Smart Lock Motor GM825F
The GM825F Smart Lock Motor is a compact 4.5 VDC DC gearmotor designed for smart door locks, electronic locks, cabinet locks, and access-control mechanisms requiring controlled low-speed torque in a space-constrained transmission package. The supplied GM825FMN30 reference configuration uses a 1:240 gear ratio, delivering 48 RPM rated speed and 40 mN·m (400 gf·cm) rated torque, with a gearbox efficiency of 25%–45%. Its integrated geartrain and compact mounting geometry support embedded lock-body designs, while voltage, speed, output interface, wiring, noise, and service-life targets can be evaluated for OEM smart-lock projects.
Product Overview
The GM825F Smart Lock Motor is a compact 4.5 VDC DC gearmotor designed for smart door locks, electronic locks, cabinet locks, and access-control mechanisms requiring controlled low-speed torque in a space-constrained transmission package. The supplied GM825FMN30 reference configuration uses a 1:240 gear ratio, delivering 48 RPM rated speed and 40 mN·m (400 gf·cm) rated torque, with a gearbox efficiency of 25%–45%. Its integrated geartrain and compact mounting geometry support embedded lock-body designs, while voltage, speed, output interface, wiring, noise, and service-life targets can be evaluated for OEM smart-lock projects.
Model Information
| Model | Motor Type | Product Category |
| GM825F / GM825FMN30 | DC Brushed Gearmotor | Smart Lock / Electronic Lock Motor |
Main Parameters
| Rated Voltage | 4.5 VDC |
| Gear Ratio | 1:240 |
| Gearbox Efficiency | 25%–45% |
| Max. Rated Gearbox Torque | 1–2 kgf·cm |
| Max. Gearbox Break Torque | 2.5–3.5 kgf·cm |
| Overall Height Shown | 54.96 mm |
| Housing Width Shown | 21.21 mm |
| Gearbox Thickness Shown | 14.8 mm |
Gearmotor Technical Data
| Gearmotor Model | Ratio | Voltage | No-Load Speed | No-Load Current | Rated Speed | Rated Current | Rated Torque | Stall Current | Stall Torque |
| GM825FMN30 | 1:240 | 4.5 VDC | 55 RPM | ≤ 65 mA | 48 RPM | ≤ 180 mA | 40 mN·m / 400 gf·cm | ≤ 1350 mA | 0.16 N·m / 1.6 kgf·cm |
Mechanical Interface & Mounting
| Overall height shown | 54.96 mm |
| Housing width shown | 21.21 mm |
| Gearbox thickness shown | 14.8 mm |
| Motor section height shown | 32.1 mm |
| Center interface shown | Ø6 mm |
| Lead wire shown | 1571# 26AWG; red 100 mm / black 110 mm |
| Connector shown | 1.5-2P |
| Rotation reference | CCW |
Dimension Drawing
Engineering Advantages for Smart Lock Projects
Compact smart-lock drive package
The compact GM825F integrated housing is suited to smart-lock and electronic-lock mechanisms where installation space and transmission packaging are tightly constrained. The supplied drawing shows a 54.96 mm overall height, 21.21 mm housing width, and 14.8 mm gearbox thickness.
Low-voltage drive matching
The supplied 4.5 VDC, 1:240 reference configuration delivers 48 RPM rated speed and 40 mN·m (400 gf·cm) rated torque. Final selection should be validated at the lock’s minimum operating voltage and under the actual latch load.
Torque / speed matching for lock mechanisms
The supplied gearbox specification lists 1–2 kgf·cm maximum rated torque capacity and 2.5–3.5 kgf·cm maximum break torque. The reference operating point is 0.4 kgf·cm rated torque, providing a basis for matching opening time, current consumption, and load margin.
Current data for driver and protection design
Specified no-load, rated, and stall-current limits provide a basis for battery, driver, and protection design. Stall duration should still be limited by the control system to reduce motor heating and transmission stress.
Integrated mounting and wiring interface
The supplied drawing provides the housing, center-interface, lead-wire, connector, and rotation-reference dimensions required for integration into the customer’s smart-lock body or actuator module.
Customization-oriented engineering
Voltage, gear ratio, output interface, wiring/terminal, noise, current, and lifetime targets can be evaluated around the customer’s actual lock body, load, battery condition, and duty cycle.
Main Applications
Smart Door Locks
Drive for latch / bolt transmission mechanisms requiring compact packaging, low-voltage operation and repeatable opening/closing motion.
Electronic Cabinet & Locker Locks
Suitable for compact electromechanical locking mechanisms where installation space and controlled actuation are important.
Hotel / Access-Control Lock Mechanisms
Can be evaluated for lock-body actuation requiring repeated cycles and consistent low-voltage drive performance.
Customized Locking Mechanisms
For non-standard lock bodies, the motor, ratio, pinion/interface, lead wire and terminal can be evaluated against the customer’s mechanism and test standard.
Customization Range
Electrical Configuration
Working voltage / winding configuration, rotation direction, lead wire length and terminal options.
Performance Matching
Gear ratio, target output speed, rated load point, current limit and torque margin based on the real lock mechanism.
Mechanical Interface
Output pinion / shaft interface, mounting features and connection to the customer’s lock-body transmission.
Noise & Reliability
Gear meshing, backlash, lubrication, motor operating point, assembly consistency and complete-lock resonance optimization.
Control / Feedback Integration
Hall sensor, encoder or other feedback functions can be evaluated when required by the project; availability depends on the final structure and specification.
FAQ
Q1. How can noise be reduced in a smart lock gear motor?
Low-noise performance depends on motor speed, gear material and accuracy, gear ratio, backlash, lubrication, assembly consistency, lock-body resonance, and the control profile. For reliable evaluation, noise should be tested in the actual smart lock mechanism, including startup, running, reversing, and end-position impact, rather than relying only on no-load motor noise.
Q2. Can a smart lock motor still provide enough torque when the battery is low?
Yes, but the motor and gearbox must be selected based on the minimum operating voltage of the battery, not only the rated voltage. Low-voltage testing should simulate real conditions such as increased latch friction, door pressure, low temperature, and repeated unlocking to verify starting current, unlocking time, torque margin, and temperature rise.
Q3. How should stall or jam protection be handled in a smart lock motor system?
Stall protection should be handled by the motor, lock mechanism, and control system together. Common methods include current detection, operation timeout, end-position detection, reverse recovery, mechanical limits, and fault alarms. Peak current and stall duration should also be controlled to reduce the risk of motor overheating or mechanical damage.
Q4. How do I place an order with Shunli Motor?
Please send us your application requirements or motor specifications. Our engineering team will develop a suitable solution, confirm the technical details, and provide samples for evaluation. Once the samples are approved, we will arrange mass production. Shipping methods can be selected based on your delivery requirements.
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