Cooling fan clutch

Abstract

A disk-shaped cover has a first toothed portion at one surface thereof. A housing is coupled with the cover such that a space is defined therebetween. The housing has a second toothed portion at one surface thereof, facing the first toothed portion. A shaft is rotatably disposed through a middle portion of the housing. A fan is fixedly connected to the housing and rotatable with the housing. A rotor is mounted in the space between the cover and the housing, engaged with and rotatable with the shaft, with third and fourth toothed portions at both surfaces thereof, engaged with the first and second toothed portions, respectively. An operation unit controls an amount of fluid supplied to the space between the cover and the housing to control a frictional force generated between the rotor, the housing, and the cover. A control unit controls the operation unit based on a coolant temperature.

1 . An apparatus, comprising:
 a cover with a disk shape, comprising a first toothed portion at a radially outward portion of one side surface thereof;   a housing coupled with the cover such that a space is defined therebetween, the housing comprising a second toothed portion at a radially outward portion of one side surface thereof facing the first toothed portion;   a shaft, rotatably disposed through a middle portion of the housing;   a fan fixedly connected to the housing and rotatable with the housing;   a rotor mounted in the space between the cover and the housing, engaged with and rotatable with the shaft, comprising third and fourth toothed portions at radially outward portions of both side surfaces thereof engaged with the first and second toothed portions, respectively;   an operation unit for controlling an amount of fluid supplied to the space between the cover and the housing so as to control a frictional force generated between the rotor, the housing, and the cover; and   a control unit for controlling the operation unit based on a coolant temperature.   
   
   
       2 . The apparatus of  claim 1 , further comprising a bearing interposed between the shaft and the housing such that the housing can rotate relative to the shaft. 
   
   
       3 . The apparatus of  claim 1 , wherein the operation unit comprises:
 a fluid storage area disposed in a portion of the space between the cover and the housing, for storing the fluid;   a screen for fluidly isolating the fluid storage area, and comprising a passage through which the fluid in the fluid storage area can be supplied to another portion of the space between the cover and the housing; and   a valve for closing and opening the passage by control of the control unit.   
   
   
       4 . The apparatus of  claim 3 , wherein the operation unit further comprises:
 an electromagnet for receiving current and generating a magnetic force by the control of the control unit;   a plate configured to be moved by the magnetic force of the electromagnet; and   a valve rod connected to the plate and the valve, and moving the valve according to motion of the plate.   
   
   
       5 . The apparatus of  claim 4 , wherein the plate and the electromagnet are exterior to the housing, and the valve rod penetrates the housing. 
   
   
       6 . The apparatus of  claim 5 , further comprising a bearing interposed between the shaft and the electromagnet. 
   
   
       7 . The apparatus of  claim 4 , wherein the control unit is configured to open the valve and supply the fluid to the other portion of the space between the cover and the housing if the coolant temperature is higher than or equal to a predetermined temperature. 
   
   
       8 . The apparatus of  claim 1 , further comprising a coolant temperature sensor for detecting the coolant temperature and transmitting a signal corresponding thereto to the control unit. 
   
   
       9 . The apparatus of  claim 1 , wherein the fluid comprises silicon oil.