Why Robotic arm need speed reducers?
Robotic arm can imitate certain action functions of human hands and arms, used to grasp and carry objects or operate tools according to a fixed procedure of automatic operation device. It can replace heavy human labor to enhance mechanization and automation of production, and can operate in harmful environments to protect personal safety, and thus is widely used in industries such as machinery manufacturing, intelligent logistik, intelligent storage, automated production lines and industrial robot equipment.
Manipulators mainly consist of a hand and a motion mechanism. The hand is a part used to grip the workpiece (or tool), and has various structural forms, such as clamping type, holding type and adsorption type, depending on the shape, size, weight, material and operational requirements of the gripped object. Motion mechanism, so that the hand to complete a variety of rotation (oscillation), movement or composite movement to lift the prescribed action, change the position and posture of the gripped object. The movement mechanism of lifting, telescoping, rotating and other independent movement mode; robot why reducer, the main consideration is the following three roles.
1. to obtain a low speed, to obtain a large torque, to obtain better operating characteristics.
2. Add a reducer can reduce the rotational inertia, generally the square of the speed ratio is reduced, which is important for the control, can be timely control of the start-stop, variable speed. Through the reducer to increase the torque is also equivalent to increase the input power, can reduce the input motor power required (in the need for speed control occasions), the general situation of the motor to be more expensive than the reducer, so consider using a reducer, such as robotic drive system.
3. reducer in the drive there is a role in protecting the motor, running reducer to withstand the larger torque, overload is transmitted to the motor only the amount of overload divided by the value of the reduction ratio, if the motor directly by the motor may cause damage to the motor. In the overload is very large when the reducer will be damaged first, and the reducer only need to replace spare parts can be restored to use, the cost is relatively low, if the motor is directly damaged repair is relatively slow, the cost is also high.
Manipulator design generally requires to achieve light weight, lille størrelse, højt drejningsmoment (large bearing capacity), smooth drive, flexible response, good stability, high security needs, manipulator joint reducer is generally required by the large drive ratio, højt drejningsmoment, high torque stiffness, small return, easy assembly, lille størrelse, light weight and some other characteristics.
Manipulator special planetary reducer can improve the closed-loop accuracy and better control the control loop. Because there is a large reduction ratio of 50:1, the robot reducer out of the shaft is disturbed by the transmission to the motor side than the direct drive shrinks 37dB, making the closed-loop accuracy in the reducer out of the shaft appears higher. På samme tid, the rotor equivalent rotational inertia is increased to 2500 times, making the control loop hysteresis link dominated by rotor inertia, while the rotor is directly driven by the electromagnetic force so that there is no torque hysteresis due to stiffness, which is better than direct drive to control.
Manipulator can use planetary reducer, DC brush reducer, DC brushless reducer, stepper reducer, hollow cup reducer and RV reducer, harmonic reducer as the drive reducer motor, technical parameters, performance characteristics and other needs can be customized according to the application industry scenario.
