HYDRAULIC DRIVE SYSTEM AND IMPROVED CONTROL VALVE ASSEMBLY THEREFOR

Title:

HYDRAULIC DRIVE SYSTEM AND IMPROVED CONTROL VALVE ASSEMBLY THEREFOR

Document Type and Number:

Japanese Patent JP2005319993

Kind Code:

A

Abstract:

To provide a control valve assembly that is for use in a hydraulic drive system in which a pump-motor unit can either receive drive torque from a drive-line or transmit torque thereto, and has high response and low pressure drop to improve fuel efficiency.

The control valve assembly 43 is arranged between the pump-motor unit 35 and a high pressure accumulator 41, and includes a mode valve 45 normally biased closed by pressure in a control cavity 89 controlled by a pilot valve assembly 49 in response to an electrical signal. A step-orifice valve 47 of a poppet member 79 provides a larger orifice into the control cavity 89 when pressure therein is high, and a smaller orifice into the control cavity when pressure therein is low. Thus, a large volume of flow can occur from the high-pressure accumulator 41 to the pump-motor unit 35 in motor mode with a low pressure drop.

Inventors:

SINGH RODNEY V

Application Number:

JP2005130164A

Publication Date:

November 17, 2005

Filing Date:

April 27, 2005

Export Citation:

Click for automatic bibliography generation Help

Assignee:

EATON CORP

International Classes:

B60K6/12; B60K17/10; B60T1/10; F15B1/02; F15B11/02; F15B13/04; F15B13/042; F15B13/043; F15B21/14; F16D31/02; (IPC1-7): B60T1/10; B60K17/10; F15B11/02

Domestic Patent References:

JPH1120490A	1999-01-26
JP2000002205A	2000-01-07
JP2005308205A	2005-11-04
JPH06156222A	1994-06-03
JPH06339764A	1994-12-13

Attorney, Agent or Firm:

Calyx
Miyazaki Yoshio
Mitsuo Tateishi
Kaoru Onozuka
Akio Tagami
High Masahiro
Toshio Nakamura
Tsutomu Kato
Yusuke Murakoshi
Tomoaki Komiya

Previous Patent: DRIVING AUXILIARY FUNCTION FOR LETTING VEHICLE COME TO REST ON SLOPE

Next Patent: COVER FOR STEERING WHEEL