantially greater than the diameter of the round end portions of the member M. The portions 24 are also of sufilcient length to permit reciprocation of the members 2! without interfering with each other as the rotor turns.

For the purpose of compensating for any wear which might ultimately take place between the vanes 23 and the inner periphery of the pump chamber i6, and also to maintain an adequate seal between these parts, suitable biasing springs 25 are associated with respective ones of the vanes 28. .As indicated in the drawings, each of the springs 25 is of relatively short spiral form and is disposed in surrounding relation with its associated guide member 2|, being interposed between the vane 2| and a shoulder 2| deflned by the flattened portion 24 of the guide member. Friction between the springs 2| and the rotor I1 is eliminated due to the fact that the radial slots II and diametrical bores 2| which connect opposite pairs of the slots is are somewhat larger than the diameter of the springs 28 and, in fact, larger than the width of rectangular portions 24 of the guide members. Thus the biasing springs 28 are subjected to no wear while the pump II is running.

In operation, each pair of opposed vanes II, together with its connecting member 2! and biasing springs 25, is subjected as a unit to bodily reciprocation with respect to the rotor I'I. Under normal circumstances there is negligible, if any, deflection of the springs 25 during such movement. Furthermore, since all of the foregoing parts are of relatively small mass and hence low inertia, they can be reciprocated at a fairly rapid rate without creating excessive vibration within the pump II. By the same token, this characteristic permits the pump Hi to operate smoothly at high speeds and discharge capacities.

In the light of the foregoing, it will be appreciated that a pump has been provided in which are obtained the advantages of independent vanes of small mass over rigidly connected pairs of vanes. Moreover, these beneficial results are secured without the necessity for axially spacing the guides or biasing springs of respective pairs of vanes. This makes it possible to adopt a minimum number of standardized forms for the vanes, guide members, and springs in each pump, thus considerably simplifying its construction, and reducing its size and manufacturing cost.

I claim as my invention:

1. In a vane type pump having a barrel and a rotor journaled eccentrically within said barrel, the combination of a plurality of pairs of diametrically opposed vanes supported by said rotor for sliding movement radially thereof, coplanar guide members disposed between the diametrically opposed vanes of said respective pairs of vanes, each said guide member having a partially flattened rectangular central portion deflning shoulders thereon, and a biasing spring interposed between each of said vanes and an adjacent one of said shoulders of said flattened rectangular portion, each of said springs being adapted to urge its corresponding vane radially outward for maintenance of engagement between the latter and the inner periphery of said barrel.

2. In a rotary pump having a casing and a generally cylindrical rotor journaled therein, said rotor having diametrically opposed slots connected in pairs by substantially coplanar diametrical bores, vanes mounted in the slots for radial sliding movement with respect to said rotor, each of said vanes having a radial bore therein facing the diametrical bore associated therewith, an integral guide member interposed between the diametrically opposed vanes of each pair and housed within one of said coplanar diametrical bores, said guide members being freely movable relative to each other and also to said bores, each of said guide members having end portions of generally circular cross section slidably housed within their associated vanes, each of said guide members also having a partially flattened central portion of lesser thickness than the radius of said end portions but having a lateral dimension substantially greater than the diameter of said end portions, and biasing springs interposed between each of said vanes and said flattened central portion of its guide member, each of said springs being disposed in surrounding relation with the end portion of one of said guide members and adapted to urge its associated vane against the inner periphery of said casing.

3. In a vane type pump of the character set forth and having a plurality of pairs of diametrically opposed vanes with a plurality of guide members each interposed between the vanes of one of said pairs, each said guide member comprising the combination of integral end portions of generally circular cross section and a partially flattened central portion, the thickness of said central portion being less than the radius of said end portions, and the lateral dimension of said flattened central portion being substantially greater than the diameter of said end portions. WILLIAM F. HEINRICH.

REFERENCES CITED The following references are of record in th flle of this patent:

. UNITED STATES PA'IE'N'IS Number Name Date 1974.828 Johnson Sept. 30, 1913 FOREIGN PATENTS Number Country Date 568,184 Germany Jan. 20, 1933

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