A variable-speed speed increaser includes: an electric driving device which is configured to generate a rotational driving force; and a transmission device which is configured to change the speed of the rotational driving force generated by the electric driving device and transmit the changed rotation driving force to a driving target. The transmission device includes a sun gear which is configured to rotate about an axis, a sun gear shaft which is fixed to the sun gear and extend in an axial direction around the axis, a planetary gear which is configured to mesh with the sun gear, revolve around the axis and rotate about its own center line, an internal gear which has a plurality of teeth aligned annularly around the axis and is configured to mesh with the planetary gear, and a planetary gear carrier which has a planetary gear carrier shaft.

A coil spring unit includes a coil spring; and a metal plate supporting the coil spring, the metal plate including a plurality of supporting portions cooperative with each other to support the coil spring, wherein the supporting portions are provided by bending the metal plate at bending lines and have supporting surfaces substantially perpendicular to the bending lines, respectively, and wherein the supporting surfaces are substantially parallel with outside tangential lines of the coil spring and support the coil spring.

A gear device for a clutch contains: a drive gear, a first clutching member, and a second clutching member. The drive gear includes multiple first actuation protrusions and multiple second actuation protrusions, wherein each of the multiple first actuation protrusions has a beveled face and a flat top face, and each of the multiple second actuation protrusions has a beveled face and a flat top face. The first clutching member includes multiple third actuation protrusions, each of the multiple third actuation protrusions has a beveled face and a flat top face, and the first clutching member includes a first positioning disc and a first resilient element. The second clutching member includes multiple fourth actuation protrusions, each of the multiple fourth actuation protrusions has a beveled face and a flat top face, and the second clutching member includes a second positioning disc and a second resilient element.

A freewheel mechanism comprising two coaxial carrying members for eventually transmitting torque there between, being both members axially fixed but rotatably mounted along an axis. This mechanism further comprises longitudinal pawls housed in cavities, predominantly radially disposed in one of the carrying members, arranged to engage and disengage with a toothed ring placed between said carrying members. This mechanism allows a partial declutch of the carrying members, due to said toothed ring is always forced by longitudinal pawls, to slide bi-directionally in the axial direction, being declutching the axial movement from a first clutch position corresponding to non-freewheeling, to a second declutch position corresponding to freewheeling, and being clutching the axial movement of the toothed ring from the second declutch position to the first clutch position.

A power tool including a housing and a motor housed in the housing. There is a spring engine housed in the housing and a driver blade driven by the spring engine. Additionally, the power tool holds a pipe clamp configured to be driven into a workpiece by the driver blade.

A directional transmission mechanism, a directional sprocket apparatus using the directional transmission mechanism, and a pedal device using the directional sprocket apparatus are disclosed. The directional transmission mechanism includes a driving shaft, an output shaft, a co-rotating wheel, a reverse-rotating wheel, and a switching mechanism. The co-rotating wheel set drives the output shaft to rotate in a direction that is the same as that of the driving shaft. The reverse-rotating wheel set drives the output shaft to rotate in a direction opposite to that of the driving shaft. The switching mechanism switches the driving shaft to drive the co-rotating wheel set or drive the reverse-rotating wheel set to rotate, so as to enable the output shaft to rotate directionally. The co-rotating wheel set is connected with the driving shaft and the output shaft, and the reverse-rotating wheel set is connected with the driving shaft and the output shaft.

A differential assembly for a vehicle includes: an input member; a first output member and a second output member; a differential mechanism for differentially distributing a driving force inputted by the input member to the first output member and the second output member; a differential case that accommodates the differential mechanism; and a clutch mechanism for selectively transmitting power between the input member and the differential case, the clutch mechanism having a first engaging member and a second engaging member to be releasably connected to one another such that the clutch mechanism is in a coupled state when the first engaging member and the second engaging member are engaged, and the clutch mechanism is in a decoupled state when the first engaging member and the second engaging member are disengaged. The first engaging member includes at least one cavity in which a recess is arranged.

A drive member selection mechanism is described, including at least one drive member and at least two selector members, wherein the drive member includes a first and second face, and further includes, on each face, at least one projection, and the selector members include, on at least one face thereof, at least one complementary projection arranged to selectively engage with a projection of a drive member, the arrangement being such that the projection(s) of a selector member and the projection(s) of the first face of a drive member may be drivingly engaged in a first torque connection and the projection(s) of a selector member and the projection(s) of the second face of a drive member may be drivingly engaged in a second torque connection, wherein the second torque connection is opposed to the first torque connection.

A directional transmission mechanism, a directional sprocket apparatus using the directional transmission mechanism, and a pedal device using the directional sprocket apparatus are disclosed. The directional transmission mechanism includes a driving shaft, an output shaft, a co-rotating wheel, a reverse-rotating wheel, and a switching mechanism. The co-rotating wheel set drives the output shaft to rotate in a direction that is the same as that of the driving shaft. The reverse-rotating wheel set drives the output shaft to rotate in a direction opposite to that of the driving shaft. The switching mechanism switches the driving shaft to drive the co-rotating wheel set or drive the reverse-rotating wheel set to rotate, so as to enable the output shaft to rotate directionally. The co-rotating wheel set is connected with the driving shaft and the output shaft, and the reverse-rotating wheel set is connected with the driving shaft and the output shaft.

A motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by an impeller of the hydraulic part secured to the shaft. The motor unit comprises a dry stator and an immersed rotor, mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; and an immersed anti-backspin device, configured to mechanically block the rotation of the shaft in a predetermined direction.