The Rexroth R911310891 MSK101E-0300-NN-M1-AG2-NNNN is a high-performance synchronous servo motor from the Rexroth IndraDyn S MSK family, built for precision motion control in demanding industrial environments. This exact order number corresponds to an MSK101 frame motor with E length, 0300 winding, natural convection cooling, a multiturn optical Hiperface encoder, an A-side electrical connection, a smooth shaft with shaft sealing ring, and a holding brake. In practical use, it is the kind of servo motor selected for machines that need high torque density, dependable positional feedback, and stable operation under repeated acceleration and deceleration cycles.
Product Snapshot
| Item | Description |
|---|---|
| Brand | Rexroth |
| Order Number | R911310891 |
| Full Model | MSK101E-0300-NN-M1-AG2-NNNN |
| Product Family | IndraDyn S MSK |
| Product Type | Synchronous servo motor |
| Cooling Mode | Natural convection |
| Encoder Type | Optical multiturn Hiperface, 128 signal periods |
| Electrical Connection | Connector on A-side |
| Shaft Version | Smooth shaft with shaft sealing ring |
| Holding Brake | Holding brake 2 |
| Holding Torque | 70 Nm |
| Maximum Speed | 4600 min-1 |
| Maximum Torque | 231 Nm |
| Degree of Protection | IP65 |
| Insulation Class | 155 |
| Net Weight | 57.3 kg |
The identification and configuration above are based on the exact R911310891 listing plus Rexroth’s official MSK type-code and technical-data documents. The brake torque of holding brake 2 is listed as 70 Nm in the MSK101 technical section, while the encoder, electrical connection, shaft, and brake logic are defined in the Rexroth operating and type-code documentation.
How to Read the Exact Model Code
| Code Element | Meaning |
|---|---|
| MSK | IndraDyn S synchronous servomotor series |
| 101 | Motor frame size 101 |
| E | Frame length E |
| 0300 | Winding code 0300 |
| NN | Natural convection cooling |
| M1 | Optical multiturn absolute Hiperface encoder, 128 signal periods |
| A | Electrical connector on A-side |
| G | Smooth shaft with shaft sealing ring |
| 2 | With holding brake, brake option 2 |
| NNNN | Standard design |
This type-code breakdown matters because servo motors are rarely interchangeable by appearance alone. In real procurement and maintenance work, the frame size, winding, encoder, shaft style, brake option, and connector position all affect compatibility. A machine may accept only one narrow combination of feedback system, mounting style, and brake arrangement, so using the full code R911310891 MSK101E-0300-NN-M1-AG2-NNNN is the safest way to avoid ordering mistakes. Rexroth’s own documentation states that the type code is the basis for every order and uniquely describes the motor variant.
Main Technical Data
| Parameter | Value |
|---|---|
| Continuous torque at standstill, 60 K | 70.0 Nm |
| Continuous current at standstill, 60 K | 41.6 A |
| Continuous torque at standstill, 100 K | 80.5 Nm |
| Continuous current at standstill, 100 K | 47.8 A |
| Maximum torque | 231.0 Nm |
| Maximum current | 187.4 A |
| Torque constant at 20 °C | 1.85 Nm/A |
| Voltage constant at 20 °C | 113.8 V/1000 min-1 |
| Winding resistance at 20 °C | 0.11 ohms |
| Winding inductivity | 1.60 mH |
| Number of pole pairs | 4 |
| Rotor inertia | 0.01380 kg*m2 |
| Thermal time constant | 100.0 min |
| Maximum speed | 4600 min-1 |
| Sound pressure level | < 75 dB(A) |
| Operating temperature | 0 to 40 °C |
| Degree of protection | IP65 |
| Insulation class | 155 |
The values above come from Rexroth’s official MSK101E-0300-NN technical-data table. These figures place the motor in the heavy-duty end of the MSK platform, with clearly higher torque and current demand than the smaller 050, 060, or 061 frame motors. For engineering and commercial content alike, those are the figures that define the real performance identity of this model.
Weight Statement and Why It Needs a Note
For this exact AG2 configuration, the most defensible working weight is approximately 57.3 kg. The official MSK101E-0300-NN technical page lists 53.5 kg for the base motor and then notes higher values for versions equipped with holding brakes, ordered by brake option. Since the code AG2 explicitly includes holding brake 2, the brake-equipped figure is the correct reference for a more exact commercial description. Some reseller pages still list 53.5 kg for R911310891 because they appear to reuse the base-motor platform weight rather than the brake-equipped configuration.
That distinction is not trivial. Weight affects freight estimates, lifting methods during installation, mounting structure checks, packaging decisions, and the credibility of a product page. In industrial purchasing, buyers often compare the website description against nameplate data, installation documents, and known platform specifications. For that reason, using “approx. 57.3 kg” is more careful than presenting 53.5 kg as a fixed final number for the AG2 brake-equipped motor.
Why This Servo Motor Is Technically Valuable
The MSK101E-0300-NN-M1-AG2-NNNN is not a light servo for small indexing tasks. It is a larger-frame synchronous motor intended for industrial axes that require meaningful continuous torque, strong peak torque, and reliable feedback over repeated duty cycles. A continuous standstill torque of 70.0 Nm at 60 K and 80.5 Nm at 100 K means the motor can sustain serious static and low-speed load conditions without being limited to short intermittent peaks only. The maximum torque of 231.0 Nm gives it the overload reserve needed for acceleration events, transient process resistance, and dynamic correction under changing machine load.
The M1 encoder variant is a strong point in this model. Rexroth defines M1 as an optical multiturn Hiperface encoder with 128 signal periods, and its documentation states that multiturn encoder variants preserve absolute position information across multiple mechanical rotations. In application terms, that helps reduce dependence on repeated homing and improves restart behavior after power interruptions, which is especially useful in machines where reference recovery time directly affects uptime.
The AG2 combination is equally significant. The A-side connector layout can matter in real machine packaging, because cable routing space is often tight and fixed by the mechanical design. The G shaft version means a smooth shaft with shaft sealing ring, which is commonly selected where the driven coupling is designed around a plain shaft rather than a keyed transmission arrangement. The “2” brake option adds a 70 Nm holding brake, which makes this motor more appropriate for applications where load retention at standstill is important. Rexroth also states that the holding brake is electrically released and that it is not intended to function as a service brake for personnel protection, which is an important engineering distinction.
Typical Industrial Use Cases
| Application Area | Why This Model Fits |
|---|---|
| Packaging machinery | High torque reserve and repeatable axis control |
| Material handling systems | Strong standstill torque and multiturn feedback |
| Transfer and positioning axes | Stable positional control over repeated cycles |
| Machine tools and process machinery | High peak torque with precise servo response |
| Heavy automation modules | Suitable for larger moving masses and dynamic loads |
| Retrofit and spare-parts replacement | Exact code supports correct matching in installed systems |
This motor is best suited to applications where the axis is too demanding for a compact servo but does not justify moving into a completely different motor architecture. In that middle-to-heavy industrial range, the MSK101E-0300-NN-M1-AG2-NNNN offers a useful mix of torque, control quality, and configuration clarity. Its IP65 protection and insulation class 155 also support operation in realistic factory conditions rather than only in protected laboratory-style environments.
Buying, Replacement, and SEO Relevance
From a commercial standpoint, this exact order number is the keyword that matters most. Industrial buyers rarely search only for “Rexroth servo motor.” They usually search full strings such as “R911310891,” “MSK101E-0300-NN-M1-AG2-NNNN,” “MSK101E 231 Nm,” or “Rexroth MSK101E multiturn Hiperface servo motor.” A good product page should therefore include the exact order number, full model code, technical table, brake and encoder explanation, and a realistic weight statement. That structure is better for search indexing and also more useful for engineers, buyers, and maintenance personnel comparing candidate replacements.
Thin pages built only around repeated keywords usually perform poorly with technical buyers because they do not resolve the actual purchase question: “Is this the exact motor I need?” By contrast, a page that clearly explains what the code means, what the motor can do, and what the configuration includes is more likely to convert qualified industrial traffic. That is especially true for a model like this one, where a brake option, shaft style, encoder type, and connector position all materially affect interchangeability.
Conclusion
The Rexroth R911310891 MSK101E-0300-NN-M1-AG2-NNNN is a large-frame IndraDyn S synchronous servo motor built for serious industrial motion control. Its official platform data show 70.0 Nm continuous standstill torque at 60 K, 80.5 Nm at 100 K, 231.0 Nm maximum torque, 4600 min-1 maximum speed, IP65 protection, and insulation class 155. The exact configuration adds an optical multiturn Hiperface encoder, A-side electrical connection, smooth shaft with sealing ring, and holding brake 2 with 70 Nm brake torque. For the brake-equipped AG2 version, the most careful working weight is approximately 57.3 kg. Taken together, these characteristics make it a strong choice for OEM integration, industrial spare-parts supply, and exact replacement demand where configuration accuracy matters as much as raw performance.
