Description
The MKD071B-061-KG1-KN is a high-performance synchronous servo motor from Rexroth’s (Indramat) MKD series. These motors are designed for high-power applications requiring precision, such as CNC machine tools, printing presses, and packaging machinery. They are renowned for their high torque-to-inertia ratio and maintenance-free operation due to their brushless design and permanent magnet construction.
Availability and Procurement
- Condition: Refurbished (Standardized Industrial Bench Testing) or New Surplus.
- Warranty: 12-month technical replacement warranty.
- Lead Time: Typically ships within 3–5 business days.
- Pricing: Subject to current market demand for legacy Indramat components; contact our technical sales team for a formal quote.
Model Code Breakdown (MKD071B-061-KG1-KN)
| Code Segment | Description |
| MKD | Motor Series (Digital Synchronous Servo Motor) |
| 071 | Motor Size (Frame size 071) |
| B | Motor Length (Size B – Medium length) |
| 061 | Winding Code (Specifies torque and speed characteristics) |
| K | Feedback Type: Integrated Resolver (Multiturn absolute available depending on drive) |
| G | Shaft Design: Plain Shaft (No keyway) with shaft sealing ring |
| 1 | Holding Brake: Standard 10 Nm Brake included |
| K | Connection: Terminal Box (Electrical connection via a terminal box on top) |
| N | Standard Housing Design (Non-specialized) |
Technical Specifications
The MKD071B series is engineered for high dynamic response and thermal stability.
| Parameter | Specification |
| Continuous Torque (M_0) | Approx. 8.0 Nm |
| Peak Torque (M_{max}) | Approx. 32.0 Nm |
| Rated Speed (n_n) | 4,500 RPM |
| Number of Pole Pairs | 3 |
| Insulation Class | F (up to 155 °C) |
| Protection Category | IP65 (Total protection against dust and water jets) |
| Feedback System | Resolver |
Core Functionality and Design Features
1. Brushless Permanent Magnet Design
The MKD uses high-energy rare-earth magnets. Because there are no brushes to wear out, the motor is virtually maintenance-free and can operate at high speeds without the risk of sparking or mechanical friction loss.
2. Thermal Dissipation
The housing is designed with optimized surface areas for natural convection.
- Engineering Note: While the motor is rated for IP65, the heat is dissipated through the housing. If the motor is used in a high-duty cycle, ensure it is mounted to a metal surface that can act as a heat sink, or provide forced-air cooling.
3. Integrated Resolver
The “K” feedback code indicates a resolver. Resolvers are analog feedback devices that are extremely rugged. They are immune to the high temperatures and heavy vibrations that often cause optical encoders to fail. This makes the MKD071B ideal for “dirty” industrial environments.
Engineering Insights: Deployment and Maintenance
As a motion control specialist, I recommend the following for the MKD071B-061-KG1-KN:
1. Shaft Sealing and Maintenance
The “G” code includes a shaft sealing ring.
- Best Practice: Check the seal during annual maintenance. If the seal fails, oil from a gearbox can enter the motor housing, potentially contaminating the windings or the resolver. If you are not using a gearbox, the seal provides added protection against coolant ingress.
2. Holding Brake Management
The “1” indicates a 10 Nm holding brake.
- Warning: This is a holding brake, not a dynamic braking system. It is designed to hold the axis in place when the power is off (e.g., preventing a vertical axis from falling). Using the brake to stop a moving motor will cause rapid wear and eventual failure of the brake pads.
3. Wiring and Connection (Terminal Box)
Unlike the “plug” style connectors found on smaller motors, the “K” connection uses a terminal box.
- Tip: When wiring the terminal box, ensure the cable glands are tightened properly to maintain the IP65 rating. Use “shielded” power cables to prevent the high-frequency PWM switching of the drive from interfering with nearby sensor signals.
4. Drive Compatibility
This motor is specifically designed to work with Rexroth Indramat IndraDrive or DiaDrive (DDS, DKR, DDC) controllers.
- Critical Factor: The motor parameters (commutation angle, torque constant) are stored in the drive’s firmware or a motor data memory. Ensure the drive is correctly configured for an MKD071B to avoid over-current faults or “cogging” at low speeds.
FAQ
Q: Can I use this motor without the brake?
A: If your application does not require a holding brake (e.g., a horizontal belt), you could technically use it, but the brake will remain engaged (locked) unless you provide a constant 24V DC signal to the brake terminals to release it.
Q: What is the significance of the “061” winding?
A: The winding code determines the relationship between voltage and speed (K_v). The 061 winding is optimized for a balance of high torque at lower RPMs and a maximum speed of 4,500 RPM.
Q: Is the resolver “absolute”?
A: A standard resolver is “single-turn absolute,” meaning it knows its position within one revolution. For multiturn absolute positioning (remembering position after a power cycle), the drive usually tracks this via an internal battery or by using an MKD model with an encoder option (e.g., “N” or “P” code).
