Rotary compressor sealing vane leakage/chatter

This video is in response to some questions by NOBOX7 and Aussie50 about a chattering noise and low flow from these rotary compressors when there is no back pressure.

I took high speed video at 6000fps of the sealing vane, showing the vane separating from the rotary ring, allowing gas to escape from the high pressure side to the low pressure side.

Category:

Science & Technology

Tags:

• Rotary
• Compressor
• vane
• chatter
• HVAC
• AC
• Air
• Conditioner
• Condensing
• unit
• Rotor
• Motor
• Induction
• pump
• high
• speed

[Aussie50]

I'm just working on a vid where it appears Daikin has addressed that problem by making the vane a apart of the rotor and having it swing in a bush, maintaining full contact at the highest speeds and lowest pressures.

[tesla500]

That's the inverter based unit, right? That would definitely make sense at the high speeds those can run at.

[Aussie50]

Magnificent work man!, I wish i had your camera :D

Thank you for demonstrating that for us and providing a great view of the rotor and vane (I think they call it a vane)

[tesla500]

Thanks Ed! The camera is actually something I built myself, there's a thread about it on 4hv, linked to in the description of my video titled "First High-Speed camera test video - Spin top" (I can't post an external link in these comments for some reason)

I've been too lazy to do it so far, but I can post the design info, and anyone could build one for about $600

[chrstphrharp1]

My step father was an engineer at GE in the early fifties and designed the first rotary compressor. He retired in 69 and started the Fedders Compressor company and the redesigned rotary compressor. It never out preformed the GE design but was cheaper to build and work just as well in 15,000 btu units and smaller. The 39 and 48 frame units were standard, the 55 and 63 frames just never had the reliability and were eventully scraped.

[Aussie50]

yeah fitting/pipe failures would be cool but you need over 600psi to rupture refrigeration lines

I could make a test rig for clamped/press fittings though

[Aussie50]

you'd have to fit a regulator to the discharge in order to keep back pressure safe whilst using it as a Vac pump

[NOBOX7]

nice set up ,aim that baby at some high current contacts or on a commuter of a vaccum cleaner ,actualy any spark footage would be cool

[NOBOX7]

thanks for the vid ,,ya no one day i plane to do a hose /pressure video to show the

limmits of barbed fittings and hose clamps and the quick connect pipe fittings,

also it would be neet to induce a rupture on a copper pipe to view the behavior of the incedent

[NOBOX7]

great vid friend its neet to see the actual reason for the low pressure clatter,great vid

[diymania]

The gap is small but it can be heard very well as that loud tapping noise.

The downside with a rotary is that the higher the pressure the tighter the seal, so if you crimped the high pressure line, this compresor would pump itself up until the casing explodes or till the motor is no longer strong enuf to turn the thing against the pressure..

[Aussie50]

wow, sounds good!, I'll have to pay anotehr visit to 4hv then, been a while since I was on that site.

[Aussie50]

yeah, 3 phase DC, when it decided to run it would scream!, very high speed twin rotor