Parts of a Centrifuge – Labeled Diagram, Inside and Out

All 13 parts on the diagram

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Lid open 9

Lid It closes over the rotor chamber during a run.
Rotor The part that spins. It carries the tubes.
Centrifuge tubes They hold the samples.
Tube holders (shields) Each one holds a tube at a slant.
Housing The outer box. The controls are on its front.
Timer It sets how long the run lasts.
Speed control It sets how fast the rotor turns.
Power switch It turns the centrifuge on and off.
Feet They hold the centrifuge steady on the bench.

Cut through the middle 4

Rotor chamber The rotor spins inside it.
Motor It turns the shaft.
Shaft (drive shaft) It carries the motor's turning up to the rotor.
Rotor nut It holds the rotor on the shaft.

How this list was compiled: Every name checked on 2026-09-30 and kept only where at least two of these use it. (1) Wikipedia, Laboratory centrifuge and Centrifuge, https://en.wikipedia.org/wiki/Laboratory_centrifuge and https://en.wikipedia.org/wiki/Centrifuge : motor, rotor, centrifuge tubes, fixed-angle and swinging-bucket, what the spinning does to a sample. (2) Centrifuge, Operational Control Tests for Wastewater Treatment Facilities (a course module paid for by the US Environmental Protection Agency, ERIC ED221390), full text at https://archive.org/details/ERIC_ED221390 : lid, centrifuge tubes, shields, swinging bucket, timer. (3) to (6) four makers' manuals, names only, full texts at https://archive.org/details/uoftmanuals006 (rotor, drive shaft, holders and buckets, rotor chamber, motor, timer, speed control, main power switch, housing, base), https://archive.org/details/manualzilla-id-5756730 with https://archive.org/details/manualzilla-id-5800359 (one maker: lid, rotor, rotor nut, motor shaft, rotor chamber, tube shields, speed knob, timer, power switch, housing), https://archive.org/details/manualzilla-id-5755477 (lid, rotor, tube holders, rotor chamber, rotor knob or nut, timer, motor, suction feet) and https://archive.org/details/manualzilla-id-6031012 (rotor, shaft, rotor chamber, motor, timer, power switch, feet). Licence: own work

The drawing: Own drawing from plain geometry; nothing traced. Licence: own work

How it works

A laboratory centrifuge spins liquid samples very fast. Two drawings: the machine with its lid open, then cut through the middle to show the rotor chamber, the shaft and the motor.

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What spins

The motor turns the shaft, and the shaft turns the rotor. The rotor nut holds the rotor on the shaft. The tubes ride in tube holders set into the rotor, and the rotor spins inside the rotor chamber under the closed lid.

What the spinning does

Spinning makes the denser particles in a sample sink to the tube's bottom, while the less dense part rises to the top. The timer sets how long a run lasts, and the speed control sets how fast the rotor turns.

Centrifuge tubes are strong glass or plastic tubes made to fit the rotor exactly.

Questions and answers

What are the main parts of a centrifuge?

A housing with a lid, a rotor with tube holders for the centrifuge tubes, a rotor chamber that the rotor spins in, a motor and a shaft that turn it, and the controls: a timer, a speed control and a power switch.

What does the rotor do in a centrifuge?

The rotor is the part that spins. It carries the tubes round the shaft at high speed. A rotor can be lifted off and changed for another, which is why a nut holds it in place.

What is the difference between a fixed-angle rotor and a swinging-bucket rotor?

A fixed-angle rotor, the kind drawn here, keeps its tubes at one slant. A swinging-bucket rotor hangs its tubes in buckets that swing straight out as it spins.

Why does a centrifuge have a lid?

The lid closes over the rotor chamber while the rotor spins. On many centrifuges a lock or a switch keeps the motor from running unless the lid is closed.