Hub gears for dummies

Technological design Engineering Alexandre De Bie

Hub gears for dummiesSturmey Archer

3 Speed Hub


What’s Inside


Driver and sprocket


Hub Planetary Gearing


Hub (Wheel)

Hub Teeth


Planetary Gearing

Section

Sun (Fix)

Gear ring

4 planets


Axle and Sun gear

Sun gear

Axle


Planet Cage with Planets

4 Planet axles

4 Planets

2 Planet cage pawl Cage


Gear ring

4 Tabs2 Pawls Gear ring teeth

Bottom View


Sprocket - Planetary gearing connection

SprocketClutch

Planet axle


Planetery gearing – Hub Connection

Hub teeth Gear ring pawlCage pawl


Choosing the speed 3rd Speed

2nd Speed

1st Speed

Spring Force


3rd speed (High)Clutch rest against planet axle

How it works


Cage rotates 90°Gear ring 120°

Driver drives the planet cagePlanet cage drives the gear ring.

Cage rotates 3 timesGear ring rotates 4 times

90°120°

Gear ring connectedto hub with pawl

Hub drives as fast as gear ring

Make 3 rotation with the driverto make 4 rotations with the wheel


2nd Speed (Normal)

Contact with cage lost

Clutch rest against tabs from the gear ring


Driver drives the gear ring

Gear ring connectedto hub with pawl

Hub drives as fast as gear ring

Make 1 rotation with the driver to rotate the hub 1 time


1st Speed (Low)

Clutch rest against tabs from the gear ringAnd blocks the gear ring pawls

As in the 2nd speed no contact with the cage


2nd Speed pawl not blocked 1st Speed clutch blocks pawl

Gear ring is unable to grab in the hub teeth


Gear ring 120°Cage rotates 90°

Driver drives the gear ringGear ring drives the planet cage

Gear ring rotates 4 timesCage rotates 3 times

90°120°

Planet Cage connectedto hub with pawl

Hub drives as fast planet cage

Make 4 rotation with the driverto make 3 rotations with the wheel

Hub gears for dummies

Technology

Transcript of Hub gears for dummies