28mm Slotless Brushless DC Motor

28mm Slotless Brushless DC Motor – Product Overview

The 28mm slotless brushless DC motor is designed for applications that require higher torque and stability than micro motors, while still maintaining a compact mechanical footprint.
Thanks to its slotless stator design, 28mm slotless brushless DC motor delivers exceptionally smooth torque output, minimal vibration, and precise speed control across a wide operating range.

28mm slotless brushless DC motor is commonly selected for compact automation equipment, precision actuators, and semi-industrial motion systems where reliability and motion quality are equally important.

slotless brushless dc motor

Key Features

Slotless stator design with zero cogging torque
Higher torque capability compared to sub-22mm motors
Stable thermal behavior for continuous operation
Low acoustic noise and smooth rotation
Flexible voltage and winding configurations
Designed for OEM integration

Typical Applications of 28mm Slotless Brushless DC Motor

28mm slotless brushless DC motor suits compact systems transitioning toward industrial-level performance.

Typical applications include:

Compact industrial actuators
Precision positioning modules
Small robotic mechanisms
Automated inspection systems

Application Highlights

Smooth motion under varying load conditions
Reduced vibration for sensitive assemblies
Reliable performance in long-duty cycles
Suitable for servo-like motion control

Technical Specifications of 28mm Slotless Brushless DC Motor

The following technical data applies to the 28mm slotless brushless DC motor.

Electrical Parameters

Rated voltage options: 12-48V.
Rated speed: 6970-8430rpm(customized)
Rated Torque: 32-50mN.m(customized)
Output power: 30-37W(customized)

Optional Configurations

Hall sensors or encoder feedback
Customized shaft or connector types
Cable or terminal variations

Slotless motor.pdf

Motor Characteristics
Motor part number	28ZWWC52
Pole pairs	-	1	1	1	1	2
Terminal resistance, Phase-Phase	Ω	0.52	1.7	4.3	6.6	1.6
Terminal inductance, Phase-Phase	mH	0.0495	0.178	0.42	0.77	0.13
Winding connection method	-	Star connection	Star connection	Star connection	Star connection	Star connection
Insulation class	-	B	B	B	B	B
Duty type	-	S2	S2	S2	S2	S1
Feedback method	-	Hall sensors	Hall sensors	Hall sensors	Hall sensors	Hall sensors
Commutation angle	-	120°	120°	120°	120°	120°
Insulation strength (Withstand voltage)	-	500VAC/1KHz/1mA/1s
Insulation resistance	-	100MΩ/500VDC
Weight	g	170	170	170	170	170
Rated voltage	V	12	24	36	48	24
Rated power	W	30	34	35	35	37
Rated torque	mN·m	32	32	32	34	50
Rated speed	RPM	6970	8430	8370	8340	7000
Rated current	A	3.13	1.69	1.17	0.86	2.00
No load speed	RPM	9270	9680	9500	9400	8500
No load current	A	0.2	0.11	0.084	0.061	0.12
Motor efficiency	%	80	84	83	85	81.5
Noise (Ambient noise 20dB, test distance 1m)	dB	<50	<50	<50	<50	<50
Thermal Resistance (No-load)	K/W	0.67	0.69	0.73	0.64	0.70
Thermal Time Constant (No-load)	S	1200	1200	1080	1100	880
Ambient temperature	℃	23	24	27	25	21.2
Max winding temperature (No-load)	℃	43.2	47.3	52.5	47.4	46.7
Torque constant	mN·m/A	10.24	18.97	27.32	39.63	25
Back-EMF constant - peak value	V/Krpm	1.52	2.81	4.04	5.87	3.70
Back-EMF constant - effective value	V/Krpm	1.07	1.99	2.86	4.15	2.62
Peak torque	mN·m	236.31	267.87	228.72	288.25	375
Peak current	A	23	14	8	7	15
Rotor inertia	g·cm²	10.2	10.2	10.2	10.2	10.2
Mechanical time constant	ms	5.06	4.82	5.88	4.29	2.61
End bell	-	Stainless steel
Bearing	-	Deep groove ball bearing
Magnet	-	Sinter NdFeB
Rotation shaft	-	Carbon steel

Dimension Drawing of 28mm slotless brushless motor 28ZWWC52

28mm slotless brushless dc motor drawing

Performance Curve of 28mm slotless brushless motor 28ZWWC52

28mm slotless brushless dc motor 36V performance curve

28mm slotless brushless dc motor 24V performance curve

FAQ –28mm Slotless Brushless DC Motor

Q1: Is 28mm slotless brushless DC motor suitable for industrial applications?

Yes, for compact and semi-industrial automation systems.

Q2: Does slotless design improve motion smoothness?

Yes, 28mm slotless brushless DC motor eliminates cogging torque entirely.

Q3: Can 28mm slotless brushless DC motor replace a small servo motor?

Yes, in applications where compact size and smooth torque are critical.

Q4: Is customization supported?

Yes, winding, voltage, and performance can be customized.

Q5: Does 28mm slotless brushless DC motor support continuous operation?

Yes, with proper thermal conditions.

Q6: Is OEM supply available?

Yes, including long-term production support.

28mm Slotless Brushless DC Motor for Compact Automation Systems