US2463871A

US2463871A - Vacuum pump lubrication

Info

Publication number: US2463871A
Application number: US597074A
Authority: US
Inventors: Hapgood Cyrus Howard
Original assignee: De Laval Separator Co
Current assignee: De Laval Separator Co
Priority date: 1945-06-01
Filing date: 1945-06-01
Publication date: 1949-03-08
Anticipated expiration: 1966-03-08

Description

March s, 1949. C. H. HAPGooD 2,463,871

VACUUM PUMP LUBRICATION 2 Sheets-Sheet l Filed June 1. 1945 March 8, 1949. c. H. HAPGooD 2,463,871

VACUUM PUMP LUBRICATION Filed June 1, 1945 2 Sheets-Sheet 2 O lo N 0( mi N Pennies Mier. s, 194e UNITED STATES PATENT; 2O F'FLIC VACUUM PUMP LUBRICATION cyrus Howard mpma, Nuaey, N. s.. signor to The De Laval Separator Company, New York,

N. Y., a corporation of New Jersey Application June 1, 1945,1Serlal No. -597,024

-6Ciaims. 1

The type of vacuum. pump to which the present invention is particularly applicable comprises a housing', a hollow rotor within and eccentric to the housing, an air inlet port to, and an air outlet port from, the air space between rotor and housing, slidable vanes carried by the'rotor and arranged radially to the rotor shaft and which extend into said air space and contact with the housing during the rotation of the rotor, a driving shaft to which the hollowrotor is secured, and a driving pulley on the shaft. Vacuum pumps of this character are disclosed in the Leitch Patent No. 1,367,554, dated'February 8, 1921, the Hall Patent No. 1,374,650, dated April 12, 1921, and patents issued tome No. 1,637,484, dated August 2, 1927, No. 1,684,395, dated September 18, 1928, and 1,971,448 dated August 28, 1934.

The objects of'my invention are: to supply oil to the pump by the action of the 'pump itself while in operation; to insure a continuous circulation of oil through the pump, theV maintenance of a constant and predetermined iilm 'of one 'end a cover plate i0 and, to the other or pulley end, a cover plate I2. These `three members enclose a pump chamber i4.

A rotor il, having therein radial slots in which Ablades i8 slide and which open into holes 20 extending entirely through the rotor, is rotatably mounted inside the housing 8 with its bottom side in contact with the bottom or" the housing 8 directly below the center of the housing.

This rotor is mounted on a drive shaft 2i supl ported in bearings 22 held in the end plates "i9 the rotor.

oil within the rotor chamber and the prevention of leakage vfrom 'the interior to the exterior of the pump; to deliver the oil to such a point in *he pump that it will seal the interior against n: leak of air from thehigh to the low pressure points of the pump; to effect the return to the oil reservoir of oil passing from the sealing zone into the working space of the pump; and' to insure that, after the operation of the pump has stopped, the oil remaining in the pump will be returned to the oil reservoir or to the intake passages outside the pump, so -that'the pump can be easily started up even in the coldest weather.

A preferred embodiment of the invention is ldrown in the drawings, in which:

Figure ;1 is a sectional view through the base along the line i-l of Figure 2, with the pump mounted on the base and from which one end plate has been removed.

Figure2 isa pian view of the base.

Figure 3 is an end View of a plate on the pulley side; and

Figure 4 is a sectional view through the pump housing along a line 4-4 indicated on the end plate of Figure 3.

In the drawings the reference character 2 designates the base provided therein with an oil reservoir 4 in which the oil is usually maintained at the level i, and I is a. cover therefor, on which the motor 'la for driving the pump may be mounted.

Mounted on and secured to one end of the base 2 is a pump housing I havingsecured to The housing is mounted on the base 2 as clearly shown in Figure ll with the packing member 29 between the base and the housing.

39 designates the air inlet to the pump which extends into the base proper and communicates by means of 'a vertical passage 32 with a cross passage 34 in the housing. This cross passage extends laterally and communicates with air inlet ports 32 in the end plates which open into the inlet'side of the rotor chamber clearly indicated in Figures 3 and 4.

'3l `designates an outlet chamber in plate I2- which. like 'a similar chamber in plate I0, communicates with the discharge side of the rotor chamber and, through a cross passage 40, with a passage 42 extending downwardly to the oil reservoir l4.

Apipe 43 from the oil reservoir d, leads to a passage 44 in the pulley end plate i2 and thence to a groove 4B which 'leads to the inside of the rotor chamber l`4.

The operation of the device is as follows: In starting up any oil which has drained back into the inlet opening 30 will be sucked up into the rotor chamber, vand the suction of the pump will draw cil through the pipe 43 and

connections

44 and 46 into the near side of the rotor chamber and some of it will cross through passages 20 to the opposite side of the rotor chamber. vSome of this oil will leak past the ends of the vrotor and -be carried with the air being pumped into the oil reservoir. Therein the oil will be separated from the air by gravity and a bame plate 48 and will collect in the reservoir, held by the wall 5l. An upwardly extending exhaust pipe (not shown) is connected to the threaded opening 52 in the base 2.

A illler opening 54 for the oil reservoir is provided which may be covered with a cap having a bayonet type of oil gauge or other means of measuring the amount of oil in the reservoir.

. The action of the pump will be such as to maintain a fllm-of oil between the end walls of the rotor chamber and the blades therein. When the pump is stopped most of the oil therein will drain back from the rotor chamber to the oil reservoir through the cross passage 40 and passage 42 and through the portsy or openings 20 and

passages

40 and 43. Any remaining oil will be-drained back into the inlet 30 and will be sucked up when the pump is started in the next operation.

The above construction insures an adequate circulation of oil and the maintenance of a desired volume of oil within the rotor chamber. It is found that if pipe 43 is closed off the vacuum at the bearings is about one half the vacuum at passage 34. The escape of oil from the pump gthrough the exhaust is substantially entirely 'prevented After the pump is stopped substan- \\tia1ly all of the oil will be drained from the rotor chamber, so that, in restarting, the diiiiculty of hard starting with congealed oil is avoided.

What I claim and desire to protect by Letters Patent is:

1. In a vacuum pump, a housing having a cylindrical rotor chamber, a rotor mounted in the chamber with the rotor axis below the center of the chamber, the housing having a bottom surface and also separate air inlet and air outlet passages opening through said bottom surface and leading upwardly therefrom through the lower part of the housing to the bottom of the rotor chamber, said passages underlying'the rotor chamber and being located on opposite sides of a vertical plane along said axis, a base separable from the housing and having an upper surface supporting said bottom surface and opposed thereto, the base having air inlet and air outlet ports opening through said upper surface on opposite sides of said vertical plane and registering, respectively, with the inlet and outlet passages, the base also having on one side of said vertical plane an air inlet leading to said inlet port and on the other side of said planean oil reservoir to which said outlet port leads, theoil reservoir extending laterally for a substantial distance beyond the rotor housing and below the level thereof, the base also having an air outlet from the oil reservoir, and a duct for delivering oil from the reservoir to the rotor chamber.

2. A vacuum pump as defined in claim 1, in which said base includesl a movable cover offset laterally from the rotor housingiand overlying at least part of the oil reservoir, the cover having a supporting surface, a motor for driving the pump and mounted on said cover surface, the part of the reservoir below the cover providing a large space for the outgoing air to reduce the pressure thereof to permit the separation of the oil from ythe air.

3. In a vacuum pump, the combination of a housing having a cylindrical chamber, a plate at each end of the housing for closing the corre- Number Name Date y 1,051,360 Wisdom Jan. 21, 1913 1,056,859 Vernon Mar. 25, 1913 1,142,544 Vernon et al June 8, 1915 1,776,921 Moessinger Sept. 30, 1930 1,799,539 Smith Apr. 7, 1931 1,906,464 Hapgood May 2, 1933 1,923,600 Warner Aug. 22, 1933 1,973,063 Grier i Sept ll, 1934 FOREIGN PATENTS Number Country Date 259,367 Italy I 1928 sponding end of the chamber, each plate having an opening therethrough, a bearing mounted in each end plate in said opening, a rotor in the chamber having a shaft supported by said bearings, the axis of the rotor shaft being below the center of the rotor chamber, the housing having an air inlet passage extending downwardly from the bottom of the chamber on one side of the vertical center of the chamber and also having an air outlet passage extending downwardly from the bottom of the chamber of the opposite side of the vertical center line of the chamber, a base on which said housing is supported, the base forming an oil reservoir and having an air outlet port leading to the reservoir from said air outlet passage in the housing, the base also having an air inlet port leading to said inlet passage in the housing, the wall of said opening in one of the end plates having an axial groove extending to the inner face of the plate, and an oil duct leading from the reservoir up to said groove for delivering oil to the bearings. l

4. A vacuum pump as deiined in claim 3, in which said grooved plate has an elongated port extending from the bottom of the chamber to above the horizontal level of the rotor axis and forming part of said air inlet passage, the grooved plate also having a short port extending from the bottom of the chamber and terminating below said horizontal level and forming part of said outlet passage, the oil groove being located at approximately said horizontal level and overlying said short port but separated therefrom.

5. A vacuum pump as defined in claim 3, comprisingl also a cap secured to the outer face of each end plate over said opening in the plate.

6. A vacuum pump as dened in claim 3, comprising also a cap secured to the outer face of each end plate, one of the caps covering one end of the shaft and the adjacent bearing to form an air-tight seal, the other cap covering the other bearing and having an opening for the shaft, and a seal within said last cap and engaging the shaft and the adjacent end plate to guard against leakage along'the shaft and said last bearing.

CYRUS HOWARD HAPGOOD.

REFERENCES CITED UNITED STATES` PATENTS