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:
Sep. 05, 1978
Filed:
Jan. 17, 1977
Howard E Chana, Troy, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A power train having a single shaft gas turbine engine having high idle speed and higher maximum torque speed and a progressively variable ratio transmission matched and controlled to provide increasing speed ratio and decreasing torque ratio relative to increasing engine torque and output speed for an accelerating drive at constant maximum tractive effort for a maximum performance vehicle starting and accelerating drive in a low output speed range up to maximum engine power and then increasing speed ratio and decreasing torque ratio for higher speed drives with reduced torque. The transmission has a hydromechanical unit having an engine driven planetary gear providing a variable speed ratio constant torque ratio drive to the input of a friction drive toric unit and a hydrostatic transmission with a constant displacement pump motor driven by the planetary gear reaction member and a variable displacement motor connected in one arrangement to drive the input and in another arrangement to drive the output which is connected by a forward reverse gear unit to drive the vehicle. The hydrostatic transmission differential pressure and motor displacement are controlled in response to engine speed and throttle position to reduce reaction member speed from the free rotary speed to zero speed to increase speed ratio from zero to a maximum and decrease torque ratio from a maximum to a minimum. The pump brake and toric unit are both controlled by speed and power requirements to provide high torque ratio at high input speed for constant maximum torque in a low output speed starting range up to maximum engine power. Then the pump brake holds the reaction member stationary to provide its highest speed ratio, and the toric unit speed ratio is increased for higher speed drives.