Magnetic bearing stator with improved spool

Abstract

A stator assembly for a magnetic bearing includes a core member formed of a ferromagnetic material, the core member including an outer annular portion and a plurality of protrusions extending radially inward from the outer annular portion and spaced circumferentially about a centerline. The plurality of bobbins is formed of an electrically insulating material and includes a first half-shell disposed against a first axial end of a separate one of the protrusions and a second half-shell disposed against a second axial end of the protrusions. The second half-shell is coupled with the first half-shell such that a projection is enclosed within a cavity defined between the two half-shells. Each of the plurality of windings includes at least one wire wound about the spool and electrically coupleable with a power source such that each winding and the protrusion surrounded by the winding provide a magnetic pole.

Description

Technical Field

[0001] The present invention relates to a magnetic bearing, and more particularly to a stator assembly for a magnetic bearing. Background Art

[0002] Magnetic bearings are known and typically include a rotor suspended within an external stator and rotating about a central axis. In active bearings, magnetic poles are created within a core member of the stator by passing an electric current through a plurality of windings. These windings are typically each wound on a bobbin which electrically insulates the coils of the winding from an inner core projection. Such a bobbin is typically formed as a tubular member having a cavity which is mounted on the core member projections by sliding the bobbin radially outwardly onto the projections. Summary of the invention

[0003] In one aspect, the present invention is a stator assembly for a magnetic bearing, the stator assembly comprising a core member formed of a ferromagnetic material, the core member having a centerline and including an outer annular portion and a plurality of protrusions. The plurality of protrusions extend radially inward from the outer annular portion and are circumferentially spaced around the centerline, each protrusion having a first axial end and an opposite second axial end. Each of the plurality of bobbins is formed of an electrically insulating material and comprises a first half shell disposed against a first axial end of a single one of the plurality of protrusions and a second half shell disposed against a second axial end of a protrusion. The second half shell is coupled to the first half shell so that a protrusion is enclosed in a cavity defined between the first half shell and the second half shell. In addition, each of the plurality of windings comprises at least one wire wound on a single one of the plurality of bobbins, each winding being electrically coupled to a power source so that each winding and the protrusion surrounded by the winding provide a pole of the stator.

[0004] On the other hand, the present invention is also a stator assembly as described in the previous paragraph, but each bobbin is provided as a pair of bobbins. Each pair of bobbins includes a pair of first half shells connected by a first skirt, each first half shell being arranged against a first axial end of a single one of two protrusions in a plurality of protrusions, and a pair of second half shells connected by a second skirt, each second half shell being arranged against a second axial end of a single one of the two protrusions. One of the second half shells is coupled to one of the two first half shells, the first half shell being arranged against the same arrangement of the two protrusions to enclose the protrusion in a cavity defined between the first and second half shells. The other of the second half shells is coupled to one of the two first half shells that is arranged against the same arrangement of the two protrusions to enclose the protrusion in a cavity defined between the first and second half shells. With this structure, the windings arranged around one bobbin of each pair of bobbins and the protrusions surrounded by the windings provide the north pole of the stator, and the windings arranged around the other bobbin of each pair of bobbins and the protrusions surrounded by the windings provide the south pole of the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The foregoing summary and detailed description of the preferred embodiments of the invention will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, there are shown in the accompanying drawings, which are drawn to scale, presently preferred embodiments. However, it should be understood that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0006] Figure 1 is a perspective view of a stator assembly according to the present invention;

[0007] Figure 2 is a perspective view of the process of assembling a pair of preferred spools onto a core member;

[0008] Figure 3 is a perspective view of the core member with a pair of second half shells installed;

[0009] Figure 4 is a perspective view of a core member with a pair of bobbins mounted thereon;

[0010] Figure 5 is a cut-away top front perspective view of one winding of a stator assembly;

[0011] Figure 6 is a top view of the interior of a preferred pair of first half shells;

[0012] Figure 7 is a bottom interior perspective view of the pair of first half shells;

[0013] Figure 8 is a cutaway top and side perspective view of a first half shell;

[0014] Fig. 9 is a top plan view of the pair of first half shells;

[0015] Fig.10 is a bottom plan view of the first half shell of the pair;

[0016] Fig.11 is a top view of the interior of a pair of preferred second half shells;

[0017] Fig.12 is a bottom interior perspective view of the second half shell of the pair;

[0018] Fig.13 is a cutaway top and side perspective view of a second half shell;

[0019] Fig.14 is a top view of the pair of second half shells; and

[0020] Fig.15 is a bottom view of the pair of second half shells. DETAILED DESCRIPTION

[0021] Certain terms used in the following description are for convenience only and are not intended to be limiting. The words "right", "left", "lower", "up", "upward", "downward" and "downward" refer to directions in the accompanying drawings to which reference is made. The words "interior", "inwardly" and "exteriorly", "outwardly" refer to directions toward and away from a specified centerline or geometric center of the element being described, respectively, and the specific meaning is apparent from the context of the specification. In addition, as used herein, the words "connect" and "couple" are intended to include a direct connection between two components without any other components interposed therebetween, as well as an indirect connection between components in which one or more other components are interposed therebetween. The term includes the words specifically mentioned above, their derivatives, and words of similar meaning.

[0022] Referring now in detail to the drawings, wherein like numerals are used to refer to like elements, Figure 1-15 1 shows a stator assembly 10 for a magnetic bearing, which includes a housing for accommodating the stator assembly 10, a rotor rotatably disposed in the stator, and a power source (only the stator is shown). The stator assembly 10 basically includes a core member 12 formed of a ferromagnetic material, a plurality of bobbins 14 formed of an electrically insulating material, and a plurality of windings 16, each winding 16 being disposed around a single bobbin 14 so as to provide a plurality of north poles N and a plurality of south poles S ( Figure 1 ).

[0023] First refer to Figure 1-4 , the core member 12 has a center line L C ( Figure 2 ), and includes an outer annular portion 22 and a radially inwardly extending portion extending from the outer annular portion and surrounding the center line L C A plurality of protrusions 24 are circumferentially spaced apart. The outer annular portion 22 has opposing first and second axial ends 22a, 22b, a plurality of inner circumferential surface portions 23A extending between each pair of adjacent protrusions 24, and an outer circumferential surface 23B. In addition, each protrusion 24 has a first axial end 24a, an opposing second axial end 24b, a free inner radial end 25a, and an outer radial end 25b integrally formed with the annular portion 22. Preferably, each protrusion 24 has a substantially rectangular cross-section and has opposing first and second circumferential side surfaces 24c, 24d extending axially between the first and second axial ends 24a, 24b. Most preferably, the two circumferential side surfaces 24c, 24d converge toward each other in a direction from the outer radial end 25a toward the inner radial end 25b, so that each protrusion 24 is substantially wedge-shaped. In addition, the core member 12 is preferably formed by a single stamping or by laser cutting of thin silicon steel sheets that are bonded together to form the complete core member 12.

[0024] Reference now Figure 1 , 25, each bobbin 14 is arranged around a single protrusion of the plurality of core member protrusions 24, and has an inner radial end 14a adjacent to the inner radial end 25a of the closed protrusion 24 and an outer radial end 14b adjacent to the outer radial end 24b of the closed protrusion 24. Each bobbin 14 is formed by two parts or sections 30A, 30B, preferably formed by two half shells 32, 34, which are axially assembled together around a single protrusion 24, as described in detail below. More specifically, each bobbin 14 includes a first section 30A or a first half shell 32 arranged against a first axial end 24a of a single one of the plurality of protrusions 24, and a second section 30A or a second half shell 34 arranged against a second axial end 24b of a protrusion 24. The second section 30B / half shell 34 is coupled to the first section 30A / first half shell 32 so that a protrusion 24 is enclosed in a cavity 31 defined between the first and second half shells 32, 34. Most preferably, each first half shell 32 is provided as a pair 33 of first half shells 32, and each second half shell 34 is provided as a pair 35 of second half shells 34, such that each joined pair 33, 35 of half shells 32, 34 provides two bobbins 14, as described in detail below. In addition, each bobbin 14 is preferably formed of a polymeric material, such as nylon, polyetherimide (PEI), acrylonitrile butadiene styrene (ABS), polyetheretherketone (PEEK), etc.

[0025] Reference Figure 1 and Figure 5 , each of the plurality of windings 16 includes at least one wire 17 wound on a separate one of the plurality of spools 14 so as to extend circumferentially around the spool 14 and radially between the spool inner end 14a and the spool outer end 14b. Preferably, the wire winding is performed by an automated process, most preferably needle winding, but may alternatively be manually wound. In any case, each winding 16 may be electrically coupled to a power source (not shown) such that each winding 16 and the protrusion 24 surrounded by the winding 16 provide a magnetic pole N or S of the stator assembly 10, while each spool 14 prevents current flow between the winding 16 and the enclosed protrusion 24. Preferably, each winding 16 is configured and electrically connected to adjacent windings 16 such that one winding 16 produces a north pole N, while the adjacent connected winding 16 produces a south pole S, and magnetic flux passes in a loop between the magnetic poles N, S, such as Figure 1Thus, using the preferred pairs 33, 35 of half shells 32, 34, each pair 15 of bobbins 14 formed thereby is configured to provide a mounting surface for windings 16 and a pair of complementary north and south poles N, S connecting wires while electrically insulating the two windings 16 from the surrounding protrusions 24. In a currently preferred embodiment, the pairs 15 of bobbins 14 and windings 16 are arranged and configured (e.g., electrically connected) to provide an arrangement of north poles N and south poles S that is a pattern of NSSNNSSN moving clockwise around the stator assembly 10, as shown. Figure 1 shown.

[0026] By forming the bobbin 14 of a two-piece structure as described above and further described below, the installation of the bobbin 14 on the protrusion 24 of the core member 12 is very convenient and easier to automate because the two bobbin segments 30A, 30B are axially moved from opposite axial directions to engage with the protrusion 24. Therefore, all bobbin segments 30A or 30B can be installed on all protrusions 24 simultaneously by a single axial movement. In contrast, the conventional single-piece bobbin must first be positioned in the central opening of the core member 12 (i.e., between the inner ends 25a of the core protrusion 24) and then moved radially outward to install the bobbin on the core protrusion. Since each core member protrusion is located at a different angular position around the centerline, each single-piece bobbin must be radially displaced in an angular direction different from the radial displacement direction of all other bobbin installed on the same core member, thereby complicating the automation of the bobbin installation process. The basic structure and function have been described above, and these and other elements of the stator assembly 10 of the present invention will be described in more detail below.

[0027] Reference now Figure 6 , 7 , 9-12, 14 and 15, the first half shell 32 of each of the plurality of bobbins 14 has an inner radial end 32a, an outer radial end 32b, an outer surface 36A, and an inner surface 36B, which define an elongated channel 37 extending radially between the inner end 32a and the outer end 32b. In this way, each first half shell 32 is connected between the first half shell 32 and a protrusion 24 in the first axial direction A1 ( Figure 2 ) is mounted on a single core member protrusion 24 with relative axial displacement on the first half shell 32, so that at least a portion of the protrusion 24 is disposed in the elongated passage 37 of the first half shell 32. Similarly, each second half shell 34 has an inner radial end 34a, an outer radial end 34b, an outer surface 38A and an inner surface 38B, which define an elongated passage 39 extending radially between the inner end 34a and the outer end 34b. With this structure, each second half shell 34 is provided with a protrusion 24 in the opposite second axial direction A2 ( Figure 2) and are mounted on a single core member protrusion 24 with relative axial displacement on the second half shell 34. As a result, at least a portion of one protrusion 24 becomes disposed within the elongated passage 39 of the second half shell 34. Thus, when the half shells 32, 34 are connected together, each protrusion 24 is enclosed or enclosed within the facing passages 37, 39 of the two half shells 32, 34.

[0028] refer to Figure 6-10 Each first half shell 32 preferably includes a first side wall 40 and a second side wall 42, which extend radially between the inner radial end 32a and the outer radial end 32b and are parallel to each other. The two side walls 40, 42 define an elongated channel 37 and are connected by a central base wall 44 having opposite circumferential ends 44a, 44b. Specifically, the first side wall 40 extends axially from the first circumferential end 44a of the base wall 44, and the second side wall 42 extends axially from the second circumferential end 44b of the base wall 44. Each side wall 40, 42 has a first edge 40a, 42a and a free second edge 40b, 42b, respectively, the first edge 40a, 42a is integral with the circumferential end 44a, 44b of the end wall 44, and the second edge 40b, 42b is configured to engage with the second half shell 34, as described below.

[0029] In order to complementarily fit around the core member protrusion 24, the two side walls 40, 42 preferably converge towards each other in the direction from the outer radial end 32b towards the inner radial end 32a, so that each half shell 32 is roughly wedge-shaped. In addition, the base wall 44 is preferably flat and is arranged against the first axial end 24a of the core member protrusion 24, so that the first half shell 32 has a roughly rectangular axial cross-section. However, in particular if the core member protrusion 24 is curved, the base wall 44 can be similarly curved so that the first half shell 32 has a roughly U-shaped axial cross-section (structure not shown). In addition, when installed around the protrusion 24, the first side wall 40 is arranged against the first circumferential end 24c of the closed protrusion 24, and the second side wall 42 is arranged against the second circumferential end 24d of the closed protrusion 24.

[0030] like Figure 8As best shown in FIG. 1 , each first half shell 32 preferably also includes a plurality of grooves 46 formed in the shell outer surface 36A and radially spaced between the inner radial end 32a and the outer radial end 32b. Each groove 46 is configured to receive a portion of at least one wire 17 of a winding 16 disposed around the bobbin 14 formed by the particular half shell 32. In this way, the grooves 46 both retain the wire 17 during winding of the wire 17 around the bobbin 14 and maintain spacing between adjacent coils of the winding 16. Most preferably, the grooves 46 include a first set of grooves 48A formed along a first corner 47a between the base wall 44 and the first side wall 40 and a second set of grooves 48B formed along a second corner 47b between the base wall 44 and the second side wall 42. The two sets of grooves 48A, 48B are preferably staggered in the radial direction to facilitate winding the wire 17 on the bobbin 14 formed by the first half shell 32. In addition, each first half-shell 32 also preferably includes a retaining flange 49 extending axially and circumferentially from the inner radial end 32a, and each flange portion 49 is configured to retain the inner radial end 16a of the winding 16 arranged around one bobbin 14 formed by the specific first half-shell 32. Specifically, each retaining flange 49 has a radial portion 49a extending radially outward from the base wall 44 and two circumferential portions 49b extending outward from the two side walls 40, 42.

[0031] Reference now Figure 11-15 , the construction of each second half shell 34 is substantially similar and complementary to that of each first half shell 32. Specifically, each second half shell 32 preferably includes a first side wall 50 and a second side wall 52, which extend radially between the inner radial end 34a and the outer radial end 34b and are parallel to each other. The two side walls 50, 52 define an elongated channel 39 and are connected by a central base wall 54 having opposite circumferential ends 54a, 54b. Specifically, the first side wall 50 extends axially from the first circumferential end 54a of the base wall 54, and the second side wall 52 extends axially from the second circumferential end 54b of the base wall 54. Each side wall 50, 52 has a first edge 50a, 52a and a free second edge 50b, 52b, respectively, the first edge 50a, 52a is integral with the circumferential end 54a, 54b of the base wall 54, and the second edge 50b, 52b is configured to engage with the second half shell 34, as described below.

[0032] In order to complementarily fit around the core member protrusion 24, the two side walls 50, 52 preferably converge toward each other in the direction from the outer radial end 34b toward the inner radial end 34a, so that each half shell 34 is generally wedge-shaped. In addition, the base wall 54 is preferably flat and is arranged against the second axial end 54a of the core member protrusion 24, so that the second half shell 32 has a generally rectangular axial cross-section, but the base wall 53 can alternatively be curved so that the second half shell 34 has a U-shaped cross-section, as described above with respect to the first half shell 32. In addition, when installed around the protrusion 24, the first side wall 50 is arranged against the second circumferential end 24c of the closed protrusion 24, and the second side wall 52 is arranged against the second circumferential end 24d of the closed protrusion 24.

[0033] like Fig.13 As best shown in FIG. 1 , each second half shell 34 preferably also includes a plurality of grooves 56 formed in the shell outer surface 38A and radially spaced between the inner radial end 34a and the outer radial end 34b. Each groove 56 is configured to receive a portion of at least one wire 17 of a winding 16 disposed around the bobbin 14 formed by the particular half shell 32 for the same reasons discussed above with respect to the grooves 46. Similar to the first half shell 32, the grooves 56 of the second half shell 34 preferably include a first set of grooves 58A formed along a first corner 57a between the base wall 54 and the first side wall 50 and a second set of grooves 58B formed along a second corner 57b between the base wall 54 and the second side wall 52, which are preferably staggered in a radial direction. Additionally, each second half shell 34 preferably also includes a retaining flange 59 extending axially and circumferentially from the half shell inner radial end 34a and configured to retain the inner radial end 16a of the associated winding 16. Specifically, each retaining flange 59 has a radial portion 59 a extending radially outward from the base wall 54 and two circumferential portions 59 b extending outward from the two side walls 50 , 52 .

[0034] Reference Figure 6 , 7, 10, 12 and 15, with the above structure, the first side walls 40, 50 of each of the first and second half shells 30, 32 are each configured to engage with a snap fit, and the second side walls 42, 52 of each of the first and second half shells 30, 32 are also each configured to engage with a snap fit. Preferably, the retaining flanges 49, 59 of the corresponding first and second half shells 30, 32 are also configured to engage with a snap fit. More specifically, each side wall 40, 42 of each first half shell 32 has an elongated step portion 40c, 42c extending inwardly from the shell inner surface 36B adjacent to each wall outer edge 40b, 42b, and each side wall 50, 52 of each second half shell 34 has an elongated step portion 50c, 52c adjacent to the wall outer edge 50b, 52b extending inwardly from the shell inner surface 38B. The two step portions 40 c , 42 c of the side wall 40 , 42 of each first half shell 32 frictionally engage with corresponding step portions 50 c , 52 c of the side wall 50 , 52 of each second half shell 34 to couple the two half shells 32 , 34 , thereby enclosing one of the core member protrusions 24 .

[0035] In addition, the two circumferential portions 49b of the retaining flange 49 of each first half-shell 32 each have a step portion 49d extending inwardly from the inner radial surface 49c, and the two circumferential portions 59b of the retaining flange 59 of each second half-shell 34 each have a step portion 59d extending inwardly from the outer radial surface 59c. The two flange step portions 49d of each first half-shell 32 are frictionally engaged with the flange step portions 59d of the associated second half-shell 34 to further enhance the snap-fit ​​engagement of the first and second half-shells 32, 34. However, the half-shells 32, 34 of each spool 14 may be formed of any other structure to provide an interlocking snap fit, or may be held together by fasteners, adhesives, or any other known means as desired.

[0036] Reference now Figure 1 , 6 , 7, 9-12, 14 and 15, as described above, each bobbin 14 is preferably provided as a pair 15 of bobbins 14 for forming a pair of north poles N and south poles S. Specifically, the first half shell 32 of each of the pairs 15 of bobbins 14 is provided as a pair 33 of first half shells 32 connected by a radially outward first skirt 60. Similarly, the second half shell 34 of each pair 15 of bobbins is provided as a pair 35 of second half shells 34 connected by a radially outward second skirt 70. Like the half shells 32, 34, the skirts 60, 70 serve to electrically insulate the wires 17 and leads (not shown) of the winding 16 and to provide mechanical rigidity to each bobbin 14.

[0037] Reference Figure 6 , 7, 9 and 10, the first skirt 60 of each pair 33 of the first shell 32 has a circumferential portion 62 disposed against one inner circumferential surface portion 23A of the core member annular portion 22 and a radial flange portion 64 disposed against the first axial end 22a of the core member annular portion 22. Each circumferential portion 62 has a first circumferential end 62a and a second circumferential end 62a, the first circumferential end 62a being integrally formed at the outer radial end of the first side wall 40 of the "left" half shell of the first half shell 32, and the second circumferential end 62a being integrally formed with the outer radial end of the second side wall 42 of the "right" half shell of the first half shell 32. Preferably, the first skirt 60 also includes a first circumferential end portion 65A extending circumferentially from the second side wall 42 of the "left" half shell 32 and a second circumferential end portion 65B extending circumferentially from the first side wall 40 of the "right" half shell 32.

[0038] In addition, each radial flange portion 64 is integrally formed with the two base walls 44 of the connected half-shell 32 and the circumferential portion 62 of the first skirt 60. Preferably, each radial flange portion 64 extends circumferentially outward beyond the outer walls 40, 42 of the connected half-shell 32 to provide a solid mounting surface 63B for the leads and wires 17. Specifically, the flange portion 64 has opposing first and second circumferential ends 64a, 64b, an inner axial surface 63A disposed against the first axial end 22a of the core member annular portion 22, and an opposing outer axial surface 63B.

[0039] like Figure 6 and 9 As shown, the radial flange portion 64 of each first skirt 60 preferably includes two elongated central shoulders 66A, 66B and two end shoulders 67A, 67B, each of which extends axially outward and circumferentially from the flange portion 64. Specifically, one elongated shoulder 66A is located near the outer radial end 32b of the "left side" of the first half shell 32, and the other shoulder 66B is located near the outer radial end 32b of the "left side" of the first half shell 32, and each shoulder 66A, 66B has an outer surface 69, and the wire 17 can be partially wrapped around the outer surface 69. As shown in FIG. Figure 5 As shown, the shoulder 66B has a retaining notch 68 configured to receive and retain in tension a portion of at least one wire 17 extending radially outward from the winding 16 disposed on the adjacent spool 14. In addition, each end shoulder 67A, 67B is located adjacent a separate circumferential end 64a, 64b, respectively, of the radial flange portion 64. Each end shoulder 67A, 67B and the elongated shoulder 66B include a gap opening 69 and a tie rod 71 for fastening a cable tie to the lead or winding wire 17.

[0040] Reference now Fig.11 , 12, 14 and 15, the second skirt 70 of each pair 35 of the second half shells 34 has a circumferential portion 72 disposed against one inner circumferential surface portion 23A of the core member annular portion 22 and a radial flange portion 74 disposed against the second axial end 22a of the core member annular portion 22. Each circumferential portion 72 has a first circumferential end 72a and a second circumferential end 72a, the first circumferential end 72a being integrally formed with the outer radial end of the first side wall 50 of the "left" half shell of the second half shell 34, and the second circumferential end 72a being integrally formed with the outer radial end of the second side wall 52 of the "right" half shell of the first half shell 34. Preferably, the second skirt 70 also includes a first circumferential end portion 75A extending circumferentially from the second side wall 52 of the "left" half shell 34 and a second circumferential end portion 75B extending circumferentially from the first side wall 50 of the "right" half shell 34.

[0041] In addition, each radial flange portion 74 of each second skirt 70 is generally flat and has opposing first and second circumferential ends 74a, 74b, an inner axial surface 76A disposed against the second axial end 22b of the core member annular portion 22, and an opposing outer axial surface 76B. Preferably, the flange portion 74 is sized to have a radial dimension that is substantially smaller than the radial dimension of the radial flange portion 64 of each first skirt 60, but has an axial thickness that is substantially greater than the radial flange portion 64. Thus, the base wall 54 of each second half-shell 34 is preferably spaced axially inwardly from the outer axial surface 76B of the flange portion 74, as shown in FIG. Fig.11 Best shown.

[0042] In addition, the circumferential portion 72 of each second skirt 70 has an axial edge 77 configured to connect with the axial edge 61 of the first skirt 60 of a particular pair 15 of the spool 14. Preferably, the circumferential portion 62 of each first skirt 60 has an elongated step portion 62c extending inwardly from the inner surface of the wall adjacent to the axial edge 63, and the circumferential portion 72 of each second skirt 70 has an elongated step portion 72c extending inwardly from the inner surface of the housing adjacent to the axial edge 77. The step portions 62c, 72c of the two circumferential portions 62, 72 are frictionally engaged to couple the first and second skirts 60, 70 so that the radial flange portions 64, 74 are held against the axial ends 22a, 22b of the core member annular portion 22.

[0043] 】Reference Figure 1 , 6, 7, 11 and 12, at least one (preferably two) of the first skirt 60 and the second skirt 70 of each pair 15 of the bobbin 14 is configured to be connected to a corresponding one of the first skirt 60 and the second skirt 70 of each pair 15 adjacent to the bobbin 14 in the circumferential direction. Specifically, each first skirt 60 has an axial recess 80 formed in the first circumferential end 65A and the end shoulder 67A, and an axial protrusion 82 extending circumferentially outward from the second circumferential end 65B and the end shoulder 67B. Each protrusion 82 of the first skirt 60 of the pair 15 of the bobbin 14 is received in the recess 80 of the first skirt 60 of the adjacent pair 15 of the bobbin 14 to couple the adjacent two pairs 15 of the bobbin 14. Similarly, each second skirt 70 has an axial protrusion 84 formed in the first circumferential end 75A and the first circumferential end 74a of the flange portion 74, and an axial recess 86 extending circumferentially outward from the second circumferential end 75B and the second end 74b of the flange portion 74. Each protrusion 84 of the second skirt 70 of the pair 15 of the bobbins 14 is received in the recess 86 of the second skirt 70 of the adjacent pair 15 of the bobbins 14 to further couple the adjacent two pairs 15 of the bobbins 14.

[0044] Although each half shell 32 or 34 is preferably provided as a pair 33, 35 of two half shells 32, 34, which provide a pair 15 of the spool 14, each spool 14 can alternatively be provided as a single component including only a first half shell 32 and a second half shell 34. In addition, the two sections 30A, 30B of each spool 14 can be formed in any manner other than half shells. For example, the first section 30A can be formed as a main body member having a central cavity 31 and a side opening, the side opening enabling the main body member to be axially mounted on the core member protrusion 24, and the second section 30B can be formed as a cover (structure not shown) that can be connected to the main body member to close the side opening. The present invention includes all structures of the two-section spool 14 described and / or depicted herein, as well as any other suitable structure that enables each spool 14 to be axially assembled to the core member protrusion 24.

[0045] The above describes in detail representative non-limiting examples of the present invention with reference to the accompanying drawings. This detailed description is only intended to teach those skilled in the art to practice more details of the preferred aspects of the present teaching, rather than to limit the scope of the present invention.

[0046] Furthermore, the combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, but are merely taught to specifically describe representative examples of the invention. Furthermore, various features of the above representative examples, and the various independent and dependent claims below, may be combined in ways not specifically and explicitly recited in order to provide additional useful embodiments of the present teachings.

[0047] All features disclosed in the specification and / or claims are intended to be disclosed individually and independently of each other, for the purpose of original written disclosure, and for the purpose of limiting the claimed subject matter, independently of the composition of features in the embodiments and / or claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity, for the purpose of original written disclosure, and for the purpose of limiting the claimed subject matter. The present invention is not limited to the above-described embodiments and may vary within the scope of the appended claims.

Claims

1. A stator assembly for a magnetic bearing, the stator assembly comprising: a core member formed of a ferromagnetic material having a centerline and including an outer annular portion and a plurality of projections extending radially inwardly from the outer annular portion and circumferentially spaced about the centerline, each projection having a first axial end and an opposite second axial end; a plurality of bobbins, each bobbin formed of an electrically insulating material and comprising a first half shell disposed against a first axial end of a single one of the plurality of protrusions and a second half shell disposed against a second axial end of the one protrusion and coupled to the first half shell such that the one protrusion is enclosed within a cavity defined between the first half shell and the second half shell; and A plurality of windings, each winding comprising at least one wire wound on a separate one of the plurality of spools, each winding being electrically connectable to a power source such that each winding and the protrusions surrounded by the winding provide a magnetic pole of the stator.

2. The stator assembly according to claim 1, wherein: a first shell half of each of the plurality of bobbins having an inner radial end, an outer radial end, and an elongated channel extending radially between the inner and outer ends, such that each first shell half is mounted on a single one of the core member protrusions by relative axial displacement in a first axial direction between the first shell half and the one protrusion such that at least a portion of the one protrusion is disposed within the elongated channel of the first shell half; and The second half shell of each of the plurality of bobbins has an inner radial end, an outer radial end and an elongated channel extending radially between the inner and outer ends, such that each second half shell is mounted on a single one of the core member protrusions by relative axial displacement between the second half shell and the one protrusion in an opposite second axial direction, such that at least a portion of the one protrusion is disposed within the elongated channel of the second half shell.

3. The stator assembly according to claim 1, wherein: Each core member projection has a first circumferential end and an opposing second circumferential end extending axially between a first axial end and a second axial end of the projection; a first half shell of each of the plurality of spools having an inner radial end, an outer radial end, a first sidewall disposed against a first circumferential end of the closure projection, and a second sidewall disposed against a second circumferential end of the closure projection, the first sidewall and the second sidewall extending radially between the inner radial end and the outer radial end; and The second half shell of each of the plurality of bobbins has an inner radial end, an outer radial end, a first side wall disposed against the first circumferential end of the closed protrusion, and a second side wall disposed against the second circumferential end of the closed protrusion, the first side wall and the second side wall extending radially between the inner radial end and the outer radial end, and each side wall having a free end, the first side wall of the first half shell being connected to the first side wall of the second half shell, and the second side wall of the first half shell being connected to the second side wall of the second half shell.

4. The stator assembly according to claim 3, wherein: an elongated channel defined between the first side wall and the second side wall of the first shell half of each spool such that each first shell half is mounted on a single one of the core member protrusions by relative axial displacement between the first shell half and the one protrusion such that at least a portion of the one protrusion is disposed within the elongated channel of the first shell half; and An elongated channel is defined between the first side wall and the second side wall of the second half shell of each bobbin, so that each second half shell is mounted on a single one of the core member protrusions by relative axial displacement between the second half shell and the one protrusion, so that at least a portion of the one protrusion is disposed within the elongated channel of the second half shell.

5. The stator assembly of claim 4, wherein the first side wall of each first half shell and the first side wall of each second half shell are each configured to engage by a snap fit, and the second side wall of each first half shell and the second side wall of each second half shell are each configured to engage by a snap fit.

6. The stator assembly of claim 1, wherein: the first half shell of each of the plurality of bobbins being provided as a pair of first half shells connected by a first skirt having a circumferential portion positionable against an inner circumferential surface portion of the core member annular portion, the inner circumferential surface portion extending between two adjacent core member protrusions and having a radial flange portion positionable against a first axial end of the core member annular portion; and The second half shell of each of the plurality of bobbins is provided as a pair of second half shells connected by a second skirt, the second skirt having a circumferential portion that can be set against the inner circumferential surface portion of the annular portion of the core member, the circumferential portion extending between two adjacent protrusions of the core member and being connectable to the circumferential portion of the first skirt, and having a radial flange portion that can be set against the second axial end of the annular portion of the core member, each half shell of the pair of second half shells being connected to a single half shell of the pair of first half shells, thereby forming two bobbins.

7. The stator assembly of claim 6, wherein the radial flange portion of the first skirt includes two elongated shoulders, each shoulder extending axially outward and circumferentially, one shoulder adjacent one of the first half-shells and the other shoulder adjacent an outer radial end of the other of the first half-shells, each shoulder having at least one of a retaining notch and a gap opening, the retaining notch being configured to hold tension on a portion of at least one wire extending radially outward from a winding disposed on an adjacent bobbin, the gap opening being used to secure a cable tie for a lead or winding wire.

8. The stator assembly of claim 6, wherein: Each core member projection has a first circumferential end and an opposing second circumferential end extending axially between a first axial end and a second axial end of the projection; Each first half shell of each pair of first half shells has an inner radial end, an outer radial end, a first side wall disposed against a first circumferential end of the closed projection, and a second side wall disposed against a second circumferential end of the closed projection, the first side wall and the second side wall extending radially between the inner radial end and the outer radial end, the first side wall of one of the pair of first half shells being integrally connected to the second side wall of the other of the pair of first side walls through a circumferential portion of the first skirt; and Each second half shell in each pair of second half shells has an inner radial end, an outer radial end, a first side wall arranged against the first circumferential end of the closed protrusion, and a second side wall arranged against the second circumferential end of the closed protrusion, the first side wall and the second side wall radially extending between the inner radial end and the outer radial end, the first side wall of one of the pair of second half shells being integrally connected to the second side wall of the other of the pair of second half shells through the circumferential portion of the second skirt, the first side wall of each first half shell being connected to the first side wall of the second half shell connected to the first half shell, and the second side wall of each first half shell being connected to the second side wall of the second half shell connected to the first half shell.

9. The stator assembly of claim 1 , wherein each of the first and second half shells of each of the plurality of bobbins has an inner radial end, an outer radial end, an outer surface, and a plurality of grooves formed in the outer surface and radially spaced apart between the inner radial end and the outer radial end, each groove being configured to receive a portion of at least one wire of a winding arranged around one bobbin.

10. The stator assembly of claim 9, wherein: each of the first and second half shells of each of the plurality of spools includes a central base wall having a first circumferential end and a second circumferential end, a first side wall extending axially from the first circumferential end of the central end wall, and a second side wall extending axially from the second circumferential end of the central end wall; and The plurality of grooves of each of the plurality of bobbins includes a first set of grooves formed along an edge between the central end wall and the first side wall and a second set of grooves formed along an edge between the central end wall and the second side wall.

11. The stator assembly of claim 1 , wherein each of the first and second half shells of each of the plurality of bobbins has an inner radial end and a retaining flange extending axially and circumferentially from the inner radial end, each flange portion being configured to retain the inner radial end of a winding arranged around one bobbin.

12. The stator assembly of claim 1, wherein: the first shell half of each of the plurality of spools having an outer radial end, and each spool further comprising a first skirt extending radially outwardly from the outer radial end of the first shell half and disposed against the first axial end of the core member annular portion; and The second shell half of each of the plurality of spools has an outer radial end, and each spool further includes a second skirt extending radially outwardly from the outer radial end of the second shell half and disposed against a second axial end of the core member annular portion.

13. A stator assembly for a magnetic bearing, the stator assembly comprising: a core member formed of a ferromagnetic material having a centerline and including an outer annular portion and a plurality of projections extending radially inwardly from the outer annular portion and circumferentially spaced about the centerline, each projection having a first axial end and an opposite second axial end; a plurality of bobbins formed of an electrically insulating material, each bobbin being provided as a pair of bobbins, the pair of bobbins comprising a pair of first half shells connected by a first skirt, each first half shell being disposed against a first axial end of a single one of two protrusions of the plurality of protrusions, and comprising a pair of second half shells connected by a second skirt, each second half shell being disposed against a second axial end of a single one of the two protrusions, one of the second half shells being coupled to the one of the two first half shells disposed against the same protrusion of the two protrusions to enclose the protrusion in a cavity defined between the first half shell and the second half shell, and the other of the second half shells being coupled to the one of the two first half shells disposed against the same protrusion of the two protrusions to enclose the protrusion in a cavity defined between the first half shell and the second half shell; and A plurality of windings, each winding comprising at least one wire wound on a separate one of a plurality of bobbins, each winding being electrically connectable to a power source, the winding disposed on one bobbin in each pair of bobbins and the protrusion surrounded by the winding providing a north pole of the stator, and the winding disposed on the other bobbin in each pair of bobbins and the protrusion surrounded by the winding providing a south pole of the stator.

14. The stator assembly of claim 13, wherein: Each core member projection has a first circumferential end and an opposing second circumferential end extending axially between a first axial end and a second axial end of the projection; Each first half shell of each pair of first half shells has an inner radial end, an outer radial end, a first side wall disposed against a first circumferential end of the closed protrusion, and a second side wall disposed against a second circumferential end of the closed protrusion, the first side wall and the second side wall extending radially between the inner radial end and the outer radial end, the first side wall of one of the pair of first half shells being integrally connected to the second side wall of the other of the pair of first half shells through a circumferential portion of the first skirt; Each second half shell in each pair of second half shells has an inner radial end, an outer radial end, a first side wall disposed against the first circumferential end of the closed protrusion, and a second side wall disposed against the second circumferential end of the closed protrusion, the first side wall and the second side wall extending radially between the inner radial end and the outer radial end, the first side wall of one of the pair of second half shells being integrally connected to the second side wall of the other of the pair of second half shells through a circumferential portion of the second skirt, each first side wall of each second half shell being connected to the first side wall of each first half shell, and each second side wall of each second half shell being connected to the second of each first half shell.

15. The stator assembly of claim 14, wherein: defining an elongated channel between the first side wall and the second side wall of each first half shell in each pair of first half shells, such that each pair of first half shells is mounted on a single pair of core member protrusions by relative axial displacement between the pair of first half shells and the pair of protrusions in a first axial direction such that at least a portion of one of the pair of protrusions is disposed within the elongated channel of a single one of the pair of first half shells; and An elongated channel is defined between the first side wall and the second side wall of each second half shell in each pair of second half shells, so that each pair of second half shells is mounted on a separate pair of core member protrusions by relative axial displacement between the pair of second half shells and the pair of protrusions in an opposite second axial direction, so that at least a portion of one of the pair of protrusions is disposed within the elongated channel of a separate one of the pair of second half shells.

16. The stator assembly of claim 14, wherein the first side wall of each first half shell in the pair of first half shells and the first side wall of each second half shell in the pair of second half shells are each configured to engage by a snap fit, and the second side wall of each first half shell in the pair of first half shells and the second side wall of each second half shell in the pair of second half shells are each configured to engage by a snap fit.

17. The stator assembly of claim 13, wherein: each first skirt having a circumferential portion positionable against an inner circumferential surface portion of a core member annular portion extending between two adjacent core member protrusions and a radial flange portion positionable against a first axial end of the core member annular portion; and Each second skirt has a circumferential portion and a radial flange portion, wherein the circumferential portion can be placed against an inner circumferential surface portion of the core member annular portion, the inner circumferential surface portion extending between two adjacent protrusions of the core member and connected to the circumferential portion of the first skirt, and the radial flange portion can be placed against a second axial end of the core member annular portion.

18. The stator assembly of claim 13, wherein at least one of the first and second skirts of each pair of bobbins is configured to connect with a corresponding one of the first and second skirts of each pair of circumferentially adjacent bobbins.

19. A stator assembly for a magnetic bearing, the stator assembly comprising: a core member formed of a ferromagnetic material having a centerline and including an outer annular portion and a plurality of protrusions extending radially inwardly from the outer annular portion and spaced circumferentially about the centerline; a plurality of bobbins, each bobbin formed of an electrically insulating material and including a first section having a first open cavity and a second section having a second open cavity, the first section being disposed against a single one of the plurality of protrusions such that a portion of the one protrusion is disposed within the first open cavity, the second section being disposed against the one protrusion such that a remaining portion of the one protrusion is disposed within the second open cavity, the second section being coupled to the first section such that the one protrusion is enclosed within the first and second sections of the bobbin; and A plurality of windings, each winding comprising at least one wire wound on a separate one of the plurality of spools, each winding being electrically connectable to a power source such that each winding and the protrusions surrounded by the winding provide a magnetic pole of the stator.

20. The stator assembly of claim 19, wherein: the first section of each of the plurality of bobbins being provided as a pair of first sections connected by a first skirt having a circumferential portion positionable against an inner circumferential surface portion of a core member annular portion extending between two adjacent core member protrusions and having a radial flange portion positionable against a first axial end of the core member annular portion; and The second section of each of the plurality of bobbins is provided as a pair of second sections connected by a second skirt, the second skirt having a circumferential portion that can be set against an inner circumferential surface portion of the annular portion of the core member, the inner circumferential surface portion extending between two adjacent protrusions of the core member and being connectable to the circumferential portion of the first skirt, and having a radial flange portion that can be set against a second axial end of the annular portion of the core member, each of the pair of second sections being connected to a single one of the pair of first sections, thereby forming two bobbins.

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