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:
Oct. 27, 1998
Filed:
Jan. 21, 1997
Takeshi Seto, Nagano, JP;
Akihito Uetake, Nagano, JP;
Tatsuya Shimoda, Nagano, JP;
Masao Ono, Kanagawa, JP;
Masatoshi Fukuda, Kanagawa, JP;
Satoshi Yamazaki, Kanagawa, JP;
Seiko Epson Corporation, Tokyo, JP;
Tokyo R & D Co., Ltd., Tokyo, JP;
Abstract
In an electric vehicle provided with an electric motor (M), a motor drive circuit (17) and a control circuit section (15) for outputting an operation command to the motor drive circuit, a variable speed drive unit for electric vehicles has a transmission apparatus (20) which engages or disengages a drive shaft (7a) which receives the drive force from a propelling motor and a driven shaft (5a) which is interconnected with propelling wheels by an electromagnetic engagement clutch (30), the transmission apparatus has the electromagnetic clutch comprised of a first clutch (22) interconnected with the drive shaft, a second clutch (25) having a rotational speed different from the first clutch, and an output side clutch (21) interconnected with the driven shaft; and the output side clutch and the first clutch or the second clutch are alternatively connected to selectively change the motor output. And, to connect the clutches mutually, the rotational speed of the clutch on the drive side is synchronized with the rotational speed of the clutch on the driven side.