Frameless torque motor
maxon EC frameless DT / HT torque motor
Brushless rotor-and-stator kits for direct integration into robot joints and exoskeletons, in a DT range for dynamics and an HT range for high torque.
Key specifications
| Outer diameter | 38–90 mm |
|---|---|
| Continuous torque (max) | 2.84 Nm |
| Power (max) | 680 W |
Summarised in our own words from maxon group (maxon motor ag)'s published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2
Notes on this data
maxon Product Range 2026/27 catalogue. Nominal torque max 2,840 mNm (DT 85 L). Diameters taken from model designations (DT 38-85, HT 60-90). Power/torque pairing in page text matched by order - check against data sheets. Max speed not published on the overview page.
Specify Motion is not affiliated with maxon group (maxon motor ag). maxon and EC frameless DT / HT are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a maxon part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Compact frameless rotor/stator kits for low-voltage (48 VDC) systems, in 45-90 mm frames with low- and high-speed windings. Suited to small rotary tables and robot joints where the motor is built into the host structure.
| Published maximum | EC frameless DT / HT | ADR-F |
|---|---|---|
| Continuous torque | 2.84 Nm | 3.75 Nm meets or exceeds |
| Peak torque | — | 11.22 Nm |
| Speed | — | 3,000 rpm |
High-voltage (600 VDC) frameless torque motor kits from 110 to 360 mm with large through-bores and integrated Hall sensors; the high-torque end of the Akribis frameless range.
| Published maximum | EC frameless DT / HT | ADR-P |
|---|---|---|
| Continuous torque | 2.84 Nm | 365 Nm meets or exceeds |
| Peak torque | — | 985.5 Nm |
In-runner frameless torque motors from 65 to 410 mm stator OD with 8-64 poles, low profile and large through-holes; windings tailored to target speed.
| Published maximum | EC frameless DT / HT | TI Series In-Runner Frameless Direct D… |
|---|---|---|
| Continuous torque | 2.84 Nm | 70 Nm meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What a frameless torque motor is
A frameless torque motor is a permanent-magnet brushless motor supplied as two parts, a rotor and a stator, with no housing, bearings or shaft. The machine builder mounts the rotor directly on the driven shaft and the stator in the machine structure, so the motor becomes part of the mechanism. Many have large through-holes and high pole counts, giving high torque at low speed with no gearbox. They need separate feedback, typically an encoder, and a servo drive.
When engineers choose a frameless torque motor
Choose a frameless motor when you want direct drive in a compact, integrated design, such as robot joints, gimbals, rotary tables and medical devices. Removing the gearbox eliminates backlash and improves stiffness and smoothness. The trade-offs are integration work and size: the builder supplies bearings, alignment, cooling and feedback, and torque per volume is lower than a geared solution. For off-the-shelf installation, a housed direct-drive motor may be simpler.
How to specify the maxon EC frameless DT / HT
Send these with your enquiry and an engineer can confirm the right EC frameless DT / HT variant or an equivalent:
- Continuous and peak torque (Nm)
- Speed (rpm)
- Outer diameter, bore and stack length (mm)
- Bus voltage and current (V, A)
- Thermal mounting and cooling
- Feedback type and resolution
- Air gap and concentricity tolerance (mm)
Common mistakes to avoid
- Leaving air gap and concentricity tolerances undefined
- Ignoring heat conduction from the stator into the housing
- Using an encoder with too low resolution for direct drive
- Forgetting rotor magnet attraction during assembly
maxon EC frameless DT / HT: frequently asked questions
What is the maxon EC frameless DT / HT?
Brushless rotor-and-stator kits for direct integration into robot joints and exoskeletons, in a DT range for dynamics and an HT range for high torque. Published series figures include outer diameter 38 mm, outer diameter 90 mm, continuous torque 2.84 Nm, power 680 W. It is made by maxon group (maxon motor ag); Specify Motion can help source it or propose an equivalent.
Who makes the maxon EC frameless DT / HT?
The maxon EC frameless DT / HT is made by maxon (maxon group (maxon motor ag)) and is listed here for engineers comparing options. Specify Motion is not affiliated with maxon group (maxon motor ag); brand names are used only to identify the product.
What is the outer diameter of the maxon EC frameless DT / HT?
The published series minimum outer diameter is 38 mm. Individual models and sizes in the EC frameless DT / HT range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the maxon EC frameless DT / HT?
Yes. On published figures, Akribis Systems ADR-F and Akribis Systems ADR-P are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the difference between a frameless and a housed torque motor?
A frameless motor is only a rotor and stator; the machine provides bearings, shaft, housing and feedback. A housed direct-drive motor adds bearings, housing and encoder in a ready-to-install unit. Frameless suits compact, integrated designs where the machine already has stiff bearings; housed suits faster installation and simpler alignment.
Why use a frameless motor instead of a gearbox?
Direct drive removes backlash, wear and compliance in the gear train, giving smoother motion and stiffer control. It also allows a large hollow shaft for cabling. The trade-off is that torque must come from the motor alone, so it is larger for a given torque.
Further reading: How to select a frameless torque motor · Frameless motor sizing robot joints · Frameless and torque motors
Other frameless torque motor series
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