Automotive closure motion
Planetary Gearmotor for Automotive Tailgate Strut Systems
Engineering guide for integrating a 28 mm planetary gearmotor into powered tailgate struts, covering mechanism inputs, interfaces, noise, thermal, and endurance tests.
Planetary gearmotor application path
Illustrative relationship; architecture and approval conditions are project-specific.
System view
The gearmotor is one element in a changing load path.
Tailgate motion depends on the vehicle hinge geometry, gas spring or powered strut arrangement, spindle or transmission, control strategy, and load through the full travel. The motor and ratio must be evaluated at representative mechanism positions—not from tailgate mass alone.
Vehicle command
Controller voltage, current limit, direction, position or anti-pinch logic.
28 mm gearmotor
Motor curve, planetary ratio, efficiency, output interface, temperature and noise.
Strut transmission
Spindle, coupling, bearings, housing, stroke, friction and structural load.
Tailgate motion
Opening and closing time, force margin, holding behavior and end positions.
Application fit
A strong starting point when compact torque must fit inside the strut architecture.
The 28 mm platform is most relevant when the available radial package is constrained and the project team can define the mechanism and validation conditions.
Strong fit for evaluation
- Powered tailgate or liftgate strut mechanisms
- Compact electromechanical spindle actuators
- Programs requiring project-specific shaft, spline, wire, or connector interfaces
- Teams prepared to validate motion, noise, temperature, and endurance in the actual system
Must be confirmed
- Required force and speed across the complete travel
- Available diameter, length, support bearings, and coupling arrangement
- Vehicle voltage range, controller current limit, and protection behavior
- Back-drive, holding, obstruction, synchronization, and manual-operation requirements
Engineering inputs
Five input groups define the first useful configuration.
Complete information is helpful, but not required for the first discussion. Mark uncertain values and provide a reference strut, drawing, test data, or movement video when available.
Mechanism geometry
Hinge and strut mounting points, stroke, spindle lead or transmission relationship, opening angle, and representative positions.
Load and timing
Tailgate load condition, required push or pull force, movement time, breakaway condition, peak points, and holding behavior.
Electrical architecture
Nominal and operating voltage, controller current limit, direction control, feedback, connector, pinout, and wire routing.
Installation interfaces
Maximum envelope, output spline or coupling, bearing support, mounting, housing constraints, sealing boundary, and adjacent components.
Program targets
Noise setup, temperature range, duty cycle, cycle life, validation standard, sample timing, and estimated annual volume.
Validation framework
Approve the application against defined conditions, not a catalog ratio.
The exact test plan belongs to the customer program. A practical verification matrix connects each risk to a measurable condition and record.
| Area | What to verify | Key conditions |
|---|---|---|
| Motion performance | Opening and closing time, speed profile, force or torque margin, direction and end-position behavior | Specified voltage, temperature, tailgate load, mechanism position and controller state |
| Electrical & thermal | Running, starting and peak current; motor and gearbox temperature; protection response | Representative run/rest cycle, low-voltage condition, repeated cycles and worst-case ambient |
| Noise & feel | Airborne or structure-borne noise, vibration, backlash effects and perceived smoothness | Defined distance, background level, mounting, load, speed, temperature and measurement method |
| Durability | Wear, lubrication condition, interface retention, functional drift and failure mode | Agreed cycle profile, load distribution, temperature, orientation and inspection intervals |
| System safety | Obstruction response, holding, back-drive, synchronization and manual-operation behavior | Customer control logic and vehicle-level risk assessment |
From component to program
Coordinate the interfaces around the primary motion component.
When the scope extends beyond the gearmotor, KEY-CRON can coordinate relevant Pearl River Delta manufacturing resources around a controlled drawing and validation baseline.
Explore manufacturing and coordination capabilities →- Gearmotor ratio, motor and output interface
- Injection-molded gears, carriers, covers or housings
- Machined or sheet-metal brackets and interfaces
- Wire harness, connector and basic electronic assembly
- Sample build, inspection, test records, packing and production handoff
Start the application review
Send the strut information you already have.
A complete vehicle specification is not required for the first discussion. A mechanism drawing, reference sample, movement video, force/current data, or installation envelope is enough to identify the next engineering questions.
FAQ
Common tailgate strut gearmotor questions.
Can a 28 mm planetary gearmotor be selected from tailgate weight alone?
No. Tailgate weight does not describe the changing moment arm, strut geometry, gas spring contribution, spindle relationship, friction, movement time, or worst mechanism position. These inputs must be evaluated together.
Is the gearbox ratio fixed for every powered tailgate strut?
No. The ratio is selected with the motor, spindle or transmission, voltage, current limit, movement time, force requirement, duty cycle, and available package. Standard ratios are starting points for application validation.
Can the shaft, spline, wiring, and connector be adapted?
Yes, subject to technical and commercial review. The output interface, wire length, connector, pinout, motor direction, mounting, and adjacent housing constraints can be defined around the program.
What should be agreed for a tailgate noise requirement?
Define the measurement distance, mounting, voltage, load, speed, travel position, temperature, background noise, equipment, and pass/fail value. A dBA target without test conditions is not enough for approval.
This page describes an engineering application path, not a vehicle-level approval or a universal tailgate specification. Final configuration and validation criteria must be confirmed for the actual strut, vehicle mechanism, electrical architecture, and applicable customer requirements.