Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
HYDRAULIC DRIVE COOLING FAN UNIT
Document Type and Number:
Japanese Patent JP3853255
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide a hydraulic drive fan cooler which assures high reliability and high durability at a low cost.
SOLUTION: The hydraulic drive cooling fan unit has a cooling fan 16 for creating a cooling wind for cooling an engine 2, a hydraulic motor 17 for a fan for driving the fan 16, and a pump 19 for the fan for discharging a hydraulic oil to the motor 17 for the fan. The cooling fan unit comprises: a pilot pump 7 of a substantially constant pressure, a choke 10 and an orifice 12 provided in a pilot duct 9 from the pump 7 and having different passing flow rate characteristics in response to the viscosity of the hydraulic oil, and a bleed-off valve 21 for controlling the bleed-off flow rate of a bypass duct 20 branched from a discharge duct 18 to the motor 17 from the pump 19 by using the pressure Pa of the duct 11 provided between the choke 10 and the orifice 12.


Inventors:
Junya Kawamoto
Takashi Kanai
Katsura Nasu
Yasuki Tsuriga
Application Number:
JP2002148216A
Publication Date:
December 06, 2006
Filing Date:
May 22, 2002
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
Hitachi Construction Machinery Co., Ltd.
International Classes:
E02F9/00; F01P7/04; F01P5/04; F04D15/00; F15B11/08; (IPC1-7): F01P7/04; F01P5/04; F04D15/00; F15B11/08; //E02F9/00
Domestic Patent References:
JP2001303955A
JP64012022A
Attorney, Agent or Firm:
Kasuga Toshiaki