Frameless Motor

70 mm Frameless BLDC Motor

Compact frameless motor designed for embedded rotary motion systems requiring high torque density, smooth operation, and flexible mechanical integration.

Available in 70ZWC20X-1 and 70ZWC25X-1 configurations, with Hall sensor feedback, a large rotor inner bore, and an optimized slot-pole combination to reduce cogging torque.

70 mm frameless BLDC motor

Motor Characteristics

70 mm Frameless BLDC Motor

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Specification Unit 70ZWC20X-1 70ZWC25X-1
Stator Outer Diametermm69 ±0.03769 ±0.037
Rotor Inner Diametermm42 +0.03942 +0.039
Overall Length (L)mm15.921.5
Stack Length (L1)mm10.315.9
Rotor Length (L2)mm20.5 ±0.226 ±0.2
Number of Slots-1818
Pole Pairs-1010
Phase-to-Phase ResistanceΩ0.320.22
Phase-to-Phase InductancemH0.520.35
Winding Connection Method-Star ConnectionStar Connection
Insulation Class-FF
Duty Type-S2S2
Feedback Method-Hall SensorHall Sensor
Commutation Angle-120°120°
Insulation Strength-500VAC / 1mA / 1s500VAC / 1mA / 1s
Insulation Resistance-100MΩ / 500VDC100MΩ / 500VDC
Stator Weightg167.5224
Rotor Weightg7290
No-Load SpeedRPM43504400
No-Load CurrentA0.5 REF1.3 REF
Rated VoltageVDC4848
Rated PowerW216456
Rated TorqueN·m0.551.3
Rated SpeedRPM37503350
Rated CurrentA5.411.4
Torque ConstantNm/A0.1090.13
Back-EMF Constant, Effective ValueVrms/Krpm8.19.6
Peak TorqueN·m1.652.6
Peak CurrentA14.221
Rotor Inertiag·cm²358455

Dimensional Drawing

70ZWC20X-1 dimensional drawing
70ZWC25X-1 dimensional drawing

Torque Performance Curves

70ZWC20X-1 torque performance curve
70ZWC25X-1 torque performance curve

Lead Wire Configuration

Lead-Out Type Lead-Out Color Function
UL1332 AWG18YellowU Phase
UL1332 AWG18RedV Phase
UL1332 AWG18BlackW Phase
70 mm frameless motor lead wire diagram

Customization Options

Embedded Installation

Designed for integration into customer housings, mounting structures, and compact mechanical assemblies.

Large Inner Bore

The rotor’s open bore supports flexible mechanical design and system-level integration.

Cooling System Integration

Stator installation can be reviewed around customer cooling requirements and packaging needs.

Performance Tuning

Motor windings, torque, speed, feedback, and application requirements can be reviewed for custom system needs.

Downloads

70ZWC20X-1
70ZWC25X-1

Part Number Builder

70 ZW C 20 / 25 X - 1
70

70 mm motor size

ZW

Slotted brushless DC motor

C

Circular frameless motor shape

20 / 25

Motor length designation

X

Coreless motor casing designation

-1

Standard customer sequence number

48 VDC

Rated voltage

Custom

Mounting, cooling, winding, feedback, torque, speed, and integration options may be customized.

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