Frameless torque motor
Schaeffler RIB torque motors (IDAM)
Slotted internal-rotor frameless torque motors with diameters up to 1,030 mm and peak torque up to 40,000 Nm, designed for water-jacket cooling at a 600 V DC link.
Key specifications
| Voltage (max) | 600 V |
|---|---|
| Outer diameter (max) | 1,030 mm |
| Peak torque (max) | 40,000 Nm |
| Cooling | Liquid jacket (water) cooling |
Summarised in our own words from Schaeffler AG's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Notes on this data
Circumferential speed limit up to 10 m/s for RIB; rpm limits are in the product tables (not read). voltage_V_max = typical DC link 600 V.
Specify Motion is not affiliated with Schaeffler AG. Schaeffler and RIB torque motors (IDAM) 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 Schaeffler part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These series from our supply network is the closest match on published figures.
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.
View series →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 Schaeffler RIB torque motors (IDAM)
Send these with your enquiry and an engineer can confirm the right RIB torque motors (IDAM) 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
Schaeffler RIB torque motors (IDAM): frequently asked questions
What is the Schaeffler RIB torque motors (IDAM)?
Slotted internal-rotor frameless torque motors with diameters up to 1,030 mm and peak torque up to 40,000 Nm, designed for water-jacket cooling at a 600 V DC link. Published series figures include voltage 600 V, outer diameter 1,030 mm, peak torque 40,000 Nm. It is made by Schaeffler AG; Specify Motion can help source it or propose an equivalent.
Who makes the Schaeffler RIB torque motors (IDAM)?
The Schaeffler RIB torque motors (IDAM) is made by Schaeffler (Schaeffler AG) and is listed here for engineers comparing options. Specify Motion is not affiliated with Schaeffler AG; brand names are used only to identify the product.
What is the voltage of the Schaeffler RIB torque motors (IDAM)?
The published series maximum voltage is 600 V. Individual models and sizes in the RIB torque motors (IDAM) 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 Schaeffler RIB torque motors (IDAM)?
Yes. On published figures, TI Series In-Runner Frameless Direct Drive Torque Motors is 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
Spec builder
Specify what you need instead of RIB torque motors (IDAM)
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Let our experienced engineers do the hard work for you
Tell us how you use the Schaeffler RIB torque motors (IDAM): the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.