US2427347A - Vacuum pumping apparatus - Google Patents

Description

Sept- 16; 1947- P. F. BEssY vAcnnl PUuPIuG APPARATUS Filed Oct. 18. 1944 nventor Peter essg Patented Sept. 16; 1947'- UNITED STATES PATENT OFFICE VACUUM PUMPING APPARATUS Peter F. Bessy, Detroit, Mich. Application'October 18, 1944, Serial No. 559,180 I (o1. 23o-2) 3 Claims.

This invention relates to vacuum pumping ap' paratus and particularly to the production of a vacuum for energizing a windshield wiper or other automotive appliance. y

In the practice now common, vacuum motors such as are used on motor -vehicles to actuate windshield Wipers and other appliances' derive energy from the vehicle engine through provision of a suction line leading to the engine intake.`v

Such arrangements are open to serious objection for the reason that the applied vacuum effect has a wide range of fluctuation and falls oli materially asengine load increases and in many installations, fails completely to energize themotor, when conditions are especially adverse.y Such arrangements, therefore, 'are least dependable under conditions rendering their satisfactory performance most vital.

It has been proposed to eliminate reliance aforementioned on vacuum induced in the engine cylinders by deriving a vacuum from a gear type of pump driven by the engine, crank case oil being circulated through such pump for sealing purlposes. This is believed an unsatisfactory solution of the problem because crankcase oil is an engine lubricant and as such is too thin to `properly seal an inexpensive rotary pump. Moreover, the initial thinness of said oil is materially increased through engine heat. -Also suchoil frequently is badly fouled by carbon from the cylinders.

An object of the invention is to provide an apparatus that will apply dependable energy to a vacuum motor under substantially all conditions of engine operation.

Another object is to utilize an inexpensive type of bladed, rotary pump for evacuating the suction line of a vacuum motor, and to maintain the necessary seal at the blades-of such motor by circulating a suitable quantityof oil through the pump chamber.

A further object is to adapt my improved pumping., apparatus to be installed and operated independently of the lubrication system of the vehicle engine, so that it may use a sealing oil of viscosity best suited to the desired seal rather than to engine lubrication.

A further object is to provide for the actuation of a vacuum motor either by) a small pump or by vacuum induced,l in the engine cylinders, Whichever is at 'a given time more powerful.

A further object is to safeguard theA apparatus vacuum motor.

t.against any access of the circulating oil to the These and various other objects are attained 5 2 by lthe construction hereinafter described and illustrated in the accompanying drawing, wherein:

Fig. 1 is a diagrammatic viewv of the apparatus prising a disk 4 smaller than said chamber and occupying a substantially tangential relation to its periphery, and a plurality of blades 5 slidingly fitted in slots of said disk and projecting beyond the disk periphery to engage that of the chamber 2. The disk and blades are of an equal width such as to maintain sealing contact With the side walls of said chamber. Said disk is centrally secured on and driven by a shaft 6, suitably journaled in said casing, and centrifugal force urges the blades outwardly and against the periphery of the chamber 2 when the disk is driven,

the blades sliding in or out according as they approach or recede from the pointof tangency. It is preferred to journal the shaft in ball bearings mounted in the casing at opposite sides of the impeller, one such bearing 'I being set into an embossed central portion of the cover 3 and the other, 8 occupying a` housing formed by an annular ange 9 on the casing I. An oil seal I0 of ordinary construction is press tted in said housing in exterior contact with the bearing 8. The described pump may be supported and driven in any desired manner and,A as illustrated, is bolted to a. bracket II serving to attach it to the engine l2 of a motor vehicle (not shown), being driven by a pulley I3 rotated by the fan driving belt I4.

An inexpensive pump of the described character would be quite unsatisfactory for vacuum purposes in absence of some provision for adequately sealing the sliding intersections of the blades with the pump casing, and it has been found that a quite satisfactory seal is obtained by continuously flowing through the pump a small quantity of a fairly heavy oil. It has been further found that such oil may be conveniently delivered to and discharged from the pump together with the impelled air. Thus an oil reservoir I5 is exteriorly mounted on the engine I2 and has 3 a restricted outlet IB discharging from its bottoml manifold and oil connection I6 is a pipe I9 ex- 4 n `since, the oil circulation involves only a trliiing diminution.

tending to an ordinary vacuum motor 20 actuatlng any desired appliance -as for example the illustrated Windshield wiper 2|. Thus thepump takes effect on the vacuum motor jointly through the pipes I1 and I9. It is preferred Vto insert a check valve 22 in the pipe I1 between its connections I6 and I9, such valve allowing a free ilow toward the pumpbut positively preventing reverse iiow. Such valve has two essential functions,- namely, the prevention of oil delivery either to .the vacuum motor or to the intake manifold. In absence of the check valve, shutting oi of the engine would produce an oil flow to the motor to satisfy the vacuum left in such motor. In the' next subsequent use of the wiper there would be an exhaust of such oil from the motor, whereby the windshield would be badly smeared. Also in absence of said check valve, there would be a ilow of oil into the intake manifold Whenever engine suction exceeds that of the pump, with result that the reservoir I would soon be emptied ardized.

il.. f

, It is to be noted nally that my system is. quite easily installed and entails no objectionable perforation of the engine crank-case, nor any disturbance oi lubrication systems -as now stand- What I claim is: 1. In a vacuum motor drive system, the combination with a vacuum-inducing power-plant and a vacuum-inducing rotary pump, of intercommunicating suction connections .'irom the power plantand the inlet oi.' said pump to an area to be evacuated, means for maintaining a -a vacuum-inducing rotary pump, of a connection and the wiper would be inopera 've or only partially operative during such oil fl w.

Air and oil discharging from the pump I are conducted-by a pipe 23 to the upper portion of the reservoir I5, the air being Vented from the upper portion of the reservoir through an outlet 24.

In operation of the described system of energizing a vacuum motor, all operatingl conditions are fully met, the motor being responsive to either the pump I or engine manifold, whichever is pro- ,ductive of higher. vacuum. When the engine vacuum drops oi due to a heavy load or to engine acceleration, the pump will prevent any corresponding decrease in efciency of the motor. When the engine is idling at a speed inadequate to get the best results from the pump, the engine will be producing a high vacuum and will assure eflicient operation of the motor.

As compared to a system attempting to use engine oil for establishing a pump seal, the construction described has Vital advantages. When a heavy oil is best suited to sealing purposes but poorly suited to engine lubrication, it is clear thatpoor results must follow from Aan eiort to make one oil serve both purposes. The present between the inlet of said pump, the low pressure area of said power plant, and an area to be evacuated whereby evacuation may be eiected by either the power plant or pump, means for delivering oil to said connection for sealing the pump, and a check valve resisting oil ow through said connection to either the power plant low pressure area or the, area to be evacuated.

`3. In a vacuum motor drive system, the combination with a vacuum-inducing power plant and a vacuum-inducing rotary pump, of an oil reservoir exteriorly mounted upon said power plant and vented to the atmosphere above the normal oil level, of intercommunicating suction connections from the power plant and the inlet of "the pump to an area to be evacuated, a restricted oil delivery connection from said reservoir to said suction connection opening into said reservoir from the pump-outlet, and means resisting oil ow in said connections to the power plant and area to be evacuated.

PE'IER, F. BESSY.

REFERENCES CITED The following references are of record in the le of this patent:

Hueber et al Feb. 25, 1936

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