Gear assembly

A gear assembly comprising a first gear and a second gear, the gears being complementary conformal gears supported for rotation about respective rotation axes, wherein:

• one of the gears is configured to receive a drive torque and exert a driving tooth contact force, along a line of action, on the other of said gears via engagement of teeth of each of the first and second gears, so as to transmit the drive torque to the other of said gears, said other of the gears exerting a resistive tooth contact force to said one of the gears, along the line of action, as a consequence of the drive torque;
• the first gear is supported by a mounting which is configured to allow movement of the rotation axis of the first gear, and to exert a reaction force on the first gear in a reaction direction during transmission of the drive torque from said one of the gears to the other of the gears;
• the first and second gears can take a first position relative to one another in which they have a first centre distance, and a second position in which they have a second centre distance;
• the gear assembly is configured such that with the gears transmitting the drive torque while positioned in the second position, the line of action of the gears is not parallel to the reaction direction such that the reaction force, and the one of the driving tooth contact force and the resistive tooth contact force which is exerted on the first gear, produce a resultant force on the first gear;
• and
• the resultant force urges the first gear to move relative to the second gear so as to move the gears away from the second position and towards the first position.