Cam mechanisms are used in the many kinds of machinery for a long time because they have lots of benefits. They can transfer the rotating movement of motor to the translating or oscillating movement easily. And we can get a high capacity and trust in the high speed driving machine. Cam type transfer unit is the feeding mechanism which uses the cam's repeating movement. It is used to feed the materials to the machine like press. It consists of three cams, which are feed cam, lift cam, and clamp cam, and they operated synchronously.
The value and direction of torque is always changed through one cycle in the cam mechanisms. Especially, large-capacity cam type transfer unit has a great large torque value and fluctuation. These characteristics of torque have a bad effect on the unit. The unit has to have a thick cam shaft to endure the fatigue and torsion effect and a large-sized motor. So, it is needed to reduce the torque value and fluctuation on the cam shaft to operate the unit safely. There are two ways to reduce the torque. One is the reduction by itself and the other is reduction by another cam called torque reduction cam. Torque reduction cam generates the opposite torque and reduces the torque.
This paper treats the whole works to design the torque reduction cam.
At first, we have to calculate the exact torque value on the cam shaft. The module to calculate the torque on the cam shaft is developed and it is useful to every types of cam, for example, single cam and conjugate cam.
To design the torque reduction cam is not easy. The torque reduction cam is the cam which generates the required torque and there are many variables to determine the torque applied to the cam shaft. So, step-by-step method is suggested and the torque reduction cam designed by the developed module reduces the extreme torque value in the way of generating the compensating torque. The first step is to input the variables of cams and linkage for the torque reduction unit. The second step is to input the motion of follower and this step determines the efficiency of reduction. The motion of follower is obtained by considering extreme value of the total torque of the transfer unit. After all required variables are inputted, the torque reduction cam is created and it can be verified. When it is verified, reduced torque is important, but the characteristics of cams like velocity, acceleration, jerk, and pressure angle is more important. If the designed torque reduction cam is not satisfied, first and second steps should be repeated.
At the last section, the module to design the torque reduction cam is verified by the experiment.
