US2070203A - Oil pump - Google Patents

Description

Feb. 9, 1937. b. "GREG'G 2,070,203

011. PUMP Filed Nov. 5, 1934 BY xfa/Lw?? ATTORNEY.

Patented Feb. 9, 1937 UNITED STATES PATENT OFFICE Eclipse Aviation Corporation, East Orange,

N. J., a corporation of New Jersey 'Application November 5, 1934, Serial No. 751,604

8 Claims.

This invention relates to pumps and more particularly to reciprocating pumps that are suitable for pumping small quantities of liquid.

An object of the invention is to provide a uid 5 pump which will supply small quantities of fluid in a predetermined amount at each stroke of the piston.

Another object of the invention is to providea reciprocating fluid pump in which the amount of fluid that is pumped may be readily varied.

Another object of the invention is to provide a reciprocating uid pump in which the amount of fluid pumped may be varied without changing the pump speed.

Another object of the invention is to provide a reciprocating uid pump in which the pumping capacity may be varied by changing the angular position of the piston with respect to its recipro cal position.

0 Other objects of the invention will be apparent from the following description in connection with which certain embodiments of the invention have been shown in the accompanying drawing in which:

Fig. 1 is a side elevation partly in section of a vane type air pump having an oil pump constructed in accordance with the invention;

Fig. 2 is an end view of the oil pump shown in Fig. 1';

Fig. 3 is a view partly in section, the sectional portion being taken on line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on line 44 of Fig. 1;

Fig. 5 is a sectional view taken on line 5-5 of 5 Fig. 1;

Fig. 6 is an enlarged View showing a modified form of cylinder construction; and

Fig. 7 is an enlarged end view of the oil pump piston, taken along line 1-1 of Fig. 4.

J Referring to the drawing, the air pump upon which the improved oil pump is mounted is indicated generally at I0 and is of well known construction, having a rotor I! eccentrically mounted in casing I2 by bearing'l3. Slidable vanes I4 are mounted in the rotor, and the inlet andoutlet ports to the air pump are shown at I6 and I1. respectively, (Fig. 5). Inlet port I6 is connected to the atmosphere through a cored passageway y 20 that is formed in the oiler head by means of l pipe I8, and the outlet is connected through a similar passage, not shown, to discharge pipe I3. In air pumps for certain purposes it is desirable to supply lubricant thereto in measured quantities so that the minimum amount of lubricant i is supplied to adequately lubricate the same. An

over-supply may allow some of the oil to enter the outlet pipe and be detrimental to the functioning of devices that are operated by the air pump. For example, if the air pump be used to inate rubber articles it is very desirable to reduce the oil supply to a minimum and thus prevent deterioration of the rubber from the excess oil that is passed through the outlet line.

The oil pump embodying the present invention is secured to thel casing I2 by screws 2| and is driven by shaft 22 having a squared end 24 which is mounted within a squared opening 25 formed in the rotor I I. Shaft 22 is rotatably mounted in the oil pump housing26 by bearings 21 and 28 and is provided with a worm 29 in mesh with the worm wheel 3|. A bushing 32 forming the oil pump cylinder is pressed within the casing 26 within which is mounted the reciprocating piston 33, the outer end of the cylinder being closed by a threaded plug 34 having a cylindrical projection 36 projecting within the cylinder to determine the clearance volume of the pump, it being apparent that plug 34 can be readily changed and another one substituted to provide any clearance that is desired. Cylinder 32 is preferably positioned horizontally and connected with compartment 31 by an oil inlet port 38, oil being supplied to the compartment 31 by any suitable means, such as a separate pump (not shown) by means of oil supply pipe 4I. A metering disc 42 is provided in the oil supply line for regulation of the quantity of oil delivered, but this is not essential. It is desirable, however, to keep an adequate supply of oil in the reservoir 31 so that inlet 38 may be covered at all times. The piston 33 is provided with a pin 44 which is slldably mounted in a groove 46 formed in the interior of worm wheel 3|. A member 41 is secured to piston 33 by any desired means, such as rivet 48, and contains a groove 49 formed by two parallel cam surfaces 5I and 52. A pin 53 is secured to sleeve 54 and projects within the groove 49. Sleeve 54 is rotatable in the housing and secured in any desired angular position by screw 56. Screw slot 51 is provided for angular adjustment of the sleeve by any suitable tool. Sleeve 54 surrounds the cam groove 49 and is provided with a reduced portion 59 forming a bearing vfor the piston 33. The outlet port 6I of the cylinder is in communication with the air inlet compartment 20 which communicates with the air'pump I0. The pump inlet port 38 and outlet port 6I are controlled by a slot 63 formed in piston 33 which is in communicat-cn with the cylinder by an end slot 64.

In the operation of the pump. compartment 31 is supplied with oil from any suitable source and inlet port 38 is submerged. Rotation of shaft 22 causes piston 33 to rotate and during the rotation thereof, the piston is also reciprocated bymeans of the pin 53 and the cam slot 49. It will be apparent that the piston is shown in its extreme position toward the right and further rotation'will cause it to move toward the left, as viewed in Fig. 4. It is assumed that a charge of oil has been drawn into the cylinder during a previous portion of the cycle, and it is apparent that the movement of the piston toward the left will force oil from the cylinder through the slots 64 and 63 into the air inlet chamber 20 from which it will be delivered to the air pump by port I6 for lubrication thereof.

In the embodiment shown in Fig. 4 the stroke is substantially equal to the width of the ports 6| and 38 and the slot 33 extends over substantially one-half of the piston circumference. The sleeve 54 is 'shown in an adjusted position to deliver onehalf the cylinder displacement during one pump cycle. Rotation of sleeve 54 through 90 degrees in either direction from the position shown will cause the pump todeliver its full cylinder displacement during each cycle, and rotation of the sleeve through degrees will reducethe delivery to substantialy one-half the cylinder displacement.

The cycle of operation of the pump with the sleeve 54 in the position shown is as follows:

The first quarter of revolution moves the piston one-half stroke toward the left and discharges one-half the cylinder displacement to air 'chamber 20.

The second quarter of revolution moves they piston to its extreme position toward the left, but

during this portion of the stroke the inlet port 38 is uncovered by slot 63 and the exhaust port 6I is closed, therefore any oil remaining in the cylinder is returned to chamber 31.

The third quarter of revolution moves the piston one-half stroke toward the right and draws oil into the cylinder from the inlet chamber 31 through port 38.

'I'he fourth quarter revolution moves the piston to its extreme right position and suction is applied to the exhaust port 6l, but no oil is drawn into the cylinder as chamber 20 is the air intake chamber of the air pump and is much larger than the displacement-space of the oil pump, therefore there is no oil adjacent the port 6i and the piston draws air into the oil pump cylinder during the last half of the intake stroke, and no oil is removed from the chamber.

Maximum delivery Rotation of the sleeve 54 through 90 degrees in K Minimum 'delivery Rotation of sleeve 54y through 180 degrees from the position of Fig. 4 moves the piston its full stroke toward the left and the operation is as follows:

The rst quarter revolution applies suction to the same, a cam on said piston, a sleeve providthe exhaust port 6 I and only air is drawn into the cylinder for the first half of the suction stroke.

The second quarter revolution applies suction to the inlet port 38, and the remaining half of the suction stroke draws oil from chamber 31, with the result that the cylinder contains half oil and half air at the end of the suction stroke.

The third quarter revolution applies pressure to inlet port 38, but the greater portion of the oil has reached the lower side of the cylinder, therefore the iirst half of the piston delivery stroke returns the air and possibly some of the oil to chamber 31.

The fourth quarter revolution applies pressure to the exhaust port 6 l and the oil remaining in the cylinder, which is substantially one-half of the cylinder displacement, is delivered to chamber 20.

In the modification illustrated in Fig. 6, the outlet port 1I is not controlled by piston movement but is placed somewhat beyond the end of the stroke and is provided with a check valve 12 for preventing the return of oil to the cylinder.

In this form of the invention the operation is quite similar to the form previously described, except that regulation of the quantity of oil pumped is controlled entirely by adjusting the position of slot 63 with reference to the inlet port 38.

While certain embodiments of the invention have been illustrated and described, it is understood that this showing and description are illustrative only and the invention is not regarded as limited to the form shown and described, or otherl wise, except by the terms of the following claims.

of said piston during rotation thereof, and means for manually rotating the sleeve from the exterior of the housing to adjust the delivery of the pump.

2. In a pump thecombination of a housing, a cylinder therein having inlet and outlet ports, a piston insaid cylinder controlling said ports a gear surrounding said piston and having a feathered connection with said piston for rotating ing a bearing for said piston; means secured tothe sleeve and coacting with the cam for reciprocating said piston, and means for manually rotating the sleeve from the exterior of the housing.

3. In a pump the combination of a housing, a cylinder therein having aligned inlet and outlet` ports, a piston in said cylinder having a slot for controlling said ports, a gear concentric with the piston and having a feathered connection with said piston for rotating the same, a sleeve abutting said gear and providing a bearing for said piston, a cam on said piston, means secured tol ,said sleeve and-coacting with the cam for reciprocating said piston, means for manually rotating the sleeve from the exterior of the housing, and

with,a piston having a slidable driving connec- I ing within said groove for causing reciprocation 70 means for restraining the sleeve against rotation. Y

tion with said worm gear and arranged to 'control said ports, spaced cam means on said piston forming a groove therebetween, a sleeve concentric with said piston rotatably mounted in said housing, means on said sleeve projecting into said groove, and means for restraining rotation of said sleeve.

5. In a pump the combination of a housing. a cylinder therein having inlet and outlet ports, a rotatable worm, a. worm gear meshing therewith, a piston having a slidable driving connection with said worm gear and arranged to control said ports, spaced cam means on said piston forming a groove therebetween, a sleeve concentric with said piston rotatably mounted in said housing, said sleeve having a reduced portion forming a bearing for said piston, means on said sleeve projecting into said groove, and means for restraining rotation of said sleeve. v

6. In a pump the combination of a housing, a cylinder therein having inlet and outlet ports, a rotatable Worm, a worm gear meshing therewith, a piston having a slidable driving connection with said worm gear and arranged to control said ports, spaced cam means on said piston forming a parallel sided groove therebetween, a sleeve concentric with-said piston" rotatably mounted in said housing, a pin secured to said sleeve prosaid s1eeve.

7. In a pump the combination of a housing,

l a cylinder therein having inlet and outlet ports.

a groove4 therebetween, a sleeve'concentric with said piston rotatably mounted in said housing and abutting said worm gear, said sleeve having a l reduced portion forming a bearing for said piston,

a pin secured to said sleeve-projecting into said groove, and means 'for restraining rotation of said sleeve.

8. In a pump the combination of a housing, a horizontal cylinder therein` having,vertically arranged inlet and exhaust ports, said inlet port being arranged above said exhaust port, a liquid reservoir` above said inlet port and in communication therewith, an air chamber below and in communication with said exhaust port having a volume greater than the cylinder displacement of the pump, a piston in said cylinder controlling said ports, means for'rotating said piston during the reclprocation thereof, cam means secured to the piston or reciprocating the same. a sleeve providing a bearing for said piston, a cam follower secured to the sleeve and coacting with said said sleeve.

DAVID GREGG.

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