Resistance regulating device for wheel of training machine
A resistance regulating device for a wheel of a training device is disclosed. The resistance regulating device comprises a rotary mechanism pivotally connected with a stationary mechanism and a motor with other components to rotate the rotary mechanism and hence a distance between magnets of the rotary mechanism and the wheel is changed. In addition, an optical detection device may be used to detect and define a minimum resistance and a maximum resistance and hence to adjust a resistance in a stepless manner. An emergency brake mechanism may be further employed.
1. A resistance adjusting device used for a wheel of a training machine, comprising:
a stationary mechanism being fixed with the training machine;
a rotary mechanism being pivoted to the stationary mechanism by a pivot and comprising a plurality of magnets for providing a resistance to the wheel;
a link member pivotally connecting to a first end of the rotary mechanism;
a motor being connected with the link member;
a screw having a first end connected to the motor and being rotatable by the motor;
a nut pivotally connecting with the stationary mechanism, a second end of the screw passing through the nut and being movably engaged with an inner thread of the nut; and
an optical detection device for detecting the resistance and defining a minimum resistance and a maximum resistance;
wherein the optical detection device comprises:
a control circuit board electrically connected to the motor;
a control member having a first end fixed to the rotary mechanism and a second end suspended above the control circuit board;
a first sensor located on the control circuit board for detecting the second end of the control member so as to determine a minimum resistance position of the screw; and
a second sensor located on the control circuit board for detecting the second end of the control member so as to determine a maximum resistance position of the screw;
whereby the motor drives the screw to rotate, causing the rotary mechanism to rotate about the pivot, and thereby changing a distance between the plurality of magnets and the wheel, so as to increase or decrease the resistance.
2. The resistance adjusting device as set forth in claim 1 , further comprising an emergency brake mechanism for stopping the wheel.
3. The resistance adjusting device as set forth in claim 2 , wherein the emergency brake mechanism comprises:
a trigger fixed with the training machine;
a cable having a first end and a second end, the first end of the cable being connected to the trigger;
a control block being pivoted to the stationary mechanism, the second end of the cable being connected to the control block;
a fixing piece fixed with the stationary mechanism;
a spring, the cable passing through the fixing piece and the spring, the spring having a first end connected to the control block and a second end connected to the fixing piece; and
a friction pad connected with the control block.
4. The resistance adjusting device as set forth in claim 2 , wherein the emergency brake mechanism comprises at least one friction pad located at least one side of the rotary mechanism, and the training machine comprises an emergency button for triggering a signal to instruct the motor driving the screw, causing the at least one friction pad to contact the wheel so that the wheel is stopped.
5. The resistance adjusting device as set forth in claim 1 , wherein when the first sensor or the second sensor detects the second end of the control member, a stop signal is outputted to the motor, and the motor stops driving the screw according to the stop signal.
6. The resistance adjusting device as set forth in claim 1 , wherein each the first sensor and the second sensor comprises an infrared emitter and an infrared receiver or comprises a light-emitting diode and a light receiver.
7. The resistance adjusting device as set forth in claim 1 , wherein a number of revolutions of the screw is determined according to a required resistance corresponding to a position between the minimum resistance position and the maximum resistance position of the screw.
8. The resistance adjusting device as set forth in claim 1 , wherein a self-lubricating bushing is provided between the pivot and the stationary mechanism.