Gear pump for automatic transmission

摘要

An oil film is formed between side faces of a pump gear and side faces of a pump casing to thereby reduce wear and reduce sliding resistance. To form the oil film predetermined numbers of recesses are provided in both side faces of a drive gear and in both side faces of a driven gear of the gear pump. The recesses serve to hold oil. The oil held in the recesses oozes out to between the opposing and contacting side faces to thereby form the oil films therebetween.