PURPOSE: To reduce driving force at lower temperatures while increase discharge capacity at higher temperatures by forming a pump body with a material having a thermal expansion coefficient smaller than that of gears on the driving side and driven side.
CONSTITUTION: A driving side gear 1 and a driven side gear 2 are respectively installed on shafts 8, 9 which are rotatably held by a pump body 3 in a mutually meshed condition. The pump body 3 is formed with a material having a thermal expansion coefficient smaller than that of the gears 1, 2. Thereby, clearances becomes smaller increasing pump efficiency at higher temperatures, while driving resistances between the gears and the pump body and between the mutual gears are reduced at lower temperatures.
MIYAMOTO MASAMI
FUJII NOBUHIRO
SUETSUGU HAJIME
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