機器
accuracy
binding
circle
closeup
cog
cogwheel
concept
connection
cooperation
detail
engaged
engine
engineering
equipment
gear
gearbox
gearing
heavy
industrial
industry
interlocked
iron
large
machinery
macro
mechanical
mechanism
metal
metallic
motor
nobody
objects
old
part
power
precision
railway
reliability
rotation
steel
strong
teamwork
technology
teeth
together
togetherness
transmission
vintage
wheel