Mechanical coolant pump

Abstract

A mechanical coolant pump for an internal combustion engine includes a pump housing configured to be stationary. The pump housing comprises an internal pneumatic actuator supplied by a pneumatic supply device. A pump wheel comprises a pump wheel shaft. The pump wheel shaft is rotatably supported by the pump housing. A driven shaft is directly connected to a pulley-wheel. An internal pneumatic clutch unit comprises a fixed clutch disk attached to the driven shaft or to the pump wheel shaft, and an axially slidable clutch disk. The slidable clutch disk is arranged at the pump wheel shaft or at the driven shaft and is rotatably fixed to the pump wheel shaft or to the driven shaft. The internal pneumatic actuator axially actuates the slidable clutch disk. The driven shaft is connectable to the pump wheel shaft via the internal pneumatic clutch unit.

What is claimed is: 
     
         1 - 9 . (canceled) 
     
     
         10 . A mechanical coolant pump for an internal combustion engine, the mechanical coolant pump comprising:
 a pump housing configured to be stationary, the pump housing comprising an internal pneumatic actuator configured to be supplied by a pneumatic supply device;   a pump wheel comprising a pump wheel shaft, the pump wheel shaft being configured to be rotatably supported by the pump housing;   a driven shaft directly connected to a pulley-wheel; and   an internal pneumatic clutch unit comprising:
 a fixed clutch disk attached to the driven shaft or to the pump wheel shaft, and 
 a slidable clutch disk configured to be axially slidably, the slidable clutch disk being arranged at the pump wheel shaft or at the driven shaft and being configured to be rotatably fixed to the pump wheel shaft or to the driven shaft, 
   wherein the internal pneumatic actuator is configured to axially actuate the slidable clutch disk, and   wherein the driven shaft is connectable to the pump wheel shaft via the internal pneumatic clutch unit.   
     
     
         11 . The mechanical coolant pump as recited in  claim 10 , wherein the internal pneumatic actuator is defined by the slidable clutch disk and the pump housing. 
     
     
         12 . The mechanical coolant pump as recited in  claim 10 , wherein the pump wheel shaft or the driven shaft comprises a slide bar at a clutch-sided end, the slidable clutch disk being slidably arranged at the slide bar and configured to be rotatably fixed by the slide bar. 
     
     
         13 . The mechanical coolant pump as recited in  claim 10 , further comprising a pretensioning element, the pretensioning element being configured to pretention the slidable clutch disk into an engaged position by 
     
     
         14 . The mechanical coolant pump as recited in  claim 13 , wherein the pretensioning element is supported by the pump wheel shaft or by the driven shaft. 
     
     
         15 . The mechanical coolant pump as recited in  claim 13 , wherein the pretensioning element is a compression spring. 
     
     
         16 . The mechanical coolant pump as recited in  claim 10 , wherein the pump housing further comprises a pneumatic opening arranged between the slidable clutch disk and the pump wheel or the pulley-wheel, the pneumatic opening being connected to the pneumatic supply device. 
     
     
         17 . The mechanical coolant pump as recited in  claim 10 , wherein the pump housing further comprises an inner side wall, the slidable clutch disk comprises a circumference with a ring-like sealing element, and further comprising a circular gap arranged between the slidable clutch disk and the inner side wall of the pump housing, wherein the ring-like sealing element is configured to seal the circular gap between the slidable clutch disk and the inner side wall of the pump housing. 
     
     
         18 . The mechanical coolant pump as recited in  claim 10 , further comprising a shaft sealing arranged between the slidable clutch disk and the pump wheel shaft.