Method for operating a hybrid drive and hybrid drive
First Claim
1. A method for operating a hybrid drive having an electric machine configured to be operated in generator mode or motor mode and a hydraulic drive with a hydraulic piston and a piston rod in mechanical engagement with the electric machine, the method comprising the steps of:
- determining an operating direction and an operating force requested by the hybrid drive,switching a valve or valve combination connected to the hydraulic drive into a position such that the hydraulic drive is effective in the determined operating direction,determining a difference between a force produced by the hydraulic drive and the requested operating force,when the force produced by the hydraulic drive is smaller than the requested operating force, operating the electric machine in motor mode such that the requested operating force is attained by adding a force produced by the electric machine to the force produced by the hydraulic drive, andwhen the force produced by the hydraulic drive is greater than the requested operating force, driving the electric machine in generator mode by the piston rod, thereby braking the hydraulic drive, and generating regenerated electric energy which is supplied for further use.
7 Assignments
0 Petitions
Accused Products
Abstract
A hybrid drive includes an electric motor coupled to a hydraulic drive having a double-acting hydraulic piston and a piston rod, and a substantially throttle-less valve for actuating the hydraulic drive, and a control unit for actuating the electric machine. To avoid unnecessary energy consumption, an actuating direction requested by the hybrid drive and a desired actuating force are determined, the valve is switched to a position such that the hydraulic drive is effective in the actuating direction, at least when the actuating force cannot be generated by the electric motor alone, the difference between the force generated by the hydraulic drive and the actuating force is determined, and the electric motor is operated such that the desired actuating force is achieved by adding the force generated by the motor to the force generated by the hydraulic drive, or subtracting the first from the latter.
-
Citations
11 Claims
-
1. A method for operating a hybrid drive having an electric machine configured to be operated in generator mode or motor mode and a hydraulic drive with a hydraulic piston and a piston rod in mechanical engagement with the electric machine, the method comprising the steps of:
-
determining an operating direction and an operating force requested by the hybrid drive, switching a valve or valve combination connected to the hydraulic drive into a position such that the hydraulic drive is effective in the determined operating direction, determining a difference between a force produced by the hydraulic drive and the requested operating force, when the force produced by the hydraulic drive is smaller than the requested operating force, operating the electric machine in motor mode such that the requested operating force is attained by adding a force produced by the electric machine to the force produced by the hydraulic drive, and when the force produced by the hydraulic drive is greater than the requested operating force, driving the electric machine in generator mode by the piston rod, thereby braking the hydraulic drive, and generating regenerated electric energy which is supplied for further use. - View Dependent Claims (2, 3, 4)
-
-
5. A hybrid drive, comprising:
-
an electric machine configured to be operated in generator mode or motor mode, a hydraulic drive comprising a hydraulic piston and a piston rod in mechanical engagement with the electric machine and with an actuating element or a load, a valve or a valve combination connected to the hydraulic drive and controlling an operating force and an operating direction of the hydraulic drive, wherein when the force produced by the hydraulic drive is smaller than a requested operating force of the hybrid drive, the electric machine is operated in motor mode to produce with the electric machine a force acting in an identical direction as the force produced by the hydraulic drive, and when the force produced by the hydraulic drive is greater than the requested operating force of the hybrid drive, the electric machine is driven by the piston rod and operated in generator mode to produce with the electric machine a force acting in an opposite direction as the force produced by the hydraulic drive, and to generate regenerated electric energy which is supplied for further use. - View Dependent Claims (6, 7, 8, 9, 10, 11)
-
Specification