Why the pump of coffee makers makes that horrible noise?

[dor123]

https://www.youtube.com/watch?v=i3PDMXeQjMk
I operated the tutors coffee maker to show you how a horrible "BRRRRRRRRRRRRRRRR" noise its pump makes.
This is true for household and commercial coffee makers.
Why this is happening?

[AngryHorse]

The pumps are similar to our wetvac pumps at work, their electromagnetic piston bounces off a big spring at one end of the chamber, this is what gives that loud noise!

IMG_8373.jpeg

[dor123]

Why the pump in coffee makers is a reciprocating pump? What about rotary vane pump, which is small as well?
These pumps are in use also in pressure washers.

[AngryHorse]

Here they are in their component parts

IMG_8374.jpeg

[FrontSideBus]

Down to cost tbh.

[Slyspark]

I guess it might also be the case, that this type of pump is able to create a much greater pressure. Forcing water through coffee grounds requires a surprising amountt of pressure. Given how small the pump needs to be to fit into the machine, I guess someone has decided this is the best way to achieve this?

[AngryHorse]

Yeah, in the wetvacs they pump it through a brass pinhole fan nozzle, it’s gives a wide spread underneath the vacuum head

[BC5-80]

Easy and cheap to achieve with half-wave-driven solenoid with one-way valve in series.

[FrontSideBus]

I must admit, the noise is something I quite enjoy as it means in a moment there will be coffee

[Oliver]

Years ago, I took apart one of those commercial Karcher Wet Vacs (model Puzzi 8/1) and it had one of those solenoid pumps. The pump failed and it was full of hair! I suspect the dirty water tank had been regularly used to fill machine's clean water tank, and the dirt had gotten through the fine mesh.