Orbray BMS Brushless Motor Series Overview

This document provides detailed technical specifications and mechanical data for the Orbray BMS12-21 brushless motor series, which includes models BMS12-2102 and BMS12-2104. These motors feature Hall sensors and sleeve bearings.

1. Electrical Specifications

• Nominal Voltage: 7.4 V (BMS12-2102), 12.0 V (BMS12-2104)
• No Load Speed: 22,800 rpm (BMS12-2102), 24,300 rpm (BMS12-2104)
• No Load Current: 100 mA (BMS12-2102), 70 mA (BMS12-2104)
• Stall Torque: 11.60 mNm (BMS12-2102), 12.09 mNm (BMS12-2104)
• Stall Current: 3940 mA (BMS12-2102), 2700 mA (BMS12-2104)
• Maximum Output Power: 6.9 W (BMS12-2102), 7.7 W (BMS12-2104)
• Maximum Efficiency: 71% (BMS12-2102), 70% (BMS12-2104)
• Terminal Resistance: 1.88 Ω (BMS12-2102), 4.44 Ω (BMS12-2104)
• Rated Torque: 1.83 mNm (BMS12-2102), 1.60 mNm (BMS12-2104)
• Rated Speed: 19,200 rpm (BMS12-2102), 21,100 rpm (BMS12-2104)
• Rated Current: 706 mA (BMS12-2102), 418 mA (BMS12-2104)
• Friction Torque: 0.30 mNm (BMS12-2102), 0.32 mNm (BMS12-2104)
• Back-EMF Constant: 0.316 mV/rpm (BMS12-2102), 0.481 mV/rpm (BMS12-2104)
• Torque Constant: 3.02 mNm/A (BMS12-2102), 4.59 mNm/A (BMS12-2104)
• Slope of N-T Curve: 1965 rpm/mNm (BMS12-2102), 2009 rpm/mNm (BMS12-2104)
• Mechanical Time Constant: 2.71 ms (BMS12-2102), 2.77 ms (BMS12-2104)
• Rotor Inertia: 0.12 g·cm² (both models)
• Maximum Allowable Torque: 5.80 mNm (BMS12-2102), 6.05 mNm (BMS12-2104)

2. Mechanical Data

• Shaft Radial Play: Specified but exact values not clearly stated
• Shaft Axial Play: Specified but exact values not clearly stated
• Maximum Shaft Radial Load: Data referenced but specific values not clearly extracted
• Maximum Shaft Axial Load: Data referenced but specific values not clearly extracted
• Operating Temperature Range: -20°C to +80°C
• Maximum Coil Temperature: Not explicitly stated
• Weight: Approximately 134 g

3. Electrical Connections and Features

• Motors include Hall sensors with outputs for U, V, and W phases.
• Input voltage range for Hall sensors: 1.6 V to 5.5 V (nominal 3.0 V)
• Connection specifications for gear, encoder, and driver are referenced on pages 69 and 70 (not included here).

4. Performance Graphs

Speed and current characteristics are provided, showing motor speed up to 30,000 rpm and current up to 6,000 mA. These graphs illustrate the relationship between torque, speed, and current for both motor models.

5. Additional Notes

• Specifications are subject to change without notice.
• Measurements are taken at specified points from the flange (exact distances not clearly stated).
• Only motors with Hall sensors are available in this series.

6. Manufacturer Information

Orbray Co. Ltd.
3-8-22 Shinden, Adachi-ku, Tokyo 123-8511, Japan
Tel: +81-3-5390-7620
Website: https://orbray.com/en/
Email: [email protected] (international), [email protected] (Japan)