A gear includes a toothed portion, a boss, a first connector, a second connector, and a dynamic damper. The toothed portion is disposed at a radially outer side of the gear. The boss is disposed at a radially inner side of the gear. The first connector connects the toothed portion and the boss. The second connector connects the toothed portion and the boss. The second connector faces the first connector such that the toothed portion, the boss, the first connector, and the second connector define a sealed space. The dynamic damper is disposed in the sealed space.

A gear includes a toothed portion, a boss, a first connector, a second connector, and a dynamic damper. The toothed portion is disposed at a radially outer side of the gear. The boss is disposed at a radially inner side of the gear. The first connector connects the toothed portion and the boss. The second connector connects the toothed portion and the boss. The second connector faces the first connector such that the toothed portion, the boss, the first connector, and the second connector define a sealed space. The dynamic damper is disposed in the sealed space.

One object is to provide a speed reducer provided with a buffer mechanism for reducing an external force and capable of reliably measuring a load torque during an operation. A speed reducing device includes a speed reducing mechanism for reducing a rotation speed of an output with respect to an input between an input rotary shaft and an output rotary shaft, a housing that houses the speed reducing mechanism, and a buffer unit formed of an elastic member and having a cushion force acting mainly in a substantially rotational tangential direction. An amount of displacement of the housing generated by the buffer unit is measured by a measurement device.

One object is to provide a speed reducer provided with a buffer mechanism for reducing an external force and capable of reliably measuring a load torque during an operation. A speed reducing device includes a speed reducing mechanism for reducing a rotation speed of an output with respect to an input between an input rotary shaft and an output rotary shaft, a housing that houses the speed reducing mechanism, and a buffer unit formed of an elastic member and having a cushion force acting mainly in a substantially rotational tangential direction. An amount of displacement of the housing generated by the buffer unit is measured by a measurement device.

An example system includes a transmission having a first plurality of gears and an extent of backlash. The system also includes a first motor connected to an input shaft of the transmission and a second motor connected to an output shaft of the transmission through a second plurality of gears. A first gear ratio of a first plurality of gears is greater than a second gear ratio of the second plurality of gears. The system may receive a command to change a direction of rotation of the output shaft from a first direction to a second direction. In response to the received command, the first motor may drive the transmission through a first portion of the extent of backlash deadband. The second motor may drive the transmission through a second portion of the extent of backlash deadband. The second portion may be greater than the first portion.

An example system includes a transmission having a first plurality of gears and an extent of backlash. The system also includes a first motor connected to an input shaft of the transmission and a second motor connected to an output shaft of the transmission through a second plurality of gears. A first gear ratio of a first plurality of gears is greater than a second gear ratio of the second plurality of gears. The system may receive a command to change a direction of rotation of the output shaft from a first direction to a second direction. In response to the received command, the first motor may drive the transmission through a first portion of the extent of backlash deadband. The second motor may drive the transmission through a second portion of the extent of backlash deadband. The second portion may be greater than the first portion.

Timepiece wheel with play take-up, including a toothing, each tooth of which includes first and second half-teeth each including a part of the tooth profile, and movable with respect to each other against elastic return means, the wheel including, axially stacked, a first and a second half-wheel respectively carrying the first and second half-teeth and having limited rotational mobility with respect to each other, about the axis of this toothing, and against the elastic return means, the toothing of each half-wheel overhanging the other half-wheel, each half-wheel including hollows inside each of which is movable an opposite half-tooth, between two successive half-teeth.

Timepiece wheel with play take-up, including a toothing, each tooth of which includes first and second half-teeth each including a part of the tooth profile, and movable with respect to each other against elastic return means, the wheel including, axially stacked, a first and a second half-wheel respectively carrying the first and second half-teeth and having limited rotational mobility with respect to each other, about the axis of this toothing, and against the elastic return means, the toothing of each half-wheel overhanging the other half-wheel, each half-wheel including hollows inside each of which is movable an opposite half-tooth, between two successive half-teeth.

A pinion gear meshes with a drive gear. The drive gear is connected to a handle shaft of a fishing reel that winds a fishing line onto a spool supported by a reel body by rotational operation of the handle shaft rotatably supported to the reel body to transmit the rotation of the handle shaft. The pinion gear includes a gear portion and a shaft. The gear portion meshes with the drive gear. The shaft portion, to which the gear portion is non-rotatably fitted, is integrally rotatable with the gear portion. The gear portion and the shaft portion are formed from different materials, and the specific gravity of the shaft portion is smaller than the specific gravity of the gear portion.

A gearwheel for a balance shaft includes a gear ring and a gear core, where the gear ring is fabricated of a first metal and the gear core of a second metal, where the second metal has a lower density than the first metal, where the gear core and the gear ring are compressed to each other at an inner surface of the gear ring, the gearwheel further including formfitting elements to form an additional formfitting between the gear ring and the gear core, where, as seen in a circumferential direction along the inner surface of the gear ring, a distance between two adjacent formfitting elements is larger than an extension of the formfitting element along the circumferential direction.