Motorized roller tube system having dual-mode operation
A motorized system for reeling and unreeling a flexible member on a roller tube between fully open wound and fully closed unwound conditions to minimize sound pressure level has a rotatable roller tube and a flexible member that winds on the tube. A d-c motor drives the tube through a gear reduction. The motor has a motor speed versus torque characteristic extending linearly from high maximum RPM, low minimum torque, to low minimum RPM high maximum torque with peak efficiency at a given RPM. The motor moves the member between the two positions at a motor speed less than the given peak efficiency RPM and less than 50% of high maximum RPM with efficiency less than 25% of peak efficiency, intentionally at a high torque and low efficiency. The motor has two or more modes each moving the member at predetermined different linear speed.
1. A motorized roller tube system comprising:
a rotatably supported roller tube;
a flexible member engaging the roller tube for winding receipt of the flexible member by the roller tube;
a DC motor having an output shaft rotated at a motor speed, the DC motor having a low efficiency, high torque region of operation and a high efficiency, low torque region of operation defining a peak efficiency;
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; and
a controller connected to the motor for controlling the motor to wind or unwind the flexible member with respect to the roller tube,
the controller being configured to control the motor in at least two operating modes comprising a first mode and a second mode, each providing for movement of the flexible member at a predetermined linear speed, and wherein the linear speed for each one of the operating modes is different from the linear speeds for the other modes, the linear speed being greater in the first mode than in the second mode;
wherein the controller is configured to operate the motor when the motor is energized to rotate always at an operating speed that is less than 50 percent of a maximum motor speed of which the motor is capable when the motor operates in the second mode and at an efficiency less than 25% of the peak efficiency.
2. The motorized roller tube system according to claim 1 , wherein the first operating mode comprises a set-up mode and the second operating mode comprises an ultra low speed ultra-low-speed mode; and
wherein in the ultra-low-speed mode the motor rotates at an operating speed that is always less than 50 percent of the maximum motor speed of which the motor is capable.
3. The motorized roller tube system according to claim 2 , wherein the linear speed of the set-up mode is at least two times faster than the linear speed of the ultra-low-speed mode.
4. The motorized roller tube system according to claim 2 , wherein the motorized roller tube system produces a noise level when operating in each of the at least two operating modes, and wherein the noise level produced when the system is operating in the ultra-low-speed mode is approximately 3 dBA or more below the noise level produced when the system is operating in the set-up mode.
5. The motorized roller tube system according to claim 1 , wherein the controller is responsive to an illuminance level input to the controller to adjust the position of the flexible member.
6. The motorized roller tube system according to claim 5 , wherein the linear speed is approximately one inch per second or less when the motor rotates at the operating speed that is less than 50 percent of the maximum motor speed of which the motor is capable.
7. The motorized roller tube system according to claim 2 , wherein the motorized roller tube system produces a sound pressure level when operating in the ultra-low-speed mode of operation between 38 dBA and 40 dBA at a distance of approximately three feet from the roller tube in an ambient sound pressure level of approximately 38 dBA.
8. The motorized roller tube system according to claim 1 , wherein the controller is responsive to a plurality of control signals including a control signal associated with each of the at least two operating modes.
9. The motorized roller tube system according to claim 8 , wherein the controller is responsive to a set-up mode control signal and an ultra-low-speed mode control signal, and wherein the controller controls the motor in response to each of the control signals to move the flexible member at a predetermined linear speed, the set-up mode linear speed being at least two times greater than the ultra-low-speed mode linear speed.
10. The motorized roller tube system according to claim 1 , wherein the motor has a motor torque that is always greater than 50 percent of a maximum torque capability of the motor when the motor rotates at the operating speed that is less than 50 percent of the maximum motor speed of which the motor is capable.
11. The motorized roller tube system according to claim 1 , wherein the motor rotates in the second mode at an operating speed that is always less than or equal to approximately one-fourth of the maximum motor speed of which the motor is capable.
12. The motorized roller tube system according to claim 2 , wherein the operating speed of the motor in the set-up mode is approximately 1000 rpm, and the operating speed of the motor in the ultra-low-speed mode is approximately 300 rpm.
13. A motorized roller tube system comprising:
a rotatably supported roller tube;
a flexible member engaging the roller tube for winding receipt of the flexible member by the roller tube;
a DC motor having an output shaft rotated at a motor speed, the DC motor having a low efficiency, high torque region of operation and a high efficiency, low torque region of operation defining a peak efficiency;
a gear assembly connected to the output shaft of the motor and to the roller tube such that the gear assembly is driven by the motor and the roller tube is driven by the gear assembly, the gear assembly producing an output rotational speed that is reduced with respect to the motor speed; and
a controller connected to the motor and configured to control said motor to provide for movement of the flexible member during winding or unwinding of the flexible member at a substantially constant linear speed,
the controller responsive to a first control signal to control the motor in a first mode such that the flexible member moves at a first predetermined linear speed, the controller responsive to a second control signal to control the motor in a second mode such that the flexible member moves at a second predetermined linear speed, the first predetermined linear speed at least two times greater than the second predetermined linear speed;
wherein the controller is configured to operate the motor when the motor is energized to move the flexible member at the second predetermined linear speed to rotate always at an operating speed that is less than 50 percent of a maximum motor speed of which the motor is capable when the flexible member moves at the second predetermined linear speed and at an efficiency less than 25% of the peak efficiency.
14. The motorized roller tube system according to claim 13 , wherein the motorized roller tube system produces a sound pressure level between 38 dBA and 40 dBA at a distance of approximately three feet from the roller tube in an ambient sound pressure level of approximately 38 dBA when the flexible member moves at the second predetermined linear speed.
15. The motorized roller tube system according to claim 14 , wherein the first predetermined linear speed is approximately three inches per second.
16. The motorized roller tube system according to claim 15 , wherein the second predetermined linear speed is approximately one inch per second or less.
17. The motorized roller tube system according to claim 13 , wherein the motor has a motor torque that is always greater than 50 percent of a maximum torque capability for the motor when the flexible member moves at the second predetermined linear speed.