Problems with the connection between the mixer shaft and the sleeve
Thread Content
I wonder, among those who are highly knowledgeable in this field, if anyone knows the method of thermal fitting for connecting a stirring shaft to its sleeve. It seems to involve heating the sleeve and fitting it onto the shaft, and then fixing it to the shaft after cooling – is that a viable approach? I see that by standard, it’s mostly key connections. I called a few manufacturers and they all said it’s connected via keys. I would be grateful if you could share your insights; thank you very much!
It’s a bit like a heat-shrink pressure vessel. But it’s a technical task, right? Sometimes the mixer is quite heavy. It’s not necessarily simpler compared to keyway cutting or through-bolting, right?
I asked a certain manufacturer, and they said it’s actually not feasible.
Why does LZ want to use a heat sleeve? For a heat-fit, the sleeve and the shaft are designed to have an interference fit; during installation, the sleeve is usually heated before being fitted in, and this approach is completely viable and works well under normal operating conditions. A simple comparative analysis of the heat-shrinking and key-connected methods is as follows. The advantages of using heat-shrinking include a relatively smaller diameter for the stirring shaft and lower initial investment. The disadvantages are as follows: 1. Heat sleeve processing requires high precision, and installation and maintenance are troublesome; once it fails, it will directly cause wear of the stirring shaft (the main function of the shaft sleeve is to protect the shaft), and this loss will be significantly higher than the initial investment required due to a smaller shaft diameter. Therefore, heat shrinking is generally not used, unless specifically requested by the client.
Thank you for CNOOC’s enthusiastic reply. It was required this way on the previous drawings, but after some discussions, it was found to be not very feasible; now we plan to change it to a key connection and weld it in place
This post was last edited by wanlirn on 2019-9-25 at 13:33. We manufacture mixers on a regular basis, and for the shaft sleeves related to the bracket bearings, plain construction is used. . . I’ve never seen one with a heat sleeve
The heat-shrink fitting technique requires high standards, so it is not recommended; key fixation can be used instead.
Thank you for your reply; I’m changing to key connection now.
Thank you for your reply; I’m changing to key connection now.
If welding is being used, then what’s the need for keys? If keys are used, it’s for the purpose of disassembly later on; it’s better not to weld.
Thank you for your prompt reply. It seems you know a lot about this area. I would like to ask further: regarding the fit between the sleeve and the shaft, what should be the inner diameter of the sleeve? I’ve searched through many resources but found no information on this; it’s my first time designing a mixing shaft.