Bosch Rexroth MKD025B-144-KG1-UN AC Servo Motor

Overview

The MKD025B-144-KG1-UN is a digital AC servo motor from the Bosch Rexroth MKD synchronous motor range, the compact generation that preceded today’s MSK series and is still widely installed on machine tools, printing presses and handling systems built between 2000 and 2010. In frame size 025 with stator length B and winding 144, it delivers 0.8 Nm continuous torque at standstill at 60 K overtemperature and reaches a maximum speed of 9,000 min-1. The motor carries a resolver with integrated multiturn absolute encoder, a plain shaft with shaft sealing ring, a 1 Nm holding brake and turnable power and encoder connectors, all in an IP65 housing with only 2.3 kg mass.

Product Identification

• Type: MKD025B-144-KG1-UN
• Rexroth material number: R911288403
• Series: MKD digital AC servo motors (synchronous, permanent magnet)
• Size 025, stator length B, winding code 144

Technical Specifications

Electrical parameters, natural convection cooling, values for this version with holding brake:

• Characteristic motor speed: 9,000 min-1
• Continuous torque at standstill: 0.8 Nm at 60 K, 0.9 Nm at 100 K motor overtemperature
• Continuous current at standstill: 4.5 A at 60 K, 5.1 A at 100 K
• Peak current: 23.0 A
• Torque constant at 20 °C: 0.2 Nm/A
• Voltage constant at 20 °C: 18.2 V per 1,000 min-1
• Winding resistance at 20 °C: 2.7 Ω
• Winding inductance: 3.7 mH
• Number of pole pairs: 3

Key Features

• Compact 025 frame with only 2.3 kg rotating mass load on the axis
• 0.8 Nm continuous standstill torque with 4 Nm theoretical peak torque
• 9,000 min-1 maximum speed for high-speed spindle and feed tasks
• Resolver feedback with integrated multiturn absolute encoder, so the absolute position is retained after power-off
• 1 Nm holding brake rated 24 V DC and 0.4 A, with 3 ms clamping and 4 ms release
• Power and encoder connectors turnable through 270° for cable routing in tight machine enclosures
• IP65 protection and insulation class F for industrial environments
• Plain shaft with shaft sealing ring, balanced with the complete feather key

Application Fields

• Feed and positioning axes on machine tools and machining centres
• Printing, packaging and labelling machinery
• Handling and pick-and-place units with compact axis spacing
• Textile, wood and paper converting equipment
• Retrofit and spare-part replacement on machines originally equipped with MKD motors and EcoDrive or IndraDrive systems