Hydraulic control apparatus for vehicle power transmitting system having continuously variable transmission
US5052980A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1990 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | Feb 7, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/66259
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control apparatus for a power transmitting system for an automotive vehicle having a continuously variable transmission which has a first and a second shaft, a pair of variable-diameter pulleys provided on the first and second shafts, a belt connecting the pulleys, and a pair of hydraulic actuators for changing diameters of the pulleys, wherein a tension of the belt is controlled by regulating an actuating pressure in a driven side actuator of the hydraulic actuators which is provided on a driven one of the two shafts. The apparatus includes a pressure regulating valve which has a valve spool for regulating the actuating pressure in the driven side actuator, and a pressure-reducing chamber for receiving a pressure-reducing pilot pressure for biasing the spool for reducing the actuating pressure. The apparatus further includes a pilot pressure generator for generating the pressure-reducing pilot pressure to be applied to the pressure-reducing chamber, when the detected vehicle running speed exceeds a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.