When you choose a cam caliper motor, considering that in most practical situations, the motor needs to be stopped to extend the stopping time. You may think that ordinary motors have inertia when stopping and cannot stop accurately, so you must use a brake motor. Is this really the case?
Firstly, we need to start with the structural principle of the cam divider. The cam slant line segment on the input shaft of the cam divider drives the needle roller on the output shaft to revolve along the output axis, thereby achieving rotation of the output shaft, i.e. indexing; The cam linear segment locks the needle roller bearing, thereby achieving static positioning of the output shaft.
That is to say, as long as the needle roller bearing is in the straight section of the cam every time the motor stops, regardless of its position in the straight section, the position of the output shaft is accurate. This is also the cleverness of the cam caliper, and the key difference between the cam caliper and other indexing mechanisms.
The actual use case tells us that when the turntable is in place, that is, the inclined section of the input shaft cam has been completed and just entered the inclined section of the cam (corresponding to the angle of rest), the photoelectric or proximity switch on the input shaft will send a signal to power off the motor. Due to the inertia of the motor, the motor reducer will continue to rotate forward a little. Whether the rotation caused by this inertia passes through the straight section depends on the output speed of the reducer.
According to years of practical use cases, generally speaking, the static angle is 90 degrees, and the input shaft speed is below 45 revolutions per minute, which means the reduction ratio is 30 or above (assuming the motor speed is about 1400 revolutions per minute). At this time, the inertia causes the rotation to not complete the straight line section and cannot reach the static angle. At this time, the motor does not need to be equipped with brakes, and a regular motor can be used. On the contrary, a brake motor must be used, otherwise it is easy to pass through the straight line section and reach the static angle, resulting in inaccurate positioning.
Of course, stepper motors and servo motors do not require braking, as they can stop in a timely manner through signals without causing any movement.
When the input speed of the caliper is below 45 revolutions per minute, the brake motor is not required. On the contrary, when the input speed of the caliper is higher than 45 revolutions per minute, the brake motor should be used.