Jigs, assembly methods, motors

Abstract

This technology provides a way to easily assemble magnetized permanent magnets and yokes. [Solution] The jig of the present disclosure is a jig for assembling a permanent magnet to a yoke of a movable element of a motor, the jig comprising an attractive force adjustment part made of a magnetic material and a sliding member made of a non-magnetic material, the sliding member having a first surface on which the attractive force adjustment part is provided and a second surface facing the first surface and on which the permanent magnet slides.

Description

Technical Field

[0001] The present disclosure relates to a jig, an assembly method, and a motor.

Background Art

[0002] As a configuration of a motor, it is generally common to have a coil with a core in the stator and use a permanent magnet and a yoke in the rotor. These days, a neodymium magnet with a strong magnetic force may be used for the permanent magnet. Also, in order to efficiently utilize magnetic flux, the rotor may have a permanent magnet disposed on a yoke made of a magnetic material. At this time, since an attractive force acts between the permanent magnet and the magnetic material, it may be difficult to dispose it on the yoke.

[0003] Also, in a motor, permanent magnets are arranged at a predetermined interval, and a current is passed through a coil, which is a stator, to generate thrust. That is, it is necessary to arrange the permanent magnets on the yoke at a predetermined interval. In that case, however, an attractive force acts not only between the yokes but also between adjacent permanent magnets, making it difficult to arrange the permanent magnets at a predetermined interval.

[0004] On the other hand, for example, in Patent Document 1, when storing a magnetized permanent magnet in a case, it is stored in a magnetic case using a guide member made of a magnetic material and a non-magnetic material. Also, in Patent Document 2, the permanent magnet is provided with a shape and assembled by fitting it into a case.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the method described in Patent Document 1, when moving from a magnetic guide member to a non-magnetic guide member, an attractive force acts between the case and the guide member, which can make assembly difficult. Also, if the number of polarities increases (for example, four or more poles), there is a risk that repulsive or attractive forces will act between each permanent magnet. Furthermore, in the method described in Patent Document 2, if magnetic materials are used for the case or yoke, an attractive force acts, making assembly difficult. If magnetic materials are not used for the case or yoke, no attractive force acts, but it becomes difficult to obtain the desired torque or thrust because the magnetic flux cannot be utilized efficiently.

[0007] This disclosure aims to provide a technology that enables easy assembly of magnetized permanent magnets and yokes in the movable and stator elements of a motor. [Means for solving the problem]

[0008] The jig of this disclosure is for assembling a permanent magnet to a yoke of a movable element of a motor, the jig comprising an attractive force adjustment section made of a magnetic material and a sliding member made of a non-magnetic material, the sliding member having a first surface on which the attractive force adjustment section is provided and a second surface facing the first surface, on which the permanent magnet slides. [Effects of the Invention]

[0009] According to this disclosure, magnetized permanent magnets and yokes can be easily assembled in the movable and stator elements of a motor. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing a typical moving-type linear motor. [Figure 2] This is a schematic diagram showing an assembly jig according to the first embodiment. [Figure 3] This is a schematic diagram showing an assembly jig according to the second embodiment. [Figure 4] This is a schematic diagram showing an assembly jig according to the third embodiment. [Figure 5]This is a schematic diagram showing an assembly jig according to the fourth embodiment. [Figure 6] This is a schematic diagram showing an assembly jig according to the fifth embodiment. [Figure 7] This is a schematic diagram showing an assembly jig according to the sixth embodiment. [Figure 8] This is a schematic diagram showing an assembly jig according to the seventh embodiment. [Figure 9] This is a schematic diagram showing an assembly jig according to the seventh embodiment. [Figure 10] This is a schematic diagram showing an assembly jig according to the eighth embodiment. [Modes for carrying out the invention]

[0011] The embodiments for implementing this disclosure will be described below with reference to the attached drawings. Note that the embodiments shown below are merely examples, and for example, the details of the configuration can be modified as appropriate by those skilled in the art without departing from the spirit of this disclosure.

[0012] (First Embodiment) The first embodiment will be described below with reference to Figures 1 and 2. In this embodiment, a moving magnet type linear motor will be mainly used as an example.

[0013] Figure 1 is a schematic diagram of a typical linear motor. In a typical linear motor, the movable element 1 consists of a permanent magnet 2 and a yoke 3, and the stator 9 has a coil, which consists of a winding 10 and a core 11. By passing current through the winding 10 at predetermined timings according to each phase (UVW), attractive and repulsive forces act between it and the permanent magnet 2, and the movable element 1 obtains thrust. In order to obtain the attractive and repulsive forces that constitute thrust, a magnetic circuit is formed between the permanent magnet 2, the yoke 3, and the core 11 of the coil in the stator 9.

[0014] Here, if the material of the yoke 3 and the core 11 are made of magnetic material, magnetic flux can pass through more easily, and a large thrust can be obtained. In order to obtain a large thrust, powerful permanent magnets such as neodymium magnets are often used.

[0015] If the magnetic force of the permanent magnet 2 is increased, a large thrust force can be obtained. On the other hand, when assembling the motor, an attractive force acts between the yoke 3, the core 11, which are peripheral members, and the motor case, etc., making the assembly difficult. Further, in motor assembly, it is necessary to arrange the permanent magnets 2 at regular intervals on the yoke 3. This is because the relative positional relationship between the permanent magnet 2 and the coil is important for obtaining thrust efficiently.

[0016] When arranging the permanent magnet 2 on the yoke 3, the attractive force of the permanent magnet 2 acts on the peripheral members, making it difficult to attach it to the predetermined position. Alternatively, since the attractive force of the permanent magnet 2 itself is too strong, there is a risk of cracking when hitting the yoke 3 during assembly.

[0017] Therefore, in this embodiment, an assembly method using an assembly jig composed of an attractive force adjusting member and a sliding member will be described. Fig. 2(a) is a top view of the assembly jig, and Fig. 2(b) is a diagram schematically showing a cross section taken along A-A' in Fig. 2(a).

[0018] In Fig. 2(a), the rotor 1 has a permanent magnet 2 and a yoke 3, and the assembly jig 4 has an attractive force adjusting member 5 and a sliding member 6. In the assembly method of this embodiment, the thickness of the sliding member 6 is adjusted, and the permanent magnet 2 is slid to position it while maintaining an attractive force that does not cause it to fall.

[0019] The attractive force adjusting member 5 is made of a magnetic material such as iron, and the sliding member 6 is made of a non-magnetic material such as resin. Further, the attractive force adjusting member 5 is arranged on the back surface of the surface of the sliding member 6 where the permanent magnet 2 slides. The surface of the sliding member 6 where the attractive force adjusting member 5 is provided will be referred to as the first surface, and the surface where the permanent magnet 2 slides will be referred to as the second surface.

[0020] As shown in Figure 2(a), during assembly, the assembly jig 4 is installed above the yoke 3 as shown in Figure 2. The permanent magnet 2 is placed on the sliding member 6 of the installed assembly jig 4. When the permanent magnet 2 is placed, an attractive force acts between it and the attractive force adjustment member 5 via the sliding member 6. This attractive force is not large because the thickness of the sliding member 6 creates a magnetic gap. Assuming that the downward direction in the figure is the direction of gravity, the permanent magnet 2 would fall downward without the attractive force from the attractive force adjustment member 5.

[0021] Here, if we let F be the attractive force of the permanent magnet 2, mg be the gravitational force acting on the permanent magnet 2, and μ be the coefficient of friction of the sliding member 6, then the following relationship (Equation 1) can be obtained.

[0022] [Math 1] F × μ > mg The thickness of the sliding member 6 should be set so that the relationship is given by equation 1. Furthermore, the permanent magnet 2 can be moved relatively easily in a direction perpendicular to the direction of the attractive force, and the positioned permanent magnet 2 slides along the sliding member 6 to reach the yoke 3. After the permanent magnet 2 moves to its predetermined position on the yoke 3, it is fixed using common fixing methods such as adhesive or screws. The thickness of the sliding member 6 should be set so that the attractive force prevents it from falling due to gravity, and it is even preferable to set it so that the attractive force allows for sliding on the sliding member 6 with a small force (for example, by hand).

[0023] By using this assembly jig 4, the position of the permanent magnet 2 is fixed by the set attractive force, thus reducing displacement of the permanent magnet 2 and making it easy to install it in the predetermined position. Furthermore, since it is not directly attached to the yoke 3, it is possible to prevent the permanent magnet 2 from colliding with the yoke 3 and breaking due to its own attractive force.

[0024] Furthermore, although this embodiment describes an example of a moving magnet type linear motor, similar effects can be obtained in the assembly of permanent magnets used in the rotor of a rotary motor or the stator of a moving coil type linear motor. Also, although this embodiment describes the process assuming that downward is the direction of gravity, similar effects can be obtained regardless of the direction in which the jig is installed, as the attractive force acting between the permanent magnet 2 and the attractive force adjusting member 5 reduces the displacement of the permanent magnet 2.

[0025] (Second embodiment) Figure 3(a) is a top view of the assembly jig of this embodiment, and Figure 3(b) is a schematic representation of the cross-section AA' in Figure 3(a).

[0026] The assembly jig in Figure 3 has the configuration of Figure 2, plus a positioning member 8. The positioning member 8 may be integrated with the assembly jig 4, or it may be fixed externally with a separate fastener (not shown).

[0027] When moving the permanent magnet 2 and positioning it on the yoke 3, it is necessary to position it precisely. Conventional motors generate thrust by applying current according to the relative position of the permanent magnet and the winding. If the position is misaligned, a phase difference will occur between the current applied to the stator winding and the permanent magnet, preventing the desired thrust from being obtained.

[0028] Therefore, in this embodiment, a positioning member 8 is placed on the yoke 3 to assemble the permanent magnet 2 in order to perform accurate positioning. As shown in Figure 3, when the permanent magnet 2 moves on the yoke 3, it moves using the positioning member 8 as a guide. By placing the positioning member 8, lateral displacement in the figure is prevented, and the permanent magnet 2 is moved downward in the figure, abutting against the positioning member 8 to perform positioning.

[0029] The positioning member 8 may be angled towards the side into which the permanent magnet 2 is inserted, creating a guide-in structure. This prevents the permanent magnet 2 from getting stuck and makes insertion easier. Also, if adhesive is used to fix the permanent magnet 2 and the yoke 3, there is a concern that the positioning jig 8 may also be bonded by the excess adhesive. In that case, a gap can be provided between the bonding surface of the permanent magnet 2 and the positioning jig 8, and the guide or stopper should be positioned away from the bonding surface of the permanent magnet 2.

[0030] (Third embodiment) Figure 4(a) is a top view of the assembly jig of this embodiment, and Figure 4(b) is a schematic representation of the cross-section AA' in Figure 4(a).

[0031] The assembly jig 4 in Figure 4 has the same configuration as in Figure 2, but the mounting height h of the sliding member 6 relative to the yoke 3 when the assembly jig is installed on the movable element 1 is higher. In other words, the assembly jig is installed in such a way that a step is provided between the sliding member 6 and the yoke 3.

[0032] The permanent magnet 2 is moved onto the yoke 3 by sliding it along the sliding member 6 while being attracted to the attractive force adjustment member 5. As the permanent magnet 2 approaches the yoke 3, the attractive force F' towards the yoke 3 gradually increases, and it is pulled towards the yoke 3. The attractive force towards the jig is adjusted by the thickness of the sliding member 6 and the attractive force adjustment member 5, but the magnetic gap disappears near the point where the sliding member 6 transitions to the yoke 3. When the gap disappears, the attractive force F' towards the yoke 3 increases rapidly, and the permanent magnet 2 is pulled and moved at high speed in the direction of the yoke. At this time, if the height of the yoke 3 is higher than that of the sliding member 6, the permanent magnet 2 may hit the yoke 3 and cause cracks or chips.

[0033] In this embodiment, a mounting height h is provided between the sliding member 6 and the yoke 3. With this configuration, even if the permanent magnet 2 is pulled in the direction of the yoke 3, it will not come into contact with the yoke 3, and assembly can be performed without cracking or chipping of the permanent magnet 2 even when the permanent magnet 2 moves at high speed.

[0034] (Fourth embodiment) Figure 5(a) is a top view of the assembly jig of this embodiment, and Figure 5(b) is a schematic representation of the cross-section AA' in Figure 5(a).

[0035] The assembly jig in Figure 5 has the same configuration as in Figure 2, but the shape of the suction force adjustment member 5 is such that the gap g between it and the permanent magnet 2 narrows as it approaches the yoke 3. The sliding member 6 has a sliding surface that is parallel to the surface of the yoke 3, and the opposite surface has a shape that follows that of the suction force adjustment member 5.

[0036] With this configuration, the magnetic gap narrows as it approaches the yoke 3, and the attractive force F increases. In other words, the abrupt change in the attractive force F' towards the yoke 3, as described in the third embodiment, becomes less likely to occur. Also, when moving toward the yoke 3, the attractive force F between the permanent magnet 2 and the attractive force adjusting member 5 increases, resulting in increased sliding resistance. Even if the permanent magnet 2 is pulled toward the yoke 3, the increased sliding resistance prevents it from moving at high speed, making position adjustment easier.

[0037] (Fifth embodiment) Figure 6(a) is a top view of the assembly jig of this embodiment, and Figure 6(b) is a schematic representation of the cross-section AA' in Figure 6(a).

[0038] Figure 6 shows a configuration similar to Figure 2, but the shape of the suction force adjustment member 5 is such that the area facing the permanent magnet 2 increases as it approaches the yoke 3. In other words, when the assembly jig is installed on the yoke 3, the suction force adjustment member 5 is wider on the second side (opposite the first side) than on the side closer to the yoke 3 (the first side) when viewed from the direction normal to the surface where the suction force adjustment member 5 and the sliding member 6 are in contact. The sliding member 6 is shaped to fill the space between the suction force adjustment member 5 and the permanent magnet 2, and its sliding surface is parallel to the surface of the yoke 3.

[0039] In this configuration, as the permanent magnet 2 moves to the yoke 3, the attractive force increases as the area between the permanent magnet 2 and the attractive force adjustment member 5 increases. As the attractive force increases, the sliding resistance also increases, making it easier to attach the permanent magnet 2. Because the rate of change in attractive force with position becomes smaller, attachment and positioning become easier than in the configuration shown in Figure 2. Furthermore, if the shape is combined with that of the fourth embodiment, the attractive forces F and F' can be adjusted more precisely.

[0040] (Sixth embodiment) Figure 7(a) is a top view of the assembly jig of this embodiment, and Figure 7(b) is a schematic representation of the cross-section AA' in Figure 7(a).

[0041] In Figure 7(a), the assembly jig 4 consists of a suction force adjustment member 5. In this embodiment, a method of positioning is described in which the suction force adjustment member is used to slide the jig while maintaining a suction force that prevents it from falling.

[0042] The suction force adjusting member 5 is constructed by mixing magnetic powder such as iron with a binder material. The binder material is made of a non-magnetic material such as resin or rubber. By adjusting the amount of magnetic powder mixed with the binder, the magnetism can be adjusted, and the suction force acting between it and the permanent magnet 2 can be set.

[0043] As shown in Figure 7(a), during assembly, the assembly jig 4 is installed above the yoke 3. The permanent magnet 2 is placed on the suction force adjustment member 5 of the installed assembly jig 4. When the permanent magnet 2 is placed, an attractive force acts between it and the suction force adjustment member 5. This attractive force is determined by the amount of magnetic powder mixed in the binder and is adjusted so that it does not become too strong. Assuming that the downward direction in the figure is the direction of gravity, the permanent magnet 2 would fall downwards if there were no attractive force from the suction force adjustment member.

[0044] Here, if we let F be the attractive force of the permanent magnet, mg be the gravitational force acting on the permanent magnet 2, and μb be the coefficient of friction of the attractive force adjusting member 5, which is made of magnetic powder and binder material, then the following relationship (Equation 2) can be obtained.

[0045] [Math 2] F × μb > mg The amount of magnetic powder should be set so that it satisfies the relationship in equation 2. The amount of magnetic powder should be set so that it creates an attractive force that prevents it from falling due to gravity. It is even preferable to set it so that it creates an attractive force that allows sliding on the attractive force adjustment member 5 with a small force (for example, with your fingertips).

[0046] By using this assembly jig 4, the position of the permanent magnet 2 is fixed by the set attractive force, thus reducing displacement of the permanent magnet 2 and making it easy to install it in the predetermined position. Furthermore, since it is not directly attached to the yoke 3, it is possible to prevent the permanent magnet 2 from colliding with the yoke 3 and breaking due to its own attractive force.

[0047] Although this embodiment describes a moving magnet type linear motor, similar effects can be obtained in the assembly of permanent magnets used in the rotor of a rotary motor or the stator of a moving coil type linear motor. Furthermore, although this embodiment describes the process assuming that gravity is downwards, regardless of the direction in which the jig is installed, the attractive force acting between the permanent magnet 2 and the attractive force adjustment member 5 reduces the displacement of the permanent magnet 2, thus achieving similar effects.

[0048] (Seventh Embodiment) Figure 8(a) is a top view of the assembly jig of this embodiment, and Figure 8(b) is a schematic representation of the cross-section AA' in Figure 8(a). Similarly, Figure 9(a) is a top view of the assembly jig of this embodiment, and Figure 9(b) is a schematic representation of the cross-section AA' in Figure 9(a).

[0049] Figures 8 and 9 show a configuration similar to that of Figure 2, but with a different shape for the yoke 3. The yoke 3 has a recess 7 for applying adhesive, which is provided with a groove depth d relative to the bonding surface of the yoke 3.

[0050] The permanent magnet 2 needs to be fixed in place after being moved onto the yoke 3. Adhesive is commonly used for fixing. In the assembly jig 4 shown in Figure 2, if adhesive is applied to the surface of the yoke 3 and then it is slid from the jig during assembly, most of the adhesive will be scraped off, resulting in insufficient adhesion. In this case, adhesive is applied later, but space for bonding must be reserved beforehand for the permanent magnet 2.

[0051] Therefore, in this embodiment, the yoke 3 is provided with a recess 7 for applying adhesive, having a groove depth d, and the adhesive is applied therein to fix it in place.

[0052] As shown in Figure 8, if the recess 7 is provided in the same direction as the sliding direction, sufficient thickness can be achieved through bonding without being scraped off during assembly. Also, as shown in Figure 9, if the recess 7 is provided in a direction perpendicular to the sliding direction, the number of processing points and operations on the yoke 3 can be reduced, thus enabling bonding with lower processing costs.

[0053] The adhesive can be any known type. For example, a general mixed adhesive or a UV-curing adhesive may be used. With a general mixed adhesive, the position of the permanent magnet 2 needs to be held for a long time using a fixing jig or the like (not shown) until it is completely cured. However, with a UV-curing adhesive, curing can be done in a short time if the groove depth is appropriately adjusted. Faster curing is preferable because it eliminates the need to hold the position of the permanent magnet 2 for a long time using a fixing jig or the like.

[0054] In this embodiment, a structure is shown in which the yoke 3 is provided with grooves for applying adhesive, but the same effect can be obtained by providing grooves for applying adhesive to the permanent magnet 2.

[0055] (Eighth embodiment) Figure 10(a) is a top view of the assembly jig of this embodiment, and Figure 10(b) is a schematic representation of the cross-section AA' in Figure 10(a).

[0056] Figure 10 shows a configuration similar to Figure 2, but the shapes of the permanent magnet 2, yoke 3, and positioning member 8 are different.

[0057] The permanent magnet 2 needs to be fixed in place after being moved onto the yoke 3. Screw fastening is a common method of fixing it in place.

[0058] As shown in Figure 2, if the yoke 3 is assembled by sliding it through an assembly jig with adhesive applied to its surface, most of the adhesive will be scraped off, and the necessary bonding strength will not be achieved. In this case, adhesive will be applied later, but it is necessary to reserve space for bonding relative to the permanent magnet 2 beforehand.

[0059] Therefore, in this embodiment, the permanent magnet 2 is provided with a through hole for a screw, and the yoke 3 is provided with a screw hole as a recess 7, and the two are fixed together. If a positioning member 8 is used, a screw hole can be similarly made.

[0060] If fastening is done with screws, the time required for curing, as with adhesive, is eliminated. Furthermore, with assembly using the assembly jig 4, the position can be determined with high precision, making automated assembly using robots easier.

[0061] The effects described in each embodiment are merely a list of the most preferred effects that can result from the technology of this disclosure, and the effects of the technology of this disclosure are not limited to those described above.

[0062] This embodiment includes the following configuration.

[0063] (Item 1) A jig for assembling a permanent magnet to a yoke on a movable element of a motor, The jig comprises an attractive force adjustment section made of a magnetic material and a sliding member made of a non-magnetic material. The sliding member has a first surface on which the suction force adjustment section is provided, and a second surface facing the first surface, which is the surface on which the permanent magnet slides. A jig characterized by the following.

[0064] (Item 2) The jig according to item 1, further comprising a positioning member for positioning the permanent magnet on the second surface of the sliding member.

[0065] (Item 3) The suction force adjustment unit has a first side that faces the yoke when the permanent magnet is positioned, and a second side that faces the first side. The suction force adjustment section has a shape in which the first side is thicker than the second side. A jig as described in item 1 or 2, characterized by the features described herein.

[0066] (Item 4) The suction force adjustment unit has a first side that faces the yoke when the permanent magnet is positioned, and a second side that faces the first side. The suction force adjustment section has a shape in which the width increases as it approaches the first side, when viewed from the direction normal to the first surface. A jig as described in item 1 or 2, characterized by the features described herein.

[0067] (Item 5) The jig according to any one of items 1 to 4, characterized in that the suction force adjustment unit has magnetic powder and a binder material.

[0068] (Item 6) A method for assembling a permanent magnet to a yoke on a movable element of a motor, The process includes a sliding step in which a permanent magnet is slid on the first surface of a sliding member made of a non-magnetic material. In the sliding process, suction is performed by a suction force adjustment unit provided on the second surface facing the first surface. An assembly method characterized by the following.

[0069] (Item 7) The assembly method according to item 6, characterized in that, in the sliding step, the sliding member is installed on the movable element such that there is a step between the first surface and the yoke.

[0070] (Item 8) A motor having a movable element and a stator, Either the movable element or the stator has a permanent magnet and a yoke. A recess is provided on the surface of the yoke that is in contact with the permanent magnet. A motor characterized by the following features.

[0071] (Item 9) The yoke has a screw hole as the recess, The permanent magnet has a through hole for screwing through. A motor as described in item 8, characterized by the features described therein. [Explanation of symbols]

[0072] 1 mover 2 permanent magnets 3 York 4. Assembly jigs 5 Suction power adjustment section 6. Sliding member

Claims

1. A jig for assembling a permanent magnet to a yoke on a movable element of a motor, The jig comprises an attractive force adjustment section made of a magnetic material and a sliding member made of a non-magnetic material. The sliding member has a first surface on which the suction force adjustment section is provided, and a second surface facing the first surface, which is the surface on which the permanent magnet slides. A jig characterized by the following.

2. The jig according to claim 1, further comprising a positioning member for positioning the permanent magnet on the second surface of the sliding member.

3. The suction force adjustment unit has a first side that faces the yoke when the permanent magnet is positioned, and a second side that faces the first side. The suction force adjustment section has a shape in which the first side is thicker than the second side. The jig according to claim 1.

4. The suction force adjustment unit has a first side that faces the yoke when the permanent magnet is positioned, and a second side that faces the first side. The suction force adjustment section has a shape in which the width increases as it approaches the first side, when viewed from the direction normal to the first surface. The jig according to claim 1.

5. The jig according to claim 1, characterized in that the suction force adjustment section has magnetic powder and a binder material.

6. A method for assembling a permanent magnet to a yoke on a movable element of a motor, The process involves sliding a permanent magnet across the first surface of a sliding member made of a non-magnetic material. In the sliding process, suction is performed by a suction force adjustment unit provided on the second surface facing the first surface. An assembly method characterized by the following.

7. The assembly method according to claim 6, characterized in that, in the sliding step, the sliding member is installed on the movable element such that there is a step between the first surface and the yoke.

8. A motor having a movable element and a stator, Either the movable element or the stator has a permanent magnet and a yoke. A recess is provided on the surface of the yoke that is in contact with the permanent magnet. A motor characterized by the following features.

9. The yoke has a screw hole as the recess, The permanent magnet has a through hole for screwing through. The motor according to feature 8.

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