US1820009A - Rotary pump - Google Patents

Description

1931- R. M. BLACKMER 1,820,009 I ROTARY PUMP Filed April 2. 1928 2 Sheets-Sheet l 4 A? 30 a5 .3? 37 j ,4

woenloz L umulfll Ma Aug. 25, 1.931. R. MJBLACKMER ROTARY PUMP Filed April 2, 1928 2 Sheets-Sheet 2 cylinder 14. This shaft has secured thereto Patented Aug. 25, 1931 UNITED STATES PATENT OFFICE ROBERT 'M. BLACKMER, OF IDIlilTItO IT, MICHIGAN, ASSIGNOR T0 STEPHEN A. GRIGGS,

OF DETROIT, MICHIGAN ROTARY PUMP Application filed April 2,

The invention relates to rotary pumps and more particularly to a type of pump wherein the rotor is provided with a-rcuate shaped buckets o-r vanes projecting from the periphery thereof.

One of the objects of the invention is to provide a pump wherein the cylinder and cam are constructed of a single casting, the cam portion being integral with the other portions of the housing. Another ob ect is to provide a construction for introducing the fluid into the space between the vanes of the rotor by conducting the fluid around the ends of said vanes. A further object is to so construct the cylinder, cam and head of the pump as to facilitate the manufacture on a large production scale at a low cost.

With these'and other objects in view I have provided the improved pump construction hereinafter fully described and illustrated in the accompanying drawings, wherein Y Figure 1 is a cross section through the Figure 2 is an axialsection therethrough;

Figure 3 is an end view of the pump with the head removed;

Figure 4 is an end view of the head;

Figure 5 is a perspective view of the pump with the head withdrawn from the cylinder to show the fluid ports. I

Referring -now to the embodiment of my invention as illustrated in the drawings, the pump comprises a casing 10 mounted on a base 11 and provided with suitable inlet and outlet'fittings 12 and 13 respectively which as shown are arranged at substantially right angles to each other. The casing has a hollow interior forming a cylinder 14, the opposite ends of which are provided with annular flanges 15 and 16. 17 and 18 are cylinder heads each havingan inwardly projecting ring 19, the outer diameter of which is adapted to fit the cylinder 14. The heads are retained in position abutting thefianges 16 and 15 by suitable means such as the bolts 20. v

21 is the rotor shaft journaled in the heads 17 and 18 and extending through the 1928. Serial No. 266,648.

a cylindrical rotor 22, the outer diameter of which is smaller than the cylinder 14 leav- Y ing an annular space 23 therebetween. The rotor is provided with a series of slots 24 which in transverse cross. section as shown in Figure 1 appear as circular arcs. These slots extend lengthwise of the rotor for the greater part of its length terminating substantially at the plane of the inner face 25 of the'ring 19. Each of the slots 24 intersect the periphery of the rotor at two spaced points as indicated at 26 and 27 and the number of slots with which the. rotor is 1 provided may be varied as desired, providing a symmetrical arrangement is maintained. As illustrated there are four slots although there may be more or less than this number in some instances. For convenience in manufacture the rotor 22 has the slots extending completely through one end thereof, thereby permitting the slots to be formed by an end mill. For closing the open ends of the slots there is provided the end p1ate'28 secured to the rotor by the machine screws 29. This plate is of the same diameter as the rotor and is of substantially the same thickness as the ring 19 on the head 18.

Extending across the cylinder 14-between the inlet and outlet of the pump is in abutment or cam 30 which has a portion 31 of substantially'the same radius as the radius of the rotor 22; This portion 31 is of sufficient length to overlap the two adjacent slots in the rotor. From the portion 31 the surface of the abutment is inclined gradually in opposite directions as indicated at 32 and 33 until it merges with the cylinder 14. In each of the arcuate slots 24 there are arranged vanes or buckets and in accordance with my invention there are preferably two vanes in each slot. These vanes which are indicated by the-numerals 34 and 35 are curved transversely to conform with the arcuate slots and are preferably constructed to fit these slots snugly. The inner edges 36 and 37 of the vanes are preferably fiat, while the outer edges 38 and 39 are curved in such a manner that when they are arranged withinftheslots so as to be substantially flush with the outer periphery of the -width and the widths are determined so face 31 of the abutment.

that when one vane is riding upon the surface 31 and the other vane is riding upon the surface of the cylinder 14, the inner edges of the two vanes will just be in contact. In order to permit the separation of the two vanes 34 and 35 when neither vane is in contact with the abutment, I have provided vent passageways or bleed ports 40'extending through the rotor between its outer periphery and the central portion of each of the arcuate slots. These passagewa s are of a diameter such as to permit'the uid to pass outwardly therethrough when the vanes are forced into contact but are restricted to such an extent as to prevent any appreciable noise when the contact takes place.

The cam or abutment 30 is in accordance with the present invention made integral with the casing 10 as illustrated in Figure 1. Therefore the casing does not contain a true cylindrical inner surface but this surface is cylindrical for only a portion of its circumference, the remainder being of the cam shaped contour described above. When the casing is constructed in this manner it is cast to the approximate dimensions and the interior is thereafter broached to finish the interior surfaces.

Extending laterally of the inlet fitting 12 is a fluid passageway 42. This passageway extends for the full length of the cylinder and the width of the passageway is (as shown in Figure 1) such as to extend circumferentially from a point beyond the inclined cam surface 32 to a point 0 osite the surimilarly there is a fluid passageway 43 extending laterally of the outlet fitting 13 and arranged on the opposite side of the abutment 30. The end .of the cylinder has two segmental slbts 44 and 45 cut into the cam portion thereof as best shown in Figure 5. These slots communicate respectively with the fluid passage- 1 ways 42 and 43 and are separated by an inwardly projecting lug 46, the inner surface 47 of which is of the same radius as the cylinder 14.

As heretofore stated, each of the heads is provided with an inwardly projecting ring 19 adapted to fit the cylinder 14. This ring has a continuous portion 19a for engaging the circular portion of the cylinder 14 and is cut away for the remainder of the circumference except for a la 19?) disposed midway between the ends 0 the continuous portion. The outer surface of the lug 19b is adapted to engage the inner surface 47 'of the lug 46. When the head is assembled to the cylinder the outer surfaces of the rin 19 and the lug 19b engage the inner sur aces of the cylinder. faces of thering 19 and lug 19b serve to house the rotor 22. The flat surface 190 of the ring engages the edges of the vanes and makes a fluid tight joint therewith. The construction as above described is such that the fluid may enter and leave around the edges of the vanes by reason of the cut away portions in the cylinder and in the ring on the head. g I

In the operation of the pump the rotor is driven by any suitable means causing the vanes v to be moved around the cylinder.' The fluid entering through the inlet fitting 12 passes laterally through the passageway 42 to the opposite ends of the rotor and then radiallyinward through the recesses 44 and the cut away portions of the ring 19 past the ends of the vane into the space A bounded by the ends of the vanes 35aand 34a as indicated in Figure 1. As the rotor is rotatively advanced the vane 35w rides down the inclined cam surface 32, being forced outwardly by the centrifugal force of the rotating rotor.

Since the vane 35! is maintained in contact The inner sur- 1 tact with the cooperating vane and expelling any. fluid trapped between the vanes. The fluid is then forced outwardly through the recess 45 and fluid passageway 43 by reason of the second of the two vanes riding up the incline 33. This cycle is repeated during each rotation of the rotor and each set of vanes carries a certain amount of fluid between the inlet and outlet conduits.

What I claim as my invention is:

' 1. In a pump, a cylindrical housing, a

rotor within said housing, vanes extending outwardly from said rotor engaging the cylindrical surface of said housing, a cam abutment extending across a portion of said cylindrical housing, heads at the opposite ends of said housing having recesses for engaging said rotor, rings on said heads engaging the end edges of said vanes, said rings being cut away on opposite sides of said abutment and inlet and outlet passageways communicating respectively with the cut away portions of said rings on the opposite sides of said abutment.

2. In a rotary pump, a cylinder, an abutment extending across a portion of said cylinder, a rotor journaled concentrically .of

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said cylinder, vanes extending outwardly from said rotor, heads engaging the opposite ends of said cylinder, inwardly projecting rings'on said heads each having an outer surface for engaging said cylinder and an inner surface for engaging said rotor, said ring being cut away to form radial passageways and inlet and outlet ports communicating with said radial passageways.

3. In a pump, a casing having a cylindrical portion and a cam shaped abutment extending across the same, a rotor mounted concentrically of said cylindrical portion, vanes extending outwardly from said rotor, a pair of heads at opposite ends of said cylinder, each head having a ring engaging said cylindrical portion, said ring having an interior surface for engaging said rotor, said ring having two cut away portions on opposite sides of the central portion of said abutment and said cylinder having segmental slots communicating .with the cut away portioris of said ring.

4. In a rotary pump, a housing having an interior surface circular in cross section for a portion of its circumference and cam shaped for the remaining portion, a cylindrical rotor having vanes projecting therefrom, heads at the opposite ends of said casing, each head having a ring engaging said housing, said head having a bearing surface for the end of said rotor, said cam being provided with segmental recesses on opposite sides of the central portion thereof and said ring being cut away to correspond with said recesses and longitudinal passageways throughsaid housing communicating with the respective recesses.

5. In a rotary pump, a housing having an interior surface circular in cross section for a portion of its circumference and cam shaped for the remaining portion, a cylin- .drical rotor having vanes projecting therefrom, heads at the opposite ends of said casing, each head having a ring engaging said housing, said head having a bearing surface for the end of said rotor, said cam being provided with segmental recesses on opposite sides of the central portion thereof and said ring being cut away to correspond with said recesses, longitudinal passageways extending the full length of the housing communicating with the respective recesses, and inlet and outlet ports communicating with said longitudinal passageways.

In testimony whereof I aflix my signature.

ROBERT M. BLACKMER.

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