Orbray DC Coreless Motor Series CMS12-20 Overview

This document provides detailed technical specifications and performance data for the Orbray DC Coreless Motor Series CMS12-20, featuring precious metal commutation and sintered sleeve bearings.

1. Motor Specifications

• Nominal Voltage: 7.4 V (CMS12-2004), 12.0 V (CMS12-2010)
• No Load Speed: 22,200 rpm (7.4 V), 23,000 rpm (12 V)
• No Load Current: 13 mA (7.4 V), 8 mA (12 V)
• Stall Torque: 5.48 mNm (7.4 V), 5.77 mNm (12 V)
• Stall Current: 1744 mA (7.4 V), 1173 mA (12 V)
• Maximum Output Power: 3.2 W (7.4 V), 3.5 W (12 V)
• Maximum Efficiency: 83% (7.4 V), 84% (12 V)
• Terminal Resistance: 4.24 Ω (7.4 V), 10.23 Ω (12 V)
• Rated Torque: 0.435 mNm (7.4 V), 0.447 mNm (12 V)
• Rated Speed: 20,410 rpm (7.4 V), 21,211 rpm (12 V)
• Rated Current: 150 mA (7.4 V), 99 mA (12 V)
• Friction Torque: 0.04 mNm (both voltages)
• Back-EMF Constant: 0.331 V/rpm (7.4 V), 0.518 V/rpm (12 V)
• Torque Constant: 3.16 mNm/A (7.4 V), 4.95 mNm/A (12 V)
• Slope of N-T Curve: 4049 rpm/mNm (7.4 V), 3989 rpm/mNm (12 V)
• Mechanical Time Constant: 8.9 ms (7.4 V), 8.8 ms (12 V)
• Rotor Inertia: 0.21 g·cm² (both voltages)
• Maximum Allowable Torque: 1.83 mNm (7.4 V), 1.92 mNm (12 V)

2. Mechanical and Environmental Data

• Maximum Shaft Axial Load at Standstill: 7.8 N (measured 5 mm from flange)
• Bearing Type: Sintered sleeve bearing

3. Additional Features and Components

• Gear options: SPG12 / SSG12
• Encoder options: ETD12-2C / 2D / 2E (refer to pages 38 and 39 for details)

4. Performance Curves

The document includes torque versus speed and current graphs for both voltage variants, illustrating motor behavior under load. Key observations include linear torque-speed characteristics and current consumption trends.

5. Notes and Recommendations

• Specifications are subject to change without notice.
• Measurements such as axial load are taken at specified distances from the flange for accuracy.

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]