Coil support members

Abstract

A method of manufacturing a coil support member in which a thermosetting or thermoplastic material is introduced into a mold cavity and hardened, wherein one or more components are positioned within the mold cavity during the manufacturing process before the thermosetting or thermoplastic material is introduced, the components are then embedded in the thermosetting or thermoplastic material and form an integral part of the coil support member, and one or more functional filler materials are added to the thermosetting or thermoplastic material to improve the thermal matching between the integral components and the thermosetting or thermoplastic material.

Claims

1. A method in which a thermosetting or thermoplastic material is introduced into a mould cavity and hardened to produce a coil support member, the method comprising: positioning one or more components within the mould cavity before the thermosetting or thermoplastic material is introduced; thermal matching the thermosetting or thermoplastic material with the one or more components including adding one or more functional filler materials to the thermosetting or thermoplastic material modifying a coefficient of thermal expansion of the thermosetting or thermoplastic material to better match with a coefficient of thermal expansion of the one or more components; and defining the mould cavity so that the coil support member includes an external surface for supporting a coil wound about the coil support member.

2. The method according to claim 1, wherein each of the one or more components is positioned within the mould cavity using one or more positioning members.

3. The method according to claim 2, wherein a component and/or a positioning member is coated with a mould release agent before being positioned within the mould cavity.

4. The method according to claim 1, wherein the coil support member is formed by a multi-stage manufacturing process in which each stage forms a layer or part of the coil support member.

5. The method according to claim 4, wherein a different thermosetting or thermoplastic material and/or a different filler material, combination of filler materials or no filler material is used in different stages of the multi-stage manufacturing process.

6. The method according to claim 1, further comprising winding a coil around the coil support member.

7. The method according to claim 1, wherein a pre-formed coil or one or more blocks of superconducting material is positioned within the mould cavity before the thermosetting or thermoplastic material is introduced.

8. The method according to claim 1, wherein one or more structural features of the coil support member are metalized in a post-production process.

Description

DRAWING

(1) FIG. 1 shows a perspective view of a coil support member in accordance with the present invention.

(2) Although the following description concentrates on a coil support member for a superconducting coil (i.e. a coil made of superconducting wire or tape) that is intended to be installed around the rotor assembly of a rotating electrical machine such as a motor or generator, it will be readily appreciated that the present invention has wider application and can be used with coils made of a conventional material such as copper, and for installation to other equipment such as magnetic resonance imaging (MRI) scanners, electro-magnets, research beam lines and particle accelerators, fault-current limiters, and magnet energy storage devices, for example.

(3) A coil support member 1 is made from a synthetic resin material (e.g. an epoxy) that is introduced into a mould cavity and cured. The coil support member 1 includes an external surface 2 that supports a superconducting coil (not shown) and in particular has curved end regions 4 that are shaped to provide support to the endwindings of the superconducting coil. An upper plate 6 and a lower plate 8 overhang the external surface 2 such that the coil is positioned in the space 10 between the upper and lower plates.

(4) Tubular projecting parts 12 are integrally formed with the lower plate 8 and are adapted to be connected to external coolant pipes (not shown). The projecting parts 12 are in fluid communication with one or more internal coolant passages or conduits that extend within the lower plate 8 and through which cryogenic cooling fluid is circulated to cool the coil support member 1 and maintain the superconducting coil below its superconducting temperature. Any suitable mounting or fixing blocks (not shown) can be integrally formed with the lower plate 8 to allow a plurality of coil support members 1 to be installed to the rotor assembly of a rotating electrical machine. For example, the fixing blocks might include one or more internally screw-threaded bores that enable the coil support member 1 to be bolted to the rotor assembly.

(5) A pair of terminal blocks 14 are integrally formed with the upper plate 6. The ends of the superconducting coil are attached to the terminal blocks to enable an external electrical connection to be made.

(6) The coil support member 1 is produced in a single-stage process which allows the coil support member to have a complex geometry, particular in the region of the external surface 2 that supports the superconducting coil. However, it will be readily appreciated that the coil support member could be formed in a multi-stage process where at least a thermal core part and a mechanically rigid fixing part are formed sequentially using a series of mould cavities and with the option for different synthetic resins and/or functional fillers to be used at different stages. The thermal core part could be adjacent the internal cooling passages and include the external surface 2 and could be doped with filler materials that improve its thermal conductivity. The mounting or fixing blocks (not shown) could be embedded within the mechanically rigid fixing part being defined for example by at least part of the lower plate 8. The mechanically rigid fixing part could include rigid bracing or support structure components and/or could be doped with filler materials that improve its mechanical strength. Functional fillers can be used to improve thermal matching between the synthetic resin material and the various embedded components, i.e. to modify the coefficient of thermal expansion of the hardened synthetic resin so that it is a closer match with the coefficients of thermal expansion of the components The thermal matching will be across the temperature range from room temperature to the operational temperature of the coil support member. This ensures that the components and the synthetic resin material remain bonded during both cooling and operational phases and prevents cracking along the interfaces when the coil support member 1 undergoes temperature variations during operation.

(7) The mould cavity defines the shape of the finished coil support member 1. The terminal blocks 14 can be positioned within the mould cavity at a suitable location using one or more positioning members before the synthetic resin is introduced into the mould cavity so that the terminal blocks are embedded in the synthetic resin forming the upper plate 6 during the manufacturing process. Although not shown, other components can be similarly embedded in the synthetic resin by positioning them within the mould cavity. The tubular projecting parts 12 can be formed by embedding metal coolant pipes in the synthetic resin forming the lower plate 8 so that an end part of each pipe is exposed. The internal coolant passages or conduits can also be formed by metal coolant pipes embedded within the lower plate 8. External coolant pipes can be releasably or permanently connected to the exposed ends of the embedded pipes in a conventional manner. The tubular projecting parts 12 can also be formed from the synthetic resin (i.e. as an integral part of the lower plate 8) by using an appropriate shaped mould cavity and with the internal space or void of each part, and optionally also the internal coolant passages or conduits in the lower plate 8, being formed by the use of spacer components positioned in the mould cavity and which are pre-coated with a release agent so that they can be released from the surrounding synthetic resin to leave an empty space or void once it has cured and the coil support member is removed from the mould. If the tubular projecting parts 12 are formed from synthetic resin then they can be metalized by a deposition or plating process, for example, so that external metal coolant pipes or any associated connectors can be brazed to them.

(8) To manufacture the coil support member 1 the various components (e.g. the metal pipes used to form the tubular projecting parts 12 and any internal coolant passages, the terminal blocks 14 etc.) are suitably positioned within the mould cavity using one or more positioning members. The synthetic resin is then introduced into the mould cavity using conventional injection moulding equipment and is allowed to harden by following an appropriate cure schedule, which may optionally require the use of an elevated temperature. The finished coil support member 1 is then removed from the mould and subjected to any post-production process. One or more functional fillers can be added to the synthetic resin to improve or alter the properties of the coil support member 1 as described in more detail above.

(9) A superconducting coil is wound on to the finished coil support member 1 in a separate winding process which is conventional and is not described further. However, it will be appreciated that a pre-formed superconducting coil can be positioned within the mould cavity so that it is embedded within the coil support member 1 between the upper and lower plates 6, 8.

(10) The written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any device or system and performing the incorporated method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial difference from the literal language of the claims.