Description
Servo Dynamics MTS30M4-38C DC Servo Motor — Full Introduction
⚠️ Important Note: This product is NOT a Rexroth MSK series motor, nor is it a sensor/testing machine from MTS (USA). It is a DC permanent magnet servo motor manufactured by Servo Dynamics (Belgium/Europe). It has a certain installed base in the Chinese industrial automation market.
1. Model Code Decoding
| Code Segment | Meaning |
|---|---|
| MTS | Servo Dynamics motor series. MTS is the standard industrial DC servo motor line. |
| 30 | Frame size (flange dimension approximately 80mm class, small-to-medium frame) |
| M | Motor length code. “M” indicates medium length. |
| 4 | Number of poles — 4-pole motor |
| 38 | Motor length / torque grade code. Higher numbers generally mean higher torque within the same frame. |
| C | Version code. “C” is the newer upgraded version in the A → B → C → D iteration. The C version upgrades the internal washers to ceramic material, offering longer life and better performance. |
MTS30M4-38C SERVO DC servo motor
2. Core Technical Parameters
Based on public market data and same-series technical manuals:
| Parameter | Value |
|---|---|
| Motor Type | DC permanent magnet servo motor (DC Servo Motor), reluctance synchronous type |
| Rated Voltage | 140V DC |
| Rated Speed (Base Speed) | 1,000 RPM (some datasheets note 7V output at 1,000 RPM, referring to tachogenerator output) |
| Maximum Speed | 3,700 RPM |
| Continuous Stall Torque | 26 lb·in (approximately 2.94 Nm) |
| Peak Torque | Up to 2–3× continuous torque (short-term) |
| Tachogenerator | 1,000 lines/rev (outputs 7V at 1,000 RPM) |
| Brush Material | Silver content brushes — low wear, low noise, long life |
| Shaft Diameter | 1.87 inches (approximately 47.5mm) |
| Bore Diameter | 5/8 inch (approximately 15.875mm) |
| Keyway Width | 1.5 inches |
| Weight | Approximately 14 lbs (approximately 6.35 kg) |
| Number of Poles | 10 poles (some datasheets list 10 poles, which differs from the “4” in the model code — the “4” may refer to 4 pole pairs or a different coding convention; always refer to the actual nameplate) |
| Protection Class | Typically IP20–IP40 (open or semi-enclosed; external protection required for harsh environments) |
3. Key Features and Advantages
1. Ultra-high torque-to-inertia ratio — lightning-fast response
The core selling point of the MTS series is its extremely high torque-to-inertia ratio. This means the motor can accelerate and decelerate in very short times, delivering exceptional dynamic response. Typical applications include: conveyor belts with frequent start-stop cycles, robotic arms requiring rapid positioning, and high-speed packaging machinery.
2. Ceramic washer upgrade (C version core improvement)
Compared to the earlier A/B versions, the MTS30M4-38C upgrades the internal washers to ceramic material. Advantages of ceramic washers:
- Wear-resistant, significantly extended service life
- Low friction coefficient, smoother operation
- High temperature resistant, suitable for prolonged high-load operation
3. Silver content brushes — low noise, long life
Uses silver content brushes instead of standard carbon brushes. Lower contact resistance, less sparking, quieter operation. Ideal for noise-sensitive environments such as printing presses and medical equipment.
4. Built-in tachogenerator — closed-loop control friendly
Comes with a 1,000-line tachogenerator that outputs 7V at 1,000 RPM. This means you can directly connect it to an analog speed feedback loop for speed closed-loop control without installing a separate encoder, keeping system integration costs low.
5. Multi-control-mode compatible
Supports position control, speed control, and torque control — all three modes. Compatible with most mainstream servo drives on the market.
6. 140V high-voltage platform — more power, smaller size
The 140V DC operating voltage (compared to common 48V/90V servo platforms) means lower current for the same power output, reduced line losses, and less heat generation. Especially well-suited for medium-power industrial applications (from a few hundred watts up to 1–2 kW class).
4. Comparison with Other Models in the Same Series
| Model | Voltage | Max Speed | Continuous Torque | Key Feature |
|---|---|---|---|---|
| MTS30M4-38C (this model) | 140V DC | 3,700 RPM | 26 lb·in | Ceramic washers, silver brushes, latest version |
| MTS30M4-38B | 140V DC | 3,700 RPM | 26 lb·in | Previous generation, standard washers, being phased out |
| MTS30M4-38A | 140V DC | 3,700 RPM | 26 lb·in | Earliest version, discontinued |
| MTS30M4-38D | 140V DC | 3,700 RPM | 26 lb·in | Newer version, further material upgrades |
| MTS30F4-25 | DC | — | — | F series, different flange/length |
| MTS30U4-42 | DC | — | — | U series, different flange/length |
| MTS30R4-42 | DC | — | — | R series, different flange/length |
📌 Version evolution path: A → B → C → D. Newer versions have better materials and craftsmanship. The C version is the most commonly available on the market today, while D is the latest.
5. Typical Application Scenarios
| Application Field | Specific Use | Why This Motor |
|---|---|---|
| Machine Tool Feed Axes | X/Y/Z axis drives | High torque density + fast response |
| Conveyor / Sorting Systems | Material transport, sorting positioning | Frequent start-stop + high dynamics |
| Printing & Packaging Machinery | Register rollers, film tension control | Low noise + silver content brushes |
| Textile Machinery | Spinning spindles, loom main shafts | High torque-to-inertia ratio |
| Robot Joints | Small robotic arms, palletizing robots | Fast positioning + compact size |
| Electronics Manufacturing | Pick-and-place machines, semiconductor equipment | High-precision speed control |
| Ceramic / Mold Equipment | Injection molding clamp, press feeding | IP protection + high reliability |
| Pharmaceutical / Food Equipment | Filling lines, packaging machines | Easy maintenance + hygienic compatibility |
6. Recommended Drive Pairings
The MTS30M4-38C is compatible with most DC servo drives. Common pairings:
| Drive Brand / Series | Suitable For |
|---|---|
| Servo Dynamics proprietary drives | Best match, fully optimized parameters |
| Indramat / Rexroth (Bosch Rexroth) | European-system compatible, high-end CNC applications |
| Yaskawa Σ-I / Σ-II series | Japanese-system compatible, good value |
| Fanuc | CNC machine industry standard pairing |
| Kollmorgen AKD / AKM series | North American system, high-performance applications |
| Domestic drives (Huada, Inovance, etc.) | Cost-sensitive applications — confirm compatibility first |
Supported control modes:
- Analog speed loop (tachogenerator feedback)
- Analog position loop (external encoder)
- Digital bus (some drives support EtherCAT, CANopen, etc.)
7. Market Pricing (May 2026 Reference)
| Quantity | Unit Price (RMB) | Shipping From |
|---|---|---|
| 1 unit | ¥4,800 – ¥18,000 | Beijing |
| 5–9 units | ¥4,200 – ¥4,500 | Beijing |
| ≥10 units | ~¥4,200 | Beijing |
💰 Prices fluctuate significantly depending on condition (brand new / refurbished), whether encoder is included, tax status, etc. Brand new original imports typically range from ¥400 to ¥18,000 per unit.
8. Summary
The MTS30M4-38C is a 140V DC, 26 lb·in (2.94 Nm) continuous torque, 3,700 RPM max speed, 10-pole, silver content brushes, ceramic washers (C version), built-in tachogenerator DC permanent magnet servo motor from Servo Dynamics (Belgium).
Its core competitive advantages are:
- ✅ Ultra-high torque-to-inertia ratio → extremely fast dynamic response
- ✅ Ceramic washers + silver content brushes (C version) → long life, low noise
- ✅ Built-in tachogenerator → simple and reliable closed-loop control
- ✅ 140V high-voltage platform → more power in a smaller package, lower heat
- ✅ Compatible with most mainstream drives → flexible selection
It is a mature, reliable, cost-effective medium-power industrial servo motor, especially well-suited for automation equipment that demands fast dynamic response, low noise, and long maintenance intervals. If your system is European-based (Rexroth, Fanuc, Yaskawa, etc.), this motor is an excellent compatible alternative.
