Stator and cylindrical linear motor
The stator design with a connection board and yoke holes for lead wires addresses jumper wire issues, ensuring stable coil connections and reducing magnetic flux leakage, enhancing the performance and assembly of cylindrical linear motors.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TAMAGAWA SEIKI CO LTD
- Filing Date
- 2024-12-20
- Publication Date
- 2026-07-02
AI Technical Summary
Existing cylindrical linear motors face issues with jumper wires requiring space between coils and yoke, leading to performance degradation due to magnetic flux leakage and cumbersome connection processes.
A stator design with a long cylindrical yoke and a connection board that allows lead wires to pass through holes in a second yoke portion, connected via conductive parts and patterns, enabling reliable and stable coil connections while minimizing magnetic flux leakage.
The solution enables reliable and stable coil connections, suppressing performance degradation and magnetic flux leakage, resulting in a magnetically efficient cylindrical linear motor with improved assembly efficiency.
Smart Images
Figure 2026110081000001_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a stator of a tubular linear motor and a tubular linear motor, and particularly to a stator of a tubular linear motor and a tubular linear motor in which leakage magnetic flux is reduced.
Background Art
[0002] Some tubular linear motors include a stator including a long cylindrical yoke and a coil group formed by a plurality of short cylindrical coils arranged along the axial direction on the inner diameter side of the yoke. In this type of tubular linear motor, the plurality of coils included in the coil group are assigned to a plurality of different phases, and the coils of the same phase at distant positions among the plurality of different phases are connected to each other by jumper wires.
[0003] The coil group is provided with lead wires for use as jumper wires when connecting the coils of each phase. Therefore, there is a problem that the coil group having the lead wires cannot be directly inserted into the cylindrical yoke. Regarding the problem of the jumper wires in this type of linear motor, an improvement plan has been proposed in Patent Document 1.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] * In Patent Document 1, the jumper wires connecting a plurality of coils are not led out of the yoke but passed between the coils and the yoke. In this case, insertion of the coil group into the inside of the tubular yoke and connection of the jumper wires can be easily performed. However, since a certain space for the jumper wires is required between the coils and the yoke, there is a problem that the performance of the motor deteriorates.
[0006] On the other hand, by cutting a portion of the cylindrical yoke axially from one end to the other, creating a C-shaped cross-section, it becomes easier to insert the coil group with lead wires into the cylindrical yoke. However, the process of connecting the lead wires from the coils as jumper wires is cumbersome, and furthermore, a separate protective and holding mechanism is required to protect the jumper wires after connection and fix them along the yoke. In addition, magnetic flux from the movable magnet leaks from the cut-out portion of the cylindrical yoke, reducing the efficiency of the linear motor and causing various problems such as reduced thrust and cogging.
[0007] Therefore, in cylindrical linear motors that require lead wires for multiple coils, there has been a desire to realize a cylindrical linear motor that can reliably and stably connect multiple coils while suppressing performance degradation caused by magnetic flux leakage. The present invention aims to provide a stator for a cylindrical linear motor and a cylindrical linear motor that can reliably and stably connect multiple coils while suppressing performance degradation caused by magnetic flux leakage, in a cylindrical linear motor that requires lead wires to multiple coils. [Means for solving the problem]
[0008] The stator of the cylindrical linear motor according to this invention comprises a long cylindrical yoke, a coil group composed of a plurality of short cylindrical coils arranged axially on the inner diameter side of the yoke, and a connection board for electrically connecting each of the plurality of coils. The yoke has a first yoke portion having an opening cut out in a part of the circumferential region from one end to the other along the axial direction, and a second yoke portion configured to match the shape of the opening and provided with a plurality of holes through which the lead wires of each of the plurality of coils pass. The second yoke portion is fixed to the opening of the first yoke portion with the lead wires of each of the plurality of coils passed through each of the plurality of holes. The connection board has a plurality of holes through which the lead wires of each of the plurality of coils pass, conductive parts provided around each of the plurality of holes, and a connection pattern connected to the lead wires via the conductive parts and connecting the lead wires to each other. The lead wires of the plurality of coils are passed through each of the plurality of holes, the lead wires and conductive parts are connected in each of the plurality of holes, and the connection board is fixed in a state where it is superimposed on the outside of the second yoke portion.
[0009] In the stator of the cylindrical linear motor according to this invention, the coil group may be press-fitted into the first yoke portion such that the lead wires of each of the multiple coils are located at the opening.
[0010] In the stator of the cylindrical linear motor according to this invention, a plurality of coils are assigned to a plurality of different phases, and the respective lead wires of each coil in the same phase located at different positions among the plurality of different phases may be connected to each other via a connection pattern.
[0011] In the stator of the cylindrical linear motor according to this invention, the connection board may be fixed in a state where it is superimposed on the outside of the second yoke portion such that the plurality of holes provided in the second yoke portion and the plurality of holes provided in the connection board coincide.
[0012] The cylindrical linear motor according to this invention comprises a stator having a long cylindrical yoke, a coil group composed of multiple short cylindrical coils arranged axially on the inner diameter side of the yoke, and a connection board for electrically connecting each of the multiple coils, and a movable element having magnets arranged inside the stator, facing each other with a magnetic gap and movable in the axial direction, the yoke having a first yoke portion having an opening cut out in a part of the circumferential region from one end to the other along the axial direction, and a multi-pronged connector configured to match the shape of the opening and through which each of the lead wires of the multiple coils passes The first yoke has a second yoke with a number of holes, the second yoke is fixed to the opening of the first yoke with the lead wires of the multiple coils passing through each of the multiple holes, the connection board has multiple holes through which the lead wires of the multiple coils pass, conductive parts provided around each of the multiple holes, and connection patterns connected to the lead wires via the conductive parts and connecting the lead wires to each other, the lead wires of the multiple coils are passed through each of the multiple holes, the lead wires and conductive parts are connected at each of the multiple holes, and the connection board is fixed in a state where it is superimposed on the outside of the second yoke.
[0013] In the cylindrical linear motor according to this invention, the coil group may be press-fitted into the first yoke portion such that the lead wires of each of the multiple coils are located at the opening.
[0014] In the cylindrical linear motor according to this invention, a plurality of coils are assigned to a plurality of different phases, and each lead wire passing through each hole in each coil of the same phase located at a distance from each other among the plurality of different phases may be connected to each other via a wiring pattern.
[0015] In the cylindrical linear motor according to this invention, the connection board may be fixed in a state where it is superimposed on the outside of the second yoke portion such that the plurality of holes provided in the second yoke portion and the plurality of holes provided in the connection board coincide. [Effects of the Invention]
[0016] In this invention, in the stator of a cylindrical linear motor, a coil group having lead wires is inserted into a first yoke portion using an opening, and the second yoke portion is fixed to the opening of the first yoke portion with the respective lead wires of the plurality of coils passing through the respective holes of the plurality of holes. The respective lead wires of the plurality of coils are mutually connected by a wiring pattern through a conductive portion around the hole of the wiring board, and the wiring board is fixed in a state of being overlapped on the outside of the second yoke portion. Therefore, in a cylindrical linear motor that requires lead wires for a plurality of coils, it is possible to connect the plurality of coils to each other in a reliable and stable state while suppressing a decrease in performance due to magnetic flux leakage.
Brief Description of Drawings
[0017] [Figure 1] It is an exploded perspective view showing the stator of the cylindrical linear motor in Embodiment 1 in an exploded state. [Figure 2] It is an exploded perspective view showing the state before attaching the wiring board in the stator of the cylindrical linear motor in Embodiment 1. [Figure 3] It is a configuration diagram showing the wiring board in the stator of the cylindrical linear motor in Embodiment 1. [Figure 4] It is a perspective view showing the stator of the cylindrical linear motor in Embodiment 1. [Figure 5] It is a configuration diagram showing the wiring state of the wiring board in the stator of the cylindrical linear motor in Embodiment 1. [Figure 6] It is a configuration diagram showing the wiring state using the wiring board in the stator of the cylindrical linear motor in Embodiment 1. [Figure 7] It is a cross-sectional view showing the wiring state using the wiring board in the stator of the cylindrical linear motor in Embodiment 1. [Figure 8] [[ID=�1]]It is a cross-sectional view showing the cross-sectional configuration of the cylindrical linear motor in Embodiment 1. [Figure 9] It is a perspective view showing the connection state of the jumper wire in the stator of the cylindrical linear motor in Comparative Example 1. [Figure 10]It is a perspective view showing the stator of the cylindrical linear motor in Comparative Example 2.
Embodiments for Carrying Out the Invention
[0018] Hereinafter, embodiments of the cylindrical linear motor and its stator of the present invention will be described with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals.
[0019] Embodiment 1. First, the basic overall configuration of the stator 100 used in the cylindrical linear motor 10 in Embodiment 1 will be described with reference to FIGS. 1 to 7.
[0020] FIG. 1 is an exploded perspective view showing the stator 100 of the cylindrical linear motor 10 in Embodiment 1 in an exploded state. FIG. 2 is an exploded perspective view showing the state of the stator 100 of the cylindrical linear motor 10 in Embodiment 1 before attaching the connection board. FIG. 3 is a configuration diagram showing the connection board in the stator 100 of the cylindrical linear motor 10 in Embodiment 1. FIG. 4 is a perspective view showing the stator 100 of the cylindrical linear motor 10 in Embodiment 1. FIG. 5 is a configuration diagram showing the connection state of the connection board in the stator 100 of the cylindrical linear motor 10 in Embodiment 1. FIG. 6 is a configuration diagram showing the connection state using the connection board in the stator 100 of the cylindrical linear motor 10 in Embodiment 1. FIG. 7 is a cross-sectional view showing the connection state using the connection board in the stator 100 of the cylindrical linear motor 10 in Embodiment 1.
[0021] [Configuration of Stator 100] The stator 100 of the cylindrical linear motor 10 in Embodiment 1 mainly includes a yoke 110, a coil group 120, and a connection board 130. The yoke 110 is constructed in a long cylindrical shape by a first yoke section 111 and a second yoke section 112. The coil group 120 is composed of a plurality of coils 121, each in a short cylindrical shape, arranged axially on the inner diameter side of the yoke 110. Here, the direction along the axis of the cylinder constituting the yoke 110 is defined as the "axial direction," the direction along the radius of the annular cross-section of the cylinder constituting the yoke 110 is defined as the "radial direction," and the direction along the direction in which the coil group 120 is wound in an annular shape or the opposite direction is defined as the "circumferential direction." The yoke 110 and the coil group 120 are configured as either cylindrical or rectangular tubes. It is desirable that the coil group 120 be arranged so as tightly as possible against the inner surface of the yoke 110, on the radially inner side.
[0022] The first yoke portion 111 has an opening 111b in which a portion of the circumferential region is cut out along the axial direction from one end to the other. The second yoke portion 112 is configured to match the shape of the opening 111b. The second yoke portion 112 is provided with a plurality of holes 112b for passing the lead wires 122 of each of the plurality of coils 121 that constitute the coil group 120.
[0023] The coil group 120 consists of multiple coils 121, each assigned to a different phase. As an example, as shown in Figure 7, there are three sets of coils 121, each corresponding to the U-phase, V-phase, and W-phase of a three-phase AC system. Lead wires 122 are drawn out from both ends of each of the multiple coils 121. As shown in Figures 6 and 7, a specific example is provided in which there are three sets of coils 121 corresponding to the U-phase, V-phase, and W-phase, as multiple-phase and multiple sets of coils 121. Here, as three sets of three-phase coils 121, as indicated in parentheses, 121u1, 121v1, 121w1, 121u2, 121v2, 121w2, 121u3, 121v3, and 121w3 are shown as specific examples.
[0024] The connection board 130 has multiple holes 132 through which the lead wires 122 of each of the multiple coils 121 pass, conductive parts 133 provided around each of the multiple holes 132, and connection patterns 134 connected to the lead wires 122 via the conductive parts 133 and connecting the lead wires 122 to each other. If the connection board 130 is a multilayer board, conductive through-holes are formed on the walls of the holes 132, and the conductive parts 133 and the connection patterns 134 inside the connection board 130 are electrically connected via the through-holes. Alternatively, the conductive parts 133 and the connection patterns 134 may be connected on the surface of the connection board 130.
[0025] The holes 132, conductive parts 133, and wiring patterns 134 in the wiring board 130 will be explained with reference to Figures 3 to 6. The wiring board 130 is provided with holes 132a, 132b, and 132c for connecting the signal supply lines 300, as well as holes 132u for passing the lead wires 122 from the U-phase coil 121u, 132v for passing the lead wires 122 from the V-phase coil 121v, and 132w for passing the lead wires 122 from the W-phase coil 121w. Note that the holes 132a, 132b, and 132c for connecting the signal supply lines 300 can be replaced with connection pins. Around the holes 132 of the connection board 130, conductive parts 133 are provided, with conductive parts 133a, 133b, and 133c around the holes 132a, 132b, and 132c, and conductive parts 133u, 133v, and 133w around the holes 132u, 132v, and 132w. Connection patterns 134u, 134v, and 134w are provided between the conductive parts 133u, 133v, and 133w of the connection board 130, respectively, to connect in series the respective coils 121u, 121v, and 121w of the same phase located at separate positions among multiple different phases.
[0026] [Assembly of stator 100] The assembly process for the stator 100 is described below. This process is divided into the following steps: insertion of the coil group 120 into the yoke 110 (step 1), fixing of the first yoke section 111 and the second yoke section 112 (step 2), fixing of the connection board 130 to the yoke 110 (step 3), and wiring on the connection board 130 (step 4).
[0027] Step 1: As shown by the dashed line A in Figure 1, the coil group 120 is inserted into the first yoke section 111 with the lead wires 122 of each of the coils 121 constituting the coil group 120 aligned so that they are located at the opening 111b. It is preferable that the coil group 120 be press-fitted into the first yoke section 111. Here, by passing the lead wires 122 of the coil group 120 through the opening 111b of the first yoke section 111, the coil group 120 can be easily press-fitted into the first yoke section 111.
[0028] Step 2: When inserting the second yoke portion 112 into the opening 111b of the first yoke portion 111, as shown by the dashed line B in Figure 1, the lead wires 122 of each of the multiple coils 121 are passed through each of the multiple holes 112b of the second yoke portion 112, as shown in Figure 2. Then, the second yoke portion 112 is fixed to the opening 111b of the first yoke portion 111. The second yoke portion 112 can be fixed to the opening 111b of the first yoke portion 111 by fitting or by adhesive. Figure 2 shows the state after the work of steps 1 and 2 has been completed.
[0029] By performing steps 1 and 2 above, when the second yoke portion 112 is fixed to the opening 111b of the first yoke portion 111, a cylindrical yoke 110 without any notches is formed. This makes it difficult for the magnetic flux generated by the coil group 120 to leak out of the yoke 110. Furthermore, by configuring the second yoke portion 112 to be fixed to the opening 111b of the first yoke portion 111, it becomes easier to insert the coil group 120 into the first yoke portion 111 which has the opening 111b, and the assembly of the cylindrical yoke 110 without any notches is made easier.
[0030] Step 3: As shown by the dashed line C in Figures 1 and 2, the lead wires 122 of each of the multiple coils 121 are passed through each of the multiple holes 132 of the connection board 130, and the connection board 130 is positioned and fixed so that it overlaps the yoke 110. The connection board 130 is fixed to the yoke 110 by screwing, adhesive, or soldering the lead wires 122 to the conductive parts 133 as described later. The connection board 130 may be flat, but from the viewpoint of stability when it is overlapped and fixed to the yoke 110, it is desirable that it be a curved surface that matches the curvature of the surface of the yoke 110.
[0031] Step 4: The conductive parts 133 around the holes 132 of the wiring board 130 and the lead wires 122 are connected to each other by soldering or other means to create an electrical connection. Figures 4, 5, and 6 show the state after the work in steps 3 and 4 has been completed.
[0032] The following explains the wiring in Step 4 in detail. When the lead wires 122 from each of the multiple coils 121 are connected to the corresponding conductive parts 133 by soldering or the like, the u-phase coils 121u1 to 121u3 located at different locations are connected in series by the wiring pattern 134u, the v-phase coils 121v1 to 121v3 located at different locations are connected in series by the wiring pattern 134v, and the w-phase coils 121w1 to 121w3 located at different locations are connected in series by the wiring pattern 134w.
[0033] More specifically, it is as follows: As shown in Figures 6 and 7, one end of coil 121u1 is connected to one end of the external signal supply line 300u via the wiring pattern 134u, the other end of coil 121u1 is connected to one end of coil 121u2 via the wiring pattern 134u, the other end of coil 121u2 is connected to one end of coil 121u3 via the wiring pattern 134u, and the other end of coil 121u3 is connected to the other end of the external signal supply line 300u via the wiring pattern 134u. As a result, the U-phase coils 121u1, 121u2, and 121u3, which are located at different locations, are connected in series and connected to the signal supply line 300u.
[0034] Similarly, one end of coil 121v1 is connected to one end of the external signal supply line 300v via the wiring pattern 134v, the other end of coil 121v1 is connected to one end of coil 121v2 via the wiring pattern 134v, the other end of coil 121v2 is connected to one end of coil 121v3 via the wiring pattern 134v, and the other end of coil 121v3 is connected to the other end of the external signal supply line 300v via the wiring pattern 134v. As a result, the V-phase coils 121v1, 121v2, and 121v3, which are located at different locations, are connected in series and connected to the signal supply line 300v.
[0035] Furthermore, one end of coil 121w1 is connected to one end of the external signal supply line 300w via the wiring pattern 134w, the other end of coil 121w1 is connected to one end of coil 121w2 via the wiring pattern 134w, the other end of coil 121w2 is connected to one end of coil 121w3 via the wiring pattern 134w, and the other end of coil 121w3 is connected to the other end of the external signal supply line 300w via the wiring pattern 134w. As a result, the W-phase coils 121w1, 121w2, and 121w3, which are located at different locations, are connected in series and connected to the signal supply line 300w.
[0036] As described above, the connection between the lead wire 122 from the coil 121 and the conductive part 133 by soldering or the like results in the connection pattern 134, which connects the coils 121 of the same phase located at different positions among multiple different phases in series.
[0037] [Drive current and magnetic field] The drive currents Iu, Iv, and Iw for the U, V, and W phases are supplied to both ends of the coil group 120 from the signal supply lines 300u, 300v, and 300w, respectively. The drive current Iu flows through the U-phase coils 121u1, 121u2, and 121u3 connected by the connection pattern u. The drive current Iv flows through the V-phase coils 121v1, 121v2, and 121v3 connected by the connection pattern 134v. The drive current Iw flows through the W-phase coils 121w1, 121w2, and 121w3 connected by the connection pattern 134w. If the drive currents Iu, Iv, and Iw are three-phase AC, a moving magnetic field is generated in the multiple coils 121 within the coil group 120.
[0038] [Cylindrical Linear Motor 10] The configuration of the cylindrical linear motor 10 using the stator 100 in Embodiment 1 will be described below with reference to Figure 8. Figure 8 is a cross-sectional view showing the cross-sectional configuration of the cylindrical linear motor 10 in Embodiment 1. In Figure 8, the same reference numerals are used for parts that are the same as those in Figures 1 to 7, and redundant explanations will be omitted, with the focus being on the different parts.
[0039] The cylindrical linear motor 10 mainly comprises a stator 100 and a movable element 200. The stator 100 generates a moving magnetic field internally in response to externally supplied drive currents Iu, Iv, and Iw. The movable element 200 is configured to have a magnetic material that can move axially within a coil group 120 and is configured to move axially in response to the moving magnetic field.
[0040] The stator 100 comprises a yoke 110, a cylindrical portion 140, and a cylindrical portion 150. The cylindrical portion 140 is located at one end of the yoke 110 and has the same shape and diameter as the yoke 110. A shaft retainer portion 141 is provided at the tip of the cylindrical portion 140. The shaft retainer portion 141 is provided to movably support a movable shaft 240 located at one end of the movable element 200. The cylindrical portion 150 is located at the other end of the yoke 110 and has the same shape and diameter as the yoke 110. A shaft retainer portion 151 is provided at the tip of the cylindrical portion 150. The shaft retainer portion 151 is provided to movably support a movable shaft 250 located at the other end of the movable element 200.
[0041] The movable element 200 comprises a movable magnet section 201, a movable shaft 240, and a movable shaft 250. The movable magnet section 201 is composed of multiple magnets 210 and multiple pole pieces 220 arranged alternately in the axial direction. The movable magnet section 201 has an outer diameter close to the inner diameter of the coil group 120, and is configured as either a cylindrical or rectangular columnar shape to match the cross-sectional shape of the coil group 120 so as not to contact the inner circumferential surface of the coil group 120. The multiple magnets 210 are permanent magnets that are magnetized in the axial direction and arranged so that their magnetic poles alternately reverse. The pole pieces 220 are soft magnetic materials that direct the magnetic field generated by the magnets 210.
[0042] The movable shaft 240 is connected to one end of the movable magnet section 201 and transmits the movement of the movable magnet section 201 to the outside while being supported by the shaft retaining section 141. Similarly, the movable shaft 250 is connected to the other end of the movable magnet section 201 and transmits the movement of the movable magnet section 201 to the outside while being supported by the shaft retaining section 151.
[0043] In this configuration, the second yoke portion 112 is fixed to the opening 111b of the first yoke portion 111, so the yoke 110 is cylindrical without any notches. Therefore, the magnetic flux from the coil group 120 and the magnetic flux from the movable element magnet do not leak to the outside. As a result, it is possible to suppress the performance degradation caused by magnetic flux leakage in the cylindrical linear motor 10. Furthermore, by configuring the second yoke portion 112 to be fixed to the opening 111b of the first yoke portion 111, it becomes easier to insert the coil group 120 into the first yoke portion 111 which has the opening 111b, and the assembly work of the cylindrical yoke 110 without any notches becomes easier.
[0044] In the stator 100, multiple coils 121 within the coil group 120 are connected to each other using a connection board 130. This makes it possible to connect multiple coils 121 reliably and stably, eliminating the need to provide a separate protection and retention mechanism for the connection wires.
[0045] Comparative Example 1. The yoke 110A of the stator 100A of Comparative Example 1, which does not have the features of Embodiment 1, will be described with reference to Figure 9. Figure 9 is a perspective view showing the stator 100A of the cylindrical linear motor in Comparative Example 1. In Figure 9, the same reference numerals are used for parts that are the same as in Figures 1 to 8, and redundant explanations are omitted, with the focus being on the different parts. Figure 9 shows the completed state after inserting the coil group 120 into the yoke 110A and connecting the multiple coils 121 using the lead wires 122 as jumper wires 122b. Both ends of the lead wires 122 are extended outwards as external connection wires 122a.
[0046] The yoke 110A of Comparative Example 1 has an opening 110Ab in which a portion of the circumferential region is cut out along the axial direction from one end to the other. Because this yoke 110A has an opening 110Ab, it becomes easy to insert the coil group 120 having the lead wires 122 into the yoke 110A and to connect the jumper wires 122b. However, in the yoke 110A, the opening 110Ab remains open without being closed. As a result, magnetic flux from the coil group 120 and magnetic flux from the movable element magnet (not shown) leak out from the opening 110Ab of the yoke 110A. Consequently, the efficiency of the cylindrical linear motor of Comparative Example 1 decreases compared to the cylindrical linear motor 10 of Embodiment 1, leading to various problems such as reduced thrust and cogging. Furthermore, in the case of the yoke 110A, a separate protection and holding mechanism for the jumper wire 122b needs to be provided.
[0047] [Comparative Example 2] The yoke 110B of the stator 100B of Comparative Example 2, which does not have the features of Embodiment 1, will be described with reference to Figure 10. Figure 10 is a perspective view showing the stator 100B of the cylindrical linear motor in Comparative Example 2. In Figure 10, the same reference numerals are used for parts that are the same as in Figures 1 to 8, and redundant explanations are omitted, with the focus being on the different parts. Figure 10 shows the state after the process of inserting the coil group 120 into the main yoke 110B1 while passing the lead wires through the space between the main yoke 110B1 and the auxiliary yoke 110B2 has been completed, and the jumper wires are protected by the auxiliary yoke 110B2.
[0048] The yoke 110B of Comparative Example 2 has a cylindrical main yoke portion 110B1 having a C-shaped cross-section due to an opening cut out in a part of the circumferential region from one end to the other along the axial direction, and a cylindrical auxiliary yoke portion 110B2 having a U-shaped cross-section and being smaller than the main yoke portion 110B1, with the openings of the main yoke portion 110B1 and the auxiliary yoke portion 110B2 joined together. In this yoke 110B, a space is formed by the auxiliary yoke portion 110B2 near the opening of the main yoke portion 110B1, making it easy to insert the coil group 120 with lead wires into the main yoke portion 110B1. Note that the cross-sectional shape of the auxiliary yoke portion 110B2 may be a V-shape, C-shape, semicircular shape, or U-shape with an opening, in addition to a U-shape. However, magnetic flux from the coil group 120 and the movable element magnet leaks from the opening of the main yoke section 110B1 into the space of the auxiliary yoke section 110B2. As a result, although the yoke 110B of the stator 100B of Comparative Example 2 leaks less magnetic flux than that of Comparative Example 1, it leaks more magnetic flux than the yoke 110 of Embodiment 1. In other words, compared to the cylindrical linear motor 10 of Embodiment 1, the cylindrical linear motor of Comparative Example 2 suffers from reduced efficiency, reduced thrust, and various problems such as cogging. Furthermore, the yoke 110B has the problem of being larger because it uses both the main yoke section 110B1 and the auxiliary yoke section 110B2. In addition, the troublesome work of joining the main yoke section 110B1 and the auxiliary yoke section 110B2 is required.
[0049] [Effects of Embodiment 1] The stator 100 of the cylindrical linear motor 10 of Embodiment 1, and the cylindrical linear motor 10 using the stator 100, can provide the following effects.
[0050] The stator 100 of the cylindrical linear motor 10 of Embodiment 1 comprises a long cylindrical yoke 110, a coil group 120 composed of a plurality of short cylindrical coils 121 arranged axially on the inner diameter side of the yoke 110, and a connection board 130 for electrically connecting each of the plurality of coils 121. The yoke 110 has a first yoke portion 111 having an opening 111b cut out in a part of the circumferential region from one end to the other along the axial direction, and a second yoke portion 112 configured to match the shape of the opening 111b and provided with a plurality of holes 112b through which each of the lead wires 122 of the plurality of coils 121 passes. The second yoke portion 112 is fixed to the opening 111b of the first yoke portion 111 with each of the lead wires 122 of the plurality of coils 121 passed through the plurality of holes 112b.
[0051] The connection board 130 has multiple holes 132 through which the lead wires 122 of each of the multiple coils 121 pass, conductive parts 133 provided around each of the multiple holes 132, and connection patterns 134 that are connected to the lead wires 122 via the conductive parts 133 and connect the lead wires 122 to each other. The lead wires 122 of each of the multiple coils 121 pass through each of the multiple holes 132, and the lead wires 122 and conductive parts 133 are connected in each of the multiple holes 132, and the connection board 130 is fixed in a state where it is superimposed on the outside of the second yoke portion 112.
[0052] As a result, in the stator 100 of the cylindrical linear motor 10, a group of coils 120 having lead wires 122 is inserted into a first yoke portion 111 using an opening 111b, and the second yoke portion 112 is fixed to the opening of the first yoke portion with the lead wires of each of the coils passing through each of the multiple holes 112b. The connection board 130, which is superimposed on the outside of the second yoke portion 112, connects the lead wires 122 connected to the conductive portion 133 using a connection pattern 134. Therefore, in the stator 100 of a cylindrical linear motor 10 that requires lead wires 122 to multiple coils 121, it becomes possible to reliably and stably connect multiple coils to each other while suppressing performance degradation caused by magnetic flux leakage through the yoke 110.
[0053] In the stator 100 of the cylindrical linear motor 10 of Embodiment 1, the coil group 120 is press-fitted into the first yoke portion 111 such that the lead wires 122 of each of the multiple coils 121 are located at the opening 111b. Therefore, with multiple lead wires 122 passing through multiple holes 112b in the second yoke portion 112, the coil group 120 is in close contact with the yoke 110. As a result, a magnetically highly efficient stator 100 can be realized.
[0054] In the stator 100 of the cylindrical linear motor 10 of Embodiment 1, a plurality of coils 121 are assigned to a plurality of different phases, and each lead wire 122 passing through each hole 112b in each coil 121 of the same phase located at a distance from each other among the plurality of different phases is interconnected by a wiring pattern 134. This allows a moving magnetic field to be generated inside the coil group 120 in response to multi-phase drive currents supplied from an external source.
[0055] In the stator 100 of the cylindrical linear motor 10 of Embodiment 1, the connection board 130 is fixed to the outside of the second yoke portion 112 such that the multiple holes 112b provided in the second yoke portion 112 and the multiple holes 132 provided in the connection board 130 are aligned. Therefore, it becomes possible to connect multiple coils 121 in a reliable and stable manner, eliminating the need to provide a separate protection and retention mechanism for the connecting wires in the stator 100.
[0056] The cylindrical linear motor 10 of Embodiment 1 includes a stator 100 having a long cylindrical yoke 110, a coil group 120 composed of a plurality of short cylindrical coils 121 arranged axially on the inner diameter side of the yoke 110, and a connection board 130 for electrically connecting each of the plurality of coils 121, and a movable element 200 having magnets 210 arranged axially movable opposite to the stator 100 with a magnetic gap between them. The yoke 110 has a first yoke portion 111 having an opening 111b cut out in a part of the circumferential region from one end to the other along the axial direction, and a second yoke portion 112 configured to match the shape of the opening 111b and provided with a plurality of holes 112b through which each of the lead wires 122 of the plurality of coils 121 passes. Here, the second yoke portion 112 is fixed to the opening 111b of the first yoke portion 111 with the respective lead wires 122 of the multiple coils 121 passed through each of the multiple holes 112b.
[0057] The connection board 130 has multiple holes 132 through which the lead wires 122 of each of the multiple coils 121 pass, conductive parts 133 provided around each of the multiple holes 132, and connection patterns 134 that are connected to the lead wires 122 via the conductive parts 133 and connect the lead wires 122 to each other. The lead wires 122 of each of the multiple coils 121 pass through each of the multiple holes 132, and the lead wires 122 and conductive parts 133 are connected in each of the multiple holes 132, and the connection board 130 is fixed in a state where it is superimposed on the outside of the second yoke portion 112.
[0058] As a result, in the cylindrical linear motor 10, a group of coils 120 having lead wires 122 is inserted into a first yoke portion 111 using an opening 111b, and the second yoke portion 112 is fixed to the opening of the first yoke portion with the lead wires of each of the coils passing through each of the multiple holes 112b. The connection board 130, which is superimposed on the outside of the second yoke portion 112, connects the lead wires 122 connected to the conductive portion 133 using a connection pattern 134. Therefore, in a cylindrical linear motor 10 that requires lead wires 122 for multiple coils 121, it becomes possible to reliably and stably connect multiple coils to each other while suppressing performance degradation caused by magnetic flux leakage through the yoke 110.
[0059] In the cylindrical linear motor 10 of Embodiment 1, the coil group 120 is press-fitted into the first yoke portion 111 such that the lead wires 122 of each of the multiple coils 121 are located at the opening 111b. Therefore, with multiple lead wires 122 passing through multiple holes 112b in the second yoke portion 112, the coil group 120 is in close contact with the yoke 110. As a result, a cylindrical linear motor 10 equipped with a magnetically efficient stator 100 can be realized.
[0060] In the cylindrical linear motor 10 of Embodiment 1, a plurality of coils 121 are assigned to a plurality of different phases, and each lead wire 122 passing through each hole 112b in each coil 121 of the same phase located at a distance from each other among the plurality of different phases is interconnected by a wiring pattern 134. This makes it possible to generate a moving magnetic field inside the coil group 120 in response to multi-phase drive current supplied from an external source, thereby realizing a cylindrical linear motor 10 equipped with a magnetically highly efficient stator 100.
[0061] In the cylindrical linear motor 10 of Embodiment 1, the connection board 130 is fixed to the outside of the second yoke portion 112 such that the multiple holes 112b provided in the second yoke portion 112 and the multiple holes 132 provided in the connection board 130 are aligned. Therefore, it becomes possible to connect multiple coils 121 in a reliable and stable manner, eliminating the need to provide a separate protection and holding mechanism for the connecting wires in the cylindrical linear motor 10.
[0062] [Other effects] By making the yoke 110 of the stator 100 a divided structure consisting of a first yoke portion 111 having an opening 111b and a second yoke portion 112 having a shape that matches the opening 111b, insulating coating can be easily applied to the inner surfaces of the first yoke portion 111 and the second yoke portion 112 before inserting the coil group 120 into the first yoke portion 111. [Explanation of Symbols]
[0063] 10 Cylindrical linear motor, 100 Stator, 110 Yoke, 111 First yoke section, 111b Opening, 112 Second yoke section, 112b Hole, 120 Coil group, 121 Coil, 122 Lead wire, 130 Connection board, 132 Hole, 133 Conductive section, 134 Connection pattern, 140 Cylindrical section, 141 Shaft retainer section, 150 Cylindrical section, 151 Shaft retainer section, 200 Movable element, 201 Movable magnet section, 210 Magnet, 220 Pole piece, 240, 250 Movable shaft, 300 Signal supply line.
Claims
1. A long, cylindrical yoke (110), A coil group (120) is composed of a plurality of coils (121) that are each short cylindrical in shape and arranged axially on the inner diameter side of the yoke (110), A connection board (130) electrically connects each of the plurality of coils (121), Equipped with, The aforementioned yoke (110) is A first yoke portion (111) having an opening (111b) in which a portion of the circumferential region is cut out along the axial direction from one end to the other, The second yoke portion (112) is configured to conform to the shape of the opening (111b) and has a plurality of holes (112b) through which the lead wires (122) of each of the plurality of coils (121) pass, The second yoke portion (112) is fixed to the opening (111b) of the first yoke portion (111) with the respective lead wires (122) of the plurality of coils (121) passing through each of the plurality of holes (112b). The aforementioned connection board (130) is Multiple holes (132) through which the lead wires (122) of each of the multiple coils (121) pass, Conductive portions (133) provided around each of the aforementioned multiple holes (132), It has a connection pattern (134) that is connected to the lead wire (122) via the conductive part (133) and connects the lead wires (122) to each other, Each of the lead wires (122) of the plurality of coils (121) is passed through each of the plurality of holes (132), and the lead wires (122) and the conductive parts (133) are connected in each of the plurality of holes (132), and the connection board (130) is fixed in a state where it is superimposed on the outside of the second yoke portion (112). Stator of a cylindrical linear motor.
2. The coil group (120) is press-fitted into the first yoke portion (111) such that the lead wires (122) of each of the plurality of coils (121) are positioned in the opening (111b). A stator for a cylindrical linear motor according to claim 1.
3. The aforementioned multiple coils (121) are assigned to multiple different phases, Each of the lead wires (122) in each of the coils (121) of the same phase located at different positions among the plurality of different phases are interconnected via the connection pattern (134). A stator for a cylindrical linear motor according to claim 1.
4. The connection board (130) is fixed to the outside of the second yoke portion (112) such that the plurality of holes (112b) provided in the second yoke portion (112) and the plurality of holes (132) provided in the connection board (130) are aligned. A stator for a cylindrical linear motor according to any one of claims 1 to 3.
5. A stator (100) having a long cylindrical yoke (110), a group of coils (120) consisting of a plurality of short cylindrical coils (121) arranged axially on the inner diameter side of the yoke (110), and a connection board (130) that electrically connects each of the plurality of coils (121), The system comprises a movable element (200) having a magnet (210) positioned inside the stator (100) facing it via a magnetic gap and movable in the axial direction, The aforementioned yoke (110) is A first yoke portion (111) having an opening (111b) in which a portion of the circumferential region is cut out along the axial direction from one end to the other, The second yoke portion (112) is configured to conform to the shape of the opening (111b) and has a plurality of holes (112b) through which the lead wires (122) of each of the plurality of coils (121) pass, The second yoke portion (112) is fixed to the opening (111b) of the first yoke portion (111) with the respective lead wires (122) of the plurality of coils (121) passing through each of the plurality of holes (112b). The aforementioned connection board (130) is Multiple holes (132) through which the lead wires (122) of each of the multiple coils (121) pass, Conductive portions (133) provided around each of the aforementioned multiple holes (132), It has a connection pattern (134) that is connected to the lead wire (122) via the conductive part (133) and connects the lead wires (122) to each other, Each of the lead wires (122) of the plurality of coils (121) is passed through each of the plurality of holes (132), and the lead wires (122) and the conductive parts (133) are connected in each of the plurality of holes (132), and the connection board (130) is fixed in a state where it is superimposed on the outside of the second yoke portion (112). Cylindrical linear motor.
6. The coil group (120) is press-fitted into the first yoke portion (111) such that the lead wires (122) of each of the plurality of coils (121) are positioned in the opening (111b). The cylindrical linear motor according to claim 5.
7. The aforementioned multiple coils (121) are assigned to multiple different phases, Each of the lead wires (122) passing through each of the holes (112b) in each of the coils (121) of the same phase located at a distance from each of the plurality of different phases is connected to each other via the connection pattern (134). The cylindrical linear motor according to claim 5.
8. The connection board (130) is fixed to the outside of the second yoke portion (112) such that the plurality of holes (112b) provided in the second yoke portion (112) and the plurality of holes (132) provided in the connection board (130) are aligned. A cylindrical linear motor according to any one of claims 5 to 7.