Frameless BLDC Motor
A frameless servo motor has a rotor and stator built directly into a machine’s structure to produce motion. They are often integrated with shafting, bearings and a feedback device.
By eliminating redundant components, engineers can incorporate frameless motors into extremely compact application designs. They also offer robust protection from caustic washdown fluids, weather exposure and other environmental hazards.
Increased Power Density
With a frameless motor, you gain the flexibility of mounting the stator and rotor components directly into your application. This eliminates the design constraints imposed by a housed motor’s housing, shaft, bearings and feedback system. It also reduces machine setup times and allows for easier maintenance.
This means that you can use your own design, assembly and manufacturing processes to optimize a system around this powerful and compact servo motor. This is especially useful for robotic systems such as surgical robots, collaborative robots and exoskeletons where every component counts.
A frameless BLDC motor can transmit torque directly to the load without using a shaft, gears or pulley. This increases accuracy, efficiency and power density for applications where space is at a premium.
This allows for a very compact system that can be built around the motor and incorporated with other actuator components, such as a compact harmonic, planetary or cycloidal gearset. This gives you a scalable solution that will grow with your requirements with minimal inertia and weight. Our smallest frameless motor is 38mm in diameter, 14mm long and weighs only 57g – making it the perfect choice for high-performance rotary actuators.
Improved Efficiency
Unlike brush motors, frameless DC motors do not use mechanical brushes and commutators to switch currents through the coils of the motor. As a result, they are essentially maintenance-free, produce lower Frameless BLDC motor levels of electromagnetic interference (EMI) and inertia, operate at higher voltages and can be smaller while delivering the same output power.
For engineers looking to maximize efficiency and minimize heat generation in their designs, choosing a frameless motor is a great choice. The lack of a housing, shaft and bearings allows the motor to be embedded directly into the mechanical structure of an application. This can significantly reduce system weight, size and inertia, saving on costs associated with hardware such as gears, belts and couplings.
Frameless motors can be customized to meet specific performance requirements. For example, Moog offers various winding designs that modify torque sensitivity, back EMF, DC resistance and inductance. They also offer a range of stack lengths to suit different applications and performance requirements.
Moog’s next generation frameless servo motors offer high torque density for your most compact electromagnetic package. They utilize high performance magnets to reduce stator length to half that of conventional motors and innovative magnetic steel sheets to further reduce iron loss. These technologies combine to deliver a motor that is 12% shorter, 33% more compact and with 7% higher efficiency than traditional frameless motors.
Minimalist Form Factor
BLDC motors are more compact than traditional motors with minimal housing, bearings, and shaft. This allows for easier integration into a machine design without having to accommodate extra components, such as a gearbox.
In addition, the BLDC motor consumes less electrical power for the same mechanical output, which improves the efficiency of the application and reduces operating costs in production. This feature also enables electric vehicles, drones, and portable electronics to have a longer battery life for long operations.
Frameless BLDC motors also allow engineers to mount the rotor and stator directly into the structure of an application, eliminating the need for a separate housing for protection from harsh environments. This allows for a more compact and lightweight motor with fewer unnecessary components, reducing the overall cost of the device.
Because of their ability to provide more torque in a smaller package, frameless BLDC motors are often used as the “limbs” of service robots, which help human operators complete tasks in places where restrictive safety fencing would otherwise limit their movement. They can drive robotic hands and arms to hold objects, for example. They can also be used to power articulating tools that help surgeons perform procedures without having to move around the patient. Their small size and low noise levels make them ideal for medical applications where any additional vibrations or noise can disrupt the patient’s comfort.
Versatility
A frameless motor eliminates design constraints imposed by a housing, shaft and connector. It is the ideal solution for robotics and industrial automation where space and inertia are critical considerations. It also allows for a smaller footprint and can replace heavy, less efficient hydraulic systems.
Unlike standard brushless DC motors that use a frame to support the rotor and stator, frameless motors are sold as Frameless BLDC motor manufacturer kits consisting of only the rotor and stator. Engineers can then add a housing, shafting, bearings and other components to complete the servo system.
This design freedom allows for greater power density, higher efficiency and a minimalist form factor. Kollmorgen offers a wide range of frameless motor models to meet the requirements of your application, including both torque and servo versions. Models are available in a variety of diameters, stack lengths and winding variations for optimum performance.
Additionally, the slim profile of a frameless motor lends itself to aerodynamics and visual styling. Frameless motors can be molded directly into the mechanical structure of your system for an even slimmer profile that minimizes weight and inertia. For example, a frameless motor can be integrated into the rotary or linear actuator of a robotic joint to greatly enhance the dexterity, versatility and efficiency of a robot arm or cobot.
