GB2586022A

GB2586022A - Apparatus for supporting a rotor

Info

Publication number: GB2586022A
Application number: GB1910790.3A
Authority: GB
Inventors: Fowler Steve
Original assignee: Universal Balancing Ltd
Current assignee: Universal Balancing Ltd
Priority date: 2019-07-29
Filing date: 2019-07-29
Publication date: 2021-02-03
Anticipated expiration: 2039-07-29
Also published as: GB201910790D0; GB2586022B

Abstract

A support device 110 for supporting a rotor (142, Figure 9)during a balance process allows it to rotate about an axis, wherein a carriage member 200 extends around and under a portion (144, Figure 10) of the rotor periphery, said carriage member supporting first and second rotatable members 220, each of which engages and supports the rotor, wherein the rotatable members can move towards and away from each other and towards and away from the rotor axis. Alternatively, the apparatus includes a sensing device supported by the carriage member for determining the unbalance in a rotor in a plane coincident with a plane in which the rotatable members lie. Alternatively, the support device includes a main body (313, Figure 11) and a connecting device 230 which supports the carriage member in a cantilevered configuration including one or more connecting members. The carriage member may be flexible and arcuate and may extend around up to 180 degrees of the rotor periphery. It may support third and fourth rotatable members 220 such that the rotatable members are evenly spaced around the rotor axis, have identical diameters and have parallel axes of rotation (221a-d, Figure 16).

Description

Title: Apparatus for supporting a rotor

Description of Invention

The present invention relates to an apparatus for supporting a rotor, in particular as part of a balancing process or method. In particular, the invention relates to an apparatus for determining a magnitude of unbalance in a rotor supported thereby, so that it can be subsequently corrected.

Balancing is typically carried out on rotors to overcome or lessen the problem of 'unbalance' -the uneven distribution of mass around the axis of rotation of the rotor. Unbalance is when the inertia axis of the rotor is offset from its central axis of rotation, which results from the mass of the rotor not being distributed uniformly about its central axis. Rotors suffering unbalance may generate a moment when rotating which leads to vibration.

Correction for unbalance is typically carried out by welding or attaching balance weights to the rotor at balancing planes. Rotors are designed with zones where balance weights can be added corresponding to the number of balancing planes, which for a single piece rotor, are usually near each end of the rotor.

In particular, but not exclusively, the invention relates to an apparatus for supporting a rotor of the type known as "overhung" or "outboard", so that balancing of that rotor can be undertaken. Such rotors are typically characterised in that they are supported for rotation in use at two or more support positions, with respective bearing members, along their length, but where the rotor includes a portion which is positioned outboard of (i.e. not between) those two support positions. An illustrative example of such a rotor is shown in figure 4. When such a rotor is being balanced, at least one of its balance correction planes is typically positioned outboard of (i.e. not between) the support positions of the rotor. To accommodate this, prior art supports such as those shown in figures 1 to 5 are used so as to position a pair of rotatable members, e.g. rollers, as close to the balancing plane as possible.

As shown in figure 4, there are typically two supports 10, 10a, which support opposite ends of a rotor 40. The support 10a includes a pair of rollers 18a, which support one end 41 of the rotor 40. The supporting device 10 is configured to support the overhung end 42 of the rotor 40 and includes a main body 13 which is supported on a base 12. The main body 13 is generally rectangular and extends upwardly from the base 12 where it separates into two upright portions 14, 15. Extending between the upright portions 14, 15 is a laterally extending support portion 16 to which is connected a pair of generally cylindrical extension parts 17a, 18a. Connected to free ends of the extension parts 17a, 18a are a pair of rollers 17, 18, which are supported for rotation about respective axes 19, 20. The rollers 17, 18 are therefore supported in a cantilever configuration such that they are positioned, during balancing, within a recess 43 of the overhung rotor 40 so as to engage a portion 44 of the rotor 40. Both supports 10, 10a include a flexible region 21 with one or more flexible portions 22, 23 which are configured to flex in the direction of arrows Y (see figure 3) during a balancing process so as to permit unbalance of the rotor 40 to be sensed or determined by one or more sensing devices 24 (the positions of which is figure 3 are purely illustrative).

The prior art apparatus, as illustrated by figures 1 to 5, has the disadvantage that errors can exist when measuring the unbalance of the rotor. This is because the cantilever configuration gives rise to flexing of the support in the direction of the arrow X in figure 5, which can reduce the accuracy of the unbalance as sensed/measured at the main body.

The present invention has been devised to address this problem.

According to a first aspect of the invention, we provide an apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a 5 carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the carriage member permits the first and second rotatable members to move towards and 10 away from each other and to move towards and away from the rotor axis.

According to a second aspect of the invention, we provide an apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the apparatus includes a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the carriage member for sensing unbalance of the rotor in a plane which is coincident or substantially coincident with a plane in which the rotatable members lie.

According to a third aspect of the invention, we provide an apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the support device includes a main body and wherein a connecting device including one or more connecting members supports the carriage member relative to the main body in a cantilevered configuration, wherein the apparatus includes a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the connecting device.

Further features of the various aspects of the invention are set out in the claims appended hereto.

Embodiments of the invention will now be described, by way of example only, with reference to the following figures, of which: Figure 6 and 7 are perspective views of an apparatus in accordance with the invention balancing an overhung rotor; Figures 8 and 9 are further perspective views of said apparatus, but with the rotor shown translucent; Figure 10 is a perspective, close-up, view of component parts of said apparatus; Figure 11 is a further perspective, close-up, view of component parts of said apparatus; Figure 12 is a perspective view of a first supporting device of said apparatus; Figure 13 is a further perspective view of the first supporting device of said apparatus; Figure 14 is a front view of the first supporting device of said apparatus; Figure 15 is a further perspective view of the first supporting device of said apparatus; Figure 16 is a plan view of the first supporting device of said apparatus; Figure 17 is a close-up perspective view of component parts of the first supporting device of said apparatus; Figure 18 is front view of a second embodiment of a first supporting device; Figure 19 is a perspective view of the second embodiment of a first supporting device of figure 18; Figure 20 is a further perspective view of the second embodiment of a first supporting device of figure 18; and Figure 21 is a yet further perspective view of the second embodiment of a first supporting device of figure 18.

Referring to figures 6 to 17, these show a first embodiment of an apparatus in accordance with the invention. Components similar to those shown in the apparatus in figures 1 to 5 have been given the same reference numeral with the additional of 100.

These figures show an apparatus 100 for supporting an overhung rotor 140 during a balance process, the apparatus 100 including support devices 110, 110a (spaced axially from each other along the rotor 140) for engaging with and supporting a portion 141 of the rotor 140 so that the rotor 140 is able to rotate about a rotor axis A. Support device 110a has a main body 313 (for supporting the apparatus on or relative to a fixed body, e.g. a floor surface) which is generally rectangular in axial view and extends upwardly from the base 312 where it separates into two upright portions 314, 315. Extending between the upright portions 314, 315 is a laterally extending support portion 316 to which is connected a pair of generally cylindrical rollers 317, 318. The rotatable members 317, 318 are supported for rotation about respective axes and engage with a cylindrical rotor portion 141 at an end of the rotor 140 remote from the overhung portion 142. The support device 110a includes a flexible region with one or more flexible portions 322, 323 which are configured to flex during a balancing process so as to permit unbalance of the rotor 140 to be sensed or determined by one or more sensing devices located on or supported by the main body 313.

Whilst support device 110a does not include a carriage member 200 (as is present in the support device 110 described below) this need not be the case. For example, the support device 110a could be provided with such a carriage member 200 and rotatable members. In such an embodiment, the carriage members 200 would be connected substantially in line with a plane extending through the main body 313, rather than being supported in a cantilever configuration, as for the support device 110. Advantageously, the support device 110a in such an embodiment may include one or more, preferably two, brace members 350a, b, which can optionally be activated by locking means 351a, b, so as to bypass or stiffen said one or more flexible portions 322, 323.

The brace members 350a, b, and their respective locking means 351a, b will be described in further detail later with respect of the support device 110.

The support device 110a includes one or more sensing devices for permitting unbalance of the rotor 40 to be sensed or determined during a balancing process.

The support device 110a includes, is connected to or is positioned next to a driving device for effecting rotation of the rotor 140 about the rotor axis A. Such a device may apply drive to the end of the rotor portion 141.

Support device 110 has a main body 113 (for supporting the apparatus on or relative to a fixed body, e.g. a floor surface) which is generally rectangular in axial view and extends upwardly from the base 112 where it separates into two upright portions 114, 115. Extending between the upright portions 114, 115 is a laterally extending support portion 116.

The support device 110 includes a flexible region with one or more flexible portions 122, 123 which are configured to flex during a balancing process so as to permit unbalance of the rotor 140 to be sensed or determined by one or more sensing devices located on or supported by the main body 113.

Advantageously, the support device 110 may include one or more, preferably two, brace members 150a, b, which can optionally be activated by locking means 151a, b, so as to bypass or stiffen said one or more flexible portions 122, 123. The brace members 150a, b, and their respective locking means 151a, b will be described in further detail later.

The support device 110 includes a carriage member 200 which in use extends around and under a portion of the periphery of the rotor portion 141 so as to support the rotor 140. The carriage member 200 supports four rotatable members 220a, b, c, d for rotation about respective axes 221a, b, c, d. The rotational axes 221a, b, c, d are positioned substantially at the same radial distance r from the rotor axis A, and are substantially parallel with each other and parallel with the rotor axis A. In embodiments, the axes 221a, b, c, d need not necessarily be parallel with each other or parallel with the rotor axis A. Each of the second rotatable members 220a, b, c, d engages with and supports the rotor portion 141 during its rotation. In examples, the rotatable members 200a, b, c, d may be cylindrical in shape, although they may be crown or bevelled. The rotatable members 220a, b, c, d each have an external diameter d which defines a periphery which in use engages the rotor portion 141 and wherein the external diameters d of the rotatable members are identical or substantially identical to each other. In other embodiments, the external diameter of the rotatable members 220a, b, c, d may be different from each other, with their distance from the rotor axis A varying so as to ensure engagement with the rotor portion 141 during the balancing process.

In examples, there may only be a pair of said rotatable members, or there may, in certain examples, be three or more than four of such rotatable members. Whilst in the present example, the rotatable members are shown as being positioned substantially in the same plane, they need not be. For example, one or more of the rotatable members may be positioned to one axial side of the carriage member 200 with one or more of the other rotatable members being positioned to the other axial side of the carriage member 200.

The carriage member 200 is arcuate or substantially arcuate when viewed axially -that is to say when viewed in the direction along the rotor axis A. However, it should be noted that the carriage member 200, in some examples, could take other forms. All that is necessary is that the carriage member is capable of supporting the rotatable members and, in turn, the rotor to be balanced.

In the present example, it can be seen that the carriage member 200 is long enough such that it extends around the underside of the rotor portion 141 for at least 90 degrees of the periphery of the rotor 140. In embodiments, it may extend through a shorter angular range, or greater. For examples, it may extend around at least 120 degrees of the periphery of the rotor, or substantially 180 degrees.

The arcuate carriage member 200 has first 201 and second 202 free ends, with the first rotatable member 220a being supported for rotation at or near the first free end 201 and the second rotatable member 220b being supported for rotation at or near the second free end 202. The third 220c and fourth 220d rotatable members are supported on the carriage member 220 at positions in between the first 220a and second 220b rotatable members. In the present example, the rotatable members 220a, b, c, d are positioned spaced, preferably substantially evenly, from each other around the rotor axis A. Thus, in the present example, the first and third rotatable members 220a, c are positioned to one lateral side of a plane (not shown) which extends vertically through the rotor axis A and the second and fourth rotatable members 220b, d are positioned to an opposite lateral side of said plane.

The carriage member 200 is connected to the laterally extending support portion 116 by a connecting device 230, which in this example is a pair of connecting member 231a, b. In embodiments there may be one or more than two connecting members). The connecting members 231a, b are elongate and extend away from the portion 116 substantially parallel with the rotor axis A. The two connecting members 231a, b extend parallel with each other and are positioned substantially equally either side of a plane which extends vertically through the rotor axis A. The connecting members 231a, b are of a length such that they support the carriage member 200 in a cantilever configuration such that it is positioned, during balancing, within the recess 143 of the overhung rotor 140 so as to engage the portion 144 of the rotor 140.

The connecting members 231a, b are connected to the carriage member 200 at a position in between adjacent rotatable members. Thus, in the present 30 embodiment, the connecting member 231a is connected to the carriage member 200 at a position in between the rotatable members 220a and 220c.

The connecting member 231b is connected to the carriage member 200 at a position in between the rotatable members 220b and 220d.

The carriage member 200 is configured to permit the rotatable members 220a, b, c, d (and particularly the rotatable members 220a, b) to move towards and away from each other and to move towards and away from the rotor axis A. By "move", we mean non-rotational movement. In other words, the rotatable members can move vertically and/or horizontally relative to the rotor axis and the main body of the support device. This is achieved by the carriage member 200 being flexible so as to permit the positions of the rotatable members 220a, b, c, d to move relative to each other, thus permitting all of the rotatable members 220a, b, c, d to engage the rotor during a balancing process. The arcuate shape of the carriage member 200 assists with this functionality, as does positioning the rotatable members 220a, b at or near the respective first 201 and second 202 ends of the carriage member 200.

To assist in achieving said flexibility the carriage member 200 has at least one opening or cavity therein or therethrough. In this example, the carriage member 200 has five cavities 210a, b, c, d, e. The first cavity 210a is positioned in between the rotatable member 220c,d and so is positioned substantially vertically beneath the rotor axis A. The cavities 210b, c are positioned between the rotatable members 220a and 220c. The cavities 210b, c are positioned between the rotatable members 220d and 220b.

The cavities are substantially identical to each other (although they need not be), and so only the cavity 210a will be described herein. The cavity 210a extends completely through the carriage member 210 in a direction parallel with the rotor axis A. The cavity 210a, when viewed axially, has four walls. First and second walls 211a, b are positioned at upper and lower sides of the cavity 210a, respectively. Third and fourth walls 211c, d are positioned at left and right sides of the cavity 210a, respectively, and extend between the first and second walls 211a, b.

The first and second walls 211a, b are moveable towards and away from each other and do so when an unbalanced rotor is rotated in the apparatus. Such movement of the walls is beneficial, as it permits unbalance of the rotor to be sensed at that location, such that the determined unbalanced is sensed at a balancing plane which is located as close to the overhung end 143 of the rotor 140 as practicable.

Thus, the support device 110 includes a sensing device for sensing or determining an amount of unbalance in a rotor 140, said sensing device being part of or supported by the carriage member 200. In embodiments, the sensing device may be positioned in a plane which is coincident or substantially coincident with a plane in which the rotatable members 220a, b, c, d lie. In embodiments, the sensing device may be positioned at an underside of the carriage member 200 beneath the cavity 210a. In embodiments, the sensing device may be positioned in said the cavity 210a. In embodiments, the sensing device may be positioned at another suitable location on or in the carriage member 200. Sensing the unbalance in plane with the carriage member 200 has the advantage of improved accuracy of detected unbalance.

In addition, or alternatively, the apparatus may include a sensing device, for sensing or determining an amount of unbalance in a rotor, which is part of or supported by one or both connecting member 231a, b.

In addition, or alternatively, the apparatus may include a sensing device, for sensing or determining an amount of unbalance in a rotor, which is part of or 30 supported by the main body 113.

Returning to the brace members 150a, b of the support device 110, these are mirror images of each other and thus only the brace member 150a will be described herein. The brace member 150a extends upwardly from the base 112 to one side of the main body 113 and is separated from the main body 113 by an upwardly extending channel or space 152a. The locking means 151a in this example is a manually tightenable fastener which connects the brace member 150a to the main body 113. When the fastener 151a is tightened, it urges the upper part of the brace member towards the main body 113 thus stiffening the main body and essentially bypassing the flexible portions 122, 123. In other words, the brace members optionally prevent or at least inhibit the flexible portions 122, 123 from flexing during a balancing process. Thus, during a balancing process, with the locking means 151a, b, tightened, the main body 113 is relatively stiff, meaning that sensing of unbalance can be determined at the carriage member 200 with its sensing device. If, in alternative embodiments, a sensing device is not provided at or on the carriage member 200, then the locking means 151a, b can be untightened, meaning that the flexible portions 122, 123 would then be free to flex as a result of unbalance and for that movement to be sensed by a sensing device provided on or supported by the main body 113.

The support device 110a also includes such brace members 350a, b, which can be operated in substantially the same way.

Whilst in the embodiment shown in figures 6 to 18 the support device 110a includes a pair of rollers 317, 318, it could be provided with a carriage member and rotatable members the same or substantially the same as the carriage 200 and rotatable members 220a, b, c, d. In such an embodiment, the carriage member 200 would ideally be connected directly to the main body 313, thus not requiring the connecting members 231a, b, because a cantilever configuration would not be required for the non-overhung end of the rotor. As such, the carriage member 200 would preferably be connected to the main body 313 placing the rotatable members 220a, b, c, d as close to in-line with a plane extending vertically through the main body 313.

Referring to figures 18 to 21, these show a second embodiment of a support device for supporting the overhung end of a rotor. Components similar to those shown in respect of the support device 110 have been given the same reference numeral with the additional of a prime symbol. In this embodiment, there are no brace members for bypassing flexible portions of the main body 113', because the main body 113' does not have any such portions. In this embodiment, sensing of unbalance in a rotor is determined or measured by a sensing device supported on or by the carriage member 200' and/or the connecting member 231a', b'.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.

Claims

CLAIMS1. An apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the carriage member permits the first and second rotatable members to move towards and away from each other and to move towards and away from the rotor axis.
2. An apparatus according to claim 1 wherein the carriage member is flexible such that the first and second rotatable members can each move towards and/or away from the rotor axis.
3. An apparatus according to claim 1 or claim 2 wherein the first rotatable member is positioned to one lateral side of a plane which extends vertically through the rotor axis and wherein the second rotatable member is positioned to an opposite lateral side of a plane which extends vertically through the rotor axis.
4. An apparatus according to any preceding claim wherein the carriage member has first and second free ends, with the first rotatable member being supported for rotation at or near the first free end of the carriage member and the second rotatable member being supported for rotation at or near the second free end of the carriage member.
5. An apparatus according to any preceding claim wherein the carriage member is arcuate or substantially arcuate.
6. An apparatus according to any preceding claim wherein the carriage member extends around at least 90 degrees of the periphery of the rotor.
7. An apparatus according to any preceding claim wherein the carriage member extends around at least 120 degrees of the periphery of the rotor.
8. An apparatus according to any preceding claim wherein the carriage member extends substantially around 180 degrees of the periphery of the rotor.
9. An apparatus according to any preceding claim wherein the carriage member supports, for rotation about respective axes, a third, and preferably a fourth, rotatable member.
10. An apparatus according to claim 9 wherein the third and further carriage members are supports on the carriage member at a position in between the first and second rotatable members.
11. An apparatus according to any preceding claim wherein the rotatable members are positioned spaced, preferably substantially evenly, from each other around the rotor axis.
12. An apparatus according to any preceding claim wherein the rotatable members each have an external diameter which defines a periphery which in use engages the rotor and wherein the external diameters of the rotatable members are identical or substantially identical to each other.
13. An apparatus according to any preceding claim wherein the carriage member supports the rotatable members about respective rotational axes which are positioned substantially at the same radial distance from the rotor axis.
14. An apparatus according to any preceding claim wherein the axes of rotation of the rotatable members are substantially parallel with each other and parallel with the rotor axis.
15. An apparatus according to any preceding claim wherein the carriage member is flexible so as to permit the positions of the rotatable members to move relative to each other, thus permitting all of the rotatable members to engage the rotor during a balancing process.
16. An apparatus according to any preceding claim wherein the carriage member has at least one opening or cavity therein or therethrough, said opening or cavity being defined by at least first and second walls.
17. An apparatus according to claim 16 wherein the first and second walls of the opening or cavity are moveable towards and away from each other.
18. An apparatus according to claim 16 or claim 17 wherein the opening in the carriage member is position substantially vertically beneath the rotor axis.
19. An apparatus according to claim 16, claim 17 or claim 18 wherein the carriage member includes a plurality of said openings or cavities. 25
20. An apparatus according to any preceding claim including a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the carriage member for sensing unbalance of the rotor in a plane which is coincident or substantially coincident with a plane in which the rotatable members lie.
21. An apparatus according to claim 20 as dependent on any one of claims 16 to 19 wherein said sensing device is for sensing movement in one or both of the first and/or second walls of the opening or cavity in the carriage member.
22. An apparatus according to claim 21 wherein the sensing device or a portion thereof is positioned in said opening or cavity in the carriage member.
23. An apparatus according to any preceding claim wherein the apparatus includes a second support device for supporting a second, opposite, end of the rotor
24. An apparatus according to any preceding claim wherein the apparatus includes a driving device for effecting rotation of the rotor about a rotational 15 axis
25. An apparatus according to any preceding claim wherein the apparatus includes a main body which supports the apparatus on or relative to a fixed body and wherein the carriage member is connected to the main body by a 20 connecting device including one or more connecting members.
26. An apparatus according to claim 25 wherein the connecting member is elongate and extends substantially parallel with the rotor axis.
27. An apparatus according to claim 25 or claim 26 wherein the connecting member is connected at a first end to the main body and at a second, opposite, end is connected to the carriage member.
28. An apparatus according to claim 25, claim 26 or claim 27 wherein the connecting member supports the carriage member relative to the main body in a cantilevered configuration.
29. An apparatus according to any one of claims 25 to 28 wherein the apparatus includes two or more of said connecting members, each providing a connection between the main body and the carriage member.
30. An apparatus according to claim 29 wherein the two connecting members extend parallel with each other and are positioned substantially equally either side of a plane which extends vertically through the rotor axis.
31. An apparatus according to any one of claims 25 to 30 wherein the connecting member is connected to the carriage member at a position in between adjacent rotatable members.
32. An apparatus according to any one of claims 25 to 31 including a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the connecting device.
33. An apparatus according to any one of claims 25 to 32 including a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the main body.
34. An apparatus according to any one of claims 25 to 33 wherein the main body includes one or more flexible portions which are configured to flex during a balancing process so as to permit unbalance of a rotor to be sensed or determined at a portion of the main body by a sensing device, and wherein the apparatus includes means for optionally preventing or at least inhibiting said one or more flexible portions from flexing during a balancing process.
35. An apparatus according to claim 34 wherein said means includes one or more brace members which can optionally be activated so as to bypass or stiffen said one or more flexible portions.
36. An apparatus according to claim 35 wherein a first brace member is positioned to one side of the main body and wherein a second brace member is positioned to an opposite side of the main body, preferably wherein the brace members each extend substantially upwardly towards and either side of a plane which extends vertically through the rotor axis.
37. An apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the apparatus includes a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the carriage member for sensing unbalance of the rotor in a plane which is coincident or substantially coincident with a plane in which the rotatable members lie.
38. An apparatus according to claim 37 including one or more or all of the features set out in claims 1 to 36.
39. An apparatus for supporting a rotor during a balance process, the apparatus including a support device for engaging with and supporting a portion of the rotor so that the rotor is able to rotate about a rotor axis, wherein the support device includes a carriage member which in use extends around and under a portion of the periphery of the rotor, said carriage member supporting, for rotation about respective axes, first and second rotatable members, each of which in use engages with and supports the rotor during its rotation, wherein the support device includes a main body and wherein a connecting device including one or more connecting members supports the carriage member relative to the main body in a cantilevered configuration, wherein the apparatus includes a sensing device for sensing or determining an amount of unbalance in a rotor, said sensing device being part of or supported by the connecting device.
40. An apparatus according to claim 39 including one or more or all of the features set out in claims 1 to 38.