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Patent Searching and Data


Title:
INTERNAL-GEAR TYPE OIL PUMP
Document Type and Number:
Japanese Patent JPS62681
Kind Code:
A
Abstract:

PURPOSE: To enable the leakage of a fluid from a clearance at the time of elevated temperatures to be controlled by making the driving gear from a material having the property of a linear coefficient higher than that of the driven gear.

CONSTITUTION: In a state of low temperatures, an internal-gear type oil pump maintains the required flow rate of discharge with certainty, since every component of the pump is not expanded with heat. Subsequently, when the pump is heated in a state of high temperatures, the difference of the linear expansion coefficient between a pump housing 12 and a driven gear 16 is likely to widen a body clearance C1, however, since a driving gear 15 is made from an aluminum sintered metal, which has a linear expansion coefficient higher than that of the driven gear 16, the gear 15 applies a pressing force A to the gear 16 so that the body clearance C1 is restricted to widen. In addition, following the displacement of the driven gear 16, a radial clearance C2, that is a space between the addendums of these gears 15, 16 located on the opposite side of the engaging point, is also narrowed. Thereby, the leakage of a fluid from a clearance can be restricted and the required flow rate of discharge can also be obtained.


Inventors:
Fujiwara, Eiju
Inaguma, Yoshiharu
Application Number:
JP1985000022651
Publication Date:
January 06, 1987
Filing Date:
February 06, 1985
Export Citation:
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Assignee:
TOYODA MACH WORKS LTD
International Classes:
F04C2/10; (IPC1-7): F04C2/10