The role of a robot reducer is not limited to merely reducing the motor’s rotation. It converts the motor’s fast rotation into precise motion with large torque, and it serves as the bridge of the entire system that turns the position, speed, and torque intended by the controller into actual joint motion. This article explains, from a system perspective, what position the reducer occupies within the overall robot-component structure and how it cooperates with the motor, controller, and sensors.
Table of Contents
The Basic Structure of a Robot System and the Position of the Reducer
Key Takeaway — A robot system is generally composed of the cooperation of five core components: the controller, the motor, the reducer, the sensors, and the mechanism. The robot reducer occupies the key position between the motor and the mechanism, converting and transmitting rotational motion.
A robot system looks very complex at first glance, but once the core components are organized, it resolves into a surprisingly simple structure. First there is the controller that generates the work commands; then the motor that produces rotation according to the controller’s commands; the reducer that converts that rotation into torque; the mechanism that performs the actual work (arm, leg, hand, and so on); and the sensors that measure all of this motion and feed it back to the controller—together these cooperate to form the entire system.
The role of a robot reducer sits in the bridging position between the motor and the mechanism within this system. A motor produces fast rotation well but has difficulty delivering large torque directly, while the mechanism requires appropriate torque to generate movement. In between, the reducer lowers the rotational speed and amplifies torque, so the motor’s output is converted into torque the mechanism can use.
The Role of the Motor and Robot Reducer: Turning Rotation into Torque
Key Takeaway — A motor is the component that produces fast rotation, and the reducer lowers that rotational speed and amplifies torque. The cooperation of the two components is what allows a robot joint to produce its intended motion.
The cooperative relationship between the motor and the reducer can be compared to the pedals and gear system of a bicycle. If the pedals are the motor and the rear wheel is the mechanism, then the gears that turn the fast rotation of the pedals into the strong rotation of the rear wheel play a role similar to that of the reducer. With only pedals and no gears, even pedaling quickly would make it hard for the bicycle to pull a heavy load up a hill.
The same is true in a robot system. A motor produces fast rotation well, but that rotation alone is insufficient to lift a heavy payload or support a humanoid robot’s own weight. Only when the reducer lowers the motor’s rotational speed and amplifies torque by a large margin can the mechanism finally perform its intended work.
The overall robot system produces its intended motion characteristics only when the motor’s output rotational speed and torque curve align well with the reducer’s reduction ratio and efficiency characteristics. This is precisely why the motor’s rated output and the motion cycle should be reviewed together when selecting a robot reducer.
How Reducer Selection Affects the Entire Robot System
Key Takeaway — Once chosen, a reducer is one of the core components that is difficult to change in a robot system. At the component-selection stage, the application conditions, space constraints, operating environment, and long-term reliability must all be reviewed comprehensively.
A reducer is a core component that is difficult to change once selected in a robot system. Because the reducer is located inside the joint, replacing it often requires a redesign of the entire system. For that reason, careful review at the component-selection stage is important.
When selecting a reducer, the motion conditions of the application equipment (repeatability, operating speed, load pattern), the installation-space constraints, the operating environment (temperature, vibration, dust), and reliability during long-term operation should be reviewed comprehensively. Organizing these items and then matching them with catalog specifications to choose a suitable model is the starting point of component selection.
The Bonsystems BSR 070, 080 and BCSA series are built on a pinless Pinless cycloidal structure and a thin package, forming a lineup that can respond to diverse robot application environments. Thanks to the design know-how that implements various reduction ratios within a single-stage structure, you can review a wide range of component-selection options depending on the application environment.
The Value Bonsystems Pursues in the Robot Reducer Field
Key Takeaway — Through a Pinless cycloidal structure, a thin design, a minimized part count, and the know-how to cover various reduction ratios in a single stage, Bonsystems provides precision reducer components suited to industrial robot, collaborative robot, and humanoid robot systems.
Bonsystems stands out in the robot reducer field. The pinless Pinless cycloidal structure reduces pin-component wear factors while also minimizing the number of parts, simultaneously raising assembly efficiency and long-term reliability. The thin package design provides a component form suited to the slim joint spaces of humanoid robots and collaborative robots.
In addition, through its design know-how for implementing various reduction ratios within a single-stage structure, Bonsystems has the flexibility to respond to a wide range of robot systems—from industrial articulated robots to collaborative and humanoid robots. This allows the robot reducer to perform its role as the bridge of the entire system even more effectively.
Through its cycloidal reducer lineup, including the BSR and BCSA series, Bonsystems takes its place as one pillar of the domestic robot-component industry while seeking to serve as a reliable component-supply partner for robot-system manufacturers.
Bonsystems — Specialists in Pinless cycloidal reducers and actuators
🔗 Get the reducer material → www.bonsystems.com
F.A.Q
Q: To put it simply, what is the role of a robot reducer?
A: A reducer is a precision component that converts the motor’s fast rotation into slow rotation at the output shaft and, in exchange, amplifies torque by a large margin. Within a robot system, it serves as the bridge between the motor and the mechanism, functioning as the core medium that realizes precise position, speed, and torque control.
Q: Can you build a robot with only a motor and no reducer?
A: In theory, some direct-drive robots exist, but in applications that simultaneously require large torque and precise motion—such as ordinary industrial robots, collaborative robots, and humanoid robots—a reducer is used almost as a necessity. This is because a motor alone has difficulty satisfying both large torque and precise control at the same time.
Q: How does a robot reducer cooperate with the controller and sensors?
A: The controller generates work commands, the motor produces rotation, the reducer converts that rotation into precise motion with large torque, and the sensors measure the motion and feed it back to the controller. Within this closed-loop control, the reducer’s motion characteristics directly affect the precision of the entire system.
Q: What should you pay the most attention to when selecting a reducer?
A: It is best to comprehensively review the motion conditions of the application equipment (repeatability, operating speed, load pattern), the installation-space constraints, the operating environment (temperature, vibration, dust), and reliability during long-term operation. Because a reducer is a component that is difficult to change once chosen, careful component selection is important.
Q: Which robot systems are Bonsystems cycloidal reducers suited to?
A: The Bonsystems BSR and BCSA series are a cycloidal reducer lineup designed, on the basis of a pinless Pinless structure and a thin package, to be used in diverse robot systems such as industrial articulated robots, collaborative robots, and humanoid robots. Detailed specifications can be checked in the catalog on the official Bonsystems website.
References
- [1] Korea Institute for Robot Industry Advancement (KIRIA) — https://www.kiria.org
- [2] Korea Institute of Robotics & Technology Convergence (KIRO) — https://www.kiro.re.kr
- [3] International Federation of Robotics (IFR) — https://ifr.org
- [4] Ministry of Trade, Industry and Energy (MOTIE) — https://www.motie.go.kr
