US2886135A

US2886135A - Lubricant pump

Info

Publication number: US2886135A
Application number: US508287A
Authority: US
Inventors: Lipinski Johann
Original assignee: Alex Friedmann KG
Current assignee: Alex Friedmann KG
Priority date: 1955-05-13
Filing date: 1955-05-13
Publication date: 1959-05-12
Anticipated expiration: 1976-05-12

Description

, 2,886,135 Patented May 12,1959

This.invention'r elates to a lubricant pump of that type in which one or several pump units are separately inserted in apump box and each of said pump units comprises .a

cylinder and a working piston, which is formed with one or several control ports and; is rotatable to control the .connectionof its working space with the inlet and outlet. Inthe known pumps of that type in which the pump units are individually inserted in the pump box, these units are flanged. to the pump box from the outside. Such constructions are somewhat. less expensive than constructions in which groups of pump units are combined to form a block and inserted in the pump box because the pump units for pumps having different numbersof outlets can be manufactured in larger quantities. constructions, howeven the economy {thus effected is not r t e au e u h Pump units n d t the P mp casing are of relatively complicated shape and require expensive machining operations.

It is an object of the. invention to reduce the cost of such lubricant pumps. The invention is based on the recognition thata considerable simplification in construc- In the known length is reduced and the bosses which must be provided in the pump box casting to accommodate the bores receiving the cylinders may be relatively small. In order to avoid a disturbance of the simple shape enabled by the invention the means required in that type of pumpto prevent the rotation of the cylinder and to determine its inserted position may comprise a detachable part, e. g. a pin inserted in the cylinder and engaging a groove inthe bore of the pump box, or a ledge aflixed to the pump box and cooperating with a surfaceformed on the cylinder, so that neither the outside surface of the cylinder nor the bore of the pump box has a projecting part which would considerably add to the machining expense.

Illustrative embodiments of the invention are shown in the drawing. 1

Fig. 1 is a sectional view of the pump box and a pump unit of a lubricating pump. 1

Fig. 2 is a sectional view of the pump box and a pump unit of a lubricant pump of modified construction. 1

In the embodiment according to Fig. 1, 1 represents thepump box, whichhas inserted therein the pump units comprising a cylinder 2 and a piston 3. The piston 3 is driven in theusual manner by a ball pin 6 of a tappet rod 7, which isrotatably and axially slidably mounted and is driven to oscillate and axially reciprocate through theintermediary of a hall pin 8, which engages an eccentric bore 9 of a head 10 of thedrive shaft 11. The ball' pin 6 enters a cavity 4 of the piston head 5. Thus the piston 3 does not only perform a reciprocating conveying movementubut. also a rotary control movement, in the tion is possible just in that type of lubricant pumps in ,whicl xthe control olj the working spaceis effectedfiby the rotation of the working piston and in which for that rea son only a single piston and one cylinder are required for each valveless pump unit. The invention resides essenof revolution which is or conical shape or provided with t a collar in its intermediate zone and which is held against rotation and is clamped by an outlet nipple in a bore which is reduced in conical or stepped form, whereas the intake duct which opens on the outside surface of the cylinder portion facing the interior of the casing is sealed from the discharge duct which opens adjacent to the closed cylinder end and leads. into the cavity of said outlet nipple. The formation of the cylinder as a solid of revolution represents the simplest form, which is least expensive as regards machining. This is due tothe elimination of the fixing flange for the pump unit and by the provision of a fixing member, i.e. the screw nipple, which is separate from the cylinder. The place where the pump unit is received in the pump box consists only of a bore, which is formed at its inner end with a constriction delimiting the depth of insertion of the cylinder, and at its outer end, e.g., with a thread for the nipple. Thus the machining of the pump box is minimized too. The measure of forming the bore of the pump box for the cylinder with a conical reduction has the advantage compared to the stepped formation, that the cylinder is tightly forced into the outer cone by the nipple and additional sealing members are eliminated. That construction is favourable if the inlet bore of the cylinder is to be tightly sealed against course ofwhich itconnects its working space, 14 in the known manner alternatelywiththe inlet bore 12 and the outlet bore 13. 15 represents the setting screw which determines thequantity to be delivered. V

1 The cylinder 2 is formed as a simple solid of revolution, which is provid ed with a collar 16 in its intermediateaone. That cylinder is inserted in a bore 17 of thefpurnp, box :1 and is clamped by the outlet nipple 18 agains t a shouldei 19 of the bore 17. Since a rotary piston epntrol is employed, the cylinder 2 must be built in and securedgina predetermined position. ;T o this end the cylinder has inserted therein a pin 20, which engages a groove 21 of the bore of the shoulder 19. In the corresponding control position of the piston 3 the lubricant is sucked from the interior 23 of the pump box 1 through a bore 22 of the pump box 1 and. the inlet bore 12 into the working space 14.

As the piston 3 is rotated its control groove 24 is connected to the outlet bore 13 so that the piston 3 conveys the lubricant into the outlet nipple 18. To this end the outlet bore 13 leads to a cavity 25 of the outlet nipple 18. As is shown in the drawing the outlet nipple 18 is formed at its inner end as a hollow cylinder 26, which has an external screw thread 27. Thus the cylinder 2 lies partly in the outlet nipple 18, so that the overall length and the length of the bosses 28, 2'18 provided in the pump box casting can be reduced. A gasket ring 29 is provided between the hollow-cylindrical extension 26 i let nipple 18 and the cylinder 2 as well as between the said parts and the bore 17. No seal is required between the collar 16 of thecylinder 2 and the shoulder 19 of the bore 17 because the pump unit sucks the lubricant directly from the interior 23 of the pump box 1.

embodiment according to Fig. 1 mainly by the fact that The embodiment according to Fig. 2 differs from the the upper portion of the cylinder 2' is formed with an external cone 30, which is forced into a conical bore 31 of the casing. The cylinder 2 is again clamped in the pump box 1' by the outlet nipple 18 and the outlet bore 1'8. Contraryto the construction according-to'Fig. 1-the rotation of the cylinder is prevented by a ledge 32 screwed to the pump box If and cooperating with a surface 33 formed-on the cylinder 2.

ln this case the supply of the lubricant vto the inlet bore 12 of the cylinder 2-'i s not efiected-directly'from the interior 23 f the pump-box -1"butthe-lubricantis sucked duringthe intake stroke of the piston 3 through a riser 34, a sight glass 35 and a bore'36 into the working-space 14 of the piston 3. For this reason this'embodiment requires a seal between that portion of the periphery of the cylinder in which 'the suction line 12 opens and the interior 23 of the pumpbox; that seal-.is provided by the conical formation of the cylinder and of the bore 31.

This eliminatesthe need -for inserting an additional sealing member, the compressibility of which would render the depth of insertion of the cylinder 2 indefinite and prevent an accurate setting of the quantityto be delivered.

I claim: 7

1. .A lubricant .pump comprising a pmmpbox, a bore in said pump box, a valveless pump unit inserted in said bore, said pumpunitcomprising a pump-icylinder and a piston reciprocating within the said pump cylinder and a working space in the said pump cylinder, an inlet opening and an outlet opening in the outer surface of the said pump cylinder in axial distance from each other, means for swinging the said piston about its'axis, means in the said piston for establishing communication between the said working chamber and the said inlet opening and outlet opening, respectively, when swung into its respective swing positions, the said pump cylinderbeing formed as a body of revolution, an outlet-nipple coaxialWith-the said piston and pump cylinder clamping-the said pump cylinder in the said bore, the said outlet nipple having a cavity, and means for preventing rotational movement of the said pump cylinder in the said bore, sealing -means in the middle zone of said bore and pump cylinder efiecting a tight seal between said bore and pump cylinder, the said inlet opening being arranged in the part of *thesaid pump cylinder directed inwardly to the said pump box, the said outlet opening being arranged in the outer part of the said pump cylinder and being in communication with the said cavity, the said sealing means being arranged between the said inlet opening and outlet'opening and separatin the said inletopening from the-said outlet opening.

2. In a lubricant pump as claimed in claim 1, a step in "the outer "surface of the said pump cylinder *and "a step in the said bore, the said outlet nipple clamping the said first-mentioned step against'the second-mentioned step.

3. In a lubricant pump as claimed in claim 1, a collar in the outer surface of the said pump cylinder and a step in the said bore, the said outlet nipple acting on the said collar and clamping the said collar against the said step, the said sealing means constituted by a packing arranged between the said outlet.nippleandthe:said collar.

4. In a lubricantpump as claimed in claim 1, the said pump cylinder having a conical. outer surface converging to its inner endand the said bore being conical converted to the interior of the said pump box, the conicalsurfaces forming the said sealing means.

5. In a lubricant pump as claimed in claim 1, the said means for preventing rotational movement of the said cylinder comprising a detachable part.

6. In a lubricant-pump'as claimed-in "claim 1,""a*pin inserted -in'-the said pump cylinder-and martial-groove in the said bore, the said-pin engaging the -said groove and "forming the said means for preventing -rotational movement'of that pump cylinder. p

7. -In a lubricant-pump asclaim'edin'claim l, 'a ledge fixed: on the-said pump box and a flat surface formed-on theouter surface-ofthe said pump cylinder, "cooperating with -the said ledge, 'the said ledge and "flat surface "forming the said --means for preventing rotational movement of thesaid' pump cylinder.

8. .In 'a lubricant pump as-claimed in claim -1,.1ariser connecting the-"interior of saidpump'box to the saiddfilet opening and means for sealing'the 'surface' -zone of the said cylinder which contains thesaid inlet Openingagainst the interior of the pump 'box and against said outlet opening.

References Cited in-the. file of this patent UNITED STATES PATENTS Great Britain Sept. 13, 1950 'Hajek Oct. =17; 1-9711