Torque sensor system
A rotating power tool is provided. The rotating power tool may include a bevel gear set having a bevel gear and a conductive spiral disposed on the bevel gear. The conductive spiral may be configured to, in response to the bevel gear deforming due to a torque being applied to the bevel gear, change a resistance of the conductive spiral. The rotating power tool may further include an antenna electrically connected to the conductive spiral. The antenna may be configured to emit an output signal at a frequency that is based on the resistance value of the conductive spiral. The frequency of the output signal may be indicative of an amount of torque being applied to the bevel gear.
1. A rotating power tool comprising:
a motor;
a bevel gear set comprising a bevel gear, the bevel gear set configured to be driven by the motor;
an antenna disposed on the bevel gear;
a conductive spiral electrically connected to the antenna, the conductive spiral being disposed on the bevel gear and the conductive spiral being configured to, in response to the bevel gear deforming due to a torque being applied to the bevel gear, change a resistance of the conductive spiral;
a control antenna disposed at a stationary position relative to the bevel gear; and
controller circuitry operably connected to the motor and the control antenna, the controller circuitry being configured to:
control operation of the motor;
cause the control antenna to transmit a signal to induce a current in the antenna and cause a resonant circuit formed by the antenna and the conductive spiral to resonate and emit an output signal from the antenna, the output signal having a frequency based on the resistance of the conductive spiral;
cause the control antenna to receive the output signal; and
determine a torque measurement being applied to the bevel gear based on the frequency of the output signal.
2. The rotating power tool of claim 1 , wherein the conductive spiral is disposed on a face of the bevel gear that is opposite a plurality of gear teeth.
3. The rotating power tool of claim 1 , wherein the conductive spiral is disposed on a face of the bevel gear that is opposite a plurality of gear teeth;
wherein an output shaft extends from the face of the bevel gear, the output shaft being driven by the motor via the bevel gear; and
wherein the conductive spiral is disposed on the face of the bevel gear such that the conductive spiral spirals around the output shaft.
4. The rotating power tool of claim 3 , wherein the conductive spiral is configured to change a magnitude of the resistance in a first direction in response to a shearing compression on the conductive spiral due to the applied torque on the bevel gear, and change the magnitude of the resistance in a second direction in response to a shearing tension due to the applied torque on the bevel gear.
5. The rotating power tool of claim 1 wherein the control antenna and the antenna are co-planar.
6. The rotating power tool of claim 1 wherein the conductive spiral and the antenna are co-planar.
7. The rotating power tool of claim 1 wherein the conductive spiral comprises two spirals with a thread of a first spiral being disposed between two threads of a second spiral.
8. The rotating power tool of claim 1 wherein the conductive spiral is formed by a resistive carbon paint.
9. The rotating power tool of claim 1 wherein the antenna is shaped as an arc.
10. The rotating power tool of claim 1 , wherein the control circuitry is further configured to:
compare the torque measurement to a torque setting to determine a difference; and
adjust a power to the motor based on the difference to adjust a torque output of the rotating power tool.
11. The rotating power tool of claim 1 , wherein the control circuitry is further configured to:
compare the torque measurement to a torque setting to determine a difference; and
in response to the torque measurement being within a tolerance range of a torque setting, interrupt power to the motor.
12. A rotating tool comprising:
a gear;
a conductive spiral disposed on the gear, the conductive spiral being configured to, in response to the gear deforming due to a torque being applied to the gear, change a resistance of the conductive spiral; and
an antenna electrically connected to the conductive spiral, the antenna and the conductive spiral forming a resonant circuit that is configured to resonate and emit an output signal from the antenna, the output signal having a frequency that is based on the resistance value of the conductive spiral, the frequency of the output signal being indicative of an amount of torque being applied to the gear.
13. The rotating tool of claim 12 , further comprising a output shaft disposed on the gear and the conductive spiral being disposed around the output shaft.
14. The rotating tool of claim 12 , further comprising a control antenna disposed in a housing of the rotating tool, the control antenna being configured to emit an excitation field to induce a current in the antenna, and receive the output signal emitted by the antenna.
15. The rotating tool of claim 12 , wherein the conductive spiral comprises a resistive carbon paint.
16. The rotating tool of claim 12 , wherein the antenna and the conductive spiral operate to form a resonant circuit.