The ratchet fatigue testing machine is a dedicated device specifically designed to simulate the long-term and repetitive meshing and slipping processes of ratchet mechanisms in bicycles (especially fi ...
The ratchet fatigue testing machine is a dedicated device specifically designed to simulate the long-term and repetitive meshing and slipping processes of ratchet mechanisms in bicycles (especially fixed-gear bikes), electric bicycles, and various mechanical tools such as ratchet wrenches and jacks, for the purpose of testing their fatigue resistance, wear resistance, and reliability.
Test items
1.Test wheelsets, disc brake test, wheels and spokes
2.Separate test of hubs and planetary gear fatigue test
Technical parameters
| Parameter | Specification / Range |
|---|---|
| Frequency Range | 1–3 Hz |
| Tension Range | 300–650 N |
| Lever Arm Length | 200–400 mm |
| Software Interface | Feihong Control System |
| Power Source | Servo Control System |
| Overall Dimensions | Test bench: 2000 × 650 × 1500 mm, 1 unit Control cabinet: 600 × 650 × 1430 mm, 1 unit |
| Power Supply | 220V, 50Hz, 1.5 kW |
| Applied Force Value | 650 N (±20% adjustable, accuracy ±1%) |
| Cycling Frequency | 0.5–3 Hz (adjustable) |
| Test Stroke | 10–50 mm (adjustable) |
| Data Sampling | 100 Hz (synchronously acquires force, displacement, temperature, etc.) |
| Compatible Components | Ratchets, hubs, planetary gears, wheel assemblies (20–29 inch) |
Wheelset assembly testing (including disc brake, wheel, and spokes)
1.Disc brake system fatigue test:
Test logic: Install the disc brake (disc + caliper) on the wheelset. When the electric cylinder is cyclically loaded, simultaneously trigger the "braking action" (caliper clamping the disc) to simulate the combined load of "ratchet pawl force during emergency braking + disc brake torque".
Monitoring parameters: Disc deformation (laser displacement sensor, accuracy ±0.01mm), caliper clamping force attenuation (pressure sensor), ratchet pawl wear rate (microscope-assisted observation).
Judgment criteria: After 100,000 cycles, the disc deformation ≤ 0.2mm, caliper clamping force reduction ≤ 5%, ratchet pawl wear depth ≤ 0.1mm (in compliance with ISO 4210-7 "Brake System Durability" requirements).
2. Wheel and spoke fatigue test:
Test logic: Install the entire wheel (rim + spokes) on the machine. The electric cylinder pulls the ratchet through the vertical rod, while the wheelset is driven to rotate by the roller (speed adjustable from 0 to 20 km/h), simulating the "spoke tension-relaxation cycle during cycling" (such as when the spokes are instantaneously tightened over speed bumps).
Monitoring parameters: Spoke tension fluctuation (tension meter, accuracy ±1kgf), rim radial/lateral deflection (laser beam sensor, accuracy ±0.1mm), ratchet pawl meshing noise (acoustic sensor).
Judgment criteria: After 50,000 cycles, spoke tension attenuation ≤ 10%, rim deflection ≤ 1mm, no abnormal noise (in compliance with GB 3565-2016 "Bicycle Safety Requirements").
Component independent testing (hub, planetary gear)
For the core transmission components of the wheelset, the interference of the assembly is stripped away to verify their ultimate fatigue life:
1.Hub fatigue test:
Test logic: The hub is fixed alone (without the rim), and the electric cylinder directly loads the ratchet assembly inside the hub through the vertical rod, simulating the "idle - load switching" scenario (such as the instantaneous force on the ratchet inside the hub during gear shifting while riding);
Monitoring parameters: Hub bearing temperature rise (infrared temperature measurement, accuracy ±1℃), ratchet pawl meshing clearance (feeler gauge measurement, accuracy ±0.05mm), hub shell strain (strain gauge, accuracy ±1με);
Judgment criteria: After 200,000 cycles, the bearing temperature rise ≤ 30℃, pawl clearance ≤ 0.2mm, shell strain ≤ 500με (in compliance with EN 14764 "Durability of bicycle hubs" requirements).
2. Planetary gear fatigue test:
Test logic: The planetary gear set (common in multi-speed hubs) is installed in a dedicated fixture, and the electric cylinder applies a cyclic torque to the planet carrier through the vertical rod (simulating the high-load transmission during climbing), to verify the anti-fatigue performance of the gear tooth surface and bearings;
Monitoring parameters: Gear meshing noise (acoustic sensor), tooth surface wear (3D scanner, accuracy ±0.005mm), planet carrier deformation (displacement sensor);
Judgment criteria: After 150,000 cycles, the noise ≤ 65dB, tooth surface wear ≤ 0.03mm, planet carrier deformation ≤ 0.1mm (in compliance with ISO 6406 "Bicycle gear systems" standard).
Ratchet fatigue testing machine Applicable Standards
Bicycle/Electric Bicycle Standards:
ISO 4210-8: Bicycles - Safety requirements (Part 8: Test methods for pedals and drive systems) - This standard includes the dynamic fatigue test requirements for freewheel/ratchet mechanisms.
GB 3565: Safety Requirements for Bicycles (Chinese National Standard, corresponding to ISO 4210).
EN 15194: European standard for electrically assisted bicycles (the requirements for ratchet mechanisms are higher due to motor assistance).
