US 3793739 A
A machinery base carrying several rotating components is aligned on a factory foundation, prior to shipment to an installation site foundation. At the installation site, the original factory alignment is maintained by establishing the relationship of the supporting surfaces of the foundation with the equipment in place substantially identical to that of the factory condition. This is carried out by an alignment process which utilizes reference points outside of the machinery base.
Description (OCR text may contain errors)
, United States Patent [191 3,793,739 Hoffman et al.  F b, 26, 1974 [5 PROCESS FOR INSTALLING 2,570,275 10/1951 Reading 33/286 x AS MACHINERY SUBJECT 2,705,375 4/1955 Foreman et a1 33/180 R X To Hoffman  inventors: Herbert NJ Hoffman, Lunenburg; primary Examiner john w Huckert Harry Mayor, Fltchburg, both of Assistant Examiner-Milton S. Gerstein Mass- Attorney, Agent, or Firm-John F. Ahern; James W.  Assignee: General Electric Company, Mitchell Schenectady, NY. 22 Filed: Apr. 17, 1972  ABSTRACT A machinery base carrying several rotating compo- [211 Appl' I nents is aligned on a factory foundation, prior to shipment to an installation site foundation. At the installa-  US. Cl 33/286, 33/180 R, 290/52 ion Site, the original factory alignment is maintained  Int. Cl. G01b 5/00 y a lishing the relationship of the supporting sur-  Field of Search 33/14, 286, 180R; 290/52 faces of the foundation with the equipment in place substantially identical to that of the factory condition.  Refer n Cit d This is carried out by an alignment process which uti- UNITED STATES PATENTS lizes reference points outside of the machinery base. 3,267,794 8/1966 Howe 33/286 X 3 Claims 10 Drawing Figures 5 C 7 9 1 1, ",5 1*; as
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, FACTORY FOUNDATION zMACHlNERY BASE smz FOUNDATION -Ek-TEMPORARY REFERENCE III/ \\\\\\\\\\\\ TEMPORARY SUPPORT PATENTEDFEBZB i974 SHEU 2 0f 2 OUTSIDE PROCESS FOR INSTALLING BASE-MOUNTED MACHINERY SUBJECT TO MISALIGNMENT BACKGROUND OF THE INVENTION vdeflectable foundations under less than ideal conditions, such as shipboard foundations.
Rotating .equipment is designed to operate properly when the shafts of the various components are correctly aligned and, despite the use of flexible couplings to accommodate slight misalignment, various ways have been sought to achieve the best initial alignment possible by a method which does not require alignment adjustments of the machinery components mounted on the base. The problems of alignment in base-mounted machinery such as shipboard turbine-generator'sets are set forth in US. Pat. No. 3,185,854 issued to H. N. Hoffman on May 25, 1965, assigned to the present assignee, which is incorporated herein by reference. The present invention relates to an improved process for installing base-mounted machinery, suchas disclosed in the Hoffman patent, on a site foundation.
The problem which thepresent invention is intended to solve arises from the fact that, no matter how well the equipment is aligned on its base in the factory, variations between the supporting surfaces of the factory foundation and the final site foundation with the equipment supported on it will cause'distortion of the base and subsequent misalignment of. the components mounted on it. Means are desirable to initially establish a foundation seating for the equipment, after the equipment is in place, which duplicates that in the factory. Also, means are desired for making periodic checks to determine if changes have taken place in the foundation that might affect the alignment of the machinery on the base and, if so, to take the corrective action necessary.
One of the primary problems with initially establishing and later checking the condition of the base supporting surfaces is that these are usually made inaccessible by the equipment itself. The use of the seating surfaces of the base directly for reestablishing factory base on thesupport establishing an outside reference plane which forms an extension of the support plane, and adjusting or shimrning the mounting to reestablish the base support plane, thus duplicating the factory foundation.
DRAWING The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of practice, together with further objects and advantages thereof, may best be understood by reference to the alignment and subsequent alignment checks is preferred to the use of reference points on the base displaced from these seating surfaces since it eliminates the potential errors associated with transfer measurements and damage to the reference surfaces.
Accordingly, one object of the present invention is to provide an improved process for installing and checking alignment of base-mounted machinery.
Another object of the invention is to provide an improved installation process for placing a turbinegenerator set aboard a Shipboard foundation.
Still another object of the invention is to provide an improved process for duplicating a factory foundation mounting at a site in the field for previously aligned rotating equipment. I
SUMMARY OF THE INVENTION Briefly stated, the invention comprises the steps of aligning base-mounted machinery on a previously established planar surface of known accuracy. moving the base-mounted machinery to the site, establishing a rough initial base support plane at the site, placing the following description taken in connection with the accompanying drawing in which:
FIG. 1 is a simplified plan view of base-mounted equipment on the factory foundation;
FIG. 2 is a simplified plan view of the site foundation without the equipment, with support areas for the machinery numbered and a temporary supporting chock arranged on each support'area and adjusted for height to provide a temporary planar surface;
FIG. 3 is a plan view of the equipment base supported on the site foundation; I
FIG. 4 is a plan view'of the support on one side using straight-edge leveling ofthe extending top surfaces of the temporary checks on which the machinery base is resting; v
FIG. 5 is an elevation view of a diagonal straightedge for establishing a plane among four support surfaces as applicable to FIG. 4 and FIG. 6;
FIGS. 6 and 7 are planviews illustrating the process using straightedge techniques and tight-wire techniques, respectively;
FIGS. 8 and 9 are simplified horizontal cross sections of machinery foot portions with elevated reference points, and
FIG. 10 is a simplified schematic drawing of base and reference planes.
' DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 of the drawing, a machinery base 1 carries rotating equipment such as a turbine 2, gear 3 and generator 4 which have aligned shafts connected by couplings 5, 6. The type of equipment on base 1 is not material to the present invention. The base 1 is supported by support pads 7 on a firm factory foundation 8 which is carefully prepared to ensure a level and planar seating surface for base 1 of know predetermined accuracy. Alignment is performed between the pieces of equipment 2,3, 4 so that if the factory foundation conditions are substantially duplicated, the machinery on base 1 willbe aligned at the final site.
-FIG. 2 illustrates a typical shipboard site foundation comprising parallel H beams '9, 10 attached to the ships structure. Movement of the beams between shipbuilding and launching, as well as deflection due to changes in weight distribution as the equipment is placed on the H beams would normally cause deflection of the machinery base at the site. Temporary chocks corresponding to the locations of mounting feet 7 in FIG. 1 are placed as indicated at ll, l3, l5 and 17 on H beam 9 and similarly at 12, 14, l6, 18 on beam 10. These temporary checks are proportioned to be narrower than the base support areas to permit taking height measurements beside them for fitting final chocks and are sized to extend outside of the base rails to permit checking their top surface for colinearity. A temporary reference chock support 20 is located below the intersection of two diagonals.
Digressing briefly to matters of technique which will be know to those skilled in the art, the means of establishing colinearity are shown in FIG. 4 using a straightedge technique. The height of support surface at 11 is established from a straightedge 21 laid across supports at 13, 15. Similarly, the height of the surface at 17 is established by straightedge 22 laid across supports 13, 15. Any number of support surfaces may be brought into colinearity as indicated by the additional dotted line support shown at 23.
Coplanarity of points is established as shown in FIG. 5. FIG. shows a straightedge 24 extending diagonally between typical support surfaces 13 and 16 over temporary support 20. An adjustable chock 25 with a measuring block 26 rests on support 20. The measurement 27 should be the same when the diagonal straightedge is placed over another pair of support surfaces in order to establish coplanarity ofthe support surfaces.
Referring back to FIG. 2 and starting with two selected locations such as 13, 15 on one side and 14, 16 on the other, the undersides of the temporary chocks at the four locations are shimmed until their top surfaces are coplanar, using the temporary reference chock to establish coplanarity. Next, the undersides of the temporary chocks at locations 11, 17 are shimmed until their top surfaces .are colinear with the top surfaces of chocks at points 13, 15. Similarly, chocks at points 12, 18 are shimmed until their top surfaces are colinear with the top surfaces of chocks at points 14, 16. The foregoing procedure establishes an initial base support plane. This need not be done with extreme accuracy since the invention contemplates later reestablishment of the base support plane.
The next step, as seen in FIG. 3, is to place the base 1 on the temporary chocks on the site foundation. This will normally cause foundation deflections. Coplanarity of the mounting points can no longer easily be established because they are either hidden by the base or require special apparatus because of the projecting equipment.
The next step is to establish an outside reference plane as illustrated in FIG. 3 by the following procedure. A first outside reference point A is established on a line colinear with points l6, 18. A second reference point B is established colinear with points A and 17. Lastly, a third reference point C is established colinear with points 18 and B. By this process, an outside reference plane is established which contains the three points 16, 17, 18 in the base plane, as well as reference points A, B and C.
The last step in the alignment process is to use the outside reference plane as a means of reestablishing the machinery base supporting plane, which has been distorted by placment of the machinery. This is carried out by means of straightedges or tight wires laid through points C and 17 on the one side and between points A and 18 on the other side. The shims under the temporary chocks are adjusted until the points 11, 13, l5, l7 and C are colinear and similarly points l2, 14, 16, 18 and A are colinear. Now, since these points all lie in the outside reference plane,.the site foundation mounting duplicates the factory foundation. Permanent chocks are installed in' place of the temporary chocks and shims and the-machinery is bolted in place.
Reference to FIG. 6 shows establishment of the reference plane by theme of straightedge techniques. Temporary adjustable chocks 28, 29 and 30 are placed. These can be similar to the one shown in FIG. 5. Reference point A is established by a straightedge placed in the position indicated at 31. Reference point B is established by moving the straightedge to the dotted line position shown in 32. Reference point C is established by moving the straightedge to position 33 and finally position 34 enables checking of colinearity of support points on the other side of the base.
FIG. 7 shows the use of tight wires to establish the reference plane. The apparatus shown should be selfexplanatory.
In cases where it is not feasible to establish or subsequently check the base support plane in the actual plane of the equipment support surfaces, it may be desirable to employ devices to establish parallel planes above or below the actual plane of the base support surfaces. Examples of such techniques are shown in FIGS. 8 and 9.
In FIG. 8, carefully machined screws 35 which are all identically the same height are threaded through the base foot 36 to contact the surface S supporting the .base. The tops of the screws 35 thus establish elevated reference surfaces T by which the linearity and coplana'rity of the supporting surfaces for the base can be checked by means of tight wires 37. This approach may be desirable when the support surfaces of the base are covered or obscured by the sides of the base, as shown.
An alternate technique is shown in FIG. 9 where the base foot 38 might be a rough casting. In this event, machined surfaces 39 may establish a surface T above the actual base surface S which is more convenient. Therefore, in this application, the expression base support plane or support surface also includes planes or surfaces such as T in FIGS. 8 and 9 which are parallel to the actual planes or surfaces S.
The operation of the invention will be summarized by reference to the simplified drawing of FIG. 10. The base support plane is representedat 40 and assumes a base supported at only four points, 42, 43, 44 and 45. These can be adjusted for coplanarity by use of a temporary diagonal reference point 46 and straightedges or tight wires. This base plane 40 is disturbed by the weight of the machinery placed on it and reference point 46 is no longer accessible for use in reestablishing coplanarity of the base supportpoints. An outside reference plane A-B-C coplanar with three of the four base supporting points 42, 43 and 45 is established. The extended reference plane is shown as'41. Finally, the fourth base supporting point 44.is adjusted to be coplanar with the reference plane 41, either during the initial installation, or during later checking of the foundation after passage of time.
Thus, there has been described an improved installation and subsequent checking process for basemounted equipment subject to misalignment. While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to 'coverin the appended claims all such modifications as fall Within the true spirit and scope of this invention. What is claimed is:
1. The process for installing, on a site foundation, a base having rotating equipment thereon, said base and equipment having been previously aligned while the base was resting on an original foundation of known predetermined accuracy, comprising the steps of:
a. firstly, providing a plurality of supports for receiving said base at the site foundation;
b. secondly, establishing an initial base support by arranging said supports to be at least in approximately the same plane;
c. thirdly, placing the base on said initial base support;
d. fourthly, establishing an outside reference plane substantially coplanar with some of said supports, said outside reference plane being partially defined by points proximate to and spaced apart from said base support; and
e. fifthly, arranging said supports to lie in substantially the same plane by establishing colinearity of each said support with two points in the plane of said reference plane, whereby the base support conforms to the conditions of the original foundation of known accuracy.
2. The process recited in claim 1, wherein the step of establishing an outside reference plane comprises the sub-steps of:
a. obtaining a first reference point proximate to and spaced apart from said base support, said first reference point being colinear with first and second supports;
b. obtaining a second reference point proximate to and spaced apart from said base support, said second reference point being colinear with said first reference point and a third support; and
c. obtaining a third reference point proximate to and spaced apart from said base support, said third reference point being colinear with said second reference point and said second support.
3. The process for checking planarity of a foundation comprising a plurality of supports having base-mounted equipment resting thereon, comprising the steps of:
a. establishing an outside reference plane by:
i. obtaining a first reference point proximate to and spaced apart from said base support, said first reference point being colinear with first and second supports;
ii. obtaining a second reference point proximate to and spaced apart from said base support, said second reference point being colinear with said first reference point and a third support; and iii. obtaining a third reference point proximate to and spaced apart from said base support, said third reference point being colinear with said second reference point and said second support; and i b. checking for colinearity of succeeding supports with two points in the plane of said reference plane.