Advantages of mechanical design using high torque density geared systems

Traditional set ups like worm and wheel or bevel geared systems can be replaced with spiroid gear assemblies like Spiradrive to obtain substantial reductions in size and torque density. Positional benefits such as the motor by the joint (or even inside, as part of the joint) eliminating the need of unnecessary counterweights and reducing the total size of structural components. Additional Spiradrive benefits include virtually zero backlash capabilities, its higher ratio (up to 360:1 in a single gear set), less critical mounting requirements, greater back drive efficiency when desired and lower noise levels.

In the case of a robotic arm, if the motor is placed by a gearbox that has an output shaft transmitting torque to a joint system, these components will not be close to the joint therefore requiring counterweights to balance the robotic arm. Based on torque requirements, a power unit can be located where it is most convenient, such as the electric motor powering the robotic joint. If the motor is close to the joint, then it can make use of superior torque density, lowering the requirements for additional counterweights and saving substantial structural weight and cost.

In this case, to reduce the distance between the motor’s output shaft and the joint, the size of the transmission system that adapts the motor speed and its torque to accomplish the work (i.e., moving the joint with precision and control) becomes critical for the whole system’s performance and cost. The more torque density and the smaller the size of the gearbox, the more efficient the motor will be resulting in a reduction of size of the rest of the components, hence, positively impacting costs.

The same also applies to other motion control mechanical systems like actuators or differentials.

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