Rexroth 3‑Phase Synchronous PM Motors – Series Overview & Replacement

Wake Industrial is your prime source for obtaining refurbished synchronous PM motors and expert repairs, ensuring minimal downtime for your production line. Call 1-919-443-0207 to speak with our qualified sales technicians and get a competitive quote quick. Bosch Rexroth (formerly Indramat) 3‑phase synchronous PM motors are high-performance AC servo motors energized by permanent magnets. They serve as the muscle of CNC machines, robotics, printing presses, packaging lines, and other automated systems, delivering precise motion control with high torque and speed. This guide provides a technically detailed overview of the key Rexroth synchronous motor series including their specifications and features.

MDD Series – Indramat Synchronous Motors (Legacy)

The MDD series was one of Indramat’s early digital AC servo motor lines. MDD motors are 3‑phase permanent magnet synchronous motors built for industrial tasks that demand speed, power, and accuracy. They were commonly used in machine tools, printing machines, textile equipment, robotics, and packaging systems throughout the 1990s. Key characteristics of the MDD series include integrated motor feedback for precise position and speed control, and durable IP65-rated housing for protection in harsh factory environments. The MDD family spans nine motor frame sizes with varying torque and speed ratings to suit different applications. For example, smaller MDD models like the MDD025B-N-100-N2K-040PB1 deliver lower torque for light-duty axes, while larger frames such as the MDD093C-N-020-N2L-110PB0 can provide continuous stall torques on the order of tens of Nm and nominal speeds of a few thousand RPM. These brushless servos are maintenance-free aside from occasional feedback device checks, and their lubricated bearings are built to last the motor’s lifetime.

If you have an aging MDD motor that has failed, finding a direct new replacement can be challenging since they are legacy products. This is where Wake Industrial comes in – they specialize in legacy Rexroth/Indramat servo motors. Wake Industrial offers fully tested refurbished MDD motors and can repair your existing unit, providing a cost-effective alternative to an OEM exchange. To get your MDD serviced or replaced fill out the quote form embedded on this page or email sales@wakeindustrial.com to receive a comprehensive, competitive quote within 15 minutes during business hours.

MHD Series – Legacy High-Torque Synchronous Motors

The MHD series is another Indramat legacy line of 3-phase synchronous PM motors known for higher torque capacities and robust design. Rexroth Indramat MHD motors feature electronic commutation and were offered in a wide range of configurations. They were widely deployed in applications such as large printing presses, packaging machines, and textile machinery. An advantage of the MHD motors is their sealed, maintenance-free construction – the housing is fully sealed (IP65) and the internal bearings are grease-lubricated for life. This means MHD motors can operate for years without requiring internal maintenance.

The MHD series comes in eight frame sizes – 041, 071, 090, 093, 095, 112, 115, and 131 – covering a broad torque spectrum for different power requirements. Smaller MHD motors like the  MHD041B-144-NG0-UN provide continuous stall torques on the order of 1–10 Nm (with high maximum speeds up to ~7500 RPM in some variants), while the largest frame like an MHD131B-024-NG1-AN can deliver very high torque (well above 50 Nm continuous, with peaks over 100 Nm depending on winding) for heavy industrial axes. Many models could be ordered with either natural convection cooling or optional forced-air or liquid cooling to increase their output capability. In short, MHD motors are workhorses that can deliver high torques and withstand rigorous duty cycles.

Although the MHD series is considered a legacy product today, many machines still rely on these motors. Wake Industrial supports MHD motor replacement and repair – they have access to the full line of MHD models and can refurbish units with issues. Their expert staff can assist in identifying a compatible replacement motor or repair solution, ensuring your older equipment keeps running without the need for a complete control system overhaul. With quick turnaround on repairs and a stock of popular MHD part numbers, Wake Industrial is a prime resource for keeping legacy Rexroth motors in service. To learn how Wake Industrial can support your MHD call 1-919-443-0207 or fill out the quote form on the page.

MKD Series – Versatile Digital AC Servo Motors

Bosch Rexroth Indramat MKD series motors are digital 3‑phase synchronous servo motors designed for use with intelligent drives (such as Indramat DKC or DDS controllers). In conjunction with Rexroth’s digital drive controllers, MKD motors offer cost-effective automation solutions with extensive functionality across many industries. They are found in machine tools, printing and packaging machines, materials handling systems, and even food processing lines. The MKD series is prized for its high reliability and longevity – these motors can run continuously with minimal downtime, and they exhibit a wide constant-torque speed range for flexible operation. Installation and integration are straightforward, as MKD motors were designed with standardized mounting interfaces and plug-and-play feedback cables.

One hallmark of the MKD series is the variety of configurations available to tailor the motor to the application. Notable features and options of Rexroth MKD motors include:

• Frame Sizes: Available in frame size codes from 025 up to 112. For instance, the smallest MKD025B-144-GG0-KN has a 54 mm flange, while the largest MKD112D-027-GG3-BN features a 192 mm flange – covering a broad range of torque outputs.
• Stack Lengths: Each frame size can come in multiple length designations (A, B, C, or D), offering different continuous torque ratings. This allows fine-tuning of motor torque and inertia to the machine’s needs.
• Winding Variants: Several winding code options per frame for different base speeds (e.g. high-speed vs high-torque windings).
• Feedback Options: Either a resolver for commutation and basic feedback or high-resolution digital servo feedback with an integrated multi-turn absolute encoder for precise positioning.
• Shaft & Brake: Choice of output shaft style (plain or keyed) and the option of an integrated holding brake for safe load holding at standstill. The power connectors can be oriented differently (axial or radial) to fit tight installation spaces.

These features made the MKD series incredibly versatile and popular. If you need to replace or fix an MKD motor, Wake Industrial has you covered – they stock a full range of MKD motors and can provide replacements quickly. Whether your MKD motor has a faulty encoder, burned windings, or other issues, Wake’s technicians can repair it or supply a tested refurbished unit. With their 1-year warranty and rigorous testing, you can trust that a replacement MKD from Wake Industrial will perform reliably in your system. Contact Wake Industrial now by calling  1-919-443-0207 or emailing sales@wakeindustrial.com

MSK Series – IndraDyn S High-Power Servo Motors

The MSK IndraDyn S motors represents a more modern line of 3-phase synchronous PM motors, introduced to work with the IndraDrive family of digital drives. MSK servo motors like the MSK030B-0900-NN-M1-UG0-NNNN are considered “workhorse” or all-rounder motors in the Rexroth lineup. They offer a very broad power and torque range in finely graduated sizes, all in a compact design thanks to high torque density technology. MSK motors were engineered for versatility – from handling tasks requiring only a few Nm of torque to demanding applications needing hundreds of Nm, there's an MSK model that fits. In fact, the MSK series covers continuous torque ratings roughly from 4 Nm up to ~130 Nm, with peak torques reaching 3–4× nominal, and maximum speeds ranging from around 3,200 RPM for larger motors up to 9,000 RPM for smaller ones. This makes IndraDyn S motors suitable for everything from precision pick-and-place robots to heavy automotive manufacturing equipment.

A key strength of MSK motors is their precision. They come standard with high-resolution encoders, enabling excellent positioning accuracy and repeatability for fine motion control tasks. Various encoder options are available to match the application’s feedback requirements.

Another advantage is that MSK motors seamlessly integrate with Rexroth IndraDrive servo drives, leveraging advanced features like electronic nameplate recognition, sophisticated servo tuning, and safety functions. In practice, MSK motors are used in diverse industries: packaging lines, printing machines, injection molding, metal forming, and more, where their combination of high torque in a small package and dynamic response improves machine throughput and accuracy.

If an MSK motor in your system needs replacement or repair, Wake Industrial can assist. They carry the full line of MSK IndraDyn S motors and can rapidly provide a matching unit for your needs. Wake Industrial’s team is experienced with the MSK series and can repair issues such as encoder faults, winding damage, or bearing wear. By sourcing your MSK servo motors through Wake Industrial you can avoid the long lead times that might come with ordering brand-new from the OEM, and still get a high-quality, tested component backed by warranty. Secure the Wake Industrial advantage today by calling 1-919-443-0207 to get a quick quote for your MSK.

MSM Series – IndraDyn S Compact Servo Motors

The MSM series is essentially the smaller sibling in the IndraDyn S family, featuring compact synchronous servo motors for lower power applications. Rexroth/Indramat MSM motors such as the MSM030B-0300-NN-C0-CC0 are designed with space-saving and cost-efficiency in mind – they have a very short length and small flange size yet still provide excellent dynamic response and positioning accuracy. These motors typically handle continuous power up to about 0.75 kW and deliver maximum torques from roughly 0.95 Nm up to 7 Nm, depending on the frame size. This makes the MSM series ideal for light automation tasks, such as small pick-and-place units, electronics assembly machines, lab automation devices, or any machinery where installation space is limited and only a few Newton-meters of torque are required.

Despite their small size, MSM motors don’t skimp on features. They come equipped with optical single-turn or multi-turn absolute encoders for high precision feedback. The mechanical design uses a friction-locked shaft-hub connection without backlash, ensuring very smooth, cog-free rotation even at low speeds. MSM motors are typically self-cooled by natural which simplifies their design and reduces maintenance. Their power and encoder cables use quick-connect bayonet locks for easy installation and replacement.

In practical terms, the MSM series is often run from 3×230 VAC supplies. The compact size and lower voltage make them very convenient for OEMs building modular equipment. If you have an MSM motor that has failed you can rely on Wake Industrial to find a suitable replacement MSM motor or fix the issue. Given the MSM’s role in high-throughput machinery, a fast turnaround is crucial. Wake Industrial’s inventory of IndraDyn S motors and their repair capabilities mean you can get your machine back online quickly, avoiding costly delays.

MKE Series – Explosion-Proof Synchronous Motors (ATEX)

The MKE series motors are Bosch Rexroth’s 3-phase synchronous PM servo motors purpose-built for hazardous environments. They are designed to meet strict ATEX and UL/CSA standards for use in explosive atmospheres – for example, in paint booths chemical processing, grain handling, or oil & gas facilities. The MKE series combines the high performance of a Rexroth servo motor with special safety measures such as flameproof enclosures and encapsulated windings to prevent any spark or heat from igniting surrounding gases or dust. With these certifications, a single MKE motor like the MKE047B-144-KG1-BUNN can be deployed worldwide in hazardous locations without modification.

Even with their special safety features, MKE motors deliver comparable performance to standard servos. They cover a wide torque range roughly from 4 Nm up to 187 Nm, with maximum speeds between 4,500 and 9,000 RPM depending on model. This means even heavy-duty tasks in explosive atmospheres can use an MKE servo solution. The MKE motors are built to be maintenance-free, utilizing a brushless design and lifetime-lubricated bearings just like their standard counterparts. They also have a high overload capacity, aided by efficient heat dissipation from stator windings to the housing – a critical feature because in explosion-proof designs the motors often rely on conduction cooling Optional features for MKE include holding brakes, keyway shafts, and a selection of feedback encoders, so they can mirror the functionality of standard motors while remaining safe for hazardous zones.

If you need to replace an MKE motor or require a repair, Wake Industrial can assist as a reliable source. They understand the urgency and regulatory importance of maintaining ATEX-rated equipment. Wake Industrial can supply refurbished MKE series motors that meet the original specs and certifications or facilitate repairs with proper handling to preserve the motor’s explosion-proof integrity. By obtaining your MKE replacement through Wake Industrial, you ensure that you’re getting a genuine Rexroth unit that’s been fully checked for safety compliance.

Wake Industrial – Your Partner for Rexroth Motor Repair & Replacement

When dealing with Bosch Rexroth Indramat servo motors – whether it’s the legacy MDD/MKD/MHD units or the newer MSK/MSM/MKE series – Wake Industrial stands out as a premier resource for repair and replacement. Wake Industrial is a company that specializes in industrial automation components, with a strong focus on Bosch Rexroth products. Here are a few reasons to consider Wake Industrial for your motor needs:

Comprehensive Inventory 
Wake Industrial maintains a broad stock of Rexroth servo motors and drives, including hard-to-find legacy models and the full line of current series. This means you can often get a replacement motor faster than ordering from the OEM, reducing your machine downtime.

Expert Repair Services
The company offers in-house repair services for all the motor series discussed. Their technicians are familiar with common failure modes (feedback errors, winding shorts, bearing failures, etc.) and use genuine parts to refurbish motors. Every repaired motor is fully tested to ensure it meets factory performance before return.

Quality Assurance 
All products and repairs come with a 1-year warranty, giving you peace of mind that your investment is protected. Wake Industrial’s proven track record and customer testimonials speak to their commitment to quality and customer satisfaction.

Fast Quotes & Shipping
Understanding that time is money in industrial operations, Wake Industrial provides quick turnaround on quotes (often within 15 minutes during business hours). They also offer flexible shipping options worldwide, so you can receive your motor or repaired unit as quickly as needed – including expedited and international shipping.