Yaskawa SGMRS-20A2A-YR22 SGMPH-04A1A-YR13 HW9381465-F AC Servo Motor & Speed Reducer – Obsolete Motoman Spare Part

Technical Dossier

Product Details And Specifications

Yaskawa SGMRS-20A2A-YR22 SGMPH-04A1A-YR13 HW9381465-F AC Servo Motor & Speed Reducer – Obsolete Motoman Spare Part

When the L-axis drive assembly on a Yaskawa Motoman robot fails, the production line does not pause politely. It stops. For facilities still operating legacy Motoman UP, SK, or UP6 series robots, the SGMRS-20A2A-YR22 servo motor paired with the SGMPH-04A1A-YR13 reducer and HW9381465-F mechanical interface is the exact assembly that keeps the arm moving. Yaskawa has long discontinued this configuration. OEM replacement channels are closed. The alternative — a full robot cell upgrade — carries a capital expenditure that routinely exceeds USD 300,000 per unit when engineering, integration, downtime, and revalidation costs are factored in. DriveKNMS holds verified physical stock of this assembly. This is not a listing built on broker speculation; it reflects units that have been inspected and are ready to ship.

Technical Specifications

Note: Electrical parameters specific to your robot variant should be confirmed against your original Yaskawa maintenance manual. DriveKNMS does not publish unverified specifications.

Solving the Discontinued Hardware Crisis

Yaskawa Motoman robots from the UP and SK generations were engineered for 15–20 year service lives. Many facilities extended that timeline further, and those robots are now operating well beyond their original design horizon. The L-axis servo-reducer assembly is a high-cycle, high-load component. It accumulates wear faster than most other joints in the kinematic chain, and when it fails, there is no modern drop-in equivalent that does not require mechanical rework, controller parameter changes, and in many cases, a full safety revalidation.

The industrial automation market has not provided a clean migration path. Yaskawa's current DX200 and YRC1000 controller platforms are incompatible with the older MRC and XRC teach pendant ecosystems. A robot cell that was commissioned in the late 1990s or early 2000s cannot simply receive a new arm and continue operating. The control architecture, the wiring harness, the I/O mapping, and the safety relay logic are all tied to the original hardware generation. Replacing the L-axis assembly with an identical unit is the only intervention that preserves the existing validated process without triggering a full re-engineering cycle.

For plant engineering teams managing 20 or more legacy Motoman cells, the calculus is straightforward: sourcing a verified spare assembly at a fraction of the cost of a new robot protects the capital already embedded in the line and defers a multi-million dollar modernization project until it can be planned and budgeted properly — rather than forced by an unplanned failure.

How to extend your Motoman robot asset life by 5–10 years through targeted spare part strategy:

• Identify your highest-wear joints first. L-axis and S-axis assemblies carry the greatest mechanical load in most Motoman configurations. These should be the first components held in reserve.
• Audit your robot fleet by controller generation. MRC, XRC, and NX100 controllers each have distinct spare part ecosystems. Mixing generations creates compatibility risk. Map your fleet before sourcing.
• Establish a minimum stock level of one critical assembly per robot cell. A single unplanned failure with no spare on hand can idle a cell for 8–16 weeks while sourcing is arranged through the secondary market. One unit in reserve eliminates that exposure entirely.
• Prioritize NOS (New Old Stock) over field-pulled units. NOS assemblies have not accumulated operational fatigue. For a component that will be installed into a robot expected to run for another decade, the condition of the spare matters as much as its availability.
• Document firmware and encoder versions before installation. Legacy Yaskawa servo systems are sensitive to encoder resolution mismatches. Confirm the replacement unit's encoder specification against the controller's axis parameter file before commissioning.

Condition & Reliability Assurance

DriveKNMS applies a structured 5-step quality process to all obsolete servo-mechanical assemblies before they leave our facility.

• Step 1 – Visual and mechanical inspection: External housing, shaft, and connector pins are examined for corrosion, impact damage, and seal integrity. Units with compromised housings are rejected at this stage.
• Step 2 – Electrolytic capacitor assessment: Aging electrolytic capacitors in the encoder feedback circuit are a primary failure mode in stored servo components. Each unit is assessed for capacitor condition; units showing ESR drift beyond acceptable limits are flagged.
• Step 3 – Encoder and feedback verification: The encoder output is tested for signal integrity and resolution consistency. This step catches units where the optical or magnetic encoder element has degraded during storage.
• Step 4 – Pin and connector corrosion check: All connector interfaces — motor power, encoder, and brake — are inspected under magnification. Oxidized pins are treated or the unit is rejected depending on severity.
• Step 5 – Firmware and label verification: The part number, revision code, and any embedded firmware identifiers are cross-referenced against the original Yaskawa documentation to confirm the unit matches the listed specification exactly.

Units that pass all five steps are packaged in anti-static, moisture-barrier packaging with desiccant and shipped with a condition report.

Key Features for System Maintenance

• Drop-in replacement: This assembly is mechanically and electrically identical to the original factory-installed unit. No mounting modifications, no wiring changes, no controller parameter adjustments are required for a standard swap.
• No reprogramming required: The robot controller retains all existing job files, axis parameters, and calibration data. Installation restores the axis to its previous operational state without a teach-in cycle.
• Avoids engineering reconstruction costs: A forced upgrade to a current-generation Motoman robot involves mechanical redesign of the end-of-arm tooling, I/O remapping, safety system revalidation, and operator retraining. The cost of this work routinely exceeds the value of the robot itself in older installations. A verified spare assembly eliminates this exposure.
• Supports long-term asset protection strategy: Holding critical spare assemblies for legacy robot fleets is a recognized maintenance practice in automotive, electronics, and food processing industries where robot cell replacement cycles are measured in decades, not years.

FAQ

Q: What warranty applies to this obsolete assembly?
A: DriveKNMS provides a 90-day functional warranty on all refurbished units and a 30-day warranty on New Old Stock units. Warranty covers verified functional defects identified under normal operating conditions. It does not cover damage resulting from incorrect installation or incompatible controller configurations.

Q: How do I confirm this is a genuine Yaskawa unit and not a counterfeit?
A: All units sourced by DriveKNMS are verified against Yaskawa's original part numbering and label conventions. We provide the physical unit's label photographs and, where available, original packaging documentation upon request before purchase.

Q: Should I buy more than one unit as a long-term reserve?
A: For facilities operating more than three Motoman robots of the same generation, holding two spare L-axis assemblies is a defensible maintenance investment. The secondary market for this specific assembly is finite. Once current global stock is absorbed, sourcing lead times will extend significantly. Procurement decisions made under emergency conditions are consistently more expensive than planned reserve purchases.

Q: Can this unit be used with a Yaskawa NX100 or DX100 controller?
A: Compatibility depends on the specific robot model and axis parameter configuration in your controller. We recommend confirming the encoder specification and axis parameter file against your controller documentation before ordering. Our technical team can assist with compatibility verification.