Hydraulic control system for continuously variable transmission
US4642069A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1985 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Oct 2, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/662
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control system for a continuously variable transmission having a first and a second variable-diameter pulley provided on a first and a second shaft, a transmission belt connecting the first and second pulleys to transmit power from one of the first and second pulleys to the other, and a pair of hydraulic cylinders for changing an effective diameter of the pulleys engaging the belt. The hydraulic control system includes a hydraulic source delivering a pressurized fluid, and a flow control device for controlling a flow of the pressurized fluid from said hydraulic source into one of said hydraulic cylinders, and a flow of the fluid from said one hydraulic cylinder, thereby changing the effective diameters of the pulleys to vary a speed ratio of the transmission. The control system comprises a pressure regulating device for regulating the pressurized fluid which is delivered from the hydraulic source and applied to the flow control device so that a pressure of the pressurized fluid is higher than a pressure in the above-indicated one hydraulic cylinder by a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.