초록 ▼

A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading

A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

대표청구항 ▼

What is claimed is: 1. A method for improving pumping efficiency in a viscous fan drive during operation, the viscous fan drive including an output-coupling member including a housing member coupled to a cover member, an actuator shaft partially disposed within said output-coupling member, an input-

What is claimed is: 1. A method for improving pumping efficiency in a viscous fan drive during operation, the viscous fan drive including an output-coupling member including a housing member coupled to a cover member, an actuator shaft partially disposed within said output-coupling member, an input-coupling assembly coupled to said actuator shaft and including an input-coupling member, said input-coupling-assembly and said actuator shaft capable of rotating at a given input speed, a fluid operating chamber including a shear space defined by said input-coupling member and said cover member, at least one fill hole contained in said input coupling member fluidically coupling said fluid reservoir chamber to said fluid operating chamber; and a scavenge hole including an opening contained in said cover member fluidically coupling said fluid operating chamber to said fluid reservoir chamber, the method comprising:forming a wiper element of a molded plastic material comprising a pair of spaced apart arms coupled to and extending from a radial tang member, said arm members both extending in the same direction and positioned substantially perpendicular to said tang member and the longitudinal length of said arm members being substantially the same and the longitudinal length being substantially greater than the longitudinal length of said tang member;introducing a notch to a cover wall portion of a cover member; andintroducing said wiper element between said cover wall portion and an outer periphery of an input coupling member such that said radial tang member is contained within said notch and such that the radial outer surface of said pair of spaced apart arm members have a similar radius as said cover wall portion and such that the radial inner surfaces have a similar radius as an outer periphery portion of said input coupling-member along said length and such that said opening of said scavenge port is contained between said pair of spaced apart arm members;wherein dynamic fluid sealing and pumping efficiency are improved.