機器
agricultural
antique
closeup
cogwheel
commutator
drive
electric
engine
engineering
equipment
factory
force
gearing
gears
gray
grease
grinding
harrow
historical
industrial
industry
iron
isolated
machinery
mechanical
mechanics
mechanism
mechanisms
metal
old
part
pinion
power
precision
reduction
robust
rust
safety
shaft
spring
steel
sturdy
technical
technology
wheel
workplace
workshop