Retractable thruster and drive shaft for retractable thruster

A marine vessel having a hull and a retractable thruster assembly located in the hull, the retractable thruster assembly comprising:

• a propeller unit,
• a motor,
• a drive shaft linking the motor with the propeller unit to drive the propeller unit,
• a housing for locating the propeller unit in a storage configuration, the motor being fixed with respect to the housing, the housing being fixed with respect to an opening in the hull of the marine vessel,
• an actuator operable to move the propeller unit from the storage configuration to a deployment configuration in a direction from inboard to outboard, the propeller unit being extended from the hull for use in the deployment configuration,
• wherein the drive shaft comprises a motor-side universal joint for attachment to the motor and a propeller-side universal joint for attachment to the propeller unit, the motor-side universal joint and the propeller-side universal joint permitting folding of the drive shaft at least in the storage configuration, the drive shaft further comprising:
• a motor-side telescopic section disposed adjacent the motor-side universal joint;
• a propeller-side telescopic section disposed adjacent the propeller-side universal joint;
• at least one intermediate telescopic section disposed between the motor-side telescopic section and the propeller-side telescopic section,
• wherein the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section are substantially coaxial and slidable relative to each other to accommodate an increase in distance between the propeller unit and the motor when the propeller unit is moved from the storage configuration to the deployment configuration, the drive shaft being capable of transmitting torque from the motor to the propeller unit via the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section at least when the propeller unit is in the deployment configuration.

A method for installing a retractable thruster into a marine vessel, the retractable thruster assembly comprising:

• a propeller unit,
• a motor,
• a drive shaft linking the motor with the propeller unit to drive the propeller unit,
• a housing for locating the propeller unit in a storage configuration, the motor being fixed with respect to the housing, the housing being adapted to be fixed with respect to an opening in a hull of the marine vessel,
• an actuator operable to move the propeller unit from the storage configuration to a deployment configuration in a direction from inboard to outboard, the propeller unit being extended from the hull for use in the deployment configuration,
• wherein the drive shaft comprises a motor-side universal joint for attachment to the motor and a propeller-side universal joint for attachment to the propeller unit, the motor-side universal joint and the propeller-side universal joint permitting folding of the drive shaft at least in the storage configuration, the drive shaft further comprising:
• a motor-side telescopic section disposed adjacent the motor-side universal joint;
• a propeller-side telescopic section disposed adjacent the propeller-side universal joint;
• at least one intermediate telescopic section disposed between the motor-side telescopic section and the propeller-side telescopic section,
• wherein the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section are substantially coaxial and slidable relative to each other to accommodate an increase in distance between the propeller unit and the motor when the propeller unit is moved from the storage configuration to the deployment configuration, the drive shaft being capable of transmitting torque from the motor to the propeller unit via the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section at least when the propeller unit is in the deployment configuration,
• the method including the step of providing an opening in the hull of the marine vessel and fixing the housing of the retractable thruster assembly with respect to the opening.

A kit of parts, comprising a retractable thruster assembly and an insert unit, the insert unit being for installation at a corresponding hole formed in a hull of a marine vessel, wherein the retractable thruster assembly comprises:

• a propeller unit,
• a motor,
• a drive shaft linking the motor with the propeller unit to drive the propeller unit,
• a housing for locating the propeller unit in a storage configuration, the motor being fixed with respect to the housing, the housing being adapted to be fixed with respect to an opening in the hull of the marine vessel,
• an actuator operable to move the propeller unit from the storage configuration to a deployment configuration in a direction from inboard to outboard, the propeller unit being extended from the hull for use in the deployment configuration,
• wherein the drive shaft comprises a motor-side universal joint for attachment to the motor and a propeller-side universal joint for attachment to the propeller unit, the motor-side universal joint and the propeller-side universal joint permitting folding of the drive shaft at least in the storage configuration, the drive shaft further comprising:
• a motor-side telescopic section disposed adjacent the motor-side universal joint;
• a propeller-side telescopic section disposed adjacent the propeller-side universal joint;
• at least one intermediate telescopic section disposed between the motor-side telescopic section and the propeller-side telescopic section,
• wherein the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section are substantially coaxial and slidable relative to each other to accommodate an increase in distance between the propeller unit and the motor when the propeller unit is moved from the storage configuration to the deployment configuration, the drive shaft being capable of transmitting torque from the motor to the propeller unit via the motor-side telescopic section, the intermediate telescopic section and the propeller-side telescopic section at least when the propeller unit is in the deployment configuration,
• and wherein the insert unit and the housing are adapted to be sealingly attached to each other.