Abstract: The present invention provides an improved single-layer coil for a rotating or linear electrical machine. The coil has a first endwinding that is substantially straight to a longitudinal axis of the coil and a second endwinding that is bent relative to the longitudinal axis of the coil. The coil therefore has differently shaped endwindings with one end 12 being ‘straight’ and the other end being ‘bent.

Abstract: The present invention provides a permanent magnet rotor arrangement for a rotating electrical machine including a rotor body having an outer rim. A circumferential array of magnet carriers is mounted to the rotor body by fixing members and support members and is spaced apart from the rotor body in the radial direction to define a series of axially gaps or spaces which can optionally be used as passages for cooling air. At least one pole piece made of permanent magnet material is located adjacent to a surface of each magnet carrier. The magnet carriers and pole pieces preferably have a laminated or divided construction to virtually eliminate eddy currents that may be particularly problematic in certain types and construction of electrical machine. The flux path between adjacent pole pieces flows in the circumferential direction within the magnet carriers and does not use the rotor body.

Abstract: The present invention relates to armature windings for DC electrical machines, and in particular to those that use electronic commutation and have relatively few slots per pole-pair. The armature windings are particularly well suited for use with rotating DC electrical machines that have a large diameter and a large number of poles such as those that might be directly coupled to the turbine blade assembly of a wind turbine. The armature winding is arranged in relation to the magnetic field generated by a field winding or by permanent magnets such that a number of commutation events during the time taken for the relative movement between the armature and the field system of one pole-pair is much larger than the number of coils per pole-pair.

Abstract: The present invention provides an improved single-layer coil 10 for a rotating or linear electrical machine. The coil 10 has a first endwinding 12 that is substantially parallel to a longitudinal axis LA of the coil and a second endwinding 14 that is bent away from, or towards, the longitudinal axis. The coil 10 therefore has differently shaped endwindings with one end 12 being ‘straight’ and the other end 14 being ‘bent’.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: An electrical machine has at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles in each group is sited in its reference position. At least one magnet pole in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots. The displacement of the magnet poles provides a pronounced reduction in cogging.

Abstract: The present invention provides a permanent magnet rotor arrangement for a rotating electrical machine including a rotor body having an outer rim. A circumferential array of magnet carriers is mounted to the rotor body by fixing members and support members and is spaced apart from the rotor body in the radial direction to define a series of axially gaps or spaces which can optionally be used as passages for cooling air. At least one pole piece made of permanent magnet material is located adjacent to a surface of each magnet carrier. The magnet carriers and pole pieces preferably have a laminated or divided construction to virtually eliminate eddy currents that may be particularly problematic in certain types and construction of electrical machine. The flux path between adjacent pole pieces flows in the circumferential direction within the magnet carriers and does not use the rotor body.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: The present invention relates to armature windings for DC electrical machines, and in particular to those that use electronic commutation and have relatively few slots per pole-pair. The armature windings are particularly well suited for use with rotating DC electrical machines that have a large diameter and a large number of poles such as those that might be directly coupled to the turbine blade assembly of a wind turbine. The armature winding is arranged in relation to the magnetic field generated by a field winding or by permanent magnets such that a number of commutation events during the time taken for the relative movement between the armature and the field system of one pole-pair is much larger than the number of coils per pole-pair.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material, and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: A permanent magnet rotor arrangement that is particularly suitable for low-speed large-diameter electrical generators includes a rotor 2 having a radially outer rim 4. A circumferential array of magnet carriers 12 is non-releasably affixed to the outer rim 4 of the rotor and have a radially outer surface. An inverted U-shaped pole piece retainer 18 made of non-magnetic material such as stainless steel is affixed to each magnet carrier 12 and is formed with an axially extending channel. At least one pole piece 16 made of a magnetic material such as steel is located adjacent to the radially outer surface of each magnet carrier 12 and in the channel formed in its associated pole piece retainer 18.

Abstract: An improved stator (28) for rotating electrical machines with single-layer stator windings consisting of a plurality of pre-formed coils (22) of equal angular pitch. The stator (28) has a first cylindrical surface in which a plurality of circumferentially spaced winding slots (30) are formed and in which the axially-extending winding runs (24) of the pre-formed coils (22) are positioned. The two winding runs (24) of each coil (22) will each be positioned in a winding slot (30) and the two winding slots (30) that receive the coil (22) define a winding slot pair. The improvement arises from the fact that the winding slots (30) of each winding slot pair extend into the stator (28) in substantially parallel directions. This means that the axially-extending winding runs (24) of each pre-formed coil (22) may also be substantially parallel and need not be angled towards each other.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material, and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: A permanent magnet rotor arrangement that is particularly suitable for low-speed large-diameter electrical generators includes a rotor 2 having a radially outer rim 4. A circumferential array of magnet carriers 12 is non-releasably affixed to the outer rim 4 of the rotor and have a radially outer surface. An inverted U-shaped pole piece retainer 18 made of non-magnetic material such as stainless steel is affixed to each magnet carrier 12 and is formed with an axially extending channel. At least one pole piece 16 made of a magnetic material such as steel is located adjacent to the radially outer surface of each magnet carrier 12 and in the channel formed in its associated pole piece retainer 18.

Abstract: The present invention provides an improved single-layer coil 10 for a rotating or linear electrical machine. The coil 10 has a first endwinding 12 that is substantially parallel to a longitudinal axis LA of the coil and a second endwinding 14 that is bent away from, or towards, the longitudinal axis. The coil 10 therefore has differently shaped endwindings with one end 12 being ‘straight’ and the other end 14 being ‘bent’.

Abstract: The present invention provides a permanent magnet rotor arrangement that is particularly suitable for low-speed large-diameter electrical generators. The arrangement includes a rotor 2 having a radially outer rim 4. A circumferential array of magnet carriers 12 is affixed to the outer rim 4 of the rotor and have a radially outer surface. An inverted U-shaped pole piece retainer 18 made of non-magnetic material such as stainless steel is affixed to each magnet carrier 12 and is formed with an axially extending channel. At least one pole piece 16 made of a magnetic material such as steel is located adjacent to the radially outer surface of each magnet carrier 12 and in the channel formed in its associated pole piece retainer 18.

Abstract: An electrical machine has at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles in each group is sited in its reference position. At least one magnet pole in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots. The displacement of the magnet poles provides a pronounced reduction in cogging.

Abstract: The present invention provides an electrical machine 1 with reduced cogging. The magnet poles 3 of the electrical machine are comprised of at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles 3 in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole 3 is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles 3 in each group is sited in its reference position. At least one magnet pole 3 in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots.