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:
Nov. 22, 2005
Filed:
Nov. 20, 2002
Manabu Kawakami, Amagasaki-shi, Hyogo, JP;
Ryota Ohashi, Amagasaki-shi, Hyogo, JP;
Manabu Kawakami, Amagasaki-shi, Hyogo, JP;
Ryota Ohashi, Amagasaki-shi, Hyogo, JP;
Other;
Abstract
A hydrostatic transmission, comprising a housing, an interior space of the housing serving as a fluid sump; a center section disposed in the housing so as to be submerged In the fluid sump; a hydraulic pump mounted on the center section in the housing: a hydraulic motor mounted on the center section in the housing, and a pair of first and second fluid passages formed within the center section so as to fluidly connect the hydraulic pump with the hydraulic motor. The second fluid passage has an upwardly slant opening toward the fluid sump. A draining device including a relief valve is provided in the opening of the second fluid passage. When hydraulic pressure in the second fluid passage is not more than a predetermined value but not less than that in the first fluid passage, the relief valve is opened so as to drain fluid from the second fluid passage to the fluid sump, thereby keeping the hydrostatic transmission in neutral. When hydraulic pressure in the second fluid passage is more than the predetermined value or less than that in the first fluid passage, the relief valve is closed so as to shut out fluid in the second fluid passage from the fluid sump. The draining device comprises a ball check valve which closes the relief valve by its dead weight when the hydraulic pressure in the second fluid passage is less than the first fluid passage.