In this article, we will explore the cycloidal actuator integrated with a frameless motor. The advancement of the robotics industry is expected to bring significant changes to our daily lives. Both domestic companies such as Hyundai Motor Company and global companies like BMW are actively conducting pilot tests to introduce humanoid robots into their production processes. Alongside the remarkable development of artificial intelligence, robotic technology is also evolving rapidly every day.
However, this transformation is not solely driven by advancements in software technologies. To bring robotic movements to life, a variety of hardware components are essential, among which the cycloidal actuator plays a crucial role.
What is an Actuator?
The human body is composed of various components, but the key elements that enable physical movement are the joints and muscles. No matter how many movement commands the brain sends, those commands are meaningless unless the joints and muscles execute them. The same applies to robots. An actuator is a core component that executes actual movements based on control signals received from a driver.
Actuators can be classified into various types depending on their operating mechanism. The most common types include electric, hydraulic, and pneumatic actuators, each selected based on the application field and required performance.
For instance, heavy equipment used at construction sites typically relies on hydraulic actuators, which are advantageous for delivering high torque, essential for lifting heavy objects or performing force-intensive tasks. In contrast, electric actuators are often used in industries where precise control and repetitive motion are crucial, as they operate based on electrical signals.
Exploring the Latest Technology Trends
One of the most notable trends in the robotics and automation market today is “design flexibility.” Typically, when designing a product, companies tend to use off-the-shelf components rather than fully customized parts, taking into account cost and time efficiency.
However, designing around standard components can impose limitations on the structure, shape, and size, making it difficult for engineers to realize their ideal designs or optimal configurations.
In situations where there are spatial constraints or unique mechanical requirements, engineers often face the challenge of reverse-engineering the entire system to accommodate pre-existing components. This significantly reduces design freedom and may compromise the product’s performance, appearance, or layout of functional elements.
To overcome these challenges, the industry is exploring various approaches—one of which is the adoption of frameless motors. Frameless motors consist only of a stator and a rotor, without an outer housing.
Frameless motors offer a high degree of design freedom because they can be flexibly integrated into the desired structure. While traditional off-the-shelf motors have fixed dimensions and shapes that can restrict design possibilities, frameless motors, with their open structure, allow for effective implementation even in complex geometries or confined spaces.
These advantages are particularly evident in actuator design. By incorporating a frameless motor, it becomes possible to insert a speed reducer directly into the rotor’s inner space, which is highly effective in reducing the overall thickness of the drive unit. As a result, this approach offers a more optimized solution for robotic systems where compactness and high performance are both essential.
Application Example
Let’s look at one example. We’ll compare the use of a frameless motor-based actuator in a device like an AGV (Automated Guided Vehicle) with the use of a conventional geared motor or planetary gear reducer.
Imagine a situation where the external size of the product is already fixed and cannot be adjusted. Under these conditions, various components must be efficiently arranged within a limited internal space. However, at a certain point, there is simply no more room to install additional parts, and major constraints arise in the design.
To address this, engineers might try reconfiguring circuit wiring or replacing some components with smaller, thinner alternatives—but such changes can increase design complexity and place additional strain on the overall system.
So what changes when a slim structure based on a frameless motor is used? Reducing the thickness of the actuator increases the efficiency of internal space utilization, providing more room for placing other key components such as sensors, batteries, and control units. This is a highly effective approach for maintaining system performance while securing design flexibility, even in constrained spaces.
Let’s take this a step further. Besides reducing thickness, what other methods exist to secure internal design space? For example, what if we design the drive system with an integrated structure—combining the gear reducer and motor directly into the wheel itself, also known as an “in-wheel” design? In fact, this type of configuration is commonly applied in AGV robots. It helps save space and improves design efficiency by modularizing the drive system.
Another solution we propose is the “smart actuator,” which integrates the gear reducer, motor, inverter, driver, and brake into a single unit. This integrated solution goes beyond simply reducing parts—it adds various benefits by modularizing the entire system, such as design optimization, simplified wiring, and reduced assembly time. Especially in robotics environments where space is limited and performance demands are high, the smart actuator can be a highly competitive solution.
Cycloidal Smart Actuator?
A smart actuator is a drive solution that integrates various control components—such as a reducer, motor, inverter, driver, and brake—into a single unit. Unlike the conventional approach, where each part must be individually designed, wired, and assembled, the smart actuator offers all of these elements in a pre-integrated, modular format.
As a result, it significantly reduces not only design time but also the complexity and duration of wiring and assembly processes.
The greatest strengths of this technology lie in simplified design and space savings. By eliminating the need for complex part layouts, the structure can be simplified, enabling the implementation of high-performance drive systems even in confined spaces. Thanks to its slim profile and high level of component integration, the smart actuator can be flexibly applied to various robot designs, maximizing internal design freedom.
Additionally, its integrated design brings substantial advantages in terms of reliability and maintenance. It reduces the likelihood of malfunctions caused by connections between individual parts and ensures stable performance through its unified structure. Furthermore, the entire system can be replaced or upgraded as a single unit, significantly enhancing operational efficiency and ease of maintenance.
One Step Ahead: Our Ongoing Challenge
While a smart actuator is already a highly integrated and innovative drive solution on its own, Bon Systems is going a step further by developing a product that combines cycloidal reducer technology with a frameless motor.
This is not merely a combination of components—it is a fundamentally different engineering approach that maximizes structural efficiency and performance stability, offering a clear technological distinction from conventional actuators.
The cycloidal actuator is built on a unique rolling motion gear structure that provides excellent load distribution. As a result, it delivers outstanding performance in terms of durability and torque transmission efficiency. It is more resistant to shock and experiences less wear in repetitive motion compared to typical gear systems. Notably, it can achieve a wide range of reduction ratios—from low to high—within the same compact size.
Its low-wear characteristics contribute significantly to extending the product’s lifespan and enhancing the reliability of robotic systems. This structure makes it ideal for various drive systems that must withstand continuous high loads, such as collaborative robots, logistics robots, and industrial robots.
When combined with frameless motor technology, the synergy becomes even more powerful. Frameless motors, consisting only of a stator and rotor without an outer housing, can be designed in slim and lightweight forms.
This allows them to be integrated into a variety of robot systems without being constrained by external dimensions. Moreover, not only the reducer and motor but also key control components such as the driver, brake, and inverter can be physically integrated into a single unit—resulting in a compact yet high-performance drive system.
The smart actuator developed by Bon Systems—combining the strong torque and high durability of the cycloidal gear with the thin-profile design and integration efficiency of the frameless motor—is poised to become a powerful solution in the next-generation robotics market, where space constraints and high performance are both critical.
In an era when robot design must balance flexibility, durability, performance, and structural simplicity, Bon Systems offers a practical solution that meets these complex demands.
Purchase and Development Inquiries
The BCSA series of cycloidal actuators, developed with Bon Systems’ advanced technology, can be explored in detail on our product introduction page.
In addition to standard products, we also support custom specifications. If you require a tailored solution, please provide your desired requirements, operating environment, and specifications of the motor to be used.
Based on this information, we will offer gear reducer design and development services to meet your needs.
