機器
accuracy
background
cog
cogwheels
concept
connection
crank
engineering
engineeringpart
equipment
gear
gearbox
gears
gearwheels
industrialequipment
industrialpart
industry
industrytool
iron
machinepart
mechanical
mechanicalequipment
metal
metallic
metalteeth
motion
motor
nobody
pinions
power
precision
steel
strength
technology
teeth
transmission
turning
wheel
working