Drive for rotating structure
AssigneeDaikin Industries, Ltd.
InventorsToshiyuki Sakai, Shigetoshi Shimoo
Life of this patent
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Abstract
A hydraulic excavator includes a rotation motor (31) for rotating an upper rotating structure. The rotation motor (31) includes an electric motor (32), a hydraulic motor (40), and a reduction gearbox (33). The hydraulic motor (40) includes a motor mechanism (50) and a clutch mechanism (70). The motor mechanism (50), which is a vane-type hydraulic motor, is engaged with/disengaged from a motor shaft (37) by the clutch mechanism (70). When rotation speed of the upper rotating structure is low, and a required value of output torque of the rotation motor (31) is high, an operation of driving the output shaft (35) by the hydraulic motor (40) is performed in the rotation motor (31).
Claims12
A drive for rotating a rotating structure (20) rotatably mounted on a non-rotating structure (11), the drive comprising:
- an electric motor (32) which receives electricity and generates driving force;
- a hydraulic mechanism (40, 110) which receives hydraulic fluid and generates driving force;
- and
- an output shaft (35) which is driven to rotate by the electric motor (32) and the hydraulic mechanism (40, 110), wherein
- an operation of driving the output shaft (35) only by the hydraulic mechanism (40, 110) is selectively performed when rotation speed of the rotating structure (20) is lower than a predetermined reference speed, and an operation of driving the output shaft (35) only by the electric motor (32) is performed when the rotation speed of the rotating structure (20) is not lower than the reference speed.
Dependencies are inferred from the claim text.