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Technical Drawing
RI80 without hall sensor
RI80 with hall sensor
The RI80 V2.0 KV75 frameless torque motor is an inner-rotor, frameless motor from CubeMars’ RI series. Through advanced electromagnetic optimization, it achieves a high slot fill ratio and delivers exceptional power density. With no housing or end caps—retaining only the essential stator and rotor components—it reduces volume by over 30% compared to conventional framed motors of equivalent power. This makes it ideal for embedded installation in space-constrained applications such as robotic arm joints and precision rotary platforms.
The rotor can be directly and rigidly coupled to the load (e.g., shafts or turntables), eliminating intermediate transmission elements like gears or belts. This direct-drive architecture avoids mechanical losses and precision degradation, achieving power transmission efficiency exceeding 95%, while also minimizing component wear and maintenance requirements.
The stator features a modular design, allowing customization of mounting dimensions and fixation methods based on specific application needs. The rotor is compatible with various load shaft diameters—no additional adapters required—enabling rapid integration into diverse drivetrain systems.
Additionally, the rotor height has been increased by 2 mm to facilitate precise alignment with optional Hall sensors, ensuring accurate magnetic sensing and enabling high-fidelity motion control.
Motor Dimensions
Φ85 × 27 mm
Through Bore Diameter
40.5 mm
Weight
411 g
Peak Torque
4.1 Nm
No-Load Speed
2960 rpm@48V
High Torque Density & Frameless Design
The frameless architecture offers maximum flexibility for structural integration, empowering users to tailor mounting solutions to their exact mechanical layout
Ultra-Low Cogging Torque
Optimized electromagnetic structure ensures exceptional smoothness and stability even at very low speeds
Compact Form Factor for Easy Integration
Designed for seamless embedding into robotic joints, rotating axes, and other tight-space mechanisms
High Customizability
The frameless configuration allows users to freely design support flanges, drive interfaces, encoder mounts, and other mechanical features according to their system requirements
RI80 without hall sensor
RI80 with hall sensor
| Application | Cobot Arm/Exoskeleton | Insulation Class | C |
| Driving Way | FOC | Insulation High-Voltage | 1000V 5mA/2s |
| Operation Ambient Temperature | -20℃~50℃ | Insulation Resistance | 1000V 10MΩ |
| Winding Type | Delta | Phase | 3 |
| Pole Pairs | 8 |
| Rated Voltage（V） | 24/36/48 | Ke（V/krpm） | 15.5 |
| No-Load Speed（rpm） | 1480/2220/2960 | Phase To Phase Resistance（mΩ） | 330 |
| Rated Torque（Nm） | 1.45 | Phase To Phase Inductace（μH） | 510 |
| Rated Speed（rpm） | 1135/1785/2430 | Inertia（gc㎡） | 212.49 |
| Rated Current（ADC） | 9.4 | Km（Nm/√W） | 0.2698 |
| Peak Torque（Nm） | 4.1 | Mechanical Time Constant（ms） | 0.29 |
| Peak Current（ADC） | 27.6 | Electrical Time Constant（ms） | 1.55 |
| Kv（rpm/V） | 75 | Weight（g） | 411 |
| Kt（Nm/A） | 0.155 | Maximum Torque Weight Ratio（Nm/Kg） | 9.3 |
| U | Red+16#Silicone Wire | Hv | Blue+30#Silicone Wire |
| V | Yellow+16#Silicone Wire | Hw | Green+30#Silicone Wire |
| W | Blue+16#Silicone Wire | VCC GND | Red+30#Silicone Wire Black+30#Silicone Wire |
| Hu | Yellow+30#Silicone Wire | Correspondence | Hu-U Hv-V Hw-W |
| category | Model | Rated Voltage (V) | Rated Power (W) | Rated Torque (Nm) | Rated Current (A) | Rated Speed (RPM) | Peak Torque (Nm) | Peak Current (A) | No-load Speed (RPM) | Phase to Phase Resistance (mΩ) | Phase to Phase Inductance (μH) | Pole Pairs | Weight (G) | Size (diameter *length) MM | Operation |
| RI Potting Series | RI115-PH KV40 With Connector | 48 | 823 | 5.5 | 20 | 1430 | 16 | 52 | 1920 | 134 | 245 | 20 | 1108 | Ф115*42 |  |
| RI Potting Series | RI115-PH KV40 Welded Model | 48 | 823 | 5.5 | 20 | 1430 | 16 | 52 | 1920 | 134 | 245 | 20 | 1108 | Ф115*41 | |
| RI Potting Series | RI85-PH KV85 With Connector | 48 | 637 | 2 | 16 | 3042 | 5 | 44 | 4080 | 138.5 | 239.4 | 14 | 411 | Ф85*32 | |
| RI Potting Series | RI85-PH KV85 Welded Model | 48 | 637 | 2 | 16 | 3042 | 5 | 44 | 4080 | 138.5 | 239.4 | 14 | 411 | Ф85*31.5 | |
| RI Potting Series | RI75-PH KV70 With Connector | 48 | 297 | 1.2 | 7.28 | 2365 | 3.8 | 24.2 | 3360 | 495 | 673 | 14 | 348 | Ф70*36.2 | |
| RI Potting Series | RI75-PH KV70 Welded Model | 48 | 297 | 1.2 | 7.28 | 2365 | 3.8 | 24.2 | 3360 | 495 | 673 | 14 | 348 | Ф70*34 | |
| RI Frameless Series | RI100 KV105 | 24/36/48 | 252 | 1.76 | 13.6 | 1370/2100/2825 | 4.95 | 38.6 | 2184/3276/4368 | 126 | 366.7 | 14 | 500 | Ф104*26 | |
| RI Frameless Series | RI80 V2.0 KV75 | 24/36/48 | 172 | 1.45 | 9.4 | 1135/1785/2430 | 4.1 | 9.4 | 1480/2220/2960 | 330 | 510 | 8 | 411 | Ф85*27 | |
| RI Frameless Series | RI70 KV95 | 24/36/48 | 125 | 0.94 | 7.1 | 1270/1990/2710 | 2.68 | 21 | 1956/2934/3912 | 418 | 622.7 | 14 | 270.4 | Ф76*24 | |
| RI Frameless Series | RI60 KV120 | 24/36/48 | 85 | 0.57 | 5.6 | 1440/2320/3190 | 1.63 | 16.8 | 2532/3798/5064 | 900 | 877.5 | 14 | 155.9 | Ф60*23 | |
| RI Frameless Series | RI50 KV100 | 24/36/48 | 66 | 0.58 | 4.8 | 1090/1860/2600 | 1.67 | 14.8 | 2004/3006/4008 | 1420 | 1500 | 7 | 180.8 | Ф54*27 | |
| RI Frameless Series | RI30 KV260 | 24 | 33 | 0.076 | 1.98 | 4110 | 0.23 | 7.72 | 6240 | 2.2 | 1.41 | 7 | 40g | φ38*14 | |
| RI Frameless Series | RI20 KV600 | 16 | 18 | 0.024 | 1.47 | 7452 | 0.072 | 4.4 | 9600 | 1.89 | 0.45 | 7 | 20g | φ25*14.5 | |
