Abstract: A linear motion mechanism, including a drive portion, a screw shaft which is rotationally driven about an axis by the drive portion and in which a first spiral screw groove is formed on an outer peripheral surface, a nut in which a second spiral screw groove facing the first screw groove is formed on an inner peripheral surface and which moves forward or backward relative to the screw shaft in an axial direction, in which an axis of the screw shaft extends, according to a rotation of the screw shaft, a plurality of load balls which are disposed in a transfer path formed by the first screw groove and the second screw groove and advance while rolling on the transfer path, a plurality of retainer frames which are disposed between the plurality of load balls and advances on the transfer path along with the load balls.

Abstract: A linear motion mechanism (27) is provided with: a cylinder rod (312) into which a ball screw (30) can be inserted, said cylinder rod (312) including a base end section that is connected to a nut (311) within a piston casing (36) and a tip section (312a) that is exposed on the outside of the piston casing (36); a nut-side grease supply hole (321) that is formed in the nut (311) and that includes a discharge port (323) that opens toward the outer circumferential surface of the ball screw (30); and a cylinder rod-side grease supply hole (322) that is formed in the cylinder rod (312), that includes on one end thereof an inlet (324) that opens at a position that is exposed to the outer section of the piston casing (36), and that includes another end (322b) that is connected to the nut-side grease supply hole (321).

Abstract: A steam turbine includes a turbine body; a steam flow passage; a regulating valve which regulates opening and closing of the steam flow passage with a linear motion; a switching drive mechanism which drives the regulating valve; an electronic governor which controls at least the switching drive mechanism; and a controller unit. The switching drive mechanism has an electric motor which rotates when supplied with power, a conversion mechanism which converts a rotary motion of the electric motor into a linear motion of the regulating valve, and a brake which brakes the rotary motion of the electric motor. At least one of the controller unit and the electronic governor performs control such that the brake is actuated and the position of the regulating valve is maintained when at least one of the electric motor and the controller unit breaks down.

Abstract: This governing valve drive mechanism is a governing valve drive mechanism (15) that opens/closes a steam flow path (12) with a valve body (13) in order to regulate the flow rate of steam in a steam turbine (10), and is equipped with: a valve body advancing/retreating mechanism (14) for advancing and retreating the valve body (13) toward and from the steam flow path (12); multiple sets of electric actuators (23A, 23B) each having a rotational drive source (26) and a conversion section (30) for converting rotation of the rotational drive source (26) into a linear motion; connection switching sections (38) by which the electric actuators (23A, 23B) can be individually connected to the valve body advancing/retreating mechanism (14); and a control unit (17) for controlling operations of the rotational drive sources (26) and connection switching sections (38).

Abstract: A linear motion mechanism, including a drive portion, a screw shaft which is rotationally driven about an axis by the drive portion and in which a first spiral screw groove is formed on an outer peripheral surface, a nut in which a second spiral screw groove facing the first screw groove is formed on an inner peripheral surface and which moves forward or backward relative to the screw shaft in an axial direction, in which an axis of the screw shaft extends, according to a rotation of the screw shaft, a plurality of load balls which are disposed in a transfer path formed by the first screw groove and the second screw groove and advance while rolling on the transfer path, a plurality of retainer frames which are disposed between the plurality of load balls and advances on the transfer path along with the load balls.

Abstract: A valve device includes: an opening and closing section capable of being switched between an open state and a closed state, and a drive section having a rectilinearly moving mechanism configured to move a rectilinearly movable member in forward and backward directions; a transmission section configured to bring the opening and closing section to the closed state when the rectilinearly movable member is moved forward and to bring the opening and closing section to the open state when the rectilinearly movable member is moved backward; and a switching section capable of being switched between a connected state in which the movement of the rectilinearly movable member in the forward and backward directions is able to be transmitted to the transmission section and a disconnected state in which the movement of the rectilinearly movable member in the forward and backward directions is unable to be transmitted to the transmission section.

Abstract: A steam turbine is provided with an electric motor, a plurality of controller units, a status storing unit, and a master controller. The electric motor drives a regulating valve for controlling the opening and closing of a steam passage in which steam supplied to a turbine body is circulated. The plurality of controller units control the drive of the electric motor. The status storing unit stores a parameter indicating a status of the steam turbine. When there is an abnormality in a controller unit that is controlling the drive of the electric motor, the master controller switches the controller unit to a controller unit among the controller units that is not controlling the electric motor, and causes the relevant controller unit to operate after rewriting the parameter to a parameter stored by the status storing unit before the abnormality had occurred.

Abstract: A steam turbine includes a turbine main body having blades supported rotatably, a steam channel which is connected to the turbine main body and in which steam flows, a regulating valve configured to linearly move to adjust opening/closing of the steam channel, and an opening/closing drive mechanism configured to drive the regulating valve. The opening/closing drive mechanism includes an electric motor configured to rotate by an electric power being supplied, a conversion mechanism configured to convert rotational motion of the electric motor into linear motion of the regulating valve, and a brake operated by regenerative energy of the electric motor.

Abstract: A linear motion mechanism (27) is provided with: a cylinder rod (312) into which a ball screw (30) can be inserted, said cylinder rod (312) comprising a base end section that is connected to a nut (311) within a piston casing (36) and a tip section (312a) that is exposed on the outside of the piston casing (36); a nut-side grease supply hole (321) that is formed in the nut (311) and that comprises a discharge port (323) that opens toward the outer circumferential surface of the ball screw (30); and a cylinder rod-side grease supply hole (322) that is formed in the cylinder rod (312), that comprises on one end thereof an inlet (324) that opens at a position that is exposed to the outer section of the piston casing (36), and that comprises another end (322b) that is connected to the nut-side grease supply hole (321).

Abstract: An adjusting valve drive mechanism of a steam turbine drives an adjusting valve which opens and closes a steam channel, through which steam flows, by a valve element so as to adjust a flow rate of the steam serving as a working fluid of the steam turbine. The adjusting valve drive mechanism includes a rotary motor, a spur gear which is rotated by the rotary motor, and a chain which meshes with teeth of the spur gear, advances and retracts in a predetermined advance/retract direction which is a tangential direction of the spur gear in accordance with rotation of the spur gear, and causes the adjusting valve to advance and retract.

Abstract: This governing valve drive mechanism is a governing valve drive mechanism (15) that opens/closes a steam flow path (12) with a valve body (13) in order to regulate the flow rate of steam in a steam turbine (10), and is equipped with: a valve body advancing/retreating mechanism (14) for advancing and retreating the valve body (13) toward and from the steam flow path (12); multiple sets of electric actuators (23A, 23B) each having a rotational drive source (26) and a conversion section (30) for converting rotation of the rotational drive source (26) into a linear motion; connection switching sections (38) by which the electric actuators (23A, 23B) can be individually connected to the valve body advancing/retreating mechanism (14); and a control unit (17) for controlling operations of the rotational drive sources (26) and connection switching sections (38).

Abstract: A steam turbine includes a turbine body; a steam flow passage; a regulating valve which regulates opening and closing of the steam flow passage with a linear motion; a switching drive mechanism which drives the regulating valve; an electronic governor which controls at least the switching drive mechanism; and a controller unit. The switching drive mechanism has an electric motor which rotates when supplied with power, a conversion mechanism which converts a rotary motion of the electric motor into a linear motion of the regulating valve, and a brake which brakes the rotary motion of the electric motor. At least one of the controller unit and the electronic governor performs control such that the brake is actuated and the position of the regulating valve is maintained when at least one of the electric motor and the controller unit breaks down.

Abstract: A steam turbine includes a turbine main body having blades supported rotatably, a steam channel which is connected to the turbine main body and in which steam flows, a regulating valve configured to linearly move to adjust opening/closing of the steam channel, and an opening/closing drive mechanism configured to drive the regulating valve. The opening/closing drive mechanism includes an electric motor configured to rotate by an electric power being supplied, a conversion mechanism configured to convert rotational motion of the electric motor into linear motion of the regulating valve, and a brake operated by regenerative energy of the electric motor.