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:
Jul. 14, 1987
Filed:
Dec. 24, 1984
Stephen S Baits, Rockford, IL (US);
Richard W Reynolds, Rockford, IL (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A differential transmission mechanism using an output differential for a constant speed drive has desirable characteristics including full utilization of the torque capabilities of the hydraulic trim device associated with the output differential; however, there is a limitation on the utilization of the speed capability of the hydraulic components of the trim device at the low end of the input speed range. The disclosed differential transmission mechanism utilizing an output differential has a hydraulic trim device with a first hydraulic displacement unit having a normally fixed, approximately maximum displacement connected to an element of the output differential and a second hydraulic displacement unit which is of variable displacement connected to a variable speed input shaft. Additional components of the output differential are connected to the input shaft and to an output shaft connectable to a load. A sensing device senses the speed of the output shaft to control the displacement of the variable displacement hydraulic displacement unit to control the displacement thereof to achieve a constant output speed by varying the speed of the normally fixed displacement unit as required. Additionally, a sensor senses the speed of the input shaft and, when the speed of the input shaft is below a predetermined value, controls the displacement of the normally fixed displacement unit to reduce the displacement thereof to effectively make the latter displacement unit a smaller unit which will therefore operate at a faster speed to extend the range of the constant speed drive at the low end of the input speed range.