JP6327890B2 - Linear motor armature and cooling pipe fixing method - Google Patents

Description

  The present invention relates to an armature used as a stator or mover of a linear motor, and a method for fixing a cooling pipe to a core of the armature.

  An armature used for a linear motor includes a core, a plurality of teeth provided on the core in the driving direction, and a coil wound around the teeth. If the coil generates heat when energized, the temperature of the armature core may increase and the performance of the armature may be adversely affected. As a countermeasure, a cooling pipe is usually disposed in a slot portion formed between the tooth portions (see Patent Document 1). The core is cooled by the refrigerant supplied into the cooling pipe, and the temperature rise is suppressed.

JP 2008-35698 A

  Generally, it is difficult to ensure the flatness (cylindricity) of the outer peripheral surface of the cooling pipe, and the contact area in the slot portion varies depending on the position in the pipe axis direction. Therefore, the contact thermal resistance generated between the slot portion and the cooling pipe is likely to increase, and the cooling performance of the core by the cooling pipe is reduced.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which can improve the cooling performance of the core by a cooling pipe.

  One embodiment of the present invention relates to an armature for a linear motor. The armature for the linear motor is arranged in the state where the core, the groove formed in the core, the cooling pipe arranged in the groove, and the opening side in the groove are pushed into the bottom of the groove. And a pushing member to be provided.

  Another aspect of the present invention relates to a cooling pipe fixing method. A cooling pipe fixing method is a method for fixing a cooling pipe in a groove part of a linear motor armature including a core and a groove part formed in the core, the cooling pipe being disposed in the groove part, and the groove part The cooling pipe is pushed by a pushing member from the opening side to the bottom side of the opening, and the pushing member is fixed in that state.

  According to these aspects, since the cooling pipe is pushed into the bottom of the groove by the pushing member, the contact area between the cooling pipe and the inner wall surface of the groove becomes large. Therefore, the contact thermal resistance between the cooling pipe and the groove portion is reduced, heat is easily transferred through these contact portions, and the core cooling performance by the cooling pipe is improved.

  According to an aspect of the present invention, the cooling performance of the core by the cooling pipe can be improved.

It is side surface sectional drawing which shows the linear motor with which the armature which concerns on 1st Embodiment is used. It is a disassembled perspective view which shows the armature which concerns on 1st Embodiment. It is front sectional drawing which shows the cooling pipe arrange | positioned in the groove part of the armature core which concerns on 1st Embodiment. It is an expanded side sectional view showing a cooling pipe arranged in a groove part of an armature core concerning a 1st embodiment. It is an expanded side sectional view showing the halfway state when arranging a cooling pipe and a pushing member in a slot of an armature core concerning a 1st embodiment. It is an expanded side sectional view showing an intermediate state when carrying out friction stir welding of the armature core and pushing member concerning a 1st embodiment.

(First embodiment)
FIG. 1 shows a linear motor 10 in which an armature 40 according to the first embodiment is used. The linear motor 10 includes a field element 30 and an armature 40. The field element 30 is a stator, and the armature 40 is a mover. Hereinafter, the driving direction of the linear motor 10 will be referred to as direction X, and two directions orthogonal to the direction axis of the direction X will be described as direction Y and direction Z.

  The field element 30 includes a field element core 31 and a plurality of magnets 33. The field element core 31 is a rectangular parallelepiped member extending in the driving direction X. Each magnet 33 is a permanent magnet, but may be an electromagnet. Each magnet 33 is provided such that different magnetic poles (N pole, S pole) are alternately positioned in the driving direction X.

  The armature 40 is disposed at a distance from the field element 30. FIG. 2 shows an exploded perspective view of the armature 40. The armature 40 includes an armature core 41. The armature core 41 is configured by laminating a plurality of laminated bodies 47. The laminated body 47 is an electromagnetic steel plate, but may be another metal plate. The armature core 41 may be composed of a sintered body such as sintered ferrite.

  The armature core 41 includes a rectangular parallelepiped yoke portion 42 extending in the driving direction X, a plurality of (in the figure, nine) tooth portions 43 protruding from the yoke portion 42, and on both sides of the driving portion X in the driving direction X. A plurality of (in the figure, 10) slot portions 45 are formed. The teeth part 43 and the slot part 45 are provided in the inner part 41 a of the armature core 41 facing the field element 30. In addition, the armature core 41 is provided with a plurality of (in the figure, 10) groove portions 51 in the driving direction X on the outer side portion 41b. The direction Y corresponds to the protruding direction of the tooth portion 43, and the direction Z corresponds to the depth direction of the armature core 41 (the stacking direction of the stacked body 47).

  The armature core 41 has a concavo-convex shape in which the tooth portions 43 and the slot portions 45 are alternately provided in the driving direction X, that is, a comb tooth shape. A coil 49 is wound around each tooth portion 43, and the coil 49 is disposed in the slot portion 45.

  In the above linear motor 10, thrust is generated in the armature 40 due to the interaction between the magnetic field generated by energization of the coil 49 and the magnetic field of the magnet 33, and the armature 40 moves in the driving direction X.

  The armature 40 further includes a cooling pipe 60 and a pushing member 70 in addition to the armature core 41 and the like.

  The cooling pipe 60 is made of a metal material such as copper. The cooling pipe 60 includes a plurality (ten in the drawing) of core cooling units 61 provided at intervals in the driving direction X, and a continuous unit 63 that connects the ends of the adjacent core cooling units 61. The number of the core cooling parts 61 corresponding to the number of the groove parts 51 is provided. The cross section of the core cooling part 61 is formed in a cylindrical shape. The cooling pipe 60 is provided so that each core cooling part 61 and the connecting part 63 meander in a wave shape, and a continuous flow path is formed inside thereof. The cooling pipe 60 is manufactured by bending a pipe body.

  FIG. 3 is a front sectional view showing the cooling pipe 60 arranged in the groove 51. As shown in FIGS. 1 and 3, in the cooling pipe 60, each core cooling part 61 is arranged in a separate groove part 51, and the connecting part 63 is arranged outside the armature core 41 in the depth direction Z. When a coolant such as water is fed into the cooling pipe 60, the coolant flows in the direction Q from the inflow side (P1 portion in FIG. 2) to the outflow side (P2 portion in FIG. 2) of the flow path. The armature core 41 is cooled by the refrigerant.

  FIG. 4 is an enlarged side sectional view showing the cooling pipe 60 disposed in the groove 51. The groove 51 penetrates the armature core 41 in the depth direction Z as shown in FIGS. 3 and 4. The groove 51 is formed with an opening 53 in the protruding direction Y of the teeth 43. The inner wall surface 55 of the groove portion 51 includes a bottom groove bottom surface 57 and a pair of groove side surfaces 59 extending from the groove bottom surface 57 toward the opening 53 side of the groove portion 51.

  The groove bottom surface 57 has a shape curved in a concave shape on the bottom side of the groove portion 51 so as to follow the bottom side portion 60a of the outer peripheral surface of the cooling pipe 60 disposed in the groove portion 51, and contacts the bottom side portion 60a. To do. The bottom side portion 60 a of the cooling pipe 60 is fitted so as to close a part of the bottom side in the groove 51. Each groove side surface 59 is formed in a planar shape.

  The pushing member 70 is disposed in the groove portion 51 on the opening side from the cooling pipe 60. The pushing member 70 is formed of a steel material that is the same kind of metal material as the armature core 41.

  The pushing member 70 is formed as a block body that is long in the depth direction Z of the groove 51, and has a length L2 combined with the length L1 of the groove 51, that is, a length L2 that substantially matches the length L1. The pushing member 70 has a solid cross-sectional shape that is fitted so as to close a portion surrounded by the opening-side portion 60 b of the outer peripheral surface of the cooling pipe 60 and the pair of groove side surfaces 59.

  The side wall surfaces 71 of the push-in member 70 on both sides of the driving direction X are in contact with the groove side surface 59 of the groove portion 51 facing this. The bottom wall surface 73 of the pushing member 70 on the bottom side of the groove 51 has a shape that is concavely curved toward the opening side along the opening side portion 60b of the cooling pipe 60, and contacts along the opening side portion 60a. To do. The top surface 75 of the pushing member 70 on the opening side of the groove 51 is provided so as to be flush with the outer surface 41 c of the armature core 41.

  The pushing member 70 pushes the cooling pipe 60 into the bottom side of the groove 51, and is fixed by welding (penetration welding) in this state. Welding is performed on the peripheral edge 53b of the opening 53 of the armature core 41 and the side end 77 of the push-in member 70 to be abutted against the peripheral edge 53b. By this welding, a weld joint 79 is formed along the boundary portion between the armature core 41 and the pushing member 70. Details of this welding method will be described later.

  Next, a method for fixing the cooling pipe 60 in the groove 51 of the armature core 41 will be described. FIG. 5 shows an intermediate state when the cooling pipe 60 and the pushing member 70 are disposed in the groove 51.

  First, as shown in FIG. 5A, the cooling pipe 60 is disposed in the groove 51. The cooling pipe 60 is moved until the bottom side portion 60 a contacts the groove bottom surface 57 of the groove portion 51.

  As shown in FIG. 5B, the pushing member 70 is inserted into the groove 51 with the bottom wall surface 73 of the pushing member 70 facing the bottom of the groove 51. At this time, each side wall surface 71 of the push-in member 70 is inserted in a state where it is in contact with the groove side surface 59 of the opposed groove portion 51. Thereby, the pushing member 70 is guided by the groove side surface 59, and the pushing operation becomes easy.

  The pushing member 70 is inserted until the bottom wall surface 73 comes into contact with the opening side portion 60 b of the cooling pipe 60. Here, since the cooling pipe 60 is generally difficult to ensure the flatness of the outer peripheral surface thereof, the cooling pipe 60 is liable to bend in the protruding direction Y of the teeth portion 43 depending on the position in the pipe axis direction (depth direction Z). Even when there is this undulation, the cooling pipe 60 is deformed and the undulation is corrected by pushing the pushing member 70 in contact with the cooling pipe 60 toward the bottom side. As shown in FIG. 5C, when the top surface 75 of the push-in member 70 is pushed to a position where it is flush with the outer side surface 41c of the armature core 41, the push-in is stopped.

  Next, the armature core 41 and the pushing member 70 are joined by welding. Welding is performed by friction stir welding. FIG. 6 shows an intermediate state when these are friction stir welded.

  In the friction stir welding, the rotary tool 100 is used as a friction stir tool. The rotary tool 100 includes a columnar main body 101 and a probe 103 provided at the tip of the main body 101.

  The probe 103 is brought into contact with the armature core 41 and the butting portion 80 of the pushing member 70, and the probe 103 is moved along the butting portion 80 while rotating. The peripheral portion of the probe such as the armature core 41 is softened by the frictional heat between the armature core 41 and the pushing member 70 and the probe 103. Further, the softened portion is agitated by the rotation of the probe 103, and plastic flow occurs at the butting portion 80 such as the armature core 41. When the probe 103 is moved in the depth direction Z to pass through the softened portion, the plastically flowed portion is solidified by cooling, and a welded joint 79 is formed between the armature core 41 and the pushing member 70 to join them. .

  According to this embodiment, since the cooling pipe 60 is pushed into the bottom side of the groove 51 by the pushing member 70, the contact area between the cooling pipe 60 and the inner wall surface 55 of the groove 51 is increased. Therefore, the contact thermal resistance generated between the cooling pipe 60 and the groove 51 is reduced, and heat is easily transmitted through these contact portions, and the cooling performance of the armature core 41 by the cooling pipe 60 is improved.

  Further, since the cooling pipe 60 is manufactured by bending a pipe body, radial undulation is likely to occur due to a bending force applied during the bending process. If the core cooling part 61 of the cooling pipe 60 has a large undulation in the protruding direction Y, the cooling pipe 60 protrudes from the opening 52 of the groove part 51, and the assembly of the armature 40 may be difficult. Even in this case, the swell is suppressed by the pressing of the pressing member 70, and the assembling property when the armature 40 is assembled is improved.

  In addition, when the cooling pipe 60 has waviness, the contact thermal resistance between the cooling pipe 60 and the groove part 51 changes depending on the position in the depth direction Z, and between the individual core cooling part 61 and the groove part 51 in the driving direction X. The contact thermal resistance can also vary. As a result, the cooling performance of the cooling pipe 60 may vary depending on the position of the armature core 41 in the driving direction X and the depth direction Z. In this respect, according to the present embodiment, the undulation of the cooling pipe 60 is suppressed, so that variation in cooling performance due to the position of the armature core 41 in the driving direction X and the depth direction Z can be suppressed.

  In addition, since the pushing member 70 is joined to the armature core 41 by welding, heat is more easily transmitted through the weld joint 79 than the contact portion between the pushing member 70 and the armature core 41. Therefore, the cooling performance of the armature core 41 by the cooling pipe 60 is good.

  In particular, since the pushing member 70 is joined to the armature core 41 by friction stir welding, the following advantages are obtained. Friction stir welding is solid phase bonding in which a base material to be bonded is heated to a temperature below its melting point and bonded. In fusion bonding in which the base material to be joined is heated to a melting point or higher, the metal structure of the base material becomes a melt-solidified structure, and the crystal grains become coarse and solute elements are segregated. On the other hand, the friction stir welding has the merit of ensuring the plastic workability at the welded joint 79 because the crystal grains of the base material can be kept fine and the segregation of solute elements hardly occurs. In addition, the friction stir welding has an advantage that the amount of thermal deformation at the welded joint 79 can be suppressed and the joining accuracy can be improved as compared with the fusion joining. In addition, the friction stir welding has an advantage that less power is required and less energy is required, and skill is not required for the work, as compared with the fusion welding.

  Moreover, since the pushing member 70 is fitted so that the location enclosed by the cooling pipe 60 and the groove part 51 may be block | closed, the contact area with the cooling pipe 60 and the armature core 41 becomes large. Therefore, heat is easily transferred from the cooling pipe 60 to the armature core 41 through the pushing member 70, and the cooling performance by the cooling pipe 60 is improved. In particular, since the pushing member 70 has a solid cross-sectional shape, it has better thermal conductivity and better cooling performance than the hollow cross-sectional shape.

  As mentioned above, although this invention was demonstrated based on embodiment, embodiment shows only the principle and application of this invention. In the embodiment, many modifications and arrangements can be made without departing from the spirit of the present invention defined in the claims.

  In the above-described embodiment, the example in which the armature 40 according to the present invention is applied to the mover has been described. However, the armature 40 may be applied to a stator. Also when applied to the stator, the armature 40 is provided with a tooth portion 43 on the side portion of the armature core 41 facing the mover that is the field element 30, and the coil 49 is wound around the tooth portion 43. Is done.

  The shape of the groove 51 of the armature core 41 is not limited to the above. In addition, the groove 51 in which the cooling pipe 60 is disposed is formed in the outer portion 41b opposite to the inner portion 41a of the armature core 41 in which the slot portion 45 is formed. May be used. In this case, the cooling pipe 60 is arranged on the bottom side of the slot part 45 as the groove part 51, the pushing member 70 is arranged on the opening side from the cooling pipe 60 in the slot part 45, and the coil 49 is arranged on the opening side from the pushing member 70. It may be arranged.

  The example which provided the some core cooling part 61 in the cooling pipe 60, arrange | positions each core cooling part 61 in the some groove part 51, and cools the one armature core 41 by the single cooling pipe 60 was demonstrated. In another modification, separate cooling pipes 60 may be arranged in the plurality of groove portions 51, and one armature core 41 may be cooled by the plurality of cooling pipes 60. Moreover, although the cross section of the core cooling part 61 was formed in the cylindrical shape, you may form in a square tube shape etc.

  The pushing member 70 may have a hollow cross-sectional shape instead of a solid cross-sectional shape, and the shape is not limited to the above.

  In addition to friction stir welding, the pushing member 70 may be joined to the armature core 41 by other welding methods such as fusion welding such as brazing, arc welding, or pressure welding such as spot welding. Further, the pushing member 70 may be joined by other joining methods such as press fitting and shrink fitting other than welding.

DESCRIPTION OF SYMBOLS 10 ... Linear motor, 40 ... Armature, 51 ... Groove part, 55 ... Inner wall surface, 60 ... Cooling pipe, 70 ... Pushing member.

Claims (5)

An armature for a linear motor,
The core,
A groove formed in the core;
A cooling pipe disposed in the groove;
A pushing member disposed on the opening side in the groove and fixed in a state where the cooling pipe is pushed into the bottom of the groove ,
The outer peripheral surface of the cooling pipe has an opening side portion on the opening side of the groove,
The pushing member has a bottom wall surface that is in contact with the opening side portion of the cooling pipe,
Said cooling tube, said by being pushed by the pushing member, linear motor armature, characterized that you close contact with the inner wall surface of the groove. The armature for a linear motor according to claim 1, wherein the pushing member is joined to the core by welding or friction stir welding. The pushing member includes a linear motor armature according to claim 1 or 2, characterized in that it has a sidewall surface in contact along the groove flank of the groove.   4. The armature for a linear motor according to claim 1, wherein the pushing member is fitted so as to close a portion surrounded by an outer peripheral surface of the cooling pipe and an inner wall surface of the groove portion. A method for fixing a cooling pipe in a groove portion of a linear motor armature comprising a core and a groove portion formed in the core,
A cooling pipe is disposed in the groove, and the cooling pipe is pushed by a pushing member from the opening side to the bottom side of the groove, and the pushing member is fixed in that state .
The outer peripheral surface of the cooling pipe has an opening side portion on the opening side of the groove,
The pushing member has a bottom wall surface that is in contact with the opening side portion of the cooling pipe,
The cooling pipe fixing method according to claim 1, wherein the cooling pipe is brought into close contact with an inner wall surface of the groove portion by being pushed in by the pushing member .

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