What is a frameless servo motor?

A frameless servo motor consists of only the rotor and stator - no housing, shaft, or bearings. The OEM integrates these components directly into their mechanism, enabling tighter packaging and higher system-level torque density.

Can SEI customize windings for my voltage and speed requirements?

Yes. SEI offers custom windings and sizes to match your exact voltage, speed, and torque profile. Contact our engineering team with your application parameters.

Products

Frameless Servo Motors

Frameless BLDC servomotors consist solely of the rotor and stator assembly without a traditional housing or frame. They can be directly integrated into mechanisms, allowing for flexible adaptation to various housing, bearings, and feedback devices. This facilitates high integration of terminal products and reduces their size.

Using a multi-slot, multi-pole design creates high torque density and low cogging torque output for smoother operation. Vacuum potting technology with high thermal conductivity encapsulation resin is used to enhance heat dissipation and reduce temperature rise. They can achieve very high speed and acceleration, making them well-suited for robotics applications where precise positioning and repeatable movements are important.

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Frameless BLDC servo motor rotor and stator assembly

Key Features

check_circleDirect integration - rotor/stator components fit your own housing, bearings, and feedback devices
check_circleLow inertia design for fast acceleration, tight control, and precise positioning
check_circleCustom windings and sizes to match speed, voltage, and torque requirements
check_circleQuiet, smooth operation with low cogging torque from multi-slot, multi-pole design
check_circleHigh torque density - maximum power in the smallest possible footprint
check_circleVacuum potting with high thermal conductivity resin for enhanced heat dissipation
check_circleDurable construction with premium materials for demanding conditions

Specifications

Motor type	Frameless BLDC (inner and outer rotor configurations)
Design	Multi-slot, multi-pole for high torque density and low cogging
Thermal management	Vacuum potting with high thermal conductivity encapsulation resin
Integration	Direct mount into customer housing, bearings, and encoders
Customization	Custom windings, sizes, and voltage/speed/torque profiles

Configuration Options

settingsCustom windings matched to your voltage, speed, and torque profile
settingsInner rotor and outer rotor frameless configurations
settingsIntegration with customer-selected encoders and feedback devices
settingsCustom shaft and mounting interfaces for joint assemblies
settingsPrototype through production volume programs

Applications

Humanoid robots
Collaborative robots (cobots)
Medical surgery and rehabilitation robots
Quadruped robots
Industrial robotic arms
SCARA robots

Outer Rotor Frameless Motor

Outer rotor frameless motors place the magnetic rotor on the outside of the stator, enabling direct integration into joint housings and compact robotic assemblies where the rotating element forms part of the mechanism structure.

Downloads

downloadSEI Frameless Servo Motor Catalog

FAQ

What is a frameless servo motor?: A frameless servo motor consists of only the rotor and stator - no housing, shaft, or bearings. The OEM integrates these components directly into their mechanism, enabling tighter packaging and higher system-level torque density.
Can SEI customize windings for my voltage and speed requirements?: Yes. SEI offers custom windings and sizes to match your exact voltage, speed, and torque profile. Contact our engineering team with your application parameters.