Construction machine
First Claim
1. A construction machine comprising:
- a swing structure;
a hydraulic motor for driving the swing structure;
an electric motor for driving the swing structure and being mechanically connected to the hydraulic motor;
a hydraulic pump being driven by a prime mover and for supplying hydraulic fluid to the hydraulic motor;
an operating device configured to instruct the swing structure to make a swing motion; and
a control device configured to, when demanded torque necessary for the swing motion of the swing structure instructed by the operating device can be produced by the electric motor alone, control at least either a delivery flow rate of the hydraulic pump or an output torque of the electric motor in such a manner that meter-out and meter-in pressures of the hydraulic motor that is run together with the electric motor approach each other, or in such a manner that the meter-out pressure is larger than the meter-in pressure.
1 Assignment
0 Petitions
Accused Products
Abstract
A construction machine includes: a swing structure (20); hydraulic and electric motors (25) mechanically coupled to each other; a hydraulic pump (41) that supplies hydraulic fluid to the hydraulic motor; swing control lever (72) that instructs the swing structure to make a swing motion; and a control device (80) that controls at least either a delivery flow rate of the hydraulic pump or an output torque of the electric motor in such a manner that meter-out and meter-in pressures of the hydraulic motor that is run together with the electric motor approach each other when the demanded torque necessary for the swing motion of the swing structure instructed by the swing control lever can be produced by the electric motor alone.
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Citations
5 Claims
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1. A construction machine comprising:
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a swing structure; a hydraulic motor for driving the swing structure; an electric motor for driving the swing structure and being mechanically connected to the hydraulic motor; a hydraulic pump being driven by a prime mover and for supplying hydraulic fluid to the hydraulic motor; an operating device configured to instruct the swing structure to make a swing motion; and a control device configured to, when demanded torque necessary for the swing motion of the swing structure instructed by the operating device can be produced by the electric motor alone, control at least either a delivery flow rate of the hydraulic pump or an output torque of the electric motor in such a manner that meter-out and meter-in pressures of the hydraulic motor that is run together with the electric motor approach each other, or in such a manner that the meter-out pressure is larger than the meter-in pressure. - View Dependent Claims (2, 3, 4, 5)
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Specification