CONSTRUCTION MACHINE
First Claim
1. A construction machine comprising:
- a prime mover;
a hydraulic pump driven by the prime mover;
a hydraulic motor driven by hydraulic fluid from the hydraulic pump;
an electric motor;
a storage device for delivering and receiving electric power to and from the electric motor;
a controller for electric motor control, the controller exercising drive control on the electric motor; and
a speed reduction mechanism for transmitting drive forces of the electric motor and the hydraulic motor to a swing structure;
wherein the controller for electric motor control includesinductive voltage waveform detecting means for detecting an inductive voltage waveform of the electric motor; and
magnetic pole position computing means for, in a state where the swing structure is driven only by torque of the hydraulic motor, taking in the inductive voltage waveform from the inductive voltage waveform detecting means and computing a magnetic pole position of a rotor of the electric motor on the basis of the inductive voltage waveform obtained not via a rotation position sensor.
1 Assignment
0 Petitions
Accused Products
Abstract
A construction machine has a hydraulic pump driven by a prime mover, a hydraulic motor, an electric motor, a storage device for delivering and receiving electric power to and from the electric motor, and a controller for exercising drive control of the electric motor. A speed reduction mechanism for transmitting drive forces of the electric motor and hydraulic motor to a swing structure is also provided. The controller includes inductive voltage waveform detecting means for detecting an inductive voltage waveform of the electric motor, and magnetic pole position computing means for, in a state where the swing structure is driven only by the torque of the hydraulic motor, taking in the inductive voltage waveform from the inductive voltage detecting means and computing a magnetic pole position of a rotor of the electric motor on the basis of the inductive voltage waveform and not via a rotation position sensor.
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Citations
5 Claims
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1. A construction machine comprising:
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a prime mover; a hydraulic pump driven by the prime mover; a hydraulic motor driven by hydraulic fluid from the hydraulic pump; an electric motor; a storage device for delivering and receiving electric power to and from the electric motor; a controller for electric motor control, the controller exercising drive control on the electric motor; and a speed reduction mechanism for transmitting drive forces of the electric motor and the hydraulic motor to a swing structure; wherein the controller for electric motor control includes inductive voltage waveform detecting means for detecting an inductive voltage waveform of the electric motor; and magnetic pole position computing means for, in a state where the swing structure is driven only by torque of the hydraulic motor, taking in the inductive voltage waveform from the inductive voltage waveform detecting means and computing a magnetic pole position of a rotor of the electric motor on the basis of the inductive voltage waveform obtained not via a rotation position sensor. - View Dependent Claims (2, 3, 4, 5)
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Specification