Vacuum pump with lubricant metering groove

Claim 2

In a vacuum pump having a stator disposed between first and second end plates, a shaft extending between and supported by the end plates for angular movement relative to the stator, and a rotor having vanes positioned for rotation on the shaft in engagement with the inner circumference of a pumping cavity in the stator, a lubricant distributing system comprising: the first end plate having a metering groove with an inlet end and an outlet end formed therein extending from said inlet end to said outlet end in the direction of rotation of the rotor and vanes, the rotor and vanes being arranged to sweep across the open surface of said metering groove in close proximity thereto, said metering groove being sufficiently shallow to permit the sweeping of the rotor and vanes across the open surface thereof to produce a turbine action that continuously impels a lubricant through said groove at a desired predetermined rate without being affected by contaminants that may be in the lubricant; input means to introduce the lubricant to said inlet end of said metering groove; and output means to direct the lubricant at said outlet end of said metering groove to the appropriate portion of the pump.

Claim 3

In a vacuum pump having a stator disposed between first and second end plates, a shaft extending between and supported by the end plates for angular movement relative to the stator, and a rotor having vanes positioned for rotation on the shaft in engagement with the inner circumference of a pumping cavity in the stator, a lubricant distributing system comprising: the first end plate having a continuous flow lubricating path formed therein and extending in a generally radial direction toward the shaft; a metering portion of said lubricating path interconnecting two enlarged flow portions of said lubricating path and arranged to have the rotor and vanes impel lubricant therethrough to cause a predetermined amount of lubricant to be continuously passed through said lubricating path during operation of the pump irrespective of pressure conditions and contaminants in the lubricant; insertion means to introduce the lubricant into said lubricating path; and withdrawal means to pass the lubricant from said lubricating path to the shaft supports and to the pumping cavity in the stator.

Claim 4

In a vacuum pump having a stator disposed between first and second end plates, a shaft extending between and supported by the end plates for angular movement relative to the stator, and a rotor having vanes positioned for rotation on the shaft in engagement with the inner circumference of a pumping cavity in the stator, a lubricant distributing system comprising: the first end plate having a continuous flow lubricating path formed therein and extending in a generally radial direction toward the shaft; a metering portion of said lubricating path interconnecting two enlarged flow portions of said lubricating path and arranged to have the rotor and vanes impel lubricant therethrough to cause a predetermined amount of lubricant to be continuously passed through said lubricating path during operation of the pump irrespective of pressure conditions and contaminants in the lubricant; insertion means to introduce the lubricant into said lubricating path; and withdrawal means to pass the lubricant from said lubricating path to the shaft supports and to the pumping cavity in the stator.

Claim 5

A lubricant distributing system as claimed in claim 2 wherein said metering portion is generally transverse to said enlarged flow portions and impedes lubricant flow through said lubricating path in the absence of the impelling action of the rotor and vanes.

Claim 6

A lubricant distributing system as claimed in claim 2 wherein said insertion means comprises: an opening extending through the upper ends of the second end plate and the stator; an input passage to introduce lubricant to said opening; and a vertical recess in the stator adjacent the first end plate and extending downwardly from said opening to said lubricating path.

Claim 7

A lubricant distributing system as claimed in claim 2 wherein said withdrawal means comprises: a chamber in the first end plate about the shaft to receive lubricant from said lubricating path; a keyway extending along the shaft from said chamber; an exhaust area in the second end plate communicating with the keyway; and a discharge groove to convey lubricant from said exhaust area into the pumping cavity.

Claim 8

A lubricant distributing system as claimed in claim 2 wherein: said metering portion of said lubricating path is an open groove extending in the direction of rotation of the rotor and vanes; and the rotor and vanes swEep across the surface of said groove to impel the lubricant therein through said groove at a desired predetermined rate.

Claim 9

A lubricant distributing system as claimed in claim 6 wherein said groove is shallow relative to said enlarged flow portions to provide a restricted metering groove.

Claim 10

In a multistage vacuum pump of the oil sealed type having a pump housing containing an oil bath, a stator disposed between a center plate and an exhaust end plate joined by a bolt at the upper ends thereof and all located in the oil bath, a shaft extending between and supported by the plates for angular movement relative to the stator, and a rotor having outwardly biased vanes positioned for rotation on the shaft in a pumping cavity in the stator which has intake and exhaust sections thereof, a lubricant distributing system comprising: an opening about the bolt extending through the end plate and the stator; an input passage located below the level of oil in the pump housing to introduce oil to said opening to cause oil flow through the end plate and the stator; a vertical recess in the stator adjacent the center plate and extending downwardly from said opening; a continuous flow lubricating path in the center plate comprising a first enlarged flow portion communicating with said recess and extending downwardly therefrom, a restricted metering groove having a first end communicating with said first enlarged flow portion and extending therefrom in the direction of rotation of the rotor so that the rotor and vanes sweep across the surface of said metering groove to impel oil therethrough at a predetermined rate, and a second enlarged flow portion extending from the other end of said metering groove toward the shaft; a chamber in the center plate about the shaft to receive the oil from said lubricating path; a keyway extending along the shaft from said chamber; an exhaust area in the end plate communicating with said keyway; and a discharge groove to convey oil from said exhaust area into the exhaust section of the pumping cavity at a region of low pressure.

Claim 11

In a multistage vacuum pump of the oil sealed type having a pump housing containing an oil bath, a stator disposed between a center plate and an exhaust end plate joined by a bolt at the upper ends thereof and all located in the oil bath, a shaft extending between and supported by the plates for angular movement relative to the stator, and a rotor having outwardly biased vanes positioned for rotation on the shaft in a pumping cavity in the stator which has intake and exhaust sections thereof, a lubricant distributing system comprising: an opening about the bolt extending through the end plate and the stator; an input passage located below the level of oil in the pump housing to introduce oil to said opening to cause oil flow through the end plate and the stator; a vertical recess in the stator adjacent the center plate and extending downwardly from said opening; a continuous flow lubricating path in the center plate comprising a first enlarged flow portion communicating with said recess and extending downwardly therefrom, a restricted metering groove having a first end communicating with said first enlarged flow portion and extending therefrom in the direction of rotation of the rotor so that the rotor and vanes sweep across the surface of said metering groove to impel oil therethrough at a predetermined rate, and a second enlarged flow portion extending from the other end of said metering groove toward the shaft; a chamber in the center plate about the shaft to receive the oil from said lubricating path; a keyway extending along the shaft from said chamber; an exhaust area in the end plate communicating with said keyway; and a discharge groove to convey oil from said exhaust area into the exhaust section of the pumping cavity at a region of low pressure.

Claim 12

A lubricant distributing system as claimed in claim 8 wherein said restricted metering groove is shallow relative to said enlarged flow portions and impedes lubricant flow through said lubricating path in the absence of the impelling action of the rotor and vanes.