Diesel engine water pump with improved oil control
View Patent ↗An improved diesel engine water pump includes three main features that aid in extending the maintenance-free life of the pump. The impeller shaft is carried by tapered roller shaft support bearings of which the impeller bearing has a floating outer race that is urged axially by a preload spring to provide a prescribed axial preload that maintains concentricity of the shaft with the axis and prolongs bearing life. An improved oil seal combines an oil slinger, a stationary deflector and a lip oil seal with a return passage to the engine to more effectively limit oil leakage from the pump. An improved water seal includes pressurized water jets fed from the pump volute that flush wear particles from the water seal surface and increase water seal life. Further details of these features are also disclosed.
1. A water pump of the centrifugal type adapted for use in diesel engine cooling systems, the water pump comprising:
a housing containing a shaft rotatable on an axis extending through the housing, the shaft mounting a drive member adjacent a drive end of the housing and a fluid impeller at an opposite impeller end of the housing;
axially spaced drive and impeller bearings mounted in an oil lubricated recess and supporting the shaft in the housing, each bearing having an inner race fixed on the shaft and an outer race mounted in the housing, and
an oil control in the lubricated recess and including an oil slinger mounted on the rotatable shaft adjacent the impeller bearing and operative to centrifugally direct oil from the impeller bearing into a collector connected with an oil return passage.
2. A water pump as in claim 1 wherein the oil control further includes a stationary oil seal having a deflector extending inward from the housing adjacent the oil slinger and operative to deflect bypassed oil into the return passage and a seal lip engaging the shaft and blocking the passage of bypassed oil along the shaft toward the fluid impeller.
3. A water pump as in claim 1 wherein the oil slinger is mounted on the inner race of the impeller bearing.
4. A water pump as in claim 3 wherein the oil control further includes a stationary oil seal having a deflector extending inward from the housing adjacent the oil slinger and operative to deflect bypassed oil into the return passage and a seal lip engaging the shaft and blocking the passage of bypassed oil along the shaft toward the fluid impeller.
5. A water pump an in claim 3 wherein:
the bearings are roller bearings;
the outer race of the impeller bearing is axially slidable in the housing; and
a biasing clement is positioned between the housing and the outer race of the impeller bearing, the biasing element preloading the impeller bearing with a selected preload force maintained to maximize bearing life and concentric rotation of the shaft over all operating conditions of the pump.
6. A water pump as in claim 5 wherein the oil control further includes a stationary oil seal having a deflector extending inward from the housing adjacent the oil slinger and operative to deflect bypassed oil into the return passage and a seal lip engaging the shaft and blocking the passage of bypassed oil along the shaft toward the fluid impeller.