Lenze MDS Servo Motor Modules

Technical Dossier

Product Details And Specifications

Lenze MDS Servo Motor Series: Comprehensive Module Range and Technical Overview

The Lenze MDS servo motor series represents one of the most widely deployed servo drive platforms in European and global heavy industry. Installed across chemical processing plants, nuclear auxiliary systems, oil refineries, paper mills, and automated packaging lines, the MDS family has accumulated decades of field-proven reliability in continuous-duty, high-dynamic-response applications. The series covers synchronous and asynchronous servo motor variants, spanning frame sizes from compact inline configurations to high-torque flange-mount designs. Its integration with Lenze's 9300 and ECS servo inverter families made it a default specification in OEM machine builds throughout the 1990s and 2000s, resulting in a large installed base that continues to require spare parts and replacement units today.

The Evolution of MDS Series Architecture

The MDS servo motor line was introduced by Lenze as a companion drive element to their modular servo inverter platforms. Early variants were designed around resolver feedback systems, providing closed-loop position and velocity control compatible with the Lenze 9300 servo inverter range. As the platform matured, encoder-based feedback options (incremental and absolute EnDat/SSI) were introduced to meet higher precision requirements in CNC and robotics applications.

The series branched into distinct sub-families: MDSK (compact synchronous servo motors with keyway shaft), MDSRS (synchronous motors with resolver feedback, smooth shaft), MDSS (synchronous, high-inertia variants for high-dynamic applications), and MDSM (medium-frame asynchronous servo motors). Mechanical interface standards evolved from early DIN flange configurations to IEC 72-compliant mounting, improving cross-compatibility with third-party gearboxes.

By the mid-2010s, Lenze transitioned its primary servo motor portfolio toward the MCS and MCA series, positioning MDS as a mature/legacy platform. However, the MDS series remains in active service across thousands of installed machines globally, and Lenze-authorized service partners continue to support it. Replacement and repair sourcing has shifted significantly to specialist distributors capable of cross-referencing obsolete part numbers.

MDS Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced models within the Lenze MDS servo motor family, organized by sub-series and feedback type:

MDSK Sub-Series — Compact Synchronous, Keyway Shaft

• MDSKSRS036-13: Synchronous servo motor, 0.36 Nm rated torque, resolver feedback, size 36 frame, single-ended shaft
• MDSKSRS056-13: Synchronous servo motor, 0.56 Nm rated torque, resolver feedback, size 56 frame, keyway shaft
• MDSKSRS071-13: Synchronous servo motor, 0.71 Nm rated torque, resolver feedback, size 71 frame, standard flange
• MDSKSRS100-13: Synchronous servo motor, 1.0 Nm rated torque, resolver feedback, size 100 frame, IEC flange mount
• MDSKSRS140-13: Synchronous servo motor, 1.4 Nm rated torque, resolver feedback, size 140 frame, high-speed winding
• MDSKSRS200-13: Synchronous servo motor, 2.0 Nm rated torque, resolver feedback, size 200 frame, IP65 protection class

MDSRS Sub-Series — Synchronous, Resolver Feedback, Smooth Shaft

• MDSRSRS036-13: Synchronous servo, smooth shaft, resolver, 0.36 Nm, compact inline design for space-constrained axes
• MDSRSRS056-13: Synchronous servo, smooth shaft, resolver, 0.56 Nm, standard for Lenze 9300 servo inverter pairing
• MDSRSRS071-13: Synchronous servo, smooth shaft, resolver, 0.71 Nm, suitable for multi-axis gantry systems
• MDSRSRS100-13: Synchronous servo, smooth shaft, resolver, 1.0 Nm, common in packaging OEM builds

MDSS Sub-Series — High-Inertia Synchronous Variants

• MDSSRS056-13: High-inertia synchronous servo, 0.56 Nm, resolver, optimized for load-matching in high-mass axis applications
• MDSSRS071-13: High-inertia synchronous servo, 0.71 Nm, resolver, used in winding and unwinding tension-control axes
• MDSSRS100-13: High-inertia synchronous servo, 1.0 Nm, resolver, standard in printing and converting machine axes

MDSM Sub-Series — Asynchronous Servo Motors

• MDSMRS071-13: Asynchronous servo motor, 0.71 Nm, resolver feedback, suitable for variable-speed spindle and feed axes
• MDSMRS100-13: Asynchronous servo motor, 1.0 Nm, resolver feedback, used in legacy Lenze ECS inverter installations
• MDSMRS140-13: Asynchronous servo motor, 1.4 Nm, resolver feedback, high-duty-cycle rated for continuous industrial operation

Sourcing Hard-to-Find & Obsolete MDS Series Parts

The Lenze MDS series entered end-of-production status for most variants, with Lenze's primary support focus now directed toward the MCS/MCA platform. This creates a sourcing gap for plant operators running MDS-based machines who require like-for-like replacements without undertaking full drive system retrofits.

DriveKNMS maintains a dedicated inventory of MDS series servo motors sourced from decommissioned OEM equipment, authorized surplus channels, and factory-refurbished stock. Each unit is cross-referenced against Lenze's original part numbering schema to ensure correct frame size, winding specification, feedback type, and shaft configuration. For applications where an exact MDS replacement is unavailable, DriveKNMS provides cross-reference engineering support to identify compatible MCS or third-party equivalents with matching electrical and mechanical parameters.

Quality Control for the MDS Series Range

Lenze MDS servo motors present specific test requirements due to their resolver-based feedback architecture and precision winding configurations. DriveKNMS applies the following verification procedures to all MDS units prior to dispatch:

• Resolver excitation and output signal test: Verified against Lenze reference specifications for sin/cos amplitude balance and phase accuracy, using a dedicated resolver analyzer.
• Winding resistance and insulation test: Each phase winding measured for resistance symmetry; insulation resistance tested at 500 VDC to IEC 60034-1 standards.
• No-load run test: Motor operated at rated speed on a compatible Lenze 9300 or ECS test inverter to verify smooth rotation, absence of bearing noise, and correct back-EMF output.
• Shaft runout and bearing play measurement: Mechanical inspection using dial gauge to confirm shaft concentricity within OEM tolerance.
• Thermal class verification: Winding insulation class confirmed against nameplate data (Class F or H depending on variant).
• Encoder/feedback connector integrity check: Resolver connector pins inspected for corrosion, continuity verified on all signal lines.

All test results are documented and available upon request with each unit shipment.