Dyson DC52 Technology

Dyson vacuum cleaners operate on the principle of centrifugal separation, which is also described here https://de.wikipedia.org/wiki/Fliehkraft... on Wikipedia. A centrifugal separator always has a tangential inlet, a round—usually conical—separation container, and a central immersion tube as an outlet.

In the Dyson DC52, the cyclone has three stages.

Let's start with the first stage, coarse dust separation.

The cyclone has a tangential inlet; on the Dyson, this is the rectangular intake into the dust container. The rectangular cross-section improves cyclone separation because the entry is more strongly tangential. The disadvantage is that the cross-section changes from the round hose to the rectangular shape before the container and bends twice at right angles. Therefore, the airflow under the container is a trap for sucked-up objects (toys, etc.). Bagged vacuum cleaners usually maintain a round cross-section all the way into the bag.

The sucked-in air must now follow the curvature of the round container. If something moves on a circular path, a centrifugal force always acts outward. The force is proportional to the mass. A particle, which is naturally much heavier than the same volume of air, is pressed against the container wall. If you have ever sucked up a bead or marble, you can sometimes hear and see it rotating along the container wall. This is also the reason why the container is usually scratched from the inside on older devices. If a larger object rotates inside the device, the recommendation is to switch off the device and remove the object.

Due to friction against the wall, the particle is slowed down and moves downward in spiral paths.

The air then enters the immersion tube; in the first stage of the Dyson, this is a cylindrical gap formed by the metal mesh in the middle and the central tube.

Parts of low density but with high air resistance, especially hair, get stuck on the metal mesh. However, I have also often found hair that made it all the way into the motor.

If the mesh is full of hair, the air naturally has a harder time passing through and the device loses suction power.

If the container is too full—hence the Max marking—the separated dust is too close to the air inlet and is swirled up again. Regular emptying therefore helps the device to have a long service life.

Now it also becomes clear that the vacuum cleaner should not fall over or even end up upside down during operation. If it does, all the collected dirt falls back into the tangential airflow at once. In that case, the two further separation stages can no longer separate everything, and the dust ends up in the motor and the post-motor filter (this is probably why you are currently on my page at iFixit).

A post about the next stages will follow once I disassemble a cyclone.

Electrically, the Dyson DC52 is very simple. It is one of the few devices from the 2010s that manages without electronics.

Because the housing is fully insulated, a two-core cable is sufficient (as with most vacuum cleaners). It is wound onto a spool, clamped at its hub, and ends in two spring-loaded contacts made of a special copper alloy. These press against two rings made of this material, which are attached to the rigid axle connected to the housing. The housing and the spool are then also connected by a coiled spring made of spring steel. When the cable is pulled out, the leaf spring is tensioned. A small lever presses a rubber roller against the spool and prevents it from retracting. A step on the cable rewind switch releases the rubber roller.

From the two contact rings, a white and a black strand go upward. The black one is also routed through a switch.

Both then go to the universal motor.

It has a green interference suppression capacitor so that sparks in the motor do not interfere with devices in the vicinity. But this, too, is a passive component and not electronics—and certainly not a chip programmed to ensure the device doesn't last long, as some conspiracy theorists on the net claim.

The motor has two stator windings, two carbon brushes, and an armature, which is ultimately a coil with many taps. You can also find the operating principle of a universal motor on Wikipedia https://de.wikipedia.org/wiki/Einphasen-....

The armature shaft is ball-bearing mounted and connected to an air blade on the opposite side. The windings are wired such that the air blade is always drawing in air. The compressed air then flows over the windings to the outside.

Wear parts in the motor are the carbon brushes, which are also easy to replace here.

The motor with its 1200 watts needs the air for cooling, otherwise it would burn out very quickly.

Unlike many other vacuum cleaners, I did not find any over-temperature shut-off in the Dyson.

The sequence of failures is therefore often: misused (too much dust) > post-motor filter clogs > less airflow > less cooling > increased operating temperature > premature failure of the motor.

Also, dust that has been sucked in and not separated by the cyclone can act abrasively on the carbon brushes and the commutator and reduce their service life.

If a large part gets into the air blade and blocks it, the motor draws full current without cooling; furthermore, no counter-field builds up. In this case, the fuse blows and/or the motor burns out.

Therefore, the Dyson should not be switched on without the cyclone. During a test, definitely ensure that nothing can be sucked in.

Because a suction hose can actually become blocked, the motor would quickly be in serious danger. Since there is no electronic over-temperature shut-off, a simple mechanical part mounted on the cable rewind performs this function. It is a rubber plate on a spiral spring. If the airflow is interrupted, the vacuum in the motor compartment drops significantly and the air pressure from the outside is stronger than the spring. This creates an airflow from the outside via the upper housing to the motor.

If you block the airflow with your hand, the motor noise changes after a few seconds because the spring has opened.