Kollmorgen TBM2G Frameless Servo Motors Review: Specs, Price and Applications
Kollmorgen TBM2G is a frameless brushless servo-motor family for embedding into robotic joints and other custom mechanisms. Seven frame diameters and three stack lengths provide a selection of electromagnetic packages; the finished axis still needs its own bearings, structure, feedback and drive.
Quick Verdict
TBM2G is relevant when a joint designer needs to integrate the motor around the mechanism rather than adapt a housed servo motor. Its selection range supports packaging tradeoffs, but torque, temperature and accuracy must be qualified in the final assembly. The motor alone does not establish collaborative-robot safety or an environmental protection rating.
Kollmorgen TBM2G Frameless Servo Motors at a Glance
Specification | Details |
Construction | Frameless rotor/stator motor components for embedded integration |
Frame sizes | 050, 060, 068, 076, 085, 094 and 115; nominal outer diameters 50–115 mm |
Stack selection | Three stack lengths per frame; multiple winding options |
Design voltage context | Designed for operation at 48 VDC and below |
Thermal sensing | PT1000 and PTC options in the documented family |
Commutation sensing | Optional integrated Hall sensors |
Mechanical integration | Machine designer supplies final bearing, housing and rotor/stator retention arrangement |
Thermal interpretation | Current literature discusses performance below 85°C and continuous winding capability up to 155°C; these are not allowable human-contact temperatures |
Design and Engineering Assessment
A frameless motor changes where the engineering work occurs. Instead of buying a shaft, bearings and enclosure as part of a housed servo, the designer integrates electromagnetic components into the machine. This can shorten an axis and open a central route for cables or other services. It also makes concentricity, retention and bearing support part of the product design. Evaluate those tasks before treating an attractive motor diameter as a complete joint solution.
Frame diameter, stack length and winding selection solve different constraints. A longer stack may alter torque capability and axial packaging, while the winding must match the intended speed, current and bus voltage. Gear ratio, if used, changes motor speed and reflected load; it does not eliminate transmission losses, stiffness or backlash. Size the combined motor/transmission/mechanism against a representative motion cycle, including acceleration, repeated reversals and dwell.
Temperature deserves particular care in robot applications. A winding capability is a material/electromagnetic limit, whereas the accessible joint surface, lubricant, encoder and adjacent electronics have separate limits. Heat travels through the actual stator fit and housing, so an acceptable catalog point does not establish the surface temperature of a custom joint. Verify both steady state and repeated-cycle heating with the final enclosure and cooling conditions.
The current product literature differs from older launch language on thermal figures. Use the current selected winding's documentation and distinguish the low-temperature application goal from the high winding-temperature capability. Neither figure makes the assembly safe for human contact. A collaborative application requires a system-level assessment of motion, force, stopping behavior and the complete installed machine.
Feedback, Commutation and the Final Axis
Optional Hall sensors provide commutation information; they are not a substitute for specifying the position feedback needed by the application. Select the drive, encoder arrangement, wiring and grounding as a complete architecture. If the load is connected through a gearbox or compliant mechanism, consider which motion the sensor actually measures before assigning the motor-side signal to the tool's positioning result.
Commission the assembled mechanism using a controlled low-energy procedure. Confirm direction, sensor phasing, travel limits and expected load behavior before moving to normal operation. A component motor rating is distinct from the accuracy and repeatability of the final axis.
Environmental and Maintenance Boundaries
A frameless motor does not bring the complete environmental enclosure with it. The finished housing, seals, connectors, cooling path and materials determine whether an application can tolerate liquids, dust or cleaning. Do not turn a discussion of embedded-design possibilities into an IP or washdown claim for the bare motor.
Compare service strategies early. A tightly integrated joint may require a different replacement and alignment procedure from a housed motor. Preserve the accepted fit, assembly process, feedback settings and thermal arrangement so a replacement can reproduce the qualified configuration.
Applications and Selection
Embedded robotic joints, medical mechanisms and other compact custom axes where the designer can engineer the mechanical support, thermal path and control integration.
For Kollmorgen TBM2G Frameless Servo Motors, define the actual machine duty before selecting an ordering configuration. Include the required operating point, available installation space, environment and control interfaces. The specification table describes the product or family; the surrounding machine determines which of those features matters for the intended job.
Price and Value
Price: Request a quote for the exact configuration. Compare the product, compatible control equipment, required mechanical parts, cabling and commissioning as one installed system. A component price alone does not represent the cost of a working automation axis.
Evaluate an alternative against the same duty and acceptance criteria. Match the continuous operating requirement first, then compare transient capability, feedback, mechanical fit and support. This avoids choosing between superficially similar products whose ratings describe different operating conditions.
Pros and Cons
Advantages
Seven frame sizes and multiple stack/winding selections support custom joint packaging
Frameless arrangement allows the motor to be integrated around the mechanism
Thermal and optional Hall sensor choices support a planned drive interface
Limitations
Requires complete bearing, housing, retention and thermal engineering
Winding temperature capability does not establish safe contact temperature
Axis accuracy, environmental sealing and collaborative safety belong to the complete system
Who Should Consider Kollmorgen TBM2G Frameless Servo Motors?
Consider Kollmorgen TBM2G Frameless Servo Motors for embedded robotic joints, medical mechanisms and other compact custom axes where the designer can engineer the mechanical support, thermal path and control integration. Establish the required operating point and installation interfaces before choosing the configuration, and use a representative loaded cycle as the acceptance basis.
Kollmorgen TBM2G Frameless Servo Motors FAQ
Is TBM2G a complete robotic joint?
No. It is a frameless motor family. Bearings, housing, mechanical retention, feedback, drive and the remaining joint components must be selected and qualified as a complete axis.
How many frame sizes are offered?
The documented range comprises seven frame sizes, with three stack selections per frame and multiple winding options. Choose the exact electromagnetic and sensor configuration rather than treating the family as one motor.
Does a frameless motor necessarily mean direct drive?
No. Frameless describes the integration format. The machine designer may use an appropriate transmission or direct coupling; torque, speed, stiffness and positioning analysis must reflect the chosen arrangement.
Do Hall sensors provide the final joint's positioning accuracy?
Optional Hall sensors support commutation. The final positioning requirement needs a suitable feedback arrangement, and motor-side sensing must be interpreted alongside any gearbox or compliant mechanism.
Does the winding-temperature figure mean the housing is safe to touch?
No. Winding and accessible-surface temperatures are different quantities. Validate heat flow and surface conditions in the finished joint against the application's actual limits.
Is a collaborative robot automatically safe when it uses TBM2G?
No. Collaborative safety depends on the complete machine, application, control functions and risk assessment. Selecting this motor does not establish compliance for a robot or installed cell.
What is the price?
Request a quote for the exact frame, stack, winding and sensing configuration. Compare the motor together with the drive, feedback, mechanical assembly, cooling and qualification effort.
What should be compared with a housed servo motor?
Compare the same loaded motion cycle, installation space, thermal conditions and service requirements. A frameless solution offers integration freedom, while a housed motor may simplify mechanical support and replacement.
Prices are indicative and may change. Confirm the final configuration, commercial terms and delivery schedule before ordering.
