The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1982
Filed:
Jan. 24, 1980
Hideo Teruyama, Shobu, JP;
Kayaba Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
In order to prevent a decrease in volumetric efficiency from occurring when a gear pump or motor, 10, is operated at room temperature after operating at a lower temperature or when it is operated at a higher temperature after operation at a lower temperature, the housing, 13, containing two interlocking gears 17 and 18 is made of a ferrous material, which is the same as that of the two gears, and a large number of serrated grooves, 40, are disposed in the axial direction on the low pressure side of the inner wall surfaces of the gear bower 16. Therefore in the break-in operation of the gear pump or motor when the inner wall surfaces at the low pressure side of the gear bower are cut off by the tooth crests of the two gears, built-up edges, which are then formed on the tooth crests of these gears, can drop off immediately, owing to the occurrence of impact forces when they clash with the angular parts of the grooves, and result in a smooth break-in to inner wall surfaces at the low pressure side of the gear bower. Thus the use of housings made of ferrous materials is excellent for the above temperature characteristics.