FIELD OF INVENTION
The present invention relates to angular Winding Robot for automation of angular winding of any size of brush seals used in steam turbines, gas turbines and compressors. The invention specifically relates to a mechanism which facilitates the winding of wire on a flat circular plate at a particular angle, as a part of brush seal manufacturing cycle. This apparatus makes the process of winding semi-automatic.
BACKGROUND OF THE INVENTION
Brush seals are used in various equipments like steam turbines, gas turbines and compressors to reduce the process fluid leakage and increase the internal process efficiency. Brush seals are made of a bristle packs sandwiched between a pair of backing plates. The backing plate is attached to the stationary part and the bristles extend outwardly toward rotating part. The free end of the bristles rubs against the rotating part and prevents fluid leakage. The brush seals are built with bristle packs which are an assembly of thin high temp alloy wires. The assembly is such that the wires are arranged not radially but at an angle ranging from 35° to 45°, called as cant or lay angle. The method followed for making a brush seal are multiple. Since the thin

wires need to be arranged compactly to avoid leakage through the wires and at an angle to the radial direction to minimise friction with the rotating part, the method of such laying is critical.
For winding of the thin alloy wires, different inventors have used different winding techniques. Some of the winding techniques are described below.
In the US Patent 4204629, a method of manufacture of a brush for use as a seal includes the steps of winding a filament or filaments of bristle material onto a mandrel which carries on each side thereof a side-plate of the brush so that the bristle material overlies an exposed face of each side-plate at an angle of 45°. After winding, a second side-plate is made to overlie the bristle material to sandwich it between the two plates and the side-plates and bristle material are welded or fused together at one edge thereof. The bristle material is then cut and the plates removed from the mandrel to produce two brushes with bristles projecting from the other edge at an angle.
In the US Patent 4732339, an apparatus for winding a filament onto a former includes one or more filament supply bobbins mounted on an annular carrier for rotation about a first axis for receiving a plurality of windings of the filament, and a translation device for moving the former relative to the carrier along a path which

passes through the carrier thereby enabling the filament to be wrapped around the former. A pair of pinch rollers positioned at the mid span of each bobbin act to guide the filament onto a loading surface over which the filament passes from the pinch rollers to the former. The loading surface is formed by the radially innermost portion of the carrier and is arcuate in cross section. The apparatus reduces bending of the filament as it is wound onto the former.
In the US Patent 0214628A1, a method of forming brush seal segments includes mounting a pair of full formed plates having opposite arcuate edges in back to back relation and wrapping wire about the form plates in multiple passes to form wire runs at angles, e.g., 35-45° relative to radii of the arcuate edges. Half form plates are assembled to opposite sides of the full form plates adjacent one edge of the sub assembly. The wire wrap adjacent to the one edge of the full form plates is removed. Welds are applied between each adjacent of and full form plates. The inner edges of the wrapped wire and inner frame members of the full form plates are removed. The assembly is then separated to form a pair of arcuate brush seal segments. The applied patent (Application No. 461/KOL/2012) discloses a method for manufacturing brush seals for turbo machinery operable at lower radial rotor-stator clearances with improved leakage performance.

The applied patent (Application No. 1064/KOL/2012) discloses a manual angular winding tool for manufacture of bristle pack to build brush seals.
The automation of the winding process is described in the applied patent (Application No. 201631003336) which discloses an apparatus for automation of brush seal winding process with improved bristle pack density.
The present invention is another apparatus which is compact and suitable for winding of any brush seal size to achieve the required bristle pack density. The compactness is achieved through housing of wire tensioner and wire bobbin on the mandrel provides reduction in wire transfer path.
OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose a compact angular winding robot/apparatus for automation of angular winding of any size of brush seals which is capable of providing a semi automation of angular winding for manufacturing of any size of bristle packs to build brush seal.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.1. : Shows top view of an angular winding apparatus/robot.
Fig.2. : Shows an isometric view of angular winding apparatus/robot.
Fig.3. : Shows a winding mandrel of the apparatus and its driving mechanism.
Fig.4. : Shows the winding mandrel back plate.
Fig.5. : Shows the apparatus/robot with details of wire transfer path and
winding on burn seal plate.
Fig.6. : Base plate of the apparatus.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
The present invention discloses a compact angular winding robot/apparatus which provides a semi-automatic process of winding of brush seals of any size.
As shown in Fig.1, the apparatus in accordance with the invention comprises of the telescopic arms (1) supporting brush seal plate (27) through job holding fixture I (31) and job holding fixture II (32). These telescopic arms (1) are connected firmly to

pivot post (2) which is fixed to base plate (3). This pivot post allows the free rotation of telescopic arms (1) along with the brush seal plate (27).
The pivot post (2) is moved to the required position in the pivot slot (4) on base plate (3) in accordance with the brush seal plate (27) size. Through this provision, winding of any size of brush seal plate (27) is possible with the present invention.
As shown in Fig.2, the telescopic arms (1) are at an elevation from the base plate (3) by the height of the pivot post (2). This makes the telescopic arms (1) works as cantilever beam subjected to load due to the weight of the brush seal plate (27) at the free end. Therefore, two roller supports (12 & 13) are provided under the job holding fixtures (31 & 32). One end of these supports is fixed to the job holding fixtures and the other end with rollers rests on the base plate (3). These supports are free to rotate about their axes and rolls freely on the base plate (3).
As shown in Fig.5, winding of the brush seal wire (26) on to the brush seal plate (27) is achieved through the rotation of winding mandrel (20). The rotation of mandrel (20) lays brush seal wire (26) on the brush seal plate (27) drawing from wire spool bobbin (22) via wire tensioner I (23), wire tensioner II (24) and a nozzle (25). The required rollers and guides from wire spool bobbin (22) to nozzle (25) are made of

ceramic carbide to avoid damage due to passage of brush real wire (26). Wire tensioner I (23) and wire tensioner II (24) provide the required adjustable tensioning of the brush seal wire to get the required winding quality. Wire bobbin (22) consists of number of wires bunched together and wound on to the bobbin.
As shown in Fig.3 and Fig.6, this winding mandrel is connected to a bearing (18) inner race which is free to rotate and outer race of bearing (18) is fixed to mandrel support frame (19). The four legs of support frame (19) are fixed in the slots (28) of base plate (3). This support frame position can be adjusted within the slots (28) to achieve winding angle of 40±5 degrees. It enables the compact Angular Winding Robot to carry out winding of brush seal wire (26) on brush seal plate (27) at an angle 350 to 450 to the radius of the brush seal plate (27). The winding mandrel (20) is driven by a mandrel drive motor (17) through belt drive (21). As the brush seal plate (27) is flat, the speed of the laying of wire needs to be varied in accordance with the winding position in every revolution across the width of the flat brush seat plate to avoid slackness in the winding. The speed needed at the inner and outer periphery of winding is less in comparison to the speed required at the middle of the brush seal plate (27) width.

The compact Angular Winding Robot, winding of circular flat plate through rotating mandrel (20) which carries wire tensioners (23, 24) and wire bobbin (22), making the apparatus compact. Wire transfer path is minimum as wire bobbin (22) is on the mandrel (20) itself and it needs to be transferred to the centre of the mandrel where the winding of brush seal plate is carried out.
The compact Angular Winding Robot, guides the brush seal wire / wire bunch (26) through a nozzle (25) on to the brush seal plate provides controlled wire transfer to prevent spreading of wire instead of laying as bunch.
As shown in Fig.4, this speed variation is achieved through the index notch sensor (5) facing index pin (15) and sector notch sensor (6) facing sector pins (16) on the winding mandrel back plate (14). This mandrel back plate is connected to the inner race of the bearing (18) which rotates along with the mandrel (20).
In one revolution of mandrel (20), the brush seal plate has to be moved by the distance equal to width of the wire bunch to achieve continuous winding on the brush seal plate (27). This is called as job indexing. The winding robot indexes the brush seal plate during winding according to width of the wire bunch drawn from bobbin consisting bunch of wires. The winding robot provides indexing resolution of 8 microns through a

hollow shaft mechanism. It is achieved through hollow shaft motor (10). This motor consists of hollow shaft through which a threaded shaft (11) is assembled and one end of the threaded shaft (11) is connected to the rolling support II (13). As the motor (10) rotates, the threaded shaft (11) traverse and causes the roller support (13) to be pulled/pushed. When the roller support is pulled by threaded shaft, it rotates the brush seal plate around the pivot through telescopic arms. To facilitate this rotation, the motor (10) is allowed to swivel around the pin (35) where the motor (10) is fixed to base plate.
After finishing the one layer of winding, the direction of rotation of hollow shaft motor (10) is reversed which in turn reverse the indexing direction. This operation of detecting the completion of layer is achieved through slot detection sensor (8) sensing the projected fins (29) on the edges of the each slot (30) of the brush seal plate (27). The winding is continued in each slot for the given number of layers. Then the next slot winding is commenced and this operation continues for all the slots of the brush seal plate. At the completion of last slot winding, the end of the job is sensed by the end of the job sensor (9) through the detection of pin (33) of job holding fixture I (31). The present invention positions the brush seal plate to start winding of the first slot. This is achieved through the beginning of the job sensor (7) sensing the pin (34) of the job holding fixture II (32).

A Controller takes the feedback from all five sensors [index notch sensor (5), sector notch sensor (6), beginning of the job sensor (7), end of the job sensor (9) and slot detection sensor (8)] and controls the mandrel drive motor (17) and hollow shaft motor (10) to achieve the following.
i) Winding of the brush seal plate for given number of layers.
ii) Vary the speed of the winding in each revolution with respect to position of
winding on brush seal plate width.
iii) Job indexing as per the width of the wire bunch.
iv) Positioning of the brush seal plate to start winding of the first slot.
v) Detection of completion of the job.
vi) Providing the status of winding.

WE CLAIM
1. A compact angular winding robot/apparatus (A) for automation of angular
winding of any size of brush seals comprising;
telescopic arms (1), base plate (3), pivot post (2), brush seal plate (27), pivot slot (4), roller supports (12,13), job holding fixtures (31, 32), winding mandrel (20), wire spool bobbin (22), wire tensioner I (23), wire tensioner II (24), a nozzle (25), a bearing (18), a support frame (19), slots (28) of base plate (3), a mandrel drive motor (17), belt drive (21), an index notch sensor (5), index pin (15), sector notch sensor (6), sector pins (16), a winding mandrel back plate (14), a hollow shaft motor (10), a threaded shaft (11), a slot detecting sensor (9) (8), a controller;
Characterized in that,
the plurality of telescopic arms (1,1) connected to brush seal plate (27) through job holding fixture I (31) and job holding fixture II (32), the said telescopic arms (1,1) connected firmly to pivot post (2) fixed to a base plate (3) of the said apparatus for imparting free rotation of the said arms (1,1) along with the brush seal plate (27), disposed at an elevation from the base plate (3) by the height of the said pivot post (2) making the said telescopic arms (1,1) working as cantilever beam subjected to load due to the weight of the brush seal plate (27) at the free end; wherein,

a plurality of roller supports (12,13) provided under the job holding fixtures (31, 32) with one end fixed to the said fixtures and the other end is supported on the base plate (3), the said supports being free to rotate about their axes and to roll on the base plate (3);
wherein the winding mandrel (20) driven by a drive motor (17) through belt drive (21) and it houses a wire spool bobbin (20), the wire tensioner I (23), a wire tensioner II (24), and a nozzle (25), the said mandrel (20) is disposed in the apparatus for winding of brush seal wire (26) on to the brush seal plate (27); when a bearing (18) inner race being free to rotate connected to the said winding mandrel (20) and outer race of said bearing (18) fixed to a mandrel support frame (19) having four legs fixed in a slot (28) of the base plate (3) for achieving winding angle of 40±5 degrees;
when the index notch sensor (5) facing an index pin (15) and the sector notch sensor (6) facing sector pins (16) disposed on the winding mandrel back plate (14) connected to the inner race of the bearing (18) and rotates along with the mandrel (20) for achieving speed variation;
a hollow shaft motor (10) consisting of a hollow shaft having a threaded shaft (11) assembled in the said hollow shaft and connected to a rolling support II (13) disposed for rotating the brush seal plate (27) around the pivot through telescopic arms (1), the said hollow shaft motor is disposed for imparting a movement of the brush seal

plate for one revolution of the mandrel (20) by a distance equal to width of the wire bunch for achieving continuous winding on the brush seal plate (27); wherein
the slot detecting sensor (8) is disposed for detecting the completion of layer when the end of job sensor (9) senses the end of last slot winding wherein,
the controller takes the feedback from all said five sensors (5,6,7,8 and 9) for
controlling the mandrel drive motor (17) and hollow shaft motor (10) to achieve
i) Winding of the brush seal plate for given number of layers.
ii) Vary the speed of the winding in each revolution with respect to position of
winding on brush seal plate width.
iii) Job indexing as per the width of the wire bunch.
iv) Positioning of the brush seal plate to start winding of the first slot.
v) Detection of completion of the job.
vi) Providing the status of winding.
2. A method for automation of angular winding of any size of brush seals for the
apparatus claimed in claim 1, the said method comprising;
driving the winding mandrel (20) by a mandrel drive motor (17) through belt drive (21); wherein,
the rotation of mandrel lays brush seal wire (26) on the brush seal plate (27) drawing from wire spool bobbin (22) via wire tensioner I (23) and wire tensioner II (24)

and a nozzle (25) when the said wire tensioner I (23) and wire tensioner II (24) provide adjustable tensioning of brush seal wire; wherein winding of circular flat plate is carried out through rotation of winding mandrel (20) carrying wire tensioners (23,24) and wire bobbin (20), the said bobbin (20) being on the mandrel (22) making wire transfer path minimum, the wire is transferred to the center of the mandrel to carry out winding of the brush seal plate (27).
when four legs of support frame (19) fixed in the slots (28) of the base plate (3) are adjusted within the said slots to achieve winding angle of 40±5 degrees; whereby an index notch sensor (5) facing index pin and sector notch sensor (6) facing sector pins (16) on the winding mandrel back plate (14) provides speed variation; wherein the mandrel (20) makes one revolution to move the brush seal plate by a distance equal to width of wire bunch wherein a hollow shaft motor (10) rotates and makes the threaded shaft (11) traverse and causes the connected roller support (13) to be pulled/pushed making brush seal plate (27) rotates around the pivot through telescopic arms (1); whereby slot detection sensor (8) senses the projected fins (29) on the edges of each sot (30) of the brush seal plate (27) to detect the completion of layer till the winding is complete in each slot for a given number of layers when the operation continues for all the slots of brush seal plate (27);
wherein the end of the job sensor (9) senses the completion of last slot winding;

wherein a controller takes the feedback from the all five sensors [index notch sensor (5), sector notch sensor (6), beginning of the job sensor (7), end of the job sensor (9) and slot detection sensor (8)] and controls the mandrel drive motor (17) and hollow shaft motor (10) to achieve the following.
i) Winding of the brush seal plate for given number of layers.
ii) Vary the speed of the winding in each revolution with respect to position of
winding on brush seal plate width.
iii) Job indexing as per the width of the wire bunch.
iv) Positioning of the brush seal plate to start winding of the first slot.
v) Detection of completion of the job.
3. The method for automation of angular winding as claimed in claim 2, wherein the compact angular winding robot (A) guides the brush seal wire / wire bunch (26) through a nozzle (25) onto the brush seal plate (27) providing controlled wire transfer to prevent spreading of wire instead of laying as bunch.
4. The method for automation of angular winding as claimed in claim 2, wherein the speed of laying of wire varies in accordance with the position of winding across the width of the flat brush seal plate (27) in every revolution wherein the speed at the inner

and outer periphery of winding is less in comparison to the speed at the middle of the brush seal plate (27) width.
5. The method for automation of angular winding as claimed in claim 2, wherein winding of wire on brush seal plate (27) is carried out at an angle 35°-45° to the radius of the brush seal plate.
6. The method for automation of angular winding as claimed in claim 2, wherein the brush seal plate (27) is indexed according to width of the wire bunch drawn from bobbin (22) consisting of bunch of wires when the winding robot (A) provides indexing resolution of 8 microns through a hollow shaft mechanism.
7. The method for automation of angular winding as claimed in claims 2 to 6, wherein the winding process carried out by the said apparatus (A) is semi-automatic.
8. The method for automation of angular winding as claimed in claims 2 to 7, wherein the compact angular winding robot makes the winding process semi-automatic.