機器
agriculture
antique
axle
bearing
closeup
clutch
cogwheel
coupling
drive
engineering
equipment
farming
force
gear
gearing
grease
green
grinding
historical
industrial
industry
iron
isolated
machinery
mechanical
mechanics
mechanism
mechanisms
metal
old
part
pinion
power
precision
reduction
robust
rust
shaft
socket
spring
steel
sturdy
support
technical
technology
wheel
workshop