Product category:
Gears, brakes, couplings and engines
News Release from: KTR Couplings | Subject: Rotex ZS-DKM 1
Edited by the Engineeringtalk Editorial
Team on 15 November 2006
Double coupling provides margin for pump
drives
The pump industry makes special demands on the torsionally flexible shaft couplings between electric motor and pump.
The pump industry makes special demands on the torsionally flexible shaft couplings between electric motor and pump In the case of pump drives, shaft displacement can be extremely high - especially if hot media are conveyed
This article was originally published on Engineeringtalk on 19 Sep 2006 at 8.00am (UK)
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The reason for this is that the pump is considerably more heated during the operation than the motor is.
The coefficient of heat expansion and pipeline forces which influence the pump case then lead to axial and radial displacements which can reach one or two millimetres in practice.
With such a shaft displacement, conventional and single-cardanic shaft couplings are often overstrained - high restoring forces lead to a reduction of lifetime of the bearings, the slide ring sealings and the drive.
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Therefore special designs, like for example tyre couplings, compensate for considerable shaft displacements but need more space and are comparably more expensive.
Additionally, the tyre deforms due to torque strain, leading to balance errors and consequently to vibrations and important bearing loads.
The Rotex ZS-DKM 1 from KTR offers a solution to this problem.
This torsionally flexible, double-cardanic shaft coupling principally consists of two Rotex couplings which are connected to each other.
The Rotex coupling principle has proved to be successful a million times in numerous complex applications.
Between two jaw-type hub parts which grip into each other there is a prestressed elastomer spider with high chemical and thermal resistance.
By connecting two such coupling elements by a spacer, you get a double-cardanic coupling compensating for considerable shaft displacements.
And this in case of an extremely small external diameter: all components remain in the spline of the hub parts.
The Rotex ZS-DKM 1 meets the requirements regarding the drives of process pumps.
It reduces vibration and noise and disposes good damping properties.
The restoring forces resulting from the displacement are low, even in the case of a considerable shaft displacement.
If you talk about process pumps, the spacer corresponds to the requirement concerning a radial disassembly.
The special feature is a low-cost assembly; putting into operation a simple visual check, eg with a straight-edge, is sufficient.
Large-scale laser machinings are not necessary.
KTR manufactures the Rotex ZS-DKM 1 in nine sizes from 24/28 to 90.
The length of the spacer is variable; up to six standard lengths are offered each sise.
The power data of the coupling correspond to those of IEC standard motors or standard pumps.
As the coupling consists of mass-produced standard components of the KTR modular system, KTR can supply the Rotex ZS-DKM 1 ex-stock and at low cost.
In pump drives a considerable shaft displacement often occurs.
The double-cardanic Rotex ZSDKM 1 was especially developed for such applications.
Despite its extremely compact design it compensates reliably for big shaft displacements.
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