Electric Work Vehicle, Battery Pack for Electric Work Vehicle and Contactless Charging System

• US 20180304735A1
• Filed: 06/25/2018
• Published: 10/25/2018
• Est. Priority Date: 11/16/2015
• Status: Active Grant

• Current Assignee: Kubota Corporation
• Original Assignee: Kubota Corporation
• Inventors: Ito, Hirokazu, Koike, Kazuo, Manji, Yasuhiro
• Granted Patent: US 10,493,835 B2
• Time in Patent Office: Days
• CPC Class Codes: A01D 34/66 with two or more cutters
• CPC Class Codes: A01D 34/78 electric
• CPC Class Codes: A01D 34/82 Other details
• CPC Class Codes: A01D 69/02 electric
• CPC Class Codes: B60K 1/04 of the electric storage means for propulsion exchanging batteries for electric propulsion of vehicles B60L53/80; for auxiliary purposes only B60R16/04; supplying batteries to, or removing batteries from, vehicles B60S5/06
• CPC Class Codes: B60K 17/043 Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
• CPC Class Codes: B60K 2001/005 the electric storage means
• CPC Class Codes: B60K 2001/0416 Arrangement in the rear part of the vehicle
• CPC Class Codes: B60K 2007/0046 the motor moving together with the vehicle body, i.e. moving independently from the wheel axle
• CPC Class Codes: B60K 2007/0053 the motor moving relative to the vehicle body and to the wheel axle
• CPC Class Codes: B60K 2007/0061 the motor axle being parallel to the wheel axle
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2220/42 with use of more than one motor
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/302 Cooling of charging equipment
• CPC Class Codes: B60L 53/305 : Communication interfaces
• CPC Class Codes: B60L 58/26 : by cooling
• CPC Class Codes: B60Y 2200/223 : Ridable lawn mowers
• CPC Class Codes: B60Y 2300/91 : Battery charging
• CPC Class Codes: B60Y 2304/01 : Minimizing space with more compact designs or arrangements
• CPC Class Codes: B60Y 2400/112 : Batteries
• CPC Class Codes: H01M 10/625 : Vehicles
• CPC Class Codes: H01M 10/6551 : Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings
• CPC Class Codes: H01M 10/6563 : with forced flow, e.g. by blowers
• CPC Class Codes: H01M 50/249 : specially adapted for aircraft or vehicles, e.g. cars or trains constructional details of batteries specially adapted for electric vehicles B60L50/64
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

An electric work vehicle includes: a battery pack that is arranged between a left rear wheel arranged outside of a left frame and a right rear wheel arranged outside of a right frame, the front end of the battery pack being located forward of an axle center of a rear wheel unit; a left motor that is arranged above the battery pack, in the periphery of the left rear wheel, receives a supply of power from the battery pack, and transmits rotational power to the left rear wheel; and a right motor that is arranged above the battery pack, in the periphery of the right rear wheel, receives a supply of power from the battery pack, and transmits rotational power to the right rear wheel.

Claims

1. A contactless charging system for an electric work vehicle, comprising:

a primary coil unit that includes a coil power supply circuit portion and a primary coil arranged above the coil power supply circuit portion, the primary coil unit being arranged on a ground surface;

a battery pack arranged at a rear portion of a vehicle body frame, between a left and right pair of rear wheels;

a secondary coil that electromagnetically couples with the primary coil;

a charging circuit portion configured to rectify power from the secondary coil and supply the rectified power to the battery pack; and

a coil support member for arranging the secondary coil below the battery pack.

2. The contactless charging system according to claim 1, wherein the charging circuit portion is attached to an upper portion of the battery pack.

3. The contactless charging system according to claim 1, wherein a recessed portion is formed at a rear-side lower portion of the battery pack and the secondary coil is arranged in the recessed portion.

4. The contactless charging system according to claim 1, wherein the primary coil unit is provided with an elevation mechanism configured to raise and lower the primary coil.

5. An electric mower in which a contactless charging system is incorporated, wherein

the contactless charging system comprises:

a primary coil unit that includes a coil power supply circuit portion and a primary coil arranged above the coil power supply circuit portion, the primary coil unit being arranged on a ground surface;

a battery pack arranged at a rear portion of a vehicle body frame, between a left and right pair of rear wheels;

a secondary coil that electromagnetically couples with the primary coil;

a charging circuit portion configured to rectify power from the secondary coil and supply the rectified power to the battery pack; and

a coil support member for arranging the secondary coil below the battery pack,

a mower unit hangs down elevatably at a front portion of the vehicle body frame, and

an electric motor unit configured to drive the rear wheels using power supplied from the battery pack via a motor power supply circuit portion is arranged forward of an axle center of the rear wheels, between the rear wheels.

6. The electric mower according to claim 5, wherein the electric motor unit includes a left motor that drives one rear wheel via a left transmission, and a right motor that drives the other rear wheel via a right transmission, the left motor and the left transmission being arranged between the one rear wheel and the battery pack, and the right motor and the right transmission being arranged between the other rear wheel and the battery pack.

7. The electric mower according to claim 6, wherein a lower surface of the mower unit at the highest position is lower than a lower surface of the secondary coil.