Drive assembly for a motorized roller tube system

A motorized roller tube system comprising:

• a rotatably supported roller tube for winding receipt of a flexible member, the roller tube defining an interior;
• a DC motor received within the interior of the roller tube;
• and
• a gear assembly received within the interior of the tube, the gear assembly including planetary spur gears and having a total gear ratio of approximately 20:1;
• the motor including an output shaft connected to the gear assembly and rotated at an operating motor speed of between approximately 500 rpm and approximately 1000 rpm, the motorized roller tube system creating a maximum sound pressure level of between 40 dBA and 44 dBA at a distance of approximately 3 feet from the driven end of the roller tube in an ambient sound pressure level of approximately 38 dBA when the flexible member is moving from a fully-lowered position.

A motorized roller tube system comprising:

• a rotatably supported roller tube for winding receipt of a flexible member;
• a DC motor having an output shaft rotated at an operating motor speed;
• and
• a gear assembly connected to the output shaft of the motor such that the gear assembly is driven by the motor, the gear assembly including a plurality of gear stages adapted to produce an output rotational speed that is reduced with respect to the motor speed;
• the motor having an efficiency that varies depending on the operating motor speed, the efficiency including a peak efficiency associated with a peak efficiency operating speed and wherein the efficiency associated with the operating motor speed during any movement of the flexible member is less than 50 percent of the peak efficiency.

A motorized roller tube system comprising:

• a rotatably supported roller tube for winding receipt of a flexible member;
• a DC motor having an output shaft rotated at a motor speed, the motor having a torque capability and an efficiency that varies depending on the motor speed;
• and
• a gear assembly connected to the output shaft of the motor such that the gear assembly is driven by the motor, the gear assembly including a plurality of gear stages adapted to produce an output rotational speed that is reduced with respect to the motor speed,
• the motor having a peak efficiency and an associated torque capability at a peak efficiency motor speed and wherein the motorized roller tube system operates the motor at an operating motor speed having an associated torque capability that is at least 4 times greater than the torque capability at the peak efficiency motor speed.

A motorized roller tube system comprising:

• a rotatably supported roller tube for winding receipt of a flexible member, the roller tube defining an interior;
• an AC motor received within the interior of the roller tube;
• and
• a gear assembly received within the interior of the tube, the gear assembly including planetary spur gears and having a total gear ratio of approximately 20:1;
• and an AC motor controller;
• the motor including an output shaft connected to the gear assembly and rotated at an operating motor speed between approximately 750 rpm and approximately 900 rpm,
• the motorized roller tube system creating a sound pressure level between 40 dBA and 44 dBA at a distance of approximately 3 feet from the driven end of the roller tube in an ambient sound pressure level of approximately 38 dBA.