Frameless torque motor
TQ-RoboDrive ILM Servo-Kits frameless torque motor
Premium frameless torque motor kits (stator and rotor) with DLR-derived design, from 25 mm (ILM25x04) to 115 mm (ILM115x25) stator diameter: up to 3.9 Nm nominal, 12.7 Nm peak and 570 W at 48 V, with up to 93% efficiency.
Key specifications
| Voltage (max) | 48 V |
|---|---|
| Outer diameter | 25–115 mm |
| Inner diameter (max) | 74 mm |
| Peak torque (max) | 12.7 Nm |
| Continuous torque (max) | 3.9 Nm |
| Speed (max) | 22,378 rpm |
| Power (max) | 570 W |
| Supply | 24 V or 48 V nominal by size |
| Weight | 1,070 g |
| Efficiency | up to 93% |
| Models | ILM25x04/x08/x18, ILM38x06/x12, ILM50x08/x14, ILM70x10/x18, ILM85x04/x13/x23/x26, ILM115x25 |
Summarised in our own words from TQ-Systems GmbH (TQ-Group)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2 · Source 3
Notes on this data
Values for star-serial interconnection. speed_rpm_max is the ILM25x04 nominal speed; weight_g and id_mm_max are the ILM115x25. Temperature sensor supplied as standard.
Specify Motion is not affiliated with TQ-Systems GmbH (TQ-Group). TQ-RoboDrive and ILM Servo-Kits 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 TQ-RoboDrive 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.
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 | ILM Servo-Kits | ADR-P |
|---|---|---|
| Continuous torque | 3.9 Nm | 365 Nm meets or exceeds |
| Peak torque | 12.7 Nm | 985.5 Nm meets or exceeds |
| Speed | 22,378 rpm | — |
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 | ILM Servo-Kits | TI Series In-Runner Frameless Direct D… |
|---|---|---|
| Continuous torque | 3.9 Nm | 70 Nm meets or exceeds |
| Peak torque | 12.7 Nm | — |
| Speed | 22,378 rpm | — |
Housed iron-core direct drive rotary motors with bearings and optical encoder, 110-360 mm frames, up to about 1 kNm peak at 600 VDC.
| Published maximum | ILM Servo-Kits | ADR-A |
|---|---|---|
| Continuous torque | 3.9 Nm | 407.2 Nm meets or exceeds |
| Peak torque | 12.7 Nm | 1,017.9 Nm meets or exceeds |
| Speed | 22,378 rpm | 2,000 rpm |
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 TQ-RoboDrive ILM Servo-Kits
Send these with your enquiry and an engineer can confirm the right ILM Servo-Kits 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
TQ-RoboDrive ILM Servo-Kits: frequently asked questions
What is the TQ-RoboDrive ILM Servo-Kits?
Premium frameless torque motor kits (stator and rotor) with DLR-derived design, from 25 mm (ILM25x04) to 115 mm (ILM115x25) stator diameter: up to 3.9 Nm nominal, 12.7 Nm peak and 570 W at 48 V, with up to 93% efficiency. Published series figures include voltage 48 V, outer diameter 25 mm, outer diameter 115 mm, inner diameter 74 mm. It is made by TQ-Systems GmbH (TQ-Group); Specify Motion can help source it or propose an equivalent.
Who makes the TQ-RoboDrive ILM Servo-Kits?
The TQ-RoboDrive ILM Servo-Kits is made by TQ-RoboDrive (TQ-Systems GmbH (TQ-Group)) and is listed here for engineers comparing options. Specify Motion is not affiliated with TQ-Systems GmbH (TQ-Group); brand names are used only to identify the product.
What is the voltage of the TQ-RoboDrive ILM Servo-Kits?
The published series maximum voltage is 48 V. Individual models and sizes in the ILM Servo-Kits 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 TQ-RoboDrive ILM Servo-Kits?
Yes. On published figures, Akribis Systems ADR-P and TI Series In-Runner Frameless Direct Drive Torque Motors 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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