Base station antennas with remote electronic tilt actuators for controlling multiple phase shifters
The present invention relates to base station antennas having remote electronic tilt capabilities. Actuators for multiple phase shifters are described herein. An actuator may include a motor, a linkage drive system including a plurality of drive mechanisms for driving mechanical linkages of multiple phase shifters, a linkage selection system that is configured to selectively connect the motor to a selected one of the drive mechanisms of the linkage drive system. The linkage selection system may include a support seat, a carrier disposed on the support seat, and a movement transmission mechanism.
1. An actuator for multiple phase shifters comprising:
a motor;
a linkage drive system including a plurality of drive mechanisms for driving mechanical linkages of multiple phase shifters;
a linkage selection system that is configured to selectively connect the motor to a selected one of the drive mechanisms of the linkage drive system, the linkage selection system including:
a support seat having a length direction that is transverse to a length direction of the mechanical linkage;
a carrier disposed on the support seat and configured to carry the motor back and forth along a length direction of the support seat; and
a movement transmission mechanism that is configured to switch between a movement state in which the movement transmission mechanism is configured to move the carrier and the motor to a position where an output of the motor can engage the selected one of the driving mechanisms, and a transmission state in which the movement transmission mechanism transfers a rotational movement of the output of the motor to the selected one of the drive mechanisms.
2. The actuator according to claim 1 , wherein the linkage selection system further includes a state changeover switch that is configured to switch the movement transmission mechanism between the movement state and the transmission state.
3. The actuator according to claim 2 , wherein the state changeover switch is a solenoid valve or a motor.
4. The actuator according to claim 2 , wherein the movement transmission mechanism includes a rack, a gear train that is configured to selectively mesh with the rack, and an output shaft of the movement transmission mechanism connected to the gear train.
5. The actuator according to claim 4 , wherein the rack is fixed to the support seat and extends along a length direction of the support seat.
6. The actuator according to claim 4 , wherein the gear train is mounted on one side of the carrier proximate the mechanical linkages, and the motor and the state changeover switch are mounted on another side of the carrier that is away from the mechanical linkages.
7. The actuator according to claim 4 , wherein the gear train includes a first gear that is directly connected to an output shaft of the motor and a second gear that is directly connected to an output shaft of the state changeover switch, wherein the first gear and the second gear are directly engaged or are engaged through one or more intermediate gears.
8. The actuator according to claim 7 , wherein the second gear remains engaged with both the first gear and the rack when the state changeover switch is in the movement state, and remains engaged with the first gear and disengaged from the rack when the state changeover switch is in the transmission state.
9. The actuator according to claim 7 , wherein the first gear and the second gear are both spur gears.
10. The actuator according to claim 7 , wherein the output shaft of the movement transmission mechanism is coaxially fixed to a center of the second gear.
11. The actuator according to claim 1 , wherein the support seat includes one or more guide rods and a base that supports the guide rods.
12. The actuator according to claim 11 , wherein the carrier spans the guide rod, and is configured for movement back and forth in a length direction of the support seat along the guide rod.
13. The actuator according to claim 10 , wherein the base includes a bottom plate fixed to a substrate of the actuator, and projecting arms projecting upwardly from both ends of the bottom plate and supporting the guide rod.
14. The actuator according to claim 13 , wherein the projecting arms support the guide rod above the substrate on both ends of the guide rod.
15. The actuator according to claim 4 , wherein the linkage drive system includes a support seat and a plurality of lead screws supported on the support seat.
16. The actuator according to claim 15 , wherein each lead screw is provided with a drive block for driving a reciprocal movement of the mechanical linkages, and each drive block is engaged with an external thread of a respective one of the lead screws by internal threads.
17. The actuator according to claim 15 , wherein each lead screw is provided with a connection portion on an end facing the linkage selection system that is configured to connect with an output shaft of the linkage selection system.
18. The actuator according to claim 17 , wherein the connection portion has a recess for receiving a top end of the output shaft of the linkage selection system, and the recess has a cross-sectional profile that matches a cross-sectional profile of the top end of the output shaft of the linkage selection system.
19. The actuator according to claim 2 , wherein the actuator includes a controller that is configured to control operation of the motor and operation of the state changeover switch.