Axial piston pump neutral centering mechanism
US5845559A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1997 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Aug 8, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B1/2085
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A variable displacement axial piston pump (11) having a tiltable swashplate (33) to vary pump displacement by a manual input lever (43). The pump includes a neutral centering device (45) in which a cam member (57) is fixed to the end of one trunnion member (35). The cam member (57) defines three cam surfaces (65), each having a minimum displacement portion (67) and at least one maximum displacement portion (69). In engagement with each of the cam surfaces (65) is a follower element (79) supported by a cam follower holder (73), both of which are biased by a set of Belleville washers (75), toward the cam member (57). The present invention provides a neutral centering device which is balanced and simple to assemble, not requiring any special fixtures or holders for preloading a biasing spring, but which is able to provide a substantially constant return torque.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.