| 摘要 |
A switchable water pump 600 comprises a housing 610, a shaft 650 which drives an impeller 660, a bearing 640 which is press-fitted in the housing 610 and supports the shaft, and a coil 640 inserted in a coil cage 630. The coil cage is integral with the housing. Therefore the only press-fit tolerance is between the outer diameter of the bearing and the inner diameter of the housing. The press-fit interference may range between 10 and 80 µm (microns). The housing may be made of aluminium. The parallelism between a first datum plane A of the housing, and a second datum plane B of the housing may range between 0.05 and 0.1 mm. The pump may be an internal combustion engine coolant pump. |
