An excavator has several fundamental parts that work together to dig, lift, rotate, and move. Here are the basic components most excavators share:
1. Undercarriage
This is the lower part that provides mobility and stability.
Tracks / Wheels – Most excavators use steel or rubber tracks; some use wheels.
Track frame – Supports the tracks and rollers.
Rollers, idlers, sprockets – Help the track move smoothly.
Travel motors – Power the movement of the tracks.
2. Upper Structure (House)
This rotates on the undercarriage.
Cab – The operator’s seat, controls, and displays.
Engine – Usually diesel; powers the whole machine.
Hydraulic pump – Generates hydraulic pressure for lifting and digging.
Fuel & hydraulic tanks – Store necessary fluids.
Counterweight – Balances the excavator during lifting.
3. Swing System
Allows the entire upper body to rotate 360°.
Swing motor
Swing bearing (slew ring)
4. Working Equipment (Front Attachment)
The part that does the actual digging.
Boom – Connects to the house; provides upward/downward movement.
Arm (Stick) – Extends the reach of the boom.
Bucket – Used for digging; can be switched for other attachments.
Cylinders – Hydraulic rams move the boom, arm, and bucket.
5. Hydraulic System
Powers all movement.
Hydraulic pump
Valves
Hoses and lines
Cylinders (boom, stick, bucket)
6. Attachments (Optional)
Different tools for various jobs:
Breaker/hammer
Auger
Grapple
Tiltrotator
Thumb
Ripper