초록 ▼

An electronically-controlled viscous fan drive in which the output drive to the fan is electronically controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. A radially balanced valve disk coupled to a spr

An electronically-controlled viscous fan drive in which the output drive to the fan is electronically controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. A radially balanced valve disk coupled to a spring controls the relative movement of viscous fluid from a fluid reservoir to the working chamber by sealingly engaging and disengaging a fill hole fluidically coupling the fluid reservoir to the working chamber. The clutch plate and cover and body, along with the features defined between the clutch plate and cover and body are cast to the desired size and shape, therein allowing easier and more precise manufacturing and more cost effective manufacturing as compared with traditional designs that are stamped and having machined-in features.

대표청구항 ▼

What is claimed is: 1. An electronically controlled viscous fan drive used on an internal combustion engine comprising: a cast output coupling member including a housing member coupled to a cover member; an actuator shaft partially disposed within said cast output coupling member; a cast input coup

What is claimed is: 1. An electronically controlled viscous fan drive used on an internal combustion engine comprising: a cast output coupling member including a housing member coupled to a cover member; an actuator shaft partially disposed within said cast output coupling member; a cast input coupling assembly coupled to said actuator shaft and substantially contained within said cast output coupling member, said cast input coupling assembly capable of rotating at a given input speed, a reservoir cover coupled within said output coupling member and sealingly engaged to said cast input coupling member; a pair of cold pump out slots defined by said reservoir cover and said cast input coupling member; a fluid reservoir chamber defined by said reservoir cover and said cast input coupling member; a quantity of viscous fluid contained within said fluid reservoir chamber; a pair of fill holes, each of said pair of fill holes defined between a respective one of said pair of cold pump out slots and said fluid reservoir chamber; a fluid operating chamber defined by said cast input coupling member and said cover member, said fluid reservoir chamber fluidically coupled to said fluid operating chamber through said pair of cold pump out passageways, said fluid operating chamber further being fluidically coupled to said fluid reservoir chamber through a radial passage defined within said housing member; a valve disk coupled to said actuator shaft and disposed between said input coupling member and said reservoir cover, said valve disk being closely coupled with said pair of fill holes and controlling said amount of said viscous fluid entering said fluid operating chamber from said fluid reservoir chamber through said cold pump out passageways and through said pair of fill holes, wherein said amount of viscous fluid within said fluid operating chamber and said given input speed define an output rotational speed of said cast output coupling member; an actuator coupled around a portion of said actuator shaft, said actuator capable of axial movement along the length of said input coupling assembly in response to said magnetic flux to position said valve disk relative to said pair of fill holes between an engaged position, a partially engaged position, or in a disengaged position; a spring coupled along said actuator shaft and biasing said valve disk in a first position in the absence of said magnetic flux from said actuator, said first position selected from the group consisting of said engaged position and said disengaged position; wherein said engaged position is characterized such that said valve disk is positioned wherein said pair of fill holes are not covered by said valve disk, therein allowing maximum flow of said viscous fluid from said fluid reservoir chamber to said fluid operating chamber to drive said output coupling member at a maximum rotational speed at said given input speed; wherein said disengaged position is characterized is characterized such that said valve disk is positioned wherein said pair of fill holes are covered by said valve disk to prevent flow of said amount of viscous fluid from said fluid reservoir chamber to said fluid operating chamber; and wherein said partially engaged position is characterized such that said valve disk is positioned wherein said pair of fill holes are partially covered by said valve disk to allow a limited amount of said viscous fluid to flow from said fluid reservoir chamber to said fluid operating chamber to drive said output coupling member at a rotational speed less than said maximum rotational speed. 2. The fan drive of claim 1 further comprising: an external controller; and an electrical coil electrically coupled to said external controller, said electrical coil capable of being electrically activated by said external controller to generate a magnetic flux, wherein a relative increase in amount of said magnetic flux thereby causing the movement of said actuator away from said spring in response to said relative increase and wherein a relative decrease in said amount of magnetic flux causes the movement of said actuator towards said spring in response to said relative decrease. 3. The fan drive of claim 2 further comprising at least one sensor input electrically coupled to said external controller, said at least one sensor input capable of sensing the temperature of the internal combustion engine, wherein said external controller interprets said sensed temperature to determine the amount of electrical signal to send to said electrical coil in response to said sensed engine operating condition to maintain said engine in a desired operating range. 4. The fan drive of claim 1, wherein said first position comprises said engaged position. 5. The fan drive of claim 4, wherein said spring is coupled between said valve disk and a hub portion of said cast input coupling assembly. 6. The fan drive of claim 1, wherein said first position comprises said disengaged position. 7. The fan drive of claim 6, wherein said spring is coupled between said actuator shaft and said armature. 8. The fan drive of claim 1, wherein said cast input coupling assembly comprises a cast input coupling member comprising: a hub portion, a plurality of input annular lands located outwardly from said hub portion; a pair of input drive grooves coupled within a portion of said plurality of input annular lands; and a pair of input cold pump out slots disposed between said plurality of annular lands and said hub portion. 9. The fan drive of claim 8, wherein said housing member comprises a cast housing member comprising: a plurality of housing member annular lands, said plurality of housing member annular lands and said plurality of input annular lands defining a shear space therebetween; a pair of housing member drive grooves coupled within a portion of said plurality of housing member annular lands, each of said pair of housing member drive grooves corresponding to a respective one of said pair of input drive grooves of said input coupling member and forming a respective drive groove; and a pair of housing member cold pump out slots, each of said pair of housing member cold pump out slots corresponding to a respective one of said pair of input cold pump out slots to define a cold pump out passageway therebetween. 10. The fan drive of claim 8, wherein said housing member comprises a cast cover member comprising: a plurality of cover member annular lands, said plurality of cover member annular lands and said plurality of input annular lands defining a shear space therebetween; a pair of cover member drive grooves coupled within a portion of said plurality of housing member annular lands, each of said pair of cover drive grooves corresponding to a respective one of said pair of input drive grooves of said input coupling member and forming a respective drive groove; and a pair of cover member cold pump out slots, each of said pair of cover member cold pump out slots corresponding to a respective one of said pair of input cold pump out slots to define a cold pump out passageway therebetween. 11. A method for forming an electronically controlled viscous fan drive comprising: (a) casting an input coupling assembly comprising: a hub portion, a plurality of input annular lands located outwardly from said hub portion, a pair of input drive grooves coupled within a portion of said plurality of input annular lands, and a pair of input cold pump out slots disposed between said plurality of annular lands and said hub portion; (b) casting a cover member comprising: a plurality of cover member annular lands, a pair of cover member drive grooves coupled within a portion of said plurality of cover member annular lands, and a pair of cover member cold pump out slots; (c) casting a housing member; (d) coupling a housing member to an actuator shaft; (e) coupling said cast input coupling assembly to an actuator shaft such that said plurality of input annular lands and said plurality of cover member annular lands define a shear space therebetween and further such that each of said plurality of cover member drive grooves and a respective one of said input drive grooves define a drive groove therebetween and further such that each of said pair of cover member cold pump out slots and said respective one of said pair of input cold pump out slots form a cold pump out passageway therebetween; (f) coupling a valve disk to said actuator shaft; (g) coupling a reservoir cover onto said actuator shaft; (h) coupling a spring near said actuator shaft, said spring biasing said valve disk in a first position, said first position selected from the group consisting of an engaged position and a disengaged position; (i) coupling an actuator subassembly along said actuator shaft, said actuator subassembly including a plurality of coils; (j) coupling an actuator between said actuator shaft and said actuator subassembly, said actuator capable of moving actually along the length of said actuator shaft in response to an increasing amount of strength of a magnetic flux generated from electrically activating said plurality of coils, thereby causing said valve disk to be moved from said first position to a second position in response to said movement of said actuator, said second position selected from the group consisting of an engaged position, a disengaged position, and a partially engaged position, said first position not equal to said second position; (k) coupling said cover member to said housing member such that said input coupling member, said valve disk, and said reservoir cover are substantially contained within said cover member and said housing member; (l) introducing a quantity of viscous fluid to a fluid reservoir chamber, said fluid reservoir chamber defined by said reservoir cover and said cast input coupling member; and (m) electrically coupling said plurality of coils to an external controller. 12. The method of claim 11, wherein (h) coupling a spring comprises (g) coupling a spring between said hub portion and said valve disk, said spring biasing said valve disk in an engaged position, wherein said engaged position allows said quantity of viscous fluid to flow from a fluid reservoir chamber to a fluid operating chamber, wherein said fluid reservoir chamber is defined by said reservoir cover and said cast input coupling member and wherein said fluid operating chamber is defined by said cast input coupling member and said cover member. 13. The method of claim 11, wherein (h) coupling a spring comprises (g) coupling a spring between said actuator shaft and said armature, said spring biasing said valve disk in a disengaged position, wherein said disengaged position prevents said quantity of viscous fluid to flow from a fluid reservoir chamber to a fluid operating chamber, wherein said fluid reservoir chamber is defined by said reservoir cover and said cast input coupling member and wherein said fluid operating chamber is defined by said cast input coupling member and said cover member. 14. The method of claim 11, wherein (a) casting an input coupling assembly comprises (a) casting an input coupling assembly having a first side and a second side, said first side located adjacent said cover member and said second side located adjacent said housing member when said input coupling assembly is coupled to said actuator shaft, said input coupling assembly having: a hub portion, a first plurality of input annular lands located outwardly from said hub portion on said first side, a second plurality of input annular lands located outwardly from said hub portion on said second side, a first pair of input drive grooves coupled within a portion of said first plurality of input annular lands, a second pair of input drive grooves coupled within a portion of said second plurality of input annular lands, a first pair of input cold pump out slots disposed between said first plurality of annular lands and said hub portion, and a second pair of input cold pump out slots disposed between said second plurality of annular lands and said hub portion. 15. The method of claim 14, wherein (c) casting a housing member comprises (c) casting a housing member comprising: a plurality of housing member annular lands, a pair of housing member drive grooves coupled within a portion of said plurality of housing member annular lands, and a pair of housing member cold pump out slots. 16. The method of claim 15, wherein (e) coupling said cast input coupling assembly to an actuator shaft comprises (e) coupling said cast input coupling assembly to an actuator shaft such that said first side is closely coupled to said cover member a said second side is closely coupled to said housing member, wherein said first plurality of input annular lands and said plurality of cover member annular lands define a first shear space therebetween and further such that each of said first plurality of input drive grooves and a respective one of said cover member drive grooves define a first drive groove therebetween and further such that each of said first pair of cover member cold pump out slots and said respective one of said pair of input cold pump out slots form a first cold pump out passageway therebetween; wherein said second plurality of input annular lands and said plurality of housing member annular lands define a second shear space therebetween and further such that each of said first plurality of input drive grooves and a respective one of said housing member drive grooves define a first drive groove therebetween and further such that each of said first pair of housing member cold pump out slots and said respective one of said pair of input cold pump out slots form a second cold pump out passageway therebetween. 17. The method of claim 11, wherein (a) casting an input coupling member comprises: providing a die cast mold corresponding to the input coupling member and including a hub portion, a plurality of input annular lands located outwardly from said hub portion, a pair of input drive grooves coupled within a portion of said plurality of input annular lands, and a pair of input cold pump out slots disposed between said plurality of annular lands and said hub portion; introducing a quantity of molten material to said die cast mold at a first pressure; cooling said quantity of molten material within said die cast mold; and removing the input coupling member from said die cast mold. 18. The method of claim 17, wherein introducing a quantity of molten material comprises introducing a quantity of molten aluminum alloy to said die cast mold at a pressure between about 10 and 210 Megapascals. 19. The method of claim 11, wherein (b) casting a cover member comprises: providing a die cast mold corresponding to the cover member and including a plurality of cover member annular lands, a pair of cover member drive grooves coupled within a portion of said plurality of cover member annular lands, and a pair of cover member cold pump out slots; introducing a quantity of molten material to said die cast mold at a first pressure; cooling said quantity of molten material within said die cast mold; and removing the input coupling member from said die cast mold. 20. The method of claim 19, wherein introducing a quantity of molten material comprises introducing a quantity of molten aluminum alloy to said die cast mold at a pressure between about 10 and 210 Megapascals.