A linear actuator, comprising: • a motor housing having • one end fitting, • a telescopic arm, having • an outer tube attached to the motor housing, • an inner tube having another end fitting • an extension screw contained within the telescopic arm and having • a driven end journalled at the motor housing end of the outer tube and engaging • a nut fast at a proximal end of the inner tube, rotation of the extension screw causing the inner tube to extend or retract with respect to the outer tube, wherein • three or more motors are arranged around a central axis; • three or more planet wheels are arranged around the central axis and are drivingly connected to respective ones of the three or more motors: • a sun wheel is provided in driving engagement with the extension screw, the planet wheels being drivingly connected to the sun wheel, the arrangement being such that the motors jointly, rotatingly drive the extension screw for extension or retraction of the inner tube with respect to the outer tube and the motor housing, characterised in that the three or more motors are arranged in the same motor housing. • a motor housing having • one end fitting, • one end fitting, • a telescopic arm, having • an outer tube attached to the motor housing, • an inner tube having another end fitting • an extension screw contained within the telescopic arm and having • a driven end journalled at the motor housing end of the outer tube and engaging • a nut fast at a proximal end of the inner tube, rotation of the extension screw causing the inner tube to extend or retract with respect to the outer tube, wherein • three or more motors are arranged around a central axis; • three or more planet wheels are arranged around the central axis and are drivingly connected to respective ones of the three or more motors: • a sun wheel is provided in driving engagement with the extension screw, the planet wheels being drivingly connected to the sun wheel, the arrangement being such that the motors jointly, rotatingly drive the extension screw for extension or retraction of the inner tube with respect to the outer tube and the motor housing, characterised in that the three or more motors are arranged in the same motor housing. • an outer tube attached to the motor housing, • an inner tube having another end fitting • an extension screw contained within the telescopic arm and having • a driven end journalled at the motor housing end of the outer tube and engaging • a nut fast at a proximal end of the inner tube, rotation of the extension screw causing the inner tube to extend or retract with respect to the outer tube, wherein • three or more motors are arranged around a central axis; • three or more planet wheels are arranged around the central axis and are drivingly connected to respective ones of the three or more motors: • a sun wheel is provided in driving engagement with the extension screw, the planet wheels being drivingly connected to the sun wheel, the arrangement being such that the motors jointly, rotatingly drive the extension screw for extension or retraction of the inner tube with respect to the outer tube and the motor housing, characterised in that the three or more motors are arranged in the same motor housing. • a driven end journalled at the motor housing end of the outer tube and engaging • a nut fast at a proximal end of the inner tube, rotation of the extension screw causing the inner tube to extend or retract with respect to the outer tube, • three or more motors are arranged around a central axis; • three or more planet wheels are arranged around the central axis and are drivingly connected to respective ones of the three or more motors: • a sun wheel is provided in driving engagement with the extension screw, the planet wheels being drivingly connected to the sun wheel, the arrangement being such that the motors jointly, rotatingly drive the extension screw for extension or retraction of the inner tube with respect to the outer tube and the motor housing, characterised in that the three or more motors are arranged in the same motor housing.