Hydraulic power drive unit
US5452643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1993 |
| Grant date | Sep 26, 1995 |
| Priority date | — |
| Expiry date | Apr 12, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64C3/56
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydraulic power drive unit (36) including a linear hydraulic piston cylinder unit (64) with a set of longitudinally spaced gear teeth (84) in the form of a rack. A pinion gear (86) is operatively engaged and driven by the rack (84). A differential which may include a carrier (102), planet gears (108, 110) and sun gears (120, 122) may be driven by the pinion gear (86) to selectively transfer drive power to two separate rotary drive outputs (38, 40). A switching valve (160) may be provided which is responsive to a reversal of hydraulic supply pressure. Operation of the switching valve (160) may be limited by mechanical interference between an inhibit dog (181) and a cam surface (196) on the carrier (102). The carrier (102) may also include a separate cam surface (140) positioned for actuation of separate electrical switches (146, 148) in order to monitor position of the drive outputs (38, 40).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.