Pump including a shield for protecting a pump wheel against a coolant leak along the hub of the wheel

Abstract

A pump is provided. The pump includes a flow chamber for the heat-transport fluid, a pump wheel which is placed entirely in the flow chamber and which comprises a hub, a shaft for rotating the pump wheel, having an axial end section rigidly connected to the pump wheel and fitted in the hub of the pump wheel, a motor for rotating the shaft around its axis, and means for causing a coolant for cooling the driveshaft to flow, at a temperature lower than that of the heat-transport fluid, along the driveshaft. The pump also includes a shield for protecting the pump wheel against a coolant leak along an outer peripheral surface of the hub of the pump wheel, the protective shield being attached to the pump wheel.

What is claimed is: 
     
         1 - 15 . (canceled) 
     
     
         16 . A pump for causing a heat-transport fluid to flow in a fluid circuit, the pump comprising:
 a flow chamber for the heat-transport fluid;   a pump wheel placed entirely in the flow chamber, the pump wheel including a hub;   a shaft configured to rotate the pump wheel, the shaft having an axial end section rigidly connected to the pump wheel and fitted in the hub of the pump wheel;   a motor configured to rotate the shaft around an axis of the shaft;   a cooler configured to cause a coolant for cooling the driveshaft to flow, at a temperature lower than that of the heat-transport fluid, along the driveshaft; and   a protective shield configured to protect the pump wheel against a coolant leak along an outer peripheral surface of the hub of the pump wheel, the protective shield being attached to the pump wheel.   
     
     
         17 . The pump as recited in  claim 16  wherein the protective shield is formed by an annular crown comprising a substantially cylindrical peripheral wall, coaxial to the hub and surrounding the hub. 
     
     
         18 . The pump as recited in  claim 17  wherein the peripheral wall has an inner diameter with a difference in diameter relative to an outer diameter of the hub, the difference in diameter being less than 1.5 mm. 
     
     
         19 . The pump as recited in  claim 18  wherein the difference in diameter is greater than 0.1 mm. 
     
     
         20 . The pump as recited in  claim 17  wherein the annular crown comprises an inner rim extending substantially radially toward an axis of the peripheral wall from the peripheral wall. 
     
     
         21 . The pump as recited in  claim 20  wherein the inner rim is flush with the shaft. 
     
     
         22 . The pump as recited in  claim 17  wherein the annular crown comprises an outer rim protruding from the peripheral wall opposite the axis of the peripheral wall, the outer rim running along a surface of the pump wheel. 
     
     
         23 . The pump as recited in  claim 22  wherein the protective shield is fastened to the pump wheel by the outer rim. 
     
     
         24 . The pump as recited in  claim 22  further comprising a seal inserted between the outer rim and the pump wheel. 
     
     
         25 . The pump as recited in  claim 22  wherein the annular crown comprises an inner rim extending substantially radially toward an axis of the peripheral wall from the peripheral wall, the inner rim protruding from a first axial end of the peripheral wall, the outer rim protruding from a second axial end of the peripheral wall opposite the first axial end. 
     
     
         26 . The pump as recited in  claim 16  further comprising an injector for causing the heat-transport fluid to flow in the axial end segment of the shaft fitted into the hub. 
     
     
         27 . The pump as recited in  claim 16  further comprising a key connecting the pump wheel to the shaft, the pump wheel having a first axial slot for receiving the key and the shaft having a second axial slot for receiving the key, the key and the pump wheel comprising complementary members for axial blocking of the key relative to the pump wheel. 
     
     
         28 . The pump as recited in  claim 16  wherein the first axial slot emerges in an axial end of the pump wheel through a window, the protective shield obstructing the window. 
     
     
         29 . The pump as recited in  claim 16  wherein the pump wheel is shrunk on the shaft. 
     
     
         30 . The pump as recited in  claim 16  wherein the driveshaft is oriented substantially vertically, the axial end segment fitted into the hub being a lower end segment of the shaft.