CA1253588A - Coil and method for its manufacture - Google Patents
Coil and method for its manufactureInfo
- Publication number
- CA1253588A CA1253588A CA000495915A CA495915A CA1253588A CA 1253588 A CA1253588 A CA 1253588A CA 000495915 A CA000495915 A CA 000495915A CA 495915 A CA495915 A CA 495915A CA 1253588 A CA1253588 A CA 1253588A
- Authority
- CA
- Canada
- Prior art keywords
- coil
- loops
- arm
- preloading
- retention devices
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
- H01F27/303—Clamping coils, windings or parts thereof together
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Insulating Of Coils (AREA)
- Manufacture Of Motors, Generators (AREA)
- Insulation, Fastening Of Motor, Generator Windings (AREA)
- Coil Winding Methods And Apparatuses (AREA)
- Coils Of Transformers For General Uses (AREA)
Abstract
Abstract A coil for electrical devices has at least one axially formed winding (1). The end surfaces of the coil are braced against one another in the axial direction by means of a preloading device containing a loop (2). This loop (2) is intended to be pushed onto retention devices of the preloading device and supported on these retention devices so as to be free from shear. The loops (2) are wound in several layers from elastic insulation strip impregnated with hardening synthetic resin and are hardened in a definite shape. They are held without shear in loop retention devices (6a ... 6d, 6a' ... 6d') of the preloading device and they reliably maintain the preloading for all operational cases.
A cost effective method for manufacturing this coil includes the coil being subjected to the final preloading only after winding, fixing by means of temporary strips, impregnation with casting resin and hardening of the casting resin. The final preloading is at least 0.5% of the clamping length of the loops (2).
A cost effective method for manufacturing this coil includes the coil being subjected to the final preloading only after winding, fixing by means of temporary strips, impregnation with casting resin and hardening of the casting resin. The final preloading is at least 0.5% of the clamping length of the loops (2).
Description
- : ~z~
19.12 .84 Se/eh ~ Manufacture The present invention concerns a coil in accord-ance uith the preamble to Claim 1 and a method of manu-facturing it.
An axially preloaded coil arrangement for trans-formers and chokes, in which elastic loops wound frominsulating strips are used for the transmission of the axial preloading forces from one end to the other of the coil arrangement, is 3lready kno~n from the US Patent 3,321,567, Figure 1. These loops have, at each end, an elastic eye used for fastening. These eyes are con-pressed and each of them pushed through a hole in an end retaining flange of the coil arrangement, in such a way that a fastening bolt can be pushed through the eye on the side of the retaining flange facing away from the coil arrangement. The coil arrangement is subjected to pressure by means of compress;on screws fitted in threade holes of one retaining flange, ~hich act on the end sur-face of the coil arrangement via intermediate compression layers. The reacton forces resulting from this are directly transmitted to the loops squashed between the edge of the hole and the fastening bolt.
These loops are, in consequence, subjected to shear at some locations, which has the disadvant3ge that in this way local overloads and, in consequence, mechan-ical damage eo the loops can occur. The preload;ng forceacting on the coil arrangement can only be determined indirec~ly by means of the torque applied for turning the compression scre~s. This method invoLves uncertainty so that corresponding safety factors have to be allowed for, leading to a more expensive construction of the coil arrangement.
The invention is intended to provide a remedy on these points. The invention, as characterised in the ~3~
35;~38 claims~ achieves the objective of producing a coil in which the maintenance of an accurately defined axial preload is possible by simple means, and which can be manufactured by a cost effective method.
The advantages achieved by means of the invention are mainly to be seen in that a large varie~y of coil variants can be manufactured using relatively few similar parts. The various retention variants for the loops can be combined with one another in such a way that optimum preloading conditions are achieved for the particular appLication. Furthermore, the dimensions of the loops and their retention devices can be kept relatively small so that the flow of the cooling medium through the wind-ing is hardly affected and effective coolin~ is, in con-sequence, ensured. In addition, it is possible to manu-facture coils of the most widely varying winding shapes and hence always to select the most favourable structural form for the particular requirements.
The invention is described in more detail below ZO by means of drawings illustrating only one embodiment route4 In the drawings:
Figure 1 shows, in the left-hand part, a section through a first embodiment form and, in the right hand part~ a section through a second embodiment form of the ;nvention, Figure 2 sho~s a section through a first looP retention device, shown simplified only in Figure 1, Figure 3 sho~s a section through a second embodiment form of the loop retention device, figure 4 shows, in the left-hand part, a section through a third embodiment form, and, in the right-hand part, a section through a fourth embodiment form of the invention, Figure S shows a section through a fifth embodiment form of the invention, Figure 6 shows an end view of a sixth embodiment form of the coiL in accordance with the invention, Figure 7 shows an end view of a coil segment of a _ 3 ~ 35~
seventh embodiment form of the invention, Figure 8 shows the s;de vie~, in section, of an electrical connection of the coiL according to the invention, and Figure 9 shows the end view of the electrical connection according to Figure 8.
In all the figures, parts having the same effect are indicated by the same reference signs.
Two variants of a coil according to the inventîon are shown in Figure 1. This coil has a~iaLly shaped ~indings 1 which are axialLy preloaded by means of a preloading device. The preloading device consists of retention devices in contact with the end surfaces of the windings 1 and loops Z ~hich brace these mutually opposite retention devices against one another. Each of the reten-tion devices is composed of a support spider 3 with arms 4 and loop retention devices 6a ..~ 6d, 6a' ~.. 6d' fastened to the arms 4 in axialLy extended longitudinal holes S. The loop retention devices 6a ... 6d, 6a' ...
6d', not shown in detail, have semi-circular shaped contact surfaces onto which the loops 2 are pushed. The loops Z are wound in multiple layers fro~ elastic insulating strips impregnated ~ith hardening synthetic resin, are hardened in a definite shape and fit positively onto the semi-circular shaped contact surfaces of the loop reten-tion devices 6a ... 6d, 6a' ... 6d'.
Figure Z shows one of the loop retention devices 6a .~. 6d, 6à' ... 6d' in section. The loops 2 are, generally speaking, held in pairs by each of the loop retention devices 6a .~. 6d, 6a' ... 6d'. The loops Z
each lie in a groove on a strip holder 7. The strip holder 7, in conjunct;on with the arm 4 of the support spider 3, forms the groove of rectangular cross-section, ~hose bottom is, in part, of semi-circular shape. One flank 8 of this groove ;s a part of the strip holder 7, the second flank is formed by one side of the arm 4. The section in Fi~ure 2 is laid preciseLy ~hrough the highest point of the semi-circular shaped section of the groove.
~3~
~ 4 --The upper semi-circular section of the groove adjoins two opposite and parallel straight groove sections o~ t~e strip holder 7, each flank 8 becoming lower uith increas-ing distance from the semi-circular shaped section.
Each of the two parallel, straight, mutually opposite groove sections are located on one leg 7' of the strip holder 7. The two legs limit a rectangular recess in the strip holder 7~ the longitudinal flanks of the recess being extended parallel to the bottom of thè s~raight sections of the groove. Each of the two legs has on the bottom end surface a rectan~ular contact surface 12. A
hole 9 for a bolt 10 is provided in the centre of the semi-circular shaped sect;on of the strip holder 7~ This bolt 10 connects one strip ho~der 7 with a second on the other side of the arm 4. The bolt 10 has a one-sided flat 11 in the region within the elongated hole 5. This flat 11 rests on a cuboid shaped distance piece 13, which is supported on a make-up intermediate layer 17, which rests on a braçing wedge 14. The bracing ~edge 14 has a contour on ~he side and on the bottom matched to the elongated hole S. It is secured by two washers 15 held by the bolt 10 and is guided laterally in the rectangular recess of the strip holder 7. The arm 4 rests on insulating in-termediate plates 1S which are supported on the windings 1.
Figure 3 shows, in section, another possible embod;ment form of the loop retention device 6a O~ 6d, 6a' ... bd'. It differs from that shown in Figure 3 only in that the bolt 10 has no flat ancd that the strip holder 3G 7 is in direct contact with the make-up intermediate layer 17, ~hich is supported by the bracing wedge 14.
Two further variants of a coil according to the invention may be seen in Figure 4. The windings 1 are axially preloaded by individual preloading devices evenly distributed around the periphery of the coil The reten-tion devices of these preloading devices consist of a radially directed rod 3D which rests on a distance plate 31, ~5~;88 which is supported on an intermediate plate 16. This intermediate plate 16 rests on the end surfaces of the windings 1. The mutuaLly opposite retention devices are connected together by the loops 2. The loops 2 are pushed onto the preferably round shaped rod 30 so as to make a positive connection. The rod 30 can also be designed as a tube or as half-round material.
Figure 5 shows two different retention device variants comb1ned in a common preloading device. The upper retention device consists of a support spider 3 with loop holding devices 6a, 6b~ the lo~er retention device consists of rods 30 directed ean9entially to the winding, the rods being supported on a distance plate 31 and an intermediate plate 16. ~oth the intermed;ate plate 16 and the distance plate 31 have cut-outs 29 through which the loops 2 can be fed w;thout contact.
Figure 6 shows a coil which has four-armed - support spiders 3 each having a loop retention device 6a ... 6d per ar~ with two loops 2 within the coil in each case. Also shown is a preloading device between two support arms with a radially directed rod 30 as the retention device for two loops 2. One or more of these preLoading devices c-an be additionally mounted in each coil segment between the support arms. In this way, coils already delivered can be made suitable for higher loads as a retrofit measure and at low cost.
Figure 7 shows a coil segment of a multi-layer coil with two different installation types of preloading devices with radially directed rods 30 as the retention devices for the loops 2.
F;gure 8 shows a section through the fastening of a terminal lug 32 by means of the radially directed rod 30 and two loops 2 pushed on to it~ The connecting lug 32 rests on the distance plate 31 and the insulating ir,termediate plate 16. The connecting lug is covered above by an insulating plate 33 on which the rod 30 presses. The part of the connecting lug 32 protruding towards the inside of the coil can be connected to one - 6 - ~Zs3~8~
end of the winding.
Figure 9 gives the end view of the fastening of the connecting lug according to Figure 8. The loops Z
lead without contact through the cut-outs 34 into the S fastening.
In order to explain the mode of operation, Figures 1 and 2 are considered jointly. The Loops 2 are elastic in the axial direction and this elasticity is used in order to subject the coil to preload. The loops Z are specially manufactured for each aoplication; they are wound on a jig in several layers from an insulating strip impregnated ~ith hardening synthetic resin and are hardened in a definite shape. The loops 2 are therefore only subject to relatively small manufacturing toler-ances.
As an example, the fitting of a pair of lQOPS be-tween the loop retention devices 6a and 6a' is now de-scribed. The lower loop retention device 6a' is com-pletely assembled, the two loops 2 being pushed onto the lower strip holder 7 so as to form a positive connection.
During the assembly of the upper loop retention device 6a, the loops 2 are also pushed onto the upper strip holder 7 so as to form a positive connection. The distance piece 13 is bonded to the flat 11 of the bolt 10 after the assembly Z5 of the right-hand half of the strip retention device 6a.
There is not, initially, enough space between the distance piece 13 and the bottom flank of the elongated hole 5 for the insertion of the bracing wedge 14. Using a press~
wh;ch is supported at one end via the arm 4 and the intermediate plate 16 on the end surface of the winding and, at the other end, acts on the contact surface 12 of the upper strip holder 7, and presses the latter upwards, the loops 2 are preloaded and therefore extend in the axial direction~ The preloading force is selec~ed to b-e somewha~ higher than the required value. The bracing wedge 14 can now be inserted and, if necessary, make-up intermediate layers 17 as well. The externally applied preloading force is reduced, the bracing wedge 14 ~2S~S~
becomes firmly clamped and the loops 2 undertake the maintenance of the required value of preloading ~ithout any shear loading. Only at this point are the bolts 10 of the loop retent;on devices 6a, 6a tightened and secured.
This application of the preload to the coil is generally carried out in segments because only relatively small preloading forces then have to be applied. }n addition, preloading in segments ensures be~ter accessi-bility to the assembly positions of the loop retentiondevices 6a ... 6d, 6a ... 6d .
The semi-circular shaped contact surface of the loops 2 on the strip holder 7 ensures that the loops 2 are evenly loaded in tension ~ithout shear forces becoming effective. The preloading force which can be carried per loop 2 can be increased as the number of layers of the wound, glass-fibre reinforced insulating strips increases~ It is also possible to increase the preloading forces by raisiny the number of loops Z
zn fitted. As is sho~n in Figure 1, it is also possible to place the loops 2 differently and, in fact, to suit each specific loading case. Instead of the common instal-lation of the loop retention devices 6a, 6a and 6b, 6b , it would - for example - suffice, in the case of lower Z5 load, to install the loops 2 between the loop re~ention devices 6b, 6b . Similarly, in the right-hand coil variant, the outer loop retention device 6d, 6d could be omitted. A large number of possible installation variants ensures that an optimum and economical preloading device can be provided for each application.
The loop retention device shown in Figure 3 is a somewhat simplified embodiment form of the loop retention device shown in Figure 2. It can be used advantageously for relatively lightly preloaded coils, because the bracing wedge 14 consisting of plastic is loaded in shear and is therefore less able to carry load.
Figure 4 shows particularly economical coil ~2S~S~!3 variants with individual preloading devices. During assembly, for example, the lower retention device is first assembled, the loops 2 being pushed on the rod 30 so as to prov;de a positive connec~ion and the inter-~ediate plate 16 being inserted between the rod 30 andthe end surface of the winding~ The loops 2 are then pushed onto the upper rod 30 so as to form a positive connection. Here again, the application of the preload takes place by means of a press ~hich is supported, at one end, on the upper end surface of the windings and, at the other end~ on the rod 30, pressing the latter upwards. The preloadin~ force is selected to be somewhat larger than the required value. The space between the rod 30 and the end surface of the windings is now provided ~ith the intermediate plate 16 and distance plates 31 in such a way that, after the reduction of the preLoad pro-duced externally by the press, the loops 2 are precisely loaded with ~he req~ired value of preload without being subjected to any shear Forces. The possibil;ty of making an optimum selection among the most varied installation variants for the loops 2 in the case of multi-layer windings is available here also.
The preloading device variants given in Figures 5, 6 and 7, ~hich can also be combined ~ith one another and ~ith the other variants, do not by any means show all the possible arrangements. rhis principle of solidly connecting parts, particularly retention devic~s for preloading devices, ~o the coils by means of pre-shaped loops can also be used to fasten, for example, carrying eyes or connecting lugs 3Z to coils so that they are stiff in torsion.
An embodiment example for the fastening of a con-necting lug 32 may be seen in Figures 8 and 9. During assembly, the intermediate plate 16, possibly distance plates 31, the connecting lug 32 and insulating plate 33 are stacked so as to fit on the end surfaces of the wind;ngs. T~o loops Z, ~hich are pushed onto the stack-holding rod 3û so as to provide a positive cunnection~
. ~ . . . . .. .
~S35~38 _ 9 _ are fed ~ithout contact through cut-outs 34. In the region of the opposite end surface, the two loops 2 ar~
pushed onto a further rod 30 and preloaded without shear force as already described; the connecting lug 32 is then solidly clamped.
It is also possible to design the intermediate plates 16 on the winding side in comb shape so that additional and safe spac;ng of the end ~indings is achieved ;n the case of highly loaded coils.
The whole of the preloading device is~ generally speaking, built of non-magnetic material; for particular applications, it can be manufactured completely from plastic, in which case the more highly loaded part~ must have glass-fibre reinforcement.
An embodiment example of the method according to the invention for manufacturing the coils previously described is given below. The coil is wound in a known manner; it is then fixed by temporary strips, impregnated ~ith casting resin and the casting resin subsequently hardened. After the hardening, the coil is provided with ehe preloading device. In this process, the loops 2 are pushed onto the retention devices of the preloading device so as to provide a positive connection. The loops
19.12 .84 Se/eh ~ Manufacture The present invention concerns a coil in accord-ance uith the preamble to Claim 1 and a method of manu-facturing it.
An axially preloaded coil arrangement for trans-formers and chokes, in which elastic loops wound frominsulating strips are used for the transmission of the axial preloading forces from one end to the other of the coil arrangement, is 3lready kno~n from the US Patent 3,321,567, Figure 1. These loops have, at each end, an elastic eye used for fastening. These eyes are con-pressed and each of them pushed through a hole in an end retaining flange of the coil arrangement, in such a way that a fastening bolt can be pushed through the eye on the side of the retaining flange facing away from the coil arrangement. The coil arrangement is subjected to pressure by means of compress;on screws fitted in threade holes of one retaining flange, ~hich act on the end sur-face of the coil arrangement via intermediate compression layers. The reacton forces resulting from this are directly transmitted to the loops squashed between the edge of the hole and the fastening bolt.
These loops are, in consequence, subjected to shear at some locations, which has the disadvant3ge that in this way local overloads and, in consequence, mechan-ical damage eo the loops can occur. The preload;ng forceacting on the coil arrangement can only be determined indirec~ly by means of the torque applied for turning the compression scre~s. This method invoLves uncertainty so that corresponding safety factors have to be allowed for, leading to a more expensive construction of the coil arrangement.
The invention is intended to provide a remedy on these points. The invention, as characterised in the ~3~
35;~38 claims~ achieves the objective of producing a coil in which the maintenance of an accurately defined axial preload is possible by simple means, and which can be manufactured by a cost effective method.
The advantages achieved by means of the invention are mainly to be seen in that a large varie~y of coil variants can be manufactured using relatively few similar parts. The various retention variants for the loops can be combined with one another in such a way that optimum preloading conditions are achieved for the particular appLication. Furthermore, the dimensions of the loops and their retention devices can be kept relatively small so that the flow of the cooling medium through the wind-ing is hardly affected and effective coolin~ is, in con-sequence, ensured. In addition, it is possible to manu-facture coils of the most widely varying winding shapes and hence always to select the most favourable structural form for the particular requirements.
The invention is described in more detail below ZO by means of drawings illustrating only one embodiment route4 In the drawings:
Figure 1 shows, in the left-hand part, a section through a first embodiment form and, in the right hand part~ a section through a second embodiment form of the ;nvention, Figure 2 sho~s a section through a first looP retention device, shown simplified only in Figure 1, Figure 3 sho~s a section through a second embodiment form of the loop retention device, figure 4 shows, in the left-hand part, a section through a third embodiment form, and, in the right-hand part, a section through a fourth embodiment form of the invention, Figure S shows a section through a fifth embodiment form of the invention, Figure 6 shows an end view of a sixth embodiment form of the coiL in accordance with the invention, Figure 7 shows an end view of a coil segment of a _ 3 ~ 35~
seventh embodiment form of the invention, Figure 8 shows the s;de vie~, in section, of an electrical connection of the coiL according to the invention, and Figure 9 shows the end view of the electrical connection according to Figure 8.
In all the figures, parts having the same effect are indicated by the same reference signs.
Two variants of a coil according to the inventîon are shown in Figure 1. This coil has a~iaLly shaped ~indings 1 which are axialLy preloaded by means of a preloading device. The preloading device consists of retention devices in contact with the end surfaces of the windings 1 and loops Z ~hich brace these mutually opposite retention devices against one another. Each of the reten-tion devices is composed of a support spider 3 with arms 4 and loop retention devices 6a ..~ 6d, 6a' ~.. 6d' fastened to the arms 4 in axialLy extended longitudinal holes S. The loop retention devices 6a ... 6d, 6a' ...
6d', not shown in detail, have semi-circular shaped contact surfaces onto which the loops 2 are pushed. The loops Z are wound in multiple layers fro~ elastic insulating strips impregnated ~ith hardening synthetic resin, are hardened in a definite shape and fit positively onto the semi-circular shaped contact surfaces of the loop reten-tion devices 6a ... 6d, 6a' ... 6d'.
Figure Z shows one of the loop retention devices 6a .~. 6d, 6à' ... 6d' in section. The loops 2 are, generally speaking, held in pairs by each of the loop retention devices 6a .~. 6d, 6a' ... 6d'. The loops Z
each lie in a groove on a strip holder 7. The strip holder 7, in conjunct;on with the arm 4 of the support spider 3, forms the groove of rectangular cross-section, ~hose bottom is, in part, of semi-circular shape. One flank 8 of this groove ;s a part of the strip holder 7, the second flank is formed by one side of the arm 4. The section in Fi~ure 2 is laid preciseLy ~hrough the highest point of the semi-circular shaped section of the groove.
~3~
~ 4 --The upper semi-circular section of the groove adjoins two opposite and parallel straight groove sections o~ t~e strip holder 7, each flank 8 becoming lower uith increas-ing distance from the semi-circular shaped section.
Each of the two parallel, straight, mutually opposite groove sections are located on one leg 7' of the strip holder 7. The two legs limit a rectangular recess in the strip holder 7~ the longitudinal flanks of the recess being extended parallel to the bottom of thè s~raight sections of the groove. Each of the two legs has on the bottom end surface a rectan~ular contact surface 12. A
hole 9 for a bolt 10 is provided in the centre of the semi-circular shaped sect;on of the strip holder 7~ This bolt 10 connects one strip ho~der 7 with a second on the other side of the arm 4. The bolt 10 has a one-sided flat 11 in the region within the elongated hole 5. This flat 11 rests on a cuboid shaped distance piece 13, which is supported on a make-up intermediate layer 17, which rests on a braçing wedge 14. The bracing ~edge 14 has a contour on ~he side and on the bottom matched to the elongated hole S. It is secured by two washers 15 held by the bolt 10 and is guided laterally in the rectangular recess of the strip holder 7. The arm 4 rests on insulating in-termediate plates 1S which are supported on the windings 1.
Figure 3 shows, in section, another possible embod;ment form of the loop retention device 6a O~ 6d, 6a' ... bd'. It differs from that shown in Figure 3 only in that the bolt 10 has no flat ancd that the strip holder 3G 7 is in direct contact with the make-up intermediate layer 17, ~hich is supported by the bracing wedge 14.
Two further variants of a coil according to the invention may be seen in Figure 4. The windings 1 are axially preloaded by individual preloading devices evenly distributed around the periphery of the coil The reten-tion devices of these preloading devices consist of a radially directed rod 3D which rests on a distance plate 31, ~5~;88 which is supported on an intermediate plate 16. This intermediate plate 16 rests on the end surfaces of the windings 1. The mutuaLly opposite retention devices are connected together by the loops 2. The loops 2 are pushed onto the preferably round shaped rod 30 so as to make a positive connection. The rod 30 can also be designed as a tube or as half-round material.
Figure 5 shows two different retention device variants comb1ned in a common preloading device. The upper retention device consists of a support spider 3 with loop holding devices 6a, 6b~ the lo~er retention device consists of rods 30 directed ean9entially to the winding, the rods being supported on a distance plate 31 and an intermediate plate 16. ~oth the intermed;ate plate 16 and the distance plate 31 have cut-outs 29 through which the loops 2 can be fed w;thout contact.
Figure 6 shows a coil which has four-armed - support spiders 3 each having a loop retention device 6a ... 6d per ar~ with two loops 2 within the coil in each case. Also shown is a preloading device between two support arms with a radially directed rod 30 as the retention device for two loops 2. One or more of these preLoading devices c-an be additionally mounted in each coil segment between the support arms. In this way, coils already delivered can be made suitable for higher loads as a retrofit measure and at low cost.
Figure 7 shows a coil segment of a multi-layer coil with two different installation types of preloading devices with radially directed rods 30 as the retention devices for the loops 2.
F;gure 8 shows a section through the fastening of a terminal lug 32 by means of the radially directed rod 30 and two loops 2 pushed on to it~ The connecting lug 32 rests on the distance plate 31 and the insulating ir,termediate plate 16. The connecting lug is covered above by an insulating plate 33 on which the rod 30 presses. The part of the connecting lug 32 protruding towards the inside of the coil can be connected to one - 6 - ~Zs3~8~
end of the winding.
Figure 9 gives the end view of the fastening of the connecting lug according to Figure 8. The loops Z
lead without contact through the cut-outs 34 into the S fastening.
In order to explain the mode of operation, Figures 1 and 2 are considered jointly. The Loops 2 are elastic in the axial direction and this elasticity is used in order to subject the coil to preload. The loops Z are specially manufactured for each aoplication; they are wound on a jig in several layers from an insulating strip impregnated ~ith hardening synthetic resin and are hardened in a definite shape. The loops 2 are therefore only subject to relatively small manufacturing toler-ances.
As an example, the fitting of a pair of lQOPS be-tween the loop retention devices 6a and 6a' is now de-scribed. The lower loop retention device 6a' is com-pletely assembled, the two loops 2 being pushed onto the lower strip holder 7 so as to form a positive connection.
During the assembly of the upper loop retention device 6a, the loops 2 are also pushed onto the upper strip holder 7 so as to form a positive connection. The distance piece 13 is bonded to the flat 11 of the bolt 10 after the assembly Z5 of the right-hand half of the strip retention device 6a.
There is not, initially, enough space between the distance piece 13 and the bottom flank of the elongated hole 5 for the insertion of the bracing wedge 14. Using a press~
wh;ch is supported at one end via the arm 4 and the intermediate plate 16 on the end surface of the winding and, at the other end, acts on the contact surface 12 of the upper strip holder 7, and presses the latter upwards, the loops 2 are preloaded and therefore extend in the axial direction~ The preloading force is selec~ed to b-e somewha~ higher than the required value. The bracing wedge 14 can now be inserted and, if necessary, make-up intermediate layers 17 as well. The externally applied preloading force is reduced, the bracing wedge 14 ~2S~S~
becomes firmly clamped and the loops 2 undertake the maintenance of the required value of preloading ~ithout any shear loading. Only at this point are the bolts 10 of the loop retent;on devices 6a, 6a tightened and secured.
This application of the preload to the coil is generally carried out in segments because only relatively small preloading forces then have to be applied. }n addition, preloading in segments ensures be~ter accessi-bility to the assembly positions of the loop retentiondevices 6a ... 6d, 6a ... 6d .
The semi-circular shaped contact surface of the loops 2 on the strip holder 7 ensures that the loops 2 are evenly loaded in tension ~ithout shear forces becoming effective. The preloading force which can be carried per loop 2 can be increased as the number of layers of the wound, glass-fibre reinforced insulating strips increases~ It is also possible to increase the preloading forces by raisiny the number of loops Z
zn fitted. As is sho~n in Figure 1, it is also possible to place the loops 2 differently and, in fact, to suit each specific loading case. Instead of the common instal-lation of the loop retention devices 6a, 6a and 6b, 6b , it would - for example - suffice, in the case of lower Z5 load, to install the loops 2 between the loop re~ention devices 6b, 6b . Similarly, in the right-hand coil variant, the outer loop retention device 6d, 6d could be omitted. A large number of possible installation variants ensures that an optimum and economical preloading device can be provided for each application.
The loop retention device shown in Figure 3 is a somewhat simplified embodiment form of the loop retention device shown in Figure 2. It can be used advantageously for relatively lightly preloaded coils, because the bracing wedge 14 consisting of plastic is loaded in shear and is therefore less able to carry load.
Figure 4 shows particularly economical coil ~2S~S~!3 variants with individual preloading devices. During assembly, for example, the lower retention device is first assembled, the loops 2 being pushed on the rod 30 so as to prov;de a positive connec~ion and the inter-~ediate plate 16 being inserted between the rod 30 andthe end surface of the winding~ The loops 2 are then pushed onto the upper rod 30 so as to form a positive connection. Here again, the application of the preload takes place by means of a press ~hich is supported, at one end, on the upper end surface of the windings and, at the other end~ on the rod 30, pressing the latter upwards. The preloadin~ force is selected to be somewhat larger than the required value. The space between the rod 30 and the end surface of the windings is now provided ~ith the intermediate plate 16 and distance plates 31 in such a way that, after the reduction of the preLoad pro-duced externally by the press, the loops 2 are precisely loaded with ~he req~ired value of preload without being subjected to any shear Forces. The possibil;ty of making an optimum selection among the most varied installation variants for the loops 2 in the case of multi-layer windings is available here also.
The preloading device variants given in Figures 5, 6 and 7, ~hich can also be combined ~ith one another and ~ith the other variants, do not by any means show all the possible arrangements. rhis principle of solidly connecting parts, particularly retention devic~s for preloading devices, ~o the coils by means of pre-shaped loops can also be used to fasten, for example, carrying eyes or connecting lugs 3Z to coils so that they are stiff in torsion.
An embodiment example for the fastening of a con-necting lug 32 may be seen in Figures 8 and 9. During assembly, the intermediate plate 16, possibly distance plates 31, the connecting lug 32 and insulating plate 33 are stacked so as to fit on the end surfaces of the wind;ngs. T~o loops Z, ~hich are pushed onto the stack-holding rod 3û so as to provide a positive cunnection~
. ~ . . . . .. .
~S35~38 _ 9 _ are fed ~ithout contact through cut-outs 34. In the region of the opposite end surface, the two loops 2 ar~
pushed onto a further rod 30 and preloaded without shear force as already described; the connecting lug 32 is then solidly clamped.
It is also possible to design the intermediate plates 16 on the winding side in comb shape so that additional and safe spac;ng of the end ~indings is achieved ;n the case of highly loaded coils.
The whole of the preloading device is~ generally speaking, built of non-magnetic material; for particular applications, it can be manufactured completely from plastic, in which case the more highly loaded part~ must have glass-fibre reinforcement.
An embodiment example of the method according to the invention for manufacturing the coils previously described is given below. The coil is wound in a known manner; it is then fixed by temporary strips, impregnated ~ith casting resin and the casting resin subsequently hardened. After the hardening, the coil is provided with ehe preloading device. In this process, the loops 2 are pushed onto the retention devices of the preloading device so as to provide a positive connection. The loops
2 are subjected to a preloading force somewhat above the required value by means of a press supported at one end against the erid surfaces of the co;l and acting, at the other end~ on the retention devices in such a way that the loops 2 are preloaded in the axial direction. The tensioning wedges 14 and the make-up in~ermediate layers 17 are then placed in the retention devices so that the loops 2, after the reduction of the preloading force applied externally by the press, are preloaded to the required figure. The loop retention devices are then finally tightened up and the temporary strips remo~ed.
The preload;ng of the loops 2 can be advan-tageously carried out with a relatively small and easily handled press if the preloading is carried out separately for each individual retention device~ The coil is ~2S358~3 - 10 ~
preloaded in segnents in this manner. A further advantage of this procedure is that good accessibility to the loop retention devices 6a ... 6d is continuousLy ensured, which facilitates the assembly of the tension wedge 14n The f;nal preload;ng is at least O.SX of the loading length of the loops 2 and in the majority of applications does not exceed 1.2X~
The preload;ng of the loops 2 can be advan-tageously carried out with a relatively small and easily handled press if the preloading is carried out separately for each individual retention device~ The coil is ~2S358~3 - 10 ~
preloaded in segnents in this manner. A further advantage of this procedure is that good accessibility to the loop retention devices 6a ... 6d is continuousLy ensured, which facilitates the assembly of the tension wedge 14n The f;nal preload;ng is at least O.SX of the loading length of the loops 2 and in the majority of applications does not exceed 1.2X~
Claims (18)
1. Coil for electrical devices with at least one axially formed winding (1) whose mutually opposite end surfaces are braced against one another in an axial direction by means of a preloading device, the preloading device having multi-layer wound elastic loops (2) made of insulating strip and retention devices in contact with each of the end surfaces, on which retention devices the loops (2) for transmitting the preloading force are supported, characterised in that the lopps (2) consisting of preformed material are pushed with positive connection onto the retention devices and are supported on these retention devices so as to be free from shearing action.
2. Coil according to Claim 1, characterised in that at least one of the retention devices is formed by a radially directed rod (30) which is in contact with at least one winding (1) and at most all the windings (1) of one coil segment only.
3. Coil according to Claim 2, characterised in that the rod (30) has a semi-circular shaped contact surface for the loops (2), that an electrically insulating intermediate plate (16) is provided between the rod (30) and the end surface of the coil, and that at least one spacer plate (31) can be inserted between the rod (30) and the intermediate plate (16).
4. Coil according to Claim 3, characterised in that the intermediate plates (16) have protrusions on the winding side at the same pitch as the winding layers and fitting positively between them.
5. Coil according to Claim 1, characterised in that at least one of the retention devices is formed by an arm (4) of a support spider (3) carried on one of the end surfaces of the coil on electrically insulated intermediate plates (16) and by a strip holder (7) fastened to this arm.
6. Coil according to Claim 5, characterised in that the retention device formed by one arm (4) of the support spider (3) and a strip holder (7) has a semi-circular curved groove of rectangular cross-section, the bottom and one of the two sides of this groove being formed by the strip holder (7) and the other of the two groove sides being Formed by the arm (4) of the support spider.
7. Coil according to Claim 6, characterised in that the strip holder (7) has a hole (9) for accepting a fastening part (bolt 10) and two groove sections adjoining the semi-circular shaped groove section and extending axially, each of which axially extending sections lies on one of two axially extending legs (7') of the strip holder (7).
8. Coil according to Claim 7, characterised in that at least two of the strip holders (7) are fastened to the support spider (3) by means of a bolt (10) fed through an axially extending elongated hole (5) in the arm (4) of the support spider.
9. Coil according to Claim 8, characterised in that the shaft of the bolt (10) has a flat (11) on one side in the region surrounded by the arm of the support spider, that this flat (11) serves as the contact surface for a cuboid shaped distance piece (13), which is supported on a bracing wedge (14), that make-up intermediate layers (17) can be inserted between the distance piece (13) and the bracing wedge (14), that the side of the bracing wedge (14) facing away from the distance piece (13) has a shape matched to the contour of the elongated hole and that it is secured by two washers (153 held by the bolt (10).
10. Coil according to Claim 8, characterised in that at least two strip holders (7) are supported on the bracing wedge (143, that the side of this bracing wedge (14) facing away from the strip holders (7) has a shape matched to the contour of the elongated hole, that it is secured by two washers (15) held by the bolt (10) and that make-up intermediate layers (17) can be inserted between the bracing wedge (14) and the strip holders (7).
11. Coil for electrical devices with at least one axially formed winding (1) whose mutually opposite end surfaces are braced against one another in an axial direction by means of a preloading device, the preloading device having multi-layer wound elastic loops (2) made of insulating strip and retention devices in contact with each of the end surfaces, on which retention devices the loops (2) for transmitting the preloading force are supported, characterised in that the loops (2) consisting of preformed material are pushed with positive connection onto the retention devices and are supported on these retention devices so as to be free from shearing action, that at least one of the retention devices is formed by a radially directed rod (30) which is in contact with at least one winding (1) and at most all the windings (1) of one coil segment only, that at least one of the retention devices is formed by an arm (4) of a support spider (3) carried on one of the end surfaces of the coil on electrically insulated intermediate plates (16) and by a strip holder (7) fastened to this arm, and that the retention device in contact with one of the two end surfaces of the coil is formed by at least one rod (30) and the retention device in contact with the other of the two end surfaces is formed by at least one arm (4) of the support spider (3).
12. Coil according to Claim 11 with multi-layer windings, characterised in that further rods (30) are located between neighbouring arms (4) of the support spider (3) as an additional retention device.
13. Coil according to Claim 12, characterised in that the retention device formed by one arm (4) of the support spider (3) and a strip holder (7) has a semi-circular curved groove of rectangular cross-section, the bottom and one of the two sides of this groove being formed by the strip holder (7) and the other of the two groove sides being formed by the arm (4) of the support spider.
14. Coil according to Claim 13, characterised in that the strip holder (7) has a hole (9) for accepting a fastening part (bolt 10) and two groove sections adjoining the semi-ciru-lar shaped groove section and extending axially, each of which axially extending sections lies on one of two axially extending legs (7') of the strip holder (7).
15. Coil according to Claim 14, characterised in that at least two of the strip holders (7) are fastened to the support spider (3) by means of a bolt (10) fed through an axially extending elongated hole (5) in the arm (4) of the support spider.
16. Coil according to Claim 15, characterised in that the shaft of the bolt (10) has a flat (11) on one side in the region surrounded by the arm of the support spider, that this flat (11) serves as the contact surface for a cuboid shaped distance piece (13), which is supported on a bracing wedge (14), that make-up intermediate layers (17) can be inser-ted between the distance piece (13) and the bracing wedge (14), that the side of the bracing wedge (14) facing away from the distance piece (13) has a shape matched to the contour of the elongated hole and that it is secured by two washers (15) held by the bolt (10).
17. Coil according to Claim 15, characterised in that at least two strip holders (7) are supported on the bracing wedge (14), that the side of this bracing wedge (14) facing away from the strip holders (7) has a shape matched to the contour of the elongated hole, that it is secured by two washers (15) held by the bolt (10) and that make-up intermediate layers (17) can be inserted between the bracing wedge (14) and the strip holders (7).
18. Method for manufacturing a coil according to Claim 1, in which the coil is wound, the wound coil is provided with a temporary fixing, the temporarily fixed coil is impregnated with casting resin and the impregnated coil is hardened, charac-terised in that, after hardening, the retention devices are applied to the coil and the prefabricated loops (2) are pushed onto the retention devices, that when the loops (2) are pushed on, they are preloaded in the axial direction above the requi-red value of the preloading force of the completed coil, and that bracing wedges (14) are inserted between the coil and the retention device, the bracing wedges (14) ensuring that, after the preloading force initially applied to the loops (2) has decreased, the loops (2) are subjected to the required value of the preloading force.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH6025/84-2 | 1984-12-19 | ||
| CH602584A CH666763A5 (en) | 1984-12-19 | 1984-12-19 | REEL AND METHOD FOR THEIR PRODUCTION. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1253588A true CA1253588A (en) | 1989-05-02 |
Family
ID=4302998
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000495915A Expired CA1253588A (en) | 1984-12-19 | 1985-11-21 | Coil and method for its manufacture |
Country Status (5)
| Country | Link |
|---|---|
| CN (1) | CN1003821B (en) |
| AT (1) | AT393922B (en) |
| CA (1) | CA1253588A (en) |
| CH (1) | CH666763A5 (en) |
| DE (1) | DE3504171C2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103474227B (en) * | 2013-08-30 | 2015-09-09 | 无锡晶磊电子有限公司 | A kind of tool structure for three-phase inductance coil combination |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3320567A (en) * | 1964-11-09 | 1967-05-16 | Siemens Ag | Pre-stressed winding assembly for transformers and inductance coils |
| CA965166A (en) * | 1972-12-28 | 1975-03-25 | Trench Electric Limited | Air core duplex reactor |
| DD122737A1 (en) * | 1975-12-17 | 1976-10-20 | ||
| DD128856A1 (en) * | 1976-12-10 | 1977-12-14 | Frank Koeckritz | CLAMPING DEVICE FOR SELF-TIED WINDINGS OF ELECTRICAL APPARATUS |
| DD147290A1 (en) * | 1979-11-07 | 1981-03-25 | Hermann Gildemeister | MOUNTING FOR COMPONENTS OF ARTISTIC FIBER OPTIONS |
-
1984
- 1984-12-19 CH CH602584A patent/CH666763A5/en not_active IP Right Cessation
-
1985
- 1985-02-07 DE DE19853504171 patent/DE3504171C2/en not_active Expired - Fee Related
- 1985-11-21 CA CA000495915A patent/CA1253588A/en not_active Expired
- 1985-11-22 AT AT342085A patent/AT393922B/en not_active IP Right Cessation
- 1985-12-19 CN CN85109230.6A patent/CN1003821B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3504171A1 (en) | 1986-06-26 |
| DE3504171C2 (en) | 1993-11-18 |
| CN1003821B (en) | 1989-04-05 |
| CN85109230A (en) | 1986-07-02 |
| CH666763A5 (en) | 1988-08-15 |
| ATA342085A (en) | 1991-06-15 |
| AT393922B (en) | 1992-01-10 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |