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:
Dec. 14, 1982
Filed:
Jul. 16, 1980
Yoshinori Kohzai, Hino, JP;
Yoichi Amemiya, Hachioji, JP;
Yoshiki Fujioka, Hino, JP;
Noboru Iwamatsu, Hino, JP;
Fujitsu Fanuc Limited, Tokyo, JP;
Abstract
A tachometer generator comprising a generator section for producing rectangular polyphase alternating voltages having a peak value which is proportional to the speed of the rotor, and a commutator section including contactless change-over switches for successively transferring the alternating voltages from the generator section, and sensors for producing switching signals which actuate the change-over switches in accordance with the rotational position of the rotor of the generator section. In the commutator section the sensors are equivalent in number to the change-over switches and comprise Hall devices arrayed about a rotary shaft which is coupled to the generator section. The alternating voltages which are obtained successively from the coils of the generator section as the rotary shaft rotates, are transferred in order by the change-over switches to produce a speed signal, in analog form; which is proportional to the rotating speed of the rotor. The axially extending width of the rotor is smaller than the axially extending width of the stator, the width of the rotor being approximately 80% that of the stator. A magnetic shield plate is interposed between the generator section and the sensors of the commutator section. The tachometer generator having the above arrangement generates more accurate speed signals and can be reduced in size since the generator and commutator sections are capable of being disposed closer together as a result of the provision of the magnetic shield.