Hydraulic control system for continuously variable traction roller transmission
US5136890A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1991 |
| Grant date | Aug 11, 1992 |
| Priority date | — |
| Expiry date | Mar 25, 2011 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H15/38
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control system for a continuously variable traction roller transmission comprises a shift control valve for controlling hydraulic pressure within a hydraulic cylinder apparatus. The shift control valve includes a sleeve and a spool received therein for relative motion, which assume a normal state when a gear ratio commanded corresponds to a rotational displacement of rotation shanks of roller support members wherein the hydraulic cylinder apparatus provides a predetermined force to the rotation shanks in an axial direction thereof so as to preserve a rotational displacement of the rotation shanks. The sleeve has a plurality of bores for discharging hydraulic fluid to be supplied to the hydraulic cylinder apparatus. The bores are fluidly communicated when a relative displacement between the sleeve and the spool with regard to the normal state is greater than a predetermined value, whereas the bores fail to be fluidly communicated when the relative displacement is smaller than the predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.