Patent Application
20160319665
This invention relates generally to a rotor jacking assembly, and more particularly to a rotor jacking assembly for jacking up a rotor while in place in a turbine.
In turbines and electrical generators, it is necessary to periodically replace the journal bearings of the rotor and to conduct major inspections of the turbine. Known procedures utilize a crane to lift the rotor out of the turbine and to support the rotor while journal replacement or inspections are conducted.
It is labor-intensive to remove the rotor entirely from the turbine and use of a crane is an additional expensive and time-consuming task.
One aspect of the disclosed technology relates to a rotor jacking assembly for jacking up a rotor while the rotor remains in place in the turbine.
Another aspect of the disclosed technology relates to performing a major inspection of the turbine while the rotor is jacked up but still in place in the rotor.
One exemplary but nonlimiting aspect of the disclosed technology relates to a jacking assembly for a rotor of a turbine, comprising an arc-shaped saddle configured to extend around and support a lower portion of a rotor, a lifting beam configured to extend over the rotor transversely to an axial direction of the rotor, the lifting beam being axially aligned with the arc-shaped saddle, and two connectors disposed on respective lateral sides of the rotor, each connector extending between and being coupled to the lifting beam and the arc-shaped saddle, wherein the saddle is configured to lift the rotor vertically when the lifting beam is displaced vertically.
Another exemplary but nonlimiting aspect of the disclosed technology relates to a jacking assembly for a rotor of a turbine, comprising an arc-shaped saddle configured to extend around and support a lower portion of a rotor, an arc-shaped retaining member connected to the saddle and configured to extend around an upper portion of the rotor so as to hold the saddle beneath the lower portion of the rotor, and two lifting devices disposed on respective lateral sides of the rotor, the lifting devices being configured to lift the saddle vertically.
Another exemplary but nonlimiting aspect of the disclosed technology relates to a method for replacing a journal bearing of a rotor of a turbine comprising providing an arc-shaped saddle configured to extend around and support a lower portion of a rotor, lifting the rotor by the saddle vertically to unload the weight of the rotor from the journal bearing while maintaining the rotor in the turbine, and removing at least a lower portion of the journal bearing while the rotor is lifted by the saddle.
Other aspects, features, and advantages of this technology will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of this invention.
The accompanying drawings facilitate an understanding of the various examples of this technology. In such drawings:
Referring to
The turbine 14 is coupled to the compressor 12 via a rotor or shaft 20. Also shown in
As shown in
The connectors 34 extend through respective through-holes in lifting beam 36, as shown in
A lifting device (e.g., mechanical jack 50) is positioned beneath the lifting beam 36 on each side of the rotor. The jacks 50 are configured to support a portion of the lifting beam 36. The jacks 50 are also configured to jack up lifting beam 36 which in turn causes the saddle 32 to lift the rotor. The jacks 50 use positive stop such that there is essentially no creep down over time. That is, due to their mechanical construction, the jacks can be continually loaded supporting the rotor for long periods of time (e.g., several weeks) with no creep down. The forward 22 and aft 24 ends of rotor 20 may each weight around 50,000 lbs.
As can be seen in
The jacking assembly 30 is configured to lift the rotor a distance of 0.008 to 0.0225 inches (or 0.02032 to 0.5715 mm), preferably 0.01 to 0.02 inches (or 0.254 to 0.508 mm). As such, rotor 20 is not removed from the turbine. Instead, rotor 20 is raised such a small distance that the rotor remains in the turbine while lifted just enough to unload the weight of the rotor from the journal bearing.
Jacking assembly 30 is configured to hold the rotor in the lifted position while the lower half of bearing #1 is removed, inspected or replaced. While the rotor is lifted, a major inspection may be performed on the turbine. For example, steam cleaning tools and borescopes may be used to clean and inspect the lower half stator vanes while the rotor is lifted but still in place in the turbine.
Unlike the jacking position at the forward end 22 of rotor 20, the jacking position at the aft end 24 is near an end portion of the rotor, as can be seen in
As such, a saddle 42 having an arc-shaped retaining member 45 attached thereto is utilized for jacking up the aft end 24 of rotor 20, as shown in
Similar to forward end jacking assembly 30, aft end jacking assembly 40 includes connectors 44 (e.g., threaded rods), a lifting beam 46, retaining members (e.g., nuts 48) and lifting devices (e.g., mechanical jacks 50), as shown in
As shown in
As such, the saddle 42 is positioned on the rotor with the retaining member 45 is located downwardly so as to fit into the clearance space d1, as shown in
Similar to the jacking assembly 30, jacking assembly 40 is configured to lift the rotor a distance of 0.008 to 0.0225 inches, preferably 0.01 to 0.02 inches. Referring to
While the invention has been described in connection with what is presently considered to be the most practical and preferred examples, it is to be understood that the invention is not to be limited to the disclosed examples, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
