Working machine and a method for operating a working machine

• US 10,639,982 B2
• Filed: 07/08/2014
• Issued: 05/05/2020
• Est. Priority Date: 05/07/2009
• Status: Active Grant

• Current Assignee: Volvo Construction Equipment AB (Volvo AB)
• Original Assignee: Volvo Construction Equipment AB (Volvo AB)
• Inventors: Mattsson, Per, Nordstrand, Andreas, Maki, Rikard
• Primary Examiner(s): Hansen, Colby M
• Application Number:
  US14/325,442
• Publication Number:
  US 20140318878A1
• Time in Patent Office: Days
• Field of Search: None
• CPC Class Codes: B60K 6/36 characterised by the transmission gearings
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/103 of fluid type
• CPC Class Codes: B60W 10/24 including control of energy storage means
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: B60Y 2200/415 Wheel loaders
• CPC Class Codes: B60Y 2300/785 Geared neutral
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

A working machine includes a prime mover for supplying torque to the driving wheels of the working machine, and a transmission line arranged between the prime mover and the driving wheels for transmitting torque from the prime mover to the driving wheels. The transmission line includes a gearbox arranged between the prime mover and the wheels, and the working machine further includes at least one hydraulic machine in a hydraulic system for moving an implement arranged on the working machine and/or steering the working machine, and an electric machine for driving or braking the driving wheels and/or for driving or braking the at least one hydraulic machine. The electric machine is arranged in parallel with the prime mover with respect to the transmission line and is mechanically connected to the transmission line between the prime mover and the gearbox. The gearbox is a continuously variable transmission having a variator unit, and the gearbox has an operation mode where the rotation speed of the output shaft of the gearbox is zero or close to zero independently of the rotation speed of the input shaft of the gearbox at the same time as torque can be transmitted from the input shaft to the output shaft.

Claims

1. A working machine comprising

a prime mover for supplying torque to driving wheels of the working machine, and

a transmission line arranged between the prime mover and the driving wheels for transmitting torque from the prime mover to the driving wheels, the transmission line comprising a gearbox arranged between the prime mover and the wheels,

at least one hydraulic machine in a hydraulic system for moving an implement arranged on the working machine and/or steering the working machine, and

an electric machine for driving or braking the driving wheels and/or for driving or braking the at least one hydraulic machine, the electric machine being arranged in parallel with the prime mover with respect to the transmission line such that torque can be provided to the wheels by either one or both of the prime mover and the electric machine, and being mechanically connected to the transmission line between the prime mover and the gearbox,

wherein the transmission line comprises a transmission component for engagement and disengagement of the prime mover relative to the driving wheels, the transmission component being arranged between the prime mover and the electric machine, the hydraulic machine is mechanically connected to the transmission line between the prime mover and the gearbox, and the gearbox is a continuously variable transmission having a variator unit, and the gearbox has an operation mode where the rotation speed of an output shaft of the gearbox is zero or close to zero independently of the rotation speed of an input shaft of the gearbox at the same time as torque can be transmitted from the input shaft to the output shaft.

2. A working machine according to claim 1, wherein the variator unit is a hydraulic variator.

3. A working machine according to claim 1, wherein the gearbox comprises a planetary gear wheel unit enabling the power transmitted by the gearbox to be split between the variator unit and the planetary gear wheel unit.

4. A working machine according to claim 1, wherein the transmission component is a mechanical clutch.

5. A working machine according to claim 1, wherein the working machine comprises an electric energy storage means.

6. A working machine according to claim 5, wherein the electric energy storage means is arranged to provide energy to the electric machine when the electric machine functions as an electric motor and to store electric energy when the electric machine functions as a generator.

7. A working machine according to claim 1, wherein the at least one hydraulic machine is mechanically connected to the transmission line to enable the hydraulic machine to be driven as a pump by the prime mover and/or to enable the hydraulic machine to transmit energy to the transmission line.

8. A working machine according to claim 1, wherein the at least one hydraulic machine is mechanically connected to the transmission line to enable the hydraulic machine to be driven as a pump by the electric machine and/or to enable the electric machine to be driven as a generator by the hydraulic machine.

9. A working machine according to claim 1, wherein the working machine is a wheel loader.