Electric Work Vehicle

Patent metadata

Field	Value
Publication number	US-2016297293-A1
Application number	US-201514956693-A
Country	US
Kind code	A1
Filing date	Dec 2, 2015
Priority date	Apr 8, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

An electric work vehicle includes a left motor 4 L that drives a left drive wheel 12 L and a right motor 4 R that drives a right drive wheel 12 R, a cooling liquid circulation flow path 7 connected to the left motor 4 L and the right motor 4 R, and a cooling liquid distribution mechanism 6 that, according to a travel state, adjusts a ratio between a cooling liquid flow amount that flows from a pump 72 disposed on the cooling liquid circulation flow path 7 to the left motor 4 L, and a cooling liquid flow amount that flows from the pump 72 to the right motor 4 R.

First claim

1 . An electric work vehicle comprising:
a left motor that drives a left drive wheel; a right motor that drives a right drive wheel; a cooling liquid circulation flow path connected to the left motor and the right motor; a radiator and a pump disposed on the cooling liquid circulation flow path; and a cooling liquid distribution mechanism configured to, according to a travel state, adjust a ratio between a cooling liquid flow amount that flows from the pump to the left motor and a cooling liquid flow amount that flows from the pump to the right motor.

2 . The electric work vehicle according to claim 1 , wherein
the travel state is an inclination angle in a vehicle body transverse direction of a traveling vehicle body, and the cooling liquid distribution mechanism is a distribution valve that makes a cooling liquid flow amount to a motor that drives a drive wheel located on a lower side of an inclination greater than a cooling liquid flow amount to a motor that drives a drive wheel located on an upper side of an inclination.

3 . The electric work vehicle according to claim 2 , wherein
if the inclination angle is less than or equal to a predetermined angle, the distribution valve keeps the cooling liquid flow amounts to the left and right motors at a predetermined flow amount, if the inclination angle exceeds the predetermined angle, the distribution valve causes a flow amount that is less than the predetermined flow amount to flow to the motor that drives the drive wheel located on the upper side of the inclination, and if the inclination angle exceeds the predetermined angle, the distribution valve causes a flow amount that is greater than the predetermined flow amount to flow to the motor that drives the drive wheel located on the lower side of the inclination.

4 . The electric work vehicle according to claim 1 , wherein
the travel state is a motor temperature, and the cooling liquid distribution mechanism is a distribution valve that makes a cooling liquid flow amount to a motor with a higher motor temperature greater than a cooling liquid flow amount to a motor with a lower motor temperature.

5 . The electric work vehicle according to claim 4 , wherein
the cooling liquid distribution mechanism includes a bypass that connects a cooling liquid flow path to the left motor and a cooling liquid flow path from the left motor and connects a cooling liquid flow path to the right motor and a cooling liquid flow path from the right motor, a valve body configured to be displaced to a position of shutting the bypass and a position of opening the bypass, and a temperature response action mechanism that displaces the valve body according to motor temperature.

6 . The electric work vehicle according to claim 1 , wherein
the travel state is a motor load calculated according to a motor current, and the cooling liquid distribution mechanism is a control valve that makes a cooling liquid flow amount to a motor with a higher motor load greater than a cooling liquid flow amount to a motor with a lower motor load.

Assignees

• Kubota Kk

Inventors

• Ito Hirokazu
• Koike Kazuo

Classifications

• B60K2001/0416

  Arrangement in the rear part of the vehicle · CPC title

• B60K2001/003

  with means for cooling the electrical propulsion units · CPC title

• B60K2007/0061

  the motor axle being parallel to the wheel axle · CPC title

• B60K7/0007

  the motor being electric · CPC title

• B60K1/04

  of the electric storage means for propulsion · CPC title