Drive train for a vehicle and method of controlling a drive train
First Claim
1. A drive train for a vehicle which has an internal combustion engine (1), a clutchless gearbox (8), a control unit (14) connected to the gearbox (8) for shifting the same, a hydrostatic drive (4, 5) and a hydraulic pump (4) and a hydraulic motor (5) connected in a closed circuit 10 (11), comprising,the control unit (14) being operationally connected by actuating signals (J, 0) to an adjusting device (9) on the gearbox (8) and adjusting devices (16, 3) on the motor and pump, the control unit being programmed by a characteristic curve representing a speed ratio of the hydraulic motor (5) to the hydraulic pump (4) to calculate a maximum electronic synchronous speed of the hydraulic motor to the hydraulic pump to create a loadfree state of the gearbox (8) by controlling the adjusting devices for the hydraulic pump (4) and the gearbox (8).
3 Assignments
0 Petitions
Accused Products
Abstract
A drive train comprises an internal combustion engine, a clutchless gearbox, which can be shifted by means of an electronic control unit and by means of actuating devices, without a mechanical synchronizing device, and a hydrostatic gearbox with a hydraulic pump and a hydraulic motor, which are connected in a closed circuit. The rotational speed of the hydraulic motor being controllable in dependence on a control signal to the adjusting device of the hydraulic pump and/or to the adjusting device of the hydraulic motor. The control unit calculates the control signal by means of setpoint input via an accelerator pedal or as a function of the rotational drive speed of the internal combustion engine, with shifting of the transmission stages being possible by means of the actuating devices. The control unit controls the adjusting device of the hydraulic pump as well as the actuating devices for the gearbox for the electronic synchronization of the latter by means of a characteristic curve which represents the speed ratio of the hydraulic motor to the hydraulic pump in dependence on an actuating signal to the adjusting device of the hydraulic pump for a loadfree state of the gearbox. For this purpose, in the method of controlling the drive train, the control unit calculates a maximum achievable synchronous speed of the hydraulic motor by means of a characteristic curve which represents the speed ratio of the hydraulic motor to the hydraulic pump in dependence on an actuating signal to the adjusting device of the hydraulic pump and/or to the adjusting device of the hydraulic motor for a loadfree state of the gearbox.
44 Citations
13 Claims
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1. A drive train for a vehicle which has an internal combustion engine (1), a clutchless gearbox (8), a control unit (14) connected to the gearbox (8) for shifting the same, a hydrostatic drive (4, 5) and a hydraulic pump (4) and a hydraulic motor (5) connected in a closed circuit 10 (11), comprising,
the control unit (14) being operationally connected by actuating signals (J, 0) to an adjusting device (9) on the gearbox (8) and adjusting devices (16, 3) on the motor and pump, the control unit being programmed by a characteristic curve representing a speed ratio of the hydraulic motor (5) to the hydraulic pump (4) to calculate a maximum electronic synchronous speed of the hydraulic motor to the hydraulic pump to create a loadfree state of the gearbox (8) by controlling the adjusting devices for the hydraulic pump (4) and the gearbox (8).
- 7. A method of controlling a drive train having an internal combustion engine (1), a clutchless gearbox (8) without a mechanical synchronizing device and a hydrostatic drive (4, 5) with a hydraulic pump (4), a hydraulic motor (5) and a control unit (14), characterized in that the control unit (14) calculates a maximum achievable synchronous speed of the hydraulic motor (5) by means of a characteristic curve which represents a speed ratio of the hydraulic motor (5) to the hydraulic pump (4) in response to an actuating signal to an adjusting device of the hydraulic pump (4) and/or to an adjusting device of the hydraulic motor (5) to create a loadfree state of the gearbox (8).
Specification