Hydraulic unit

Patent metadata

Field	Value
Publication number	US-9366267-B2
Application number	US-201214345109-A
Country	US
Kind code	B2
Filing date	Sep 24, 2012
Priority date	Sep 27, 2011
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

An oil-hydraulic unit includes a power module generating heat when energized. The power module is provided on the bottom surface of a recess facing hydraulic oil in a tank. Thus, the power module is cooled by the hydraulic oil in the tank. This reduces the difference in temperature between the power module and the hydraulic oil in the tank. In the oil-hydraulic unit, the temperature sensor detects the temperature of the power module. The oil temperature in the tank is estimated based on the temperature detected by the temperature sensor.

First claim

The invention claimed is:

1. A hydraulic unit comprising:
a tank configured to store hydraulic fluid;
a pump configured to suck the hydraulic fluid through an outlet of the tank;
a feed passage through which the hydraulic fluid sucked by the pump is fed to a hydraulic actuator;
a return passage through which the hydraulic fluid is returned from the hydraulic actuator to a return port of the tank;
an electric motor configured to rotate the pump; and
a power conversion device configured to convert electric power into a predetermined power and feed the converted power to the electric motor, wherein
the power conversion device includes
a power module including a heat dissipating section facing the hydraulic fluid in the tank, and
a temperature sensor configured to detect a temperature of the power module, and

the hydraulic unit further includes a fluid temperature estimator configured to estimate a temperature of the hydraulic fluid in the tank based on the temperature detected by the temperature sensor.

2. The hydraulic unit of claim 1 , wherein
the temperature sensor is provided on the heat dissipating section of the power module.

3. The hydraulic unit of claim 1 , wherein
the heat dissipating section of the power module is closer to the outlet of the tank than to the return port thereof.

4. The hydraulic unit of claim 2 , wherein
the heat dissipating section of the power module is closer to the outlet of the tank than to the return port thereof.

5. The hydraulic unit of claim 3 , wherein
a baffle is provided in the tank to regulate a flow of the hydraulic fluid from the return port to the outlet.

6. The hydraulic unit of claim 4 , wherein
a baffle is provided in the tank to regulate a flow of the hydraulic fluid from the return port to the outlet.

Assignees

• Daikin Ind Ltd

Inventors

• Nakata Tetsuo

Classifications

• F15B1/26 Primary

  Supply reservoir or sump assemblies · CPC title

• F15B19/005

  Fault detection or monitoring · CPC title

• F04B49/065

  and making use of computers · CPC title

• F04D29/5806 Primary

  Cooling the drive system · CPC title

• F15B20/002

  Electrical failure · CPC title