The present device relates to boatbuilding, and more particularly to screw propellers with safety couplings, intended for use in outboard motors and/or marine screw propellers. A screw propeller with a safety coupling comprises a screw propeller body-cum-hub, a drive coupling, a driven coupling, and a dowel pin. The driven coupling is disposed for rotation on a spacer bushing, said spacer bushing being a tail bushing of the driving coupling. The driven coupling is partially or completely disposed in an opening in the screw propeller body-cum-hub and transmits torque to the screw propeller body-cum-hub by means of a longitudinal dowel pin and/or longitudinal grooves and a spline coupling. A common opening for the dowel pin in the driving and/or the driven coupling is configured as a through opening, and/or the blind end of the opening for the dowel pin is connected by a transverse opening to the outside surface.

A diffuser-type endplate propeller driving a hull and including a propeller hub a plurality of blades is provided. The propeller hub has an axis of rotation and is connected to a transmission shaft of the hull. The blade has a blade-body and an endplate. The blade-body is connected to the propeller hub and extends outward from the propeller hub to the corresponding endplate, the endplate bends from the corresponding blade-body to extend towards a stern of the hull, and the endplate has a leading edge and a trailing edge. A cylindrical surface is imaginarily formed by the leading edges while the diffuser-type endplate propeller is rotated about the axis. Each of the endplates has a first tangent plane at the leading edge thereof, the cylindrical surface has a second tangent plane at the leading edge. An included angle is measured from the second tangent plane to the first tangent plane.

In an upper mount portion, a steering central axis related to a steering force of a steering handle and a vibration central axis related to a torque reaction force of an engine are configured to be shifted back and forth. A mount member is formed such that a spring constant related to the vibration central axis is smaller than a spring constant related to the steering central axis.

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

A marine propulsion support system includes a transom bracket, a swivel bracket, and a mounting bracket. A drive unit is connected to the mounting bracket by a plurality of vibration isolation mounts, which are configured to absorb loads on the drive unit that do not exceed a mount design threshold. A bump stop located between the swivel bracket and the drive unit limits deflection of the drive unit caused by loads that exceed the threshold. An outboard motor includes a transom bracket, a swivel bracket, a cradle, and a drive unit supported between first and second opposite arms of the cradle. First and second vibration isolation mounts connect the first and second cradle arms to the drive unit, respectively. An upper motion-limiting bump stop is located remotely from the vibration isolation mounts and between the swivel bracket and the drive unit.

A marine propulsion device includes a propeller, a propeller shaft, a bushing, a damper, and a spacer. The propeller shaft supports the propeller. The bushing is between the propeller and the propeller shaft and is unitarily rotatable with the propeller shaft. The damper is fixed to the bushing to transmit rotation of the propeller shaft to the propeller. The spacer is spaced apart from the propeller in a back-and-forth direction in front of the bushing to position the bushing in place with respect to the propeller shaft.

A marine propulsion device includes a propeller, a propeller shaft, a bushing, a damper, and a spacer. The propeller shaft supports the propeller. The bushing is between the propeller and the propeller shaft and is unitarily rotatable with the propeller shaft. The damper is fixed to the bushing to transmit rotation of the propeller shaft to the propeller. The spacer is spaced apart from the propeller in a back-and-forth direction in front of the bushing to position the bushing in place with respect to the propeller shaft.

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.