Linear motor and method for adjusting the position of the coil of a linear motor

Abstract

A linear motor has a stator and a mover. The stator has a magnetic track having a first surface and a second surface on the opposite side of the first surface. The mover has a base that moves in the first direction relative to the magnetic track, a first coil mounted to the base via a first position adjustment mechanism and facing the first surface, a first cooler fixed to a surface of the first coil on the opposite side of the magnetic track, a second coil mounted to the base via a second position adjustment mechanism and facing the second surface, and a second cooler fixed to a surface of the second coil on the opposite side of the magnetic track.

Description

Technical Field

[0001] The technology disclosed in this specification relates to linear electric motors. Background Technology

[0002] Japanese Patent Publication No. 2015-119531 (hereinafter referred to as Patent Document 1) discloses a linear motor having a stator and a mover. The stator has a magnetic track. Multiple magnets are arranged on both surfaces of the magnetic track. The mover has a base that moves along the magnetic track, and two coils (hereinafter referred to as the first coil and the second coil) mounted on the base. The first coil faces one surface of the magnetic track, and the second coil faces the other surface of the magnetic track. The mover moves along the magnetic track by controlling the current in each coil. Summary of the Invention

[0003] In the linear motor of Patent Document 1, each coil can be moved relative to the base. This allows for adjustment of the distance between each coil and the magnetic track. By adjusting the distance between each coil and the magnetic track, the thrust of the linear motor can be adjusted to an appropriate value.

[0004] The mover is sometimes equipped with a cooler for cooling the coils. If the coils are moved relative to the base as in Patent Document 1, the cooling efficiency of each coil will change, and sometimes the coils cannot be cooled effectively. This specification proposes a technique for properly cooling the coils in a linear motor in which the coils can be moved relative to the base.

[0005] The linear motor disclosed in this specification has a stator and a mover. The stator has a magnetic track having a first surface and a second surface. A plurality of magnets are arranged on the first surface along a first direction, and a plurality of magnets are arranged on the second surface opposite to the first surface along the first direction. The mover has: a base movable relative to the magnetic track along the first direction; a first position adjustment mechanism; a first coil mounted on the base via the first position adjustment mechanism and facing the first surface; a first cooler fixed to the surface of the first coil opposite to the magnetic track; a second position adjustment mechanism; a second coil mounted on the base via the second position adjustment mechanism and facing the second surface; and a second cooler fixed to the surface of the second coil opposite to the magnetic track. The first position adjustment mechanism adjusts the position of the first coil relative to the base in a second direction, the second direction being from the first coil toward the second coil. The second position adjustment mechanism adjusts the position of the second coil relative to the base in the second direction.

[0006] In this linear motor, the position of the first coil can be adjusted using a first position adjustment mechanism, and the position of the second coil can be adjusted using a second position adjustment mechanism. Furthermore, since the first cooler is fixed to the surface of the first coil, even if the first coil is moved using the first position adjustment mechanism, the positional relationship between the first coil and the first cooler will not change. Similarly, since the second cooler is fixed to the surface of the second coil, even if the second coil is moved using the second position adjustment mechanism, the positional relationship between the second coil and the second cooler will not change. Therefore, each coil can be appropriately cooled. Attached Figure Description

[0007] Figure 1 This is a perspective view of the component mounting machine 10. Figure 2 This is a top view of the component mounting machine 10. Figure 3 This is a 3D view of the X-axis linear motor 30. Figure 4 This is a side view of the X-axis linear motor 30. Figure 5 This is a plan view of the mover 50 after the head 20 has been removed. Detailed Implementation

[0008] Figure 1 , Figure 2 The component mounting machine 10 of the illustrated embodiment picks up components supplied by the feeder F and mounts them onto the substrate S. The component mounting machine 10 includes a base 12, a substrate transport device (not shown), component mounting heads 20a and 20b, X-axis linear motors 30a and 30b, and a Y-axis linear motor 24. These are housed within a housing 11. An operation panel 14, operable by an operator and displaying various information, is provided on the front surface of the housing 11. Furthermore, in the following text, the axis extending horizontally in the left-right direction of the component mounting machine 10 is referred to as the X-axis, and the axis extending horizontally in the front-back direction of the component mounting machine 10 is referred to as the Y-axis.

[0009] The substrate handling device includes a conveyor belt and an electric motor that drives the conveyor belt to rotate in a circular motion. The substrate handling device uses the electric motor to drive the conveyor belt and transport the substrate S on the conveyor belt from left to right.

[0010] On the left and right sides of the upper section of the base 12, there are strip-shaped support platforms 13 extending back and forth. Each support platform 13 has a stator 25 for a Y-axis linear motor 24. Each stator 25 has movers 26a and 26b. Movers 26a and 26b are capable of moving back and forth along the Y-axis. An X-axis linear motor 30a has a beam component 21a. An X-axis linear motor 30b has a beam component 21b. Beam components 21a and 21b are long strip components extending left and right, arranged parallel to each other. Beam component 21a is mounted from the left mover 26a to the right mover 26a. Beam component 21b is mounted from the left mover 26b to the right mover 26b. The Y-axis linear motor 24 causes the X-axis linear motors 30a and 30b to move back and forth along the Y-axis.

[0011] X-axis linear motor 30a moves head 20a left and right along the X-axis. Driven by X-axis linear motor 30a and Y-axis motor 24, head 20a moves along the X-axis and Y-axis directions. X-axis linear motor 30b moves head 20b left and right along the X-axis. Driven by X-axis linear motor 30b and Y-axis motor 24, head 20b moves along the X-axis and Y-axis directions. Heads 20a and 20b have suction nozzles for adsorbing elements. Heads 20a and 20b adsorb elements supplied by feeder F and mount the adsorbed elements onto substrate S.

[0012] Next, the structure of the X-axis linear motor 30 will be described. Furthermore, since the structures of X-axis linear motors 30a and 30b are common, X-axis linear motor 30b will be described below. Figure 3 , Figure 4 As shown, the X-axis linear motor 30b has a stator 40 and a mover 50 that moves relative to the stator 40.

[0013] The stator 40 has a beam component 21, guide rails 42a and 42b, and a magnetic track 44. For example... Figure 3 As shown, beam component 21 is a square cylindrical component that extends along the X-axis. Beam component 21 is made of carbon fiber reinforced resin (CFRP) or aramid fiber reinforced resin (AFRP).

[0014] Two protruding ribs 41a and 41b are provided on the side 21s of the beam component 21. The protruding ribs 41a and 41b extend linearly parallel to the X-axis. The protruding rib 41b is arranged at a distance from the protruding rib 41a and is located below the protruding rib 41a. A guide rail 42a is provided at the front end of the protruding rib 41a, and a guide rail 42b is provided at the front end of the protruding rib 41b. The guide rails 42a and 42b extend linearly parallel to the X-axis.

[0015] A magnetic track 44 is provided on the side 21s of the beam component 21. The magnetic track 44 is arranged vertically between the ribs 41a and 41b. The magnetic track 44 has a yoke 44a and a plurality of magnets 44b (i.e., permanent magnets). The yoke 44a is made of a high-permeability material. The yoke 44a protrudes from the side 21s and extends linearly parallel to the X-axis. The yoke 44a has a base 44a-1 and a plate portion 44a-2 with a width smaller than the base 44a-1. The base 44a-1 is the part fixed to the side 21s and extends parallel to the X-axis. The plate portion 44a-2 is a plate-shaped part that protrudes forward from the base 44a-1. The plate portion 44a-2 extends parallel to the X-axis. A plurality of magnets 44b are fixed on the upper and lower surfaces of the plate portion 44a-2. Each magnet 44b is fixed with the magnetic field direction being vertical. Multiple magnets 44b-1 fixed to the upper surface of plate 44a-2 are arranged along the X-axis. The multiple magnets 44b-1 are arranged in an alternating reverse polarity manner. Multiple magnets 44b-2 fixed to the lower surface of plate 44a-2 are arranged along the X-axis. The multiple magnets 44b-2 are arranged in an alternating reverse polarity manner. Hereinafter, the surface (i.e., the upper surface) of the magnetic track 44 formed by the multiple magnets 44b-1 will be referred to as the first surface 45a, and the surface (i.e., the lower surface) of the magnetic track 44 formed by the multiple magnets 44b-2 will be referred to as the second surface 45b.

[0016] The mover 50 has a base 58, a first coil 51a, a second coil 51b, a first cooler 52a, a second cooler 52b, a first position adjustment mechanism 53a, a second position adjustment mechanism 53b, carriages 54a and 54b, and a head 20.

[0017] The carriage 54a engages with the guide rail 42a. The carriage 54a can move along the guide rail 42a. The carriage 54b engages with the guide rail 42b. The carriage 54b can move along the guide rail 42b. The carriage 54b is disposed below the carriage 54a, spaced apart from the carriage 54a. The base 58 is mounted from the carriage 54a to the carriage 54b. Therefore, the base 58 can move along the guide rails 42a and 42b in the X-axis direction. The carriages 54a and 54b are fixed to the inner surface 58b of the base 58 (i.e., the surface on the side of the magnetic track 44).

[0018] The head 20 is fixed to the outer surface 58a of the base 58 (i.e., the surface opposite to the magnetic track 44). The head 20 is detachable from the base 58.

[0019] A first coil 51a and a second coil 51b are mounted on the inner surface 58b of the base 58. Both coils are constructed from wire wound around an iron core. Furthermore, multiple first coils 51a and second coils 51b may be provided on the mover 50. The first coil 51a is mounted on the surface 58b via a first position adjustment mechanism 53a. The second coil 51b is mounted on the surface 58b via a second position adjustment mechanism 53b.

[0020] The base 58 has an opening 58c. The opening 58c is formed by a hole that extends from surface 58a to surface 58b through the base 58. The opening 58c is located approximately at the center of the base 58. When the head 20 is mounted on surface 58a of the base 58, the opening 58c is blocked by the head 20. Figure 5 As shown, when the head 20 is removed from the surface 58a of the base 58, the surfaces of the first position adjustment mechanism 53a and the second position adjustment mechanism 53b are exposed in the opening 58c.

[0021] like Figure 4 As shown, the first coil 51a is positioned opposite the first surface 45a of the magnetic track 44 (i.e., the upper part of the magnetic track 44). A gap 60 is provided between the first coil 51a and the first surface 45a. A first position adjustment mechanism 53a connects the first coil 51a to the base 58. The first position adjustment mechanism 53a has the function of changing the mounting position of the first coil 51a relative to the base 58 in the vertical direction. The first position adjustment mechanism 53a can be any mechanism as long as it allows the first coil 51a to move vertically relative to the base 58. For example, the first position adjustment mechanism 53a can be a mechanism that uses a position adjustment screw to move the first coil 51a vertically (e.g., a fine-tuning bolt), or it can be a mechanism that uses a long hole with a long vertical dimension as a mounting hole. In this embodiment, the first position adjustment mechanism 53a has a first operating part 55a. The first operating part 55a is a component that is operated using a tool or the like (e.g., a screwdriver). When the user rotates the first operating part 55a, the first position adjustment mechanism 53a moves the first coil 51a up and down, changing the width W60 of the gap 60. The first operating part 55a is disposed within the opening 58c.

[0022] A first cooler 52a is fixed to the first coil 51a for cooling the first coil 51a. The first cooler 52a is fixed to the surface of the first coil 51a on the side opposite to the magnetic track 44 (i.e., the upper surface). The first cooler 52a can cool the first coil 51a, for example, by heat exchange with air. Since the first cooler 52a is fixed to the surface of the first coil 51a, when the first coil 51a is moved using the first position adjustment mechanism 53a, the first cooler 52a moves together with the first coil 51a, and the relative position of the first cooler 52a and the first coil 51a does not change. Therefore, the first coil 51a can be effectively cooled by the first cooler 52a regardless of its position.

[0023] The second coil 51b is positioned opposite the second surface 45b of the magnetic track 44 (i.e., the lower part of the magnetic track 44). A gap 62 is provided between the second coil 51b and the second surface 45b. A second position adjustment mechanism 53b connects the second coil 51b to the base 58. The second position adjustment mechanism 53b has the function of changing the mounting position of the second coil 51b relative to the base 58 in the vertical direction. The second position adjustment mechanism 53b can be any mechanism as long as it allows the second coil 51b to move vertically relative to the base 58. For example, the second position adjustment mechanism 53b can be a mechanism that uses a position adjustment screw to move the second coil 51b vertically (e.g., a fine-tuning bolt), or it can be a mechanism that uses a long hole with a long vertical dimension as a mounting hole. In this embodiment, the second position adjustment mechanism 53b has a second operating part 55b. The second operating part 55b is a component that is operated using a tool or the like. When the user rotates the second operating part 55b, the second position adjustment mechanism 53b moves the second coil 51b vertically, and the width W62 of the gap 62 changes. The second operating part 55b is disposed inside the opening 58c.

[0024] A second cooler 52b is fixed to the second coil 51b for cooling the second coil 51b. The second cooler 52b is fixed to the surface of the second coil 51b on the side opposite to the magnetic track 44 (i.e., the lower surface). The second cooler 52b can cool the second coil 51b, for example, by heat exchange with air. Since the second cooler 52b is fixed to the surface of the second coil 51b, when the second coil 51b is moved using the second position adjustment mechanism 53b, the second cooler 52b moves together with the second coil 51b, and the relative position of the second cooler 52b and the second coil 51b does not change. Therefore, the second coil 51b can be effectively cooled by the second cooler 52b regardless of its position.

[0025] like Figure 5As shown, when the head 20 is removed from the surface 58a of the base 58, the first operating part 55a and the second operating part 55b inside the opening 58c are exposed. Therefore, the user can access the first operating part 55a and the second operating part 55b through the opening 58c to adjust the widths W60 and W62 of the gaps 60 and 62.

[0026] like Figure 4 As shown, the first position adjustment mechanism 53a and the second position adjustment mechanism 53b are arranged vertically between the carriages 54a and 54b. With the carriages 54a and 54b arranged in this way, the gap between them is large, and the base 58 is stable. Furthermore, in this configuration, the second operation part 55b can be placed near the first operation part 55a. Therefore, it is easy to operate both the first operation part 55a and the second operation part 55b.

[0027] Current can flow through the first coil 51a and the second coil 51b via cables not shown. When current flows through the first coil 51a, a magnetic force is exerted between the first coil 51a and the magnetic rail 44. When current flows through the second coil 51b, a magnetic force is exerted between the second coil 51b and the magnetic rail 44. By controlling the current flowing through the first coil 51a and the second coil 51b, the mover 50 can be moved relative to the stator 40 in the X direction.

[0028] Next, the coil position adjustment process will be explained. The width W60 of the gap 60 between the first coil 51a and the magnetic track 44 affects the magnetic force acting on the first coil 51a, and the width W62 of the gap 62 between the second coil 51b and the magnetic track 44 affects the magnetic force acting on the second coil 51b. Therefore, if the widths W60 and W62 are inappropriate, the X-axis linear motor 30 will not receive adequate propulsion force. Furthermore, if the widths W60 and W62 are not equal, the magnetic force acting on the first coil 51a and the magnetic force acting on the second coil 51b will be unbalanced, resulting in a cogging effect. In the position adjustment process, these problems are suppressed by adjusting the widths W60 and W62.

[0029] The position adjustment process is performed after assembly on the component mounting machine 10 and before shipment. Therefore, the position adjustment process is as follows: Figure 3 As shown, the operation is performed with the magnetic track 44 arranged with the first surface 45a facing upwards, the first coil 51a arranged on the upper part of the magnetic track 44, and the second coil 51b arranged on the lower part of the magnetic track 44. In the position adjustment process, the head 20 is removed from the base 58, and the first operating part 55a and the second operating part 55b are operated. The position of the first coil 51a (i.e., width W60) is adjusted using the first position adjustment mechanism 53a, and the position of the second coil 51b (i.e., width W62) is adjusted using the second position adjustment mechanism 53b.

[0030] In the position adjustment process, widths W60 and W62 can be adjusted to obtain appropriate thrust in the X-axis linear motor 30. Furthermore, in this embodiment, the first position adjustment mechanism 53a and the second position adjustment mechanism 53b are independent. That is, the position adjustment amount of the first position adjustment mechanism 53a on the first coil 51a and the position adjustment amount of the second position adjustment mechanism 53b on the second coil 51b are independent of each other. Therefore, widths W60 and W62 can be adjusted independently, preventing imbalance between widths W60 and W62. This reduces cogging effect.

[0031] Furthermore, the widths W60 and W62 will vary depending on the orientation of the X-axis linear motor 30. For example, when... Figure 3 When the X-axis linear motor 30 is positioned laterally (i.e., with the magnetic track 44 facing laterally), the direction of the gravity applied to the mover 50 is different from the direction of the gravity applied to the mover 50 when the X-axis linear motor 30 is positioned longitudinally (i.e., with the magnetic track 44 facing longitudinally). Therefore, even if the X-axis linear motor 30 is set to a longitudinal orientation and the widths W60 and W62 are adjusted, if afterwards... Figure 3 Installing the X-axis linear motor 30 laterally in this manner may cause the widths W60 and W62 to deviate from the proper values. In contrast, during the aforementioned position adjustment process, when... Figure 3 In the actual use case, the widths W60 and W62 are adjusted by the X-axis linear motor 30, thus preventing deviations in the widths W60 and W62.

[0032] Furthermore, in this embodiment, the yoke 44a of the magnetic track 44 has a base 44a-1 with a relatively large width. Therefore, the magnetic track 44 is less prone to deflection. Thus, errors in widths W60 and W62 can be suppressed.

[0033] Furthermore, in this embodiment, the first operating part 55a and the second operating part 55b are covered by the head 20. The first operating part 55a and the second operating part 55b can be operated by removing the head 20 from the base 58. According to this structure, the head 20 can be arranged overlapping the first operating part 55a and the second operating part 55b, thus enabling miniaturization of the mover 50. Furthermore, according to this structure, the first operating part 55a and the second operating part 55b can be operated without interfering with the tool and the stator 40.

[0034] The left-right direction of the embodiment is an example of a first direction. The up-down direction of the embodiment is an example of a second direction. The beam component of the embodiment is an example of a support component.

[0035] The embodiments have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations to the specific examples illustrated above. The technical elements described in this specification or drawings can exert their technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of application. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful.

Claims

1. A linear electric motor having a stator and a mover, The stator has magnetic tracks, each having a first surface and a second surface. A plurality of magnets are arranged on the first surface along a first direction. The second surface is located on the opposite side of the first surface and also has a plurality of magnets arranged along the first direction. The mover has: The base moves relative to the magnetic track along the first direction; First position adjustment mechanism; The first coil is mounted on the base via the first position adjustment mechanism and faces the first surface; A first cooler is fixed to the surface of the first coil on the side opposite to the magnetic track; Second position adjustment mechanism; The second coil is mounted on the base via the second position adjustment mechanism and faces the second surface; as well as The second cooler is fixed to the surface of the second coil on the side opposite to the magnetic track. The first position adjustment mechanism adjusts the position of the first coil relative to the base in a second direction, where the second direction is from the first coil toward the second coil. The second position adjustment mechanism adjusts the position of the second coil relative to the base in the second direction.

2. The linear motor according to claim 1, wherein, The stator has: A first guide rail extends along the first direction; and A second guide rail extends along the first direction and is configured such that the magnetic track is located between the first guide rail and the second guide rail in the second direction. The mover has: The first carriage is mounted on the base and slides along the first guide rail; as well as The second carriage is mounted on the base and slides along the second guide rail; The first position adjustment mechanism and the second position adjustment mechanism are disposed between the first carriage and the second carriage in the second direction.

3. The linear motor according to claim 1 or 2, wherein, The stator also has supporting components. The magnetic track has: The yoke base, fixed to the support member, extends along the first direction; and The yoke plate portion is narrower than the yoke base portion and protrudes from the yoke base portion. A plurality of magnets constituting the first surface are fixed to one surface of the yoke portion. A plurality of magnets constituting the second surface are fixed to another surface of the yoke portion.

4. The linear motor according to claim 1 or 2, wherein, The mover also has a component mounting head that can be attached to and detached relative to the base. The first position adjustment mechanism has a first operating part for adjusting the position of the first coil. The second position adjustment mechanism has a second operating part for adjusting the position of the second coil. When the component mounting head is removed from the base, the first operating part and the second operating part are exposed.

5. The linear motor according to claim 4, wherein, The base has an opening. The first operating part and the second operating part are disposed within the opening. When the component mounting head is removed from the base, the opening is exposed.

6. The linear motor according to claim 1 or 2, wherein, The magnetic track is configured with the first surface facing upwards.

7. A position adjustment method, which is the position adjustment method for the first coil and the second coil of the linear motor according to claim 1 or 2. The position adjustment method includes the following steps: With the magnetic track arranged with the first surface facing upwards, the first coil arranged on the upper part of the magnetic track, and the second coil arranged on the lower part of the magnetic track, the position of the first coil is adjusted by the first position adjustment mechanism, and the position of the second coil is adjusted by the second position adjustment mechanism.

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