Anti cavitation system for two-speed motors
US6679691B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2002 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C2/105
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A two-speed gerotor motor (10) including motor valve means (19,43) to communicate fluid to and from expanding (33E) and contracting (33c) fluid volume chambers. The motor includes a shift valve spool (61) to cause the motor to operate either in the normal, low-speed, high-torque (LSHT) mode (FIG. 3) or in a high-speed, low-torque (HSLT) mode (FIG. 4). When the motor operates in HSLT mode, certain of the volume chambers comprise recirculating volume chambers (33R). The motor (10) defines a supplemental fluid passage (89) through which fluid is communicated from a system charge pump (73) to each of the recirculating volume chambers (33R). A control valve (83) is operable, in a shift mode (S) to permit fluid communication from the charge pump (73) to the supplemental fluid passage (89), thus preventing cavitation during shifting of the motor (10), especially when shifting from the HSLT mode to the LSHT mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.