Linear motor

Abstract

To obtain a linear motor in which a cooling air channel can be formed easily in a back yoke.SOLUTION: This linear motor includes a back yoke 11 having a first surface side 11c in which a groove side 11a through which cooled air passes is formed, a lid 17 provided on the back yoke 11 and closing the groove side 11c, permanent magnets 12 provided on the first surface side 11a, and coils 22 provided so as to face the permanent magnets 12, wherein a discharge hole side 17c facing the coils 22 is formed in the lid 17, and the cooled air passing through the groove side 11c is blown to the coils 22 through the discharge hole side 17c of the lid 17.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a linear motor. [Background technology]

[0002] Conventionally, a linear motor including a back yoke, a permanent magnet, and a coil has been known. The permanent magnet is provided on the back yoke. The coil is arranged to face the permanent magnet. A cooling air flow path through which cooling air passes is formed within the back yoke. An exhaust hole connected to the cooling air flow path is formed on the surface of the back yoke on which the permanent magnet is provided. The cooling air passing through the cooling air flow path is discharged from the cooling air flow path through the exhaust hole and blown onto the coil (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-209840 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the linear motor configuration described in Patent Document 1, the cooling air flow path is configured by forming a through hole in the back yoke, which poses a problem in that the work of forming the cooling air flow path in the back yoke is inefficient.

[0005] The present invention has been made to solve the above-mentioned problems, and its object is to provide a linear motor in which a cooling air flow path can be easily formed in the back yoke. [Means for solving the problem]

[0006] The linear motor of this invention comprises a back yoke having a first surface formed with a groove through which cooling air passes, a lid provided on the back yoke and covering the groove, a permanent magnet provided on the first surface, and a coil arranged opposite the permanent magnet, the lid having an exhaust hole formed opposite the coil, and the cooling air passing through the groove is blown onto the coil through the exhaust hole in the lid. In the linear motor according to the present invention, the opening of the discharge hole on the coil side is disposed closer to the coil than the first surface. [Effects of the Invention]

[0007] According to the linear motor of the present invention, the cooling air flow path can be easily formed in the back yoke. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a linear motor according to a first embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the linear motor of FIG. [Figure 3] FIG. 2 is a perspective view showing a main part of the linear motor of FIG. [Figure 4] 4 is an enlarged view showing the back yoke, permanent magnet, and lid of FIG. 3. [Figure 5] 4 is an enlarged view showing the back yoke, permanent magnet, and lid of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1 FIG. 1 is a perspective view showing a linear motor according to a first embodiment. FIG. 2 is a longitudinal cross-sectional view showing the linear motor of FIG. 1. FIG. 3 is a perspective view showing a main part of the linear motor of FIG. 1. The linear motor according to the first embodiment includes a stator 1 and a mover 2. In FIG. 3, a part of the stator 1 is shown in cross section.

[0010] The stator 1 includes a back yoke 11, a plurality of permanent magnets 12, a center yoke 13, a back yoke 14, a plurality of permanent magnets 15, a connecting member 16, a lid 17, and a lid 18.

[0011] The back yoke 11 has a long plate-like shape. One of a pair of surfaces of the back yoke 11 facing in the plate thickness direction is referred to as a first surface 11a, and the other surface is referred to as a second surface 11b.

[0012] A plurality of permanent magnets 12 are provided on the first surface 11a of the back yoke 11. The plurality of permanent magnets 12 are arranged in a row in the longitudinal direction of the back yoke 11. Each permanent magnet 12 is fixed to the first surface 11a of the back yoke 11 via an adhesive (not shown).

[0013] Center yoke 13 has a long plate shape. Center yoke 13 is arranged so that the thickness direction of back yoke 11 and the thickness direction of center yoke 13 coincide with each other. Center yoke 13 is also arranged so that the longitudinal direction of back yoke 11 and the longitudinal direction of center yoke 13 coincide with each other. Center yoke 13 is also arranged so as to face first surface 11a of back yoke 11. A plurality of permanent magnets 12 are arranged between back yoke 11 and center yoke 13.

[0014] Back yoke 14 has a long plate shape. Back yoke 14 is disposed so that the thickness direction of back yoke 11 and the thickness direction of back yoke 14 coincide with each other. Back yoke 14 is disposed so that the longitudinal direction of back yoke 11 and the longitudinal direction of back yoke 14 coincide with each other. Back yoke 14 is disposed so as to face first surface 11a of back yoke 11.

[0015] One of a pair of surfaces of back yoke 14 facing in the plate thickness direction is referred to as first surface 14a, and the other surface is referred to as second surface 14b. First surface 14a of back yoke 14 faces first surface 11a of back yoke 11.

[0016] A plurality of permanent magnets 15 are provided on the first surface 14a of the back yoke 14. The plurality of permanent magnets 15 are arranged in a row in the longitudinal direction of the back yoke 14. Each permanent magnet 15 is fixed to the first surface 14a of the back yoke 14 via an adhesive (not shown).

[0017] The connecting member 16 is provided across the back yoke 11, the center yoke 13, and the back yoke 14. The connecting member 16 is connected to one longitudinal end of each of the back yoke 11, the center yoke 13, and the back yoke 14. The back yoke 11, the center yoke 13, and the back yoke 14 are each fixed to the connecting member 16.

[0018] The mover 2 includes a plurality of bobbins 21 and a plurality of coils 22 .

[0019] The multiple bobbins 21 are arranged in a row in the longitudinal direction of the center yoke 13. Each bobbin 21 is provided on the center yoke 13. Each bobbin 21 is slidable relative to the center yoke 13 in the longitudinal direction of the center yoke 13.

[0020] The multiple coils 22 are arranged in a row in the longitudinal direction of the center yoke 13. The multiple coils 22 are also provided one for each of the multiple bobbins 21. Therefore, each coil 22, together with its corresponding bobbin 21, is slidable relative to the center yoke 13 in the longitudinal direction of the center yoke 13.

[0021] The coils 22 are arranged farther from the first surface 11a of the back yoke 11 than the permanent magnets 12. The coils 22 are also arranged so as to face the permanent magnets 12.

[0022] The coils 22 are arranged farther from the first surface 14a of the back yoke 14 than the permanent magnets 15. The coils 22 are also arranged to face the permanent magnets 15.

[0023] A current is supplied to each of the coils 22 from a power supply device (not shown). When a current is supplied to each of the coils 22, an interaction occurs between the magnetic field generated by the plurality of permanent magnets 12 and the plurality of permanent magnets 15 and the current flowing through each of the coils 22. The interaction between the magnetic field generated by the plurality of permanent magnets 12 and the plurality of permanent magnets 15 and the current flowing through each of the coils 22 causes the mover 2 to move along the longitudinal direction of the center yoke 13 relative to the stator 1.

[0024] 4 is an enlarged view showing the back yoke 11, permanent magnet 12, and lid 17 of FIG. 3. A groove 11c is formed in the first surface 11a of the back yoke 11. Cooling air passes through the groove 11c. The groove 11c is arranged to extend in the longitudinal direction of the back yoke 11. A plurality of permanent magnets 12 are provided on the first surface 11a, avoiding the groove 11c.

[0025] One longitudinal end of groove 11c extends to one longitudinal surface of back yoke 11. Cooling air enters groove 11c from one longitudinal end of groove 11c. The other longitudinal end of groove 11c extends to the other longitudinal surface of back yoke 11. A blocking member 11d that blocks groove 11c is provided at the other longitudinal end of groove 11c. Therefore, the other longitudinal end of groove 11c is blocked. Note that the other longitudinal end of groove 11c may not extend to the other longitudinal surface of back yoke 11.

[0026] The lid 17 is provided in the groove 11c. The lid 17 is disposed in an area of ​​the groove 11c on the first surface 11a side. The lid 17 also closes the opening of the groove 11c on the first surface 11a side. By closing the opening of the groove 11c on the first surface 11a side with the lid 17, a cooling air flow path 3 through which cooling air passes is formed between the back yoke 11 and the lid 17. In other words, the cooling air flow path 3 is formed by the back yoke 11 and the lid 17.

[0027] A cooling air pipe (not shown) is connected to the cooling air flow path 3. Cooling air passes through the cooling air flow path 3 via the cooling air pipe.

[0028] The lid 17 includes a lid base 17a, which is the portion inserted into the groove 11c, and a protrusion 17b provided on the lid base 17a. The lid base 17a closes the opening of the groove 11c on the first surface 11a side. The protrusion 17b protrudes from the lid base 17a in the thickness direction of the back yoke 11 toward the coil 22. Therefore, the tip of the protrusion 17b is located closer to the coil 22 than the first surface 11a of the back yoke 11.

[0029] A plurality of discharge holes 17c are formed in the lid 17. The plurality of discharge holes 17c are arranged in a row in the longitudinal direction of the back yoke 11. Each discharge hole 17c penetrates the lid 17 in the thickness direction of the back yoke 11. Each discharge hole 17c is arranged across the lid base 17a and the protruding portion 17b. Therefore, the opening of each discharge hole 17c on the coil 22 side is arranged closer to the coil 22 than to the first surface 11a. The discharge holes 17c face the plurality of coils 22.

[0030] 5 is an enlarged view showing the back yoke 14, permanent magnet 15, and lid 18 of FIG. 1. Grooves 14c are formed on the first surface 14a of the back yoke 14, similar to the first surface 11a of the back yoke 11. Cooling air passes through the grooves 14c. The grooves 14c are arranged to extend in the longitudinal direction of the back yoke 14. The multiple permanent magnets 15 are provided on the first surface 14a, avoiding the grooves 14c.

[0031] One longitudinal end of groove 14c extends to one longitudinal surface of back yoke 14. Cooling air enters groove 14c from one longitudinal end of groove 14c. The other longitudinal end of groove 14c extends to the other longitudinal surface of back yoke 14. A blocking member 14d that blocks groove 14c is provided at the other longitudinal end of groove 14c. Therefore, the other longitudinal end of groove 14c is blocked. Note that the other longitudinal end of groove 14c may not extend to the other longitudinal surface of back yoke 14.

[0032] The lid 18 is provided in the groove 14c. The lid 18 is disposed in an area of ​​the groove 14c on the first surface 14a side. The lid 18 also closes the opening of the groove 14c on the first surface 14a side. By closing the opening of the groove 14c on the first surface 14a side with the lid 18, a cooling air flow path 4 through which cooling air passes is formed between the back yoke 14 and the lid 18. In other words, the cooling air flow path 4 is formed by the back yoke 14 and the lid 18.

[0033] A cooling air pipe (not shown) is connected to the cooling air flow path 4. Cooling air passes through the cooling air flow path 4 via the cooling air pipe.

[0034] The lid 18 includes a lid base 18a, which is the portion inserted into the groove 14c, and a protrusion 18b provided on the lid base 18a. The lid base 18a closes the opening of the groove 14c on the first surface 14a side. The protrusion 18b protrudes from the lid base 18a in the thickness direction of the back yoke 14, toward the coil 22. Therefore, the tip of the protrusion 18b is located closer to the coil 22 than the first surface 14a of the back yoke 14.

[0035] A plurality of discharge holes 18c are formed in the lid 18. The plurality of discharge holes 18c are arranged in a row in the longitudinal direction of the back yoke 14. Each discharge hole 18c penetrates the lid 18 in the plate thickness direction of the back yoke 14. Each discharge hole 18c is arranged across the lid base 18a and the protruding portion 18b. Therefore, the opening of the discharge hole 18c on the coil 22 side is arranged closer to the coil 22 than the first surface 14a. The discharge hole 18c faces the plurality of coils 22.

[0036] Next, a description will be given of the assembly procedure for the linear motor according to embodiment 1. First, the lid 17 is attached to the groove 11c in the first surface 11a of the back yoke 11 via an adhesive. This forms a cooling air flow path 3 between the back yoke 11 and the lid 17, through which cooling air passes.

[0037] Thereafter, a plurality of permanent magnets 12 are attached to the first surface 11a of the back yoke 11 via an adhesive.

[0038] Thereafter, in the same manner as the back yoke 11, the lid 18 is attached to the groove 14c on the first surface 14a of the back yoke 14 via an adhesive. As a result, a cooling air flow path 4 through which cooling air passes is formed between the back yoke 14 and the lid 18.

[0039] Thereafter, a plurality of permanent magnets 15 are attached to the first surface 14a of the back yoke 14 via an adhesive.

[0040] Thereafter, the plurality of coils 22 are provided on each of the plurality of bobbins 21 , and the respective bobbins 21 are attached to the center yoke 13 .

[0041] Thereafter, back yoke 11, center yoke 13, and back yoke 14 are attached to connecting member 16. This completes the assembly procedure for the linear motor according to the first embodiment.

[0042] As described above, the linear motor according to the first embodiment includes back yoke 11, lid 17, permanent magnet 12, and coil 22. Groove 11c through which cooling air passes is formed in back yoke 11. Lid 17 is provided on back yoke 11 and closes groove 11c. Permanent magnet 12 is provided on first surface 11a of back yoke 11. Coil 22 is provided so as to face permanent magnet 12. Discharge hole 17c facing coil 22 is formed in lid 17. Cooling air passing through groove 11c is blown onto coil 22 through discharge hole 17c of lid 17. With this configuration, cooling air flow path 3 is formed by back yoke 11 and lid 17. This makes it possible to easily form cooling air flow path 3 in back yoke 11.

[0043] Furthermore, in the linear motor according to the first embodiment, the opening of discharge hole 17c on the coil 22 side is disposed closer to coil 22 than to first surface 11a. With this configuration, when permanent magnet 12 is fixed to first surface 11a of back yoke 11 via an adhesive, it is possible to prevent adhesive from blocking discharge hole 17c.

[0044] In the linear motor according to the first embodiment, the configuration of the stator 1 has been described in which the lid 17 is provided on the back yoke 11 and the lid 18 is provided on the back yoke 14. However, the stator 1 may be configured in such a way that the lid 17 is provided on the back yoke 11 and the lid 18 is not provided on the back yoke 14.

[0045] Furthermore, in the linear motor according to the first embodiment, the configuration of the stator 1 has been described as including both the back yoke 11 and the back yoke 14. However, this configuration is not limited to this. The stator 1 may have a configuration including the back yoke 11 but not the back yoke 14.

[0046] Although the linear motor according to the preferred embodiment 1 has been described above, the present invention is not limited to the linear motor according to the above-described embodiment 1. Various modifications and conversions can be made to the linear motor according to the above-described embodiment 1 without departing from the scope of the claims. [Explanation of symbols]

[0047] 1 stator, 2 moving element, 3 cooling air flow path, 4 cooling air flow path, 11 back yoke, 11a first surface, 11b second surface, 11c groove, 11d blocking member, 12 permanent magnet, 13 center yoke, 14 back yoke, 14a first surface, 14b second surface, 14c groove, 14d blocking member, 15 permanent magnet, 16 connecting member, 17 lid, 17a lid base, 17b protrusion, 17c discharge hole, 18 lid, 18a lid base, 18b protrusion, 18c discharge hole, 21 bobbin, 22 coil.

Claims

1. a back yoke (11) having a first surface (11a) in which a groove (11c) through which cooling air passes is formed; a cover (17) provided on the back yoke (11) and covering the groove (11c); a permanent magnet (12) provided on the first surface (11a); a coil (22) provided so as to face the permanent magnet (12); Equipped with The lid (17) is formed with a discharge hole (17c) facing the coil (22), The cooling air passing through the groove (11c) is blown onto the coil (22) through the exhaust hole (17c) of the lid (17).

2. 2. The linear motor according to claim 1, wherein an opening of the discharge hole (17c) on the coil (22) side is disposed closer to the coil (22) than the first surface (11a).

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