Abstract: A yaw drive method of a wind power generation apparatus, in which a second gear engaged with a first gear attached to one of tower or a wind power generation unit supported to the upper end of the tower so as to be capable of yawing and supported to a tower or to the upper end of the tower is rotated by a drive motor attached to the other of the tower or the wind power generation unit for yawing the wind power generation unit. A drive energy, which is supplied to the drive motor for a predetermined time from when the supply of the drive energy to the drive motor begins to start, is made to be smaller than the drive energy supplied to the drive motor in a common yawing.

Abstract: A yaw drive method of a wind power generation apparatus, in which a second gear engaged with a first gear attached to one of tower or a wind power generation unit supported to the upper end of the tower so as to be capable of yawing and supported to a tower or to the upper end of the tower is rotated by a drive motor attached to the other of the tower or the wind power generation unit for yawing the wind power generation unit. A drive energy, which is supplied to the drive motor for a predetermined time from when the supply of the drive energy to the drive motor begins to start, is made to be smaller than the drive energy supplied to the drive motor in a common yawing.

Abstract: A speed reducer and a yaw drive apparatus for a wind power generation apparatus, where the speed reducer has high efficiency and a short axial length, and suitable for the yaw drive apparatus. The speed reducer has three stages for speed reduction. The total reduction gear ratio of a first stage speed reducing portion 10 and a second speed reducing portion 20 is set to 1/6 to 1/60, and a third stage speed reducing portion 30 is constructed from an eccentric oscillating-type speed reduction mechanism having an internal gear member 32, external gears 34, crankshafts 35, and a carrier 37. The reduction gear ratio of the eccentric oscillating-type speed reduction mechanism is set to 1/50 to 1/140, and the total reduction gear ratio of the speed reducer is set to 1/1000 to 1/3000. A yaw drive method and the yaw drive apparatus can reduce noise, and the yaw drive apparatus is inexpensive and reduced in size.

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: A first friction clutch (54) is constructed as a negative type friction clutch and a second friction clutch (55) is constructed as a positive type friction clutch. Spring constant of a second spring (75) is made smaller than that of a first spring (65). Therefore, in the middle stage of switching the first and second friction clutches (54, 55), both of these first and second friction clutches (54, 55) enter in a connection state. Consequently, a driven member (56) is driven through either or both of the first and second clutches by a driving shaft, and the free rotation state does not occur.

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: In a brake (53) for a hydraulic motor (10), a braking piston (66) is added that can move toward and away from fixed friction discs (54) and rotating friction discs (55). A braking passage (73) leads a high-pressure fluid into the braking piston (66) to press the braking piston (66) to the friction discs (54, 55).