Vehicle drive and a control method for a vehicle drive

• US 20060142104A1
• Filed: 12/28/2004
• Published: 06/29/2006
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: AGCO GmbH and Co (AGCO Corporation)
• Original Assignee: AGCO GmbH and Co (AGCO Corporation)
• Inventors: Saller, Michael
• Granted Patent: US 7,166,049 B2
• Time in Patent Office: Days
• US Class Current: 475/5
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60Y 2200/22 Agricultural vehicles
• CPC Class Codes: F16H 2003/0933 with coaxial countershafts
• CPC Class Codes: F16H 2037/0886 with switching means, e.g. to change ranges
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/093 with two or more countershafts
• CPC Class Codes: F16H 3/44 using gears having orbital motion the gear-ratio being changed by inversion of torque direction F16H3/005
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 37/0826 with only one output shaft
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/91 Orbital, e.g. planetary gears

Abstract

A drive and a method to control the drive of an agricultural vehicle, especially of a tractor, is described. The drive includes a combustion engine (M) and an infinitely variable electro-mechanical torque split gear.

To avoid dissipation of reactive power the drive includes a shift gear (F) which has at least two input shafts (2, 3) each connected to at least one transmission step. Each of the at least two input shafts (2, 3) is in driving condition via a clutch (K1,K2) with a planetary gear (P1, P2) each with two inputs. The first input of each planetary gear (P1, P2) can be driven by a clutch (KV) from the driven shaft (1) of the combustion engine (M). The second input of each planetary gear (P1, P2) can be driven by a respective electric motor (S1, S2). At least one of the planetary gears (P1, P2) is designed to be locked-up. The drive can be operated in pure electric mode, in electro-mechanical mode or in pure mechanical mode.

Claims

1. A drive of an agricultural vehicle, especially of a tractor, with a combustion engine (M), the drive comprising an infinitely variable electrical and mechanical torque split gear (L) including a generator (G) driven by the combustion engine, an electric motor to be driven by the generator, a microprocessor to control the number of revolutions, the torque and/or the direction of revolution of the electric motor, a planetary gear having three shafts, wherein a first input of the planetary gear is connectable with the driven shaft of the combustion engine and a second input of the planetary is driven in synchronism with the shaft of the electric motor, and a shift gear (F) acting between an output of the planetary gear and a wheel drive of the vehicle, the shift gear (F) having at least two input shafts (2, 3) each connected to at least one transmission step, each of the at least two input shafts (2, 3) being in driving condition with a respective planetary gear (P1, P2) via a respective clutch (K1, K2), the first input of each planetary gear (P1, P2) being driveable by a clutch (KV) from the driven shaft (1) of the combustion engine (M) and the second input of each planetary gear (P1, P2) being driveable by a respective electric motor (S1, S2), and at least one of the planetary gear (P1, P2) being designed to be locked-up.

2. The drive of claim 1 in which both planetary gears (P1,P2) are designed to be locked-up.

3. The drive of claim 1 in which the shift gear (F) is designed to have transmission steps so that when changing between adjacent transmission steps (I, II, III, IV) power is transmitted alternately by the input shafts (2, 3) in turn.

4. The drive of claim 1 in which the shift gear (F) is a power shift transmission.

5. The drive of claim 1 in which that the transmission steps (I, II, II, IV) are designed and arranged so that an overlapping region is arranged between two adjacent transmission steps.

6. The drive of claim 1 in which the electric motors (S1, S2) are coaxially arranged with respect to the planetary gears (P1, P2).

7. The drive of claim 1 in which the generator (G) and two electric motors (S1, S2) are each adapted to transmit the nominal power of the combustion engine (M).

8. The drive of claim 1 with the arrangement of one generator (G) and two electric motors (S1, S2) in which the sum of the nominal power of the electric motors (S1, S2) is equivalent to the nominal power of the combustion engine (M).

9. The drive of claim 1 in which all of the electric machines are designed to be operated in the forward and reverse directions and to function as a motor or generator.

10. The drive of claim 1 in which the generator (G) and the motors (S1, S2) are permanent magnet synchronous units.

11. The drive of claim 1 in which a sun wheel (P11, P21) of each respective planetary gear (P1, P2) is in driving connection with the driven shaft of a respective electric motor (S1, S2) by a clutch (Ks1, Ks2).

12. The drive of claim 1 in which the generator (G) and motors (S1, S2) are arranged on a common platform which is arranged to be inserted and taken out of the housing of the torque split gear (L) as a unit and the rotor shafts of the generator (G) and motors (S1, S2) are connected with their associated components (Z1, P11, P21) of the torque split gear (L) by electrically isolating clutches (Kg, Ks1, Ks2).

13. The drive of claim 2 in which that the ring gears (P12, P22) of the planetary gears (P1, P2) are designed to be locked with the planet carriers (P13, P23) to lock-up the planetary gears.

14. The drive of claim 1 in which a clutch (KR) and a reverse drive step (KR1,KR2,KR3,KR4) is arranged between the driven shaft (1) of the combustion engine (M) and the torque split gear (L) to increase efficiency in the reverse drive direction by providing electro-mechanical reverse drive step

15. A method for controlling the drive of claim 1, when changing between an electrical step (EI to EIV) driven by one of the electric motors (S2,S2) and an electromechanical step (EMI to EMIV) driven by engine M and one of the motors (S1,S2), in which during a change from the current transmission step to the next transmission step the opening of the currently operative clutch (KD1 or KD2:

KV) of the current transmission step and the closing of the newly operative clutch (KV;

KD1 or KD2) for the new transmission step are both started a preset number of revolutions (0.5*nd) before the synchronous rotation (SP) of the inputs into the newly operative clutch (KV;

KD1 or KD2) and, in which during the change the speed of the currently operative electric motor (S1,S2) is continuously changing so that the acceleration of the vehicle in not interrupted, wherein the difference of the number of revolutions depends upon parameters set by the driver, such as the level of acceleration, the number of revolutions of the combustion engine, the position of the foot pedal, the speed of the vehicle etc.