Worm gear actuator for a marine steering apparatus

An actuator for a marine steering apparatus comprising a steering shaft, the actuator comprising:

• a housing;
• a gearmotor disposed within the housing;
• a worm gear disposed within the housing;
• a torque-transmission gear disposed within the housing, wherein the gearmotor comprises an output shaft coupled to the worm gear such that the gearmotor drives the worm gear in response to a torque from the output shaft of the gearmotor, the worm gear is coupled to the torque-transmission gear such that the worm gear drives the torque-transmission gear in response to the torque from the output shaft of the gearmotor, and when the torque-transmission gear is coupled to the steering shaft, the torque-transmission gear transmits torque to the steering shaft in response to the torque from the output shaft of the gearmotor;
• and
• a torsionally compliant coupler to absorb impact loads between the torque-transmission gear and the steering shaft when the torque-transmission gear is coupled to the steering shaft.

A marine steering apparatus comprising:

• a transom bracket configured to be mounted on a transom of a marine vessel;
• a swivel bracket pivotably coupled to the transom bracket;
• a steering shaft;
• an actuator supported by the swivel bracket such that the actuator is tiltable with the swivel bracket relative to the transom bracket, the actuator comprising:
• a housing;
• a gearmotor disposed within the housing;
• a worm gear disposed within the housing;
• and
• a torque-transmission gear disposed within the housing, wherein the gearmotor comprises an output shaft coupled to the worm gear such that the gearmotor drives the worm gear in response to a torque from the output shaft of the gearmotor, the worm gear is coupled to the torque-transmission gear such that the worm gear drives the torque-transmission gear in response to the torque from the output shaft of the gearmotor, and when the torque-transmission gear is coupled to the steering shaft, the torque-transmission gear transmits torque to the steering shaft in response to the torque from the output shaft of the gearmotor;
• wherein:
• the torque-transmission gear is coupled to the steering shaft such that the torque-transmission gear transmits the torque to the steering shaft in response to the torque from the output shaft of the gearmotor;
• the swivel bracket comprises a first mounting surface and a second mounting surface;
• the housing has a first mounting surface, a second mounting surface, and a stepped surface extending between the first mounting surface of the housing and the second mounting surface of the housing;
• the first mounting surface of the housing is mounted to the first mounting surface of the swivel bracket;
• and
• the second mounting surface of the housing is mounted to the second mounting surface of the swivel bracket.