A transmission wheel assembled of at least two segments (1) on a shaft (12), the inner arc surface (3) of which and the shaft (12) have essentially the same radius (R), and which segments' (1) outer surfaces (9) have profiled surfaces that transmit the power of the transmission wheel. Between the segments' (1) welded-together end faces (4) there are gaps on those sections of the end faces (4) that are not welded, which creates a press fit between the shaft (12) and the inner arc surface (3) of the transmission wheel. The weld connecting the transmission wheel segments' (1) end faces (4) may be incomplete, meaning that it does not reach the shaft (12).

A transmission wheel assembled of at least two segments (1) on a shaft (12), the inner arc surface (3) of which and the shaft (12) have essentially the same radius (R), and which segments' (1) outer surfaces (9) have profiled surfaces that transmit the power of the transmission wheel. Between the segments' (1) welded-together end faces (4) there are gaps on those sections of the end faces (4) that are not welded, which creates a press fit between the shaft (12) and the inner arc surface (3) of the transmission wheel. The weld connecting the transmission wheel segments' (1) end faces (4) may be incomplete, meaning that it does not reach the shaft (12).

A space and an elastic member have a first part where a distance between an outer peripheral surface of a metal bush and an inner peripheral surface of a resin member is a first distance, a second part where the distance between the outer peripheral surface and the inner peripheral surface is a second distance different from the first distance, and a third part where the distance between the outer peripheral surface and the inner peripheral surface is a third distance different from the first distance in a cross section along a radial direction of a resin gear. The first part is provided between the second part and the third part in an axial direction of the resin gear.

A worm is configured to attach to a shaft and turn a worm gear. The worm has a housing is a first exterior thread. An insert mates to the housing and has a second exterior thread. The first exterior thread and the second exterior thread form a continuous exterior thread.

A worm is configured to attach to a shaft and turn a worm gear. The worm has a housing is a first exterior thread. An insert mates to the housing and has a second exterior thread. The first exterior thread and the second exterior thread form a continuous exterior thread.

A resin gear includes an annular metal bush, an annular resin member provided around the metal bush and having a tooth profile formed in an outer peripheral portion, and an elastic member provided between the metal bush and the resin member. The elastic member has a first overhanging portion overhanging one end surface of the metal bush and one end surface of the resin member outward in an axial direction of the resin gear.

Gear drive systems used with a camera comprise a housing with an electric drive gear disposed outside of the housing. A host gear is engaged with the drive gear and is rotatably disposed on a stationary shaft extending from the housing. An adapter is attached to the host gear and extends axially outwardly therefrom. A secondary gear is attached to the adapter and comprises a plurality of teeth disposed along an outside diameter. The secondary gear is releasably attached to the adapter by retaining elements and is fixed rotatably to the adapter by registration elements. The secondary gear is attached to the adapter by a push on snap-fit, and is removed from the adapter by being pulled off, thereby avoiding the need for tools to interchange a secondary gear having a desired configuration of teeth to engage a camera optical adjustment element such as a lens ring.

Gear drive systems used with a camera comprise a housing with an electric drive gear disposed outside of the housing. A host gear is engaged with the drive gear and is rotatably disposed on a stationary shaft extending from the housing. An adapter is attached to the host gear and extends axially outwardly therefrom. A secondary gear is attached to the adapter and comprises a plurality of teeth disposed along an outside diameter. The secondary gear is releasably attached to the adapter by retaining elements and is fixed rotatably to the adapter by registration elements. The secondary gear is attached to the adapter by a push on snap-fit, and is removed from the adapter by being pulled off, thereby avoiding the need for tools to interchange a secondary gear having a desired configuration of teeth to engage a camera optical adjustment element such as a lens ring.

A bicycle rear wheel sub-assembly having a sprocket-carrying body, a cogset including a plurality of axially adjacent sprockets with at least three of the plurality of sprockets formed into a monolithic set and a ring nut securing the cogset to the sprocket-carrying body. The ring nut is formed as two parts assembled together—an axially outer first part on which a tubular body and a flange are formed, and an axially inner second part on which a threaded portion is formed. This structure provides a simple and effective coupling of the ring nut with the monolithic sub-set of the cogset and the sprocket-carrying body.

A bicycle rear wheel sub-assembly having a sprocket-carrying body, a cogset including a plurality of axially adjacent sprockets with at least three of the plurality of sprockets formed into a monolithic set and a ring nut securing the cogset to the sprocket-carrying body. The ring nut is formed as two parts assembled together—an axially outer first part on which a tubular body and a flange are formed, and an axially inner second part on which a threaded portion is formed. This structure provides a simple and effective coupling of the ring nut with the monolithic sub-set of the cogset and the sprocket-carrying body.