Cylindrical linear motor

Abstract

To provide a small-type cylinder type liner motor.SOLUTION: A cylinder type liner motor 1 of the present invention, comprises: a field magnet 6 in which a N pole and a S pole are alternately arranged in a shaft direction; an armature E including a plurality of cores 2A and 2B which has a cylinder shape, and is arranged while having an interval in the shaft direction, and a winding 3 with a plurality of phases mounted to a slot 2c of each of the cores 2A and 2B; and one inverter 20 to which a power can be conducted to each winding 3. The interval between the cores 2A and 2B is 1 / 2 of a slot pitch P, each winding 3 is mounted to the slot 2c of each of the cores 2A and 2B by being shifted from one of the cores 2A and 2B one by one in a phase. In both of the adjacent cores 2A and 2B, the winding 3 of one core 2A and the winding 3 of the other core 2B which is shifted by one phase are coupled in an inverse direction each other.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] A tubular linear motor is configured to include, for example, a cylindrical field magnet having permanent magnets laminated such that N poles and S poles alternately appear in the axial direction, and an armature that is axially movably inserted into the field magnet.

[0003] The armature includes a plurality of cores that are cylindrical and have a plurality of slots formed by annular teeth arranged axially on the outer periphery and gaps between the teeth, and windings mounted in each slot of the cores. The windings are three-phase windings of U, V, and W phases, and are mounted so as to have a phase arrangement suitable for the pole arrangement of the field magnet with respect to the slots in each core.

[0004] In the tubular linear motor configured as described above, by energizing each phase winding with a 120-degree phase difference, the axial attraction and repulsive forces generated between the permanent magnet and the armature are exerted to drive the armature as a mover (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the tubular linear motor configured as described above, although it includes a plurality of cores, there may be a case where a gap is provided between the cores for some purpose, such as for the purpose of reducing cogging thrust or providing a slider between the cores to reduce the axial misalignment of the armature with respect to the field magnet.

[0007] When it is desirable to create a gap between cores in this way, the overall length of the cylindrical linear motor in the axial direction increases, so it is advantageous to minimize the gap as much as possible. However, if the gap is set freely regardless of the slot pitch, an inverter to energize the windings of each core will be required for each core, which is not only uneconomical but also results in a larger overall size for the cylindrical linear motor, including the drive circuit.

[0008] Furthermore, in conventional cylindrical linear motors, in order to power multiple core windings with a single inverter, the gap between the cores cannot be made smaller than the slot pitch, making it difficult to further shorten the overall length of the cylindrical linear motor.

[0009] Therefore, the present invention aims to provide a compact cylindrical linear motor. [Means for solving the problem]

[0010] To achieve the above objective, the cylindrical linear motor of the present invention comprises a field magnet in which north poles and south poles are alternately arranged in the axial direction, and a cylindrical shape with a distance in the axial direction sky The armature comprises multiple cores arranged in a grid, and multiple phase windings mounted in the slots of each core, and one inverter capable of energizing each winding, wherein the spacing between cores is half the slot pitch, and the windings are mounted in the slots of the cores with a one-phase offset from one side of the core, and between adjacent cores, the windings of one core and the one-phase offset windings of the other core are connected in opposite directions.

[0011] Furthermore, another cylindrical linear motor of the present invention has a field in which north poles and south poles are alternately arranged in the axial direction, and a cylindrical shape with a distance in the axial direction skyThe armature comprises a plurality of cores arranged in a row, and three-phase windings of U-phase, V-phase, and W-phase mounted in the slots of each core, and one inverter capable of energizing each winding, with the spacing between cores being half the slot pitch, and between adjacent cores, the U-phase winding of one core and the V-phase winding of the other core are connected in opposite directions, the V-phase winding of one core and the W-phase winding of the other core are connected in opposite directions, and the W-phase winding of one core and the U-phase winding of the other core are connected in opposite directions.

[0012] In a cylindrical linear motor configured in this way, all the core windings can be energized with a single inverter. This eliminates the need for an inverter for each core, and, given that it can be driven with a single inverter, the spacing between cores can be reduced to half of the minimum slot pitch, thus shortening the overall length in the axial direction. [Effects of the Invention]

[0013] The cylindrical linear motor of the present invention can be miniaturized. [Brief explanation of the drawing]

[0014] [Figure 1] This is a longitudinal cross-sectional view of a cylindrical linear motor in one embodiment. [Figure 2] This is an example of a circuit diagram of the inverter and windings of a cylindrical linear motor according to one embodiment. [Figure 3] This is another example of a circuit diagram of the inverter and windings of a cylindrical linear motor according to one embodiment. [Figure 4] This figure shows the core of a cylindrical linear motor in a first modified example of one embodiment. [Figure 5] This is an example of the inverter, windings, and circuit diagram of a cylindrical linear motor in a first modified example of one embodiment. [Modes for carrying out the invention]

[0015] Hereinafter, the present invention will be described based on the embodiments shown in the drawings. As shown in FIG. 1, the tubular linear motor 1 in one embodiment includes a magnetic field 6 in which N poles and S poles are alternately arranged in the axial direction, a plurality of cores 2A and 2B arranged at intervals in the axial direction and having a tubular shape, and a plurality of phases of windings 3 mounted in the slots of each of the cores 2A and 2B, and an armature E, and an inverter 20 capable of energizing each of the windings 3. sky The armature E includes a plurality of cores 2A and 2B arranged at intervals in the axial direction and having a tubular shape, and a plurality of phases of windings 3 mounted in the slots of each of the cores 2A and 2B.

[0016] Hereinafter, each part of the tubular linear motor 1 will be described in detail. In the present embodiment, the magnetic field 6 includes an annular main magnetic pole permanent magnet 6a and an annular sub-magnetic pole permanent magnet 6b that are alternately stacked and inserted in the axial direction, and is configured to be tubular. Further, a tubular back yoke 8 is mounted on the outer periphery of the magnetic field 6. The magnetic field 6 and the back yoke 8 are accommodated in an annular gap formed between a cylindrical non-magnetic barrel 7 and a cylindrical non-magnetic guide tube 9 inserted into the barrel 7.

[0017] Note that the triangular marks shown on the main magnetic pole permanent magnet 6a and the sub-magnetic pole permanent magnet 6b in FIG. 1 indicate the magnetization directions. The magnetization direction of the main magnetic pole permanent magnet 6a is in the radial direction, and the magnetization direction of the sub-magnetic pole permanent magnet 6b is in the axial direction. The main magnetic pole permanent magnet 6a and the sub-magnetic pole permanent magnet 6b are arranged in a Halbach array, and on the inner peripheral side of the magnetic field 6, the S poles and N poles appear alternately in the axial direction.

[0018] Further, the axial length of the main magnetic pole permanent magnet 6a is longer than the axial length of the sub-magnetic pole permanent magnet 6b. By increasing the axial length of the main magnetic pole permanent magnet 6a, the magnetic resistance between the main magnetic pole permanent magnet 6a and the cores 2A and 2B can be reduced, and the magnetic field acting on the cores 2A and 2B can be increased, so that the mass thrust density of the tubular linear motor 1 can be improved. Here, the mass thrust density is a value obtained by dividing the maximum thrust of the tubular linear motor 1 by the mass. As the value of the mass thrust density increases, the thrust per unit mass of the tubular linear motor 1 increases.

[0019] Also, in the cylindrical linear motor 1 of the present embodiment, a back yoke 8 is provided on the outer periphery of the permanent magnets 6a and 6b. If the back yoke 8 is not provided, when the axial length of the permanent magnet 6b of the auxiliary pole becomes short, the magnetic resistance outside the magnet at the axial center of the permanent magnet 6a of the main pole increases, and the field magnetic flux becomes small. Therefore, the degree of improvement in the thrust of the cylindrical linear motor 1 when increasing the axial length of the permanent magnet 6a of the main pole becomes small. On the other hand, if the back yoke 8 is provided on the outer periphery of the permanent magnets 6a and 6b, a magnetic path with low magnetic resistance can be secured, so an increase in magnetic resistance caused by shortening the axial length of the permanent magnet 6b of the auxiliary pole is suppressed. Therefore, if the axial length of the permanent magnet 6a of the main pole is made longer than the axial length of the permanent magnet 6b of the auxiliary pole and a cylindrical back yoke 8 is provided on the outer periphery of the permanent magnets 6a and 6b, the mass thrust density of the cylindrical linear motor 1 can be greatly improved. The thickness of the back yoke 8 may be set to a thickness suitable for suppressing an increase in the external magnetic resistance of the permanent magnet 6a of the main pole.

[0020] Also, cores 2A and 2B are inserted on the inner peripheral side of the stator, and the field magnet 6 acts on the cores 2A and 2B to apply a magnetic field. Since the field magnet 6 only needs to apply a magnetic field to the movable range of the cores 2A and 2B, the installation range of the permanent magnets 6a and 6b may be determined according to the movable range of the cores 2A and 2B. Therefore, in the annular gap between the barrel 7 and the guide tube 9, it is not necessary to install the permanent magnets 6a and 6b in the range that cannot face the cores 2A and 2B. In the present embodiment, the field magnet 6 is composed of the permanent magnets 6a and 6b laminated in a Halbach array. However, as long as N poles and S poles appear alternately on the inner periphery, it may be composed of permanent magnets laminated in an array other than the Halbach array.

[0021] Also, the left end of the barrel 7, the back yoke 8, and the guide tube 9 in FIG. 1 is closed by a cap 16, and the right end of the barrel 7, the back yoke 8, and the guide tube 9 in FIG. 1 is closed by an annular head cap 15.

[0022] The armature E is composed of cylindrical cores 2A and 2B and windings 3 attached to the cores 2A and 2B, and is inserted into the guide tube 9 so as to be axially movable. In other words, in this embodiment, the armature E is positioned on the inner circumference side of the field 6 and can move relative to the field 6 in the axial direction.

[0023] In this embodiment, cores 2A and 2B each consist of a cylindrical yoke 2a, four annular teeth 2b with a rectangular cross-section in the axial direction, provided circumferentially and axially spaced on the outer circumference of the yoke 2a on the field side, and three slots 2c formed in the gaps between the teeth 2b, 2b, into which the windings 3 are mounted. Furthermore, cores 2A and 2B are arranged side by side, spaced apart in the axial direction by a distance of half the slot pitch P. The slot pitch P is equal to the distance from the axial center of one slot 2c to the axial center of the adjacent slot 2c.

[0024] As described above, the yoke 2a is cylindrical, and its cross-sectional area is such that, regardless of where the teeth 2b is cut from the inner circumference to the outer circumference of the core 2, the cross-sectional area is greater than or equal to the area of ​​the cross-section created when the teeth 2b is cut by the aforementioned cylinder.

[0025] In this embodiment, as shown in Figures 1 and 2, four teeth 2b are arranged at equal intervals in the axial direction on the outer circumference of the yoke 2a of the cores 2A and 2B, and a slot 2c is formed on the outer circumference side of the core 2 that is on the field 6 side, with a gap between the teeth 2b, 2b into which the winding 3 is mounted. In this embodiment, the teeth 2b have a rectangular cross-sectional shape, but are not limited to this, and may also have a trapezoidal cross-sectional shape, with the width of the base end being larger than the width of the tip end being the outer circumference, thereby securing a larger magnetic path cross-sectional area on the base end. The shape of the teeth 2b is not limited to the above and can be arbitrarily changed in design.

[0026] In this embodiment, a total of three slots 2c, which are air gaps, are provided between adjacent teeth 2b, 2b in Figure 1 of each core 2A, 2B. The slots 2c are provided along the circumferential direction of the core 2 and are arranged at equal pitches in the axial direction on the outer circumference of the core 2.

[0027] Then, windings 3 are wound and mounted in the slots 2c of each core 2A and 2B. Windings 3 are three-phase windings for the U, V, and W phases. In the slots 2c of each core 2A and 2B, starting from the left in Figure 1, the windings 3 are mounted in the order of U, V, and W phases, shifted by one phase at a time, in the same direction (same winding direction). Thus, the windings 3 are mounted in the same direction, shifted by one phase at a time, starting from one side of each core 2A and 2B.

[0028] Furthermore, in adjacent cores 2A and 2B, the winding 3 of one core 2A and the winding 3 of the other core 2B, which is one phase offset, are connected in opposite directions. Also, the three windings 3 in cores 2A and 2B are Y-connected at the neutral point. Here, in order to distinguish the phases of the windings 3, the U-phase winding 3 of core 2A is designated as winding 3U1, the V-phase winding 3 of core 2A is designated as 3V1, the W-phase winding 3 of core 2A is designated as 3W1, the U-phase winding 3 of core 2B is designated as 3U2, the V-phase winding 3 of core 2B is designated as 3U2, and the W-phase winding 3 of core 2B is designated as 3W2. The subscripts U, V, and W in the winding 3 designations indicate the phase distinction, and the numbers indicate the core number. Hereafter, regarding the symbols for winding 3, if it is necessary to distinguish the phase of winding 3, a subscript will be used, and if it is not necessary to distinguish the phase, a symbol without a subscript will be used. As shown in Figure 2, the first winding 3U1 from the left of one core 2A and the second winding 3V2 from the left of the other core 2B are connected in opposite directions, the second V-phase winding 3V1 from the left of one core 2A and the third winding 3W2 from the left of the other core 2B are connected in opposite directions, and the third winding 3W1 from the left of one core 2A and the first winding 3U2 from the left of the other core 2B are connected in opposite directions. The windings 3U1, 3V1, and 3W1 of each phase of core 2A are Y-connected, and the windings 3U2, 3V2, and 3W2 of each phase of core 2B are also Y-connected.

[0029] The inverter 20 has three terminals 20u, 20v, and 20w corresponding to the U, V, and W phases. Using the phase of winding 3 of core 2A as a reference, terminal 20u corresponding to the U phase is connected to winding 3U1 of core 2A, output terminal 20v corresponding to the V phase is connected to winding 3V1 of core 2A, and terminal 20w corresponding to the W phase is connected to winding 3W1 of core 2A. Therefore, when inverter 20 applies voltage to winding 3U1 of core 2A via terminal 20u, winding 3V2 of core 2B, which is connected to winding 3U1 in the opposite direction, receives the voltage in the opposite direction. Similarly, when inverter 20 applies a voltage to winding 3V1 of core 2A via terminal 20v, winding 3W2 of core 2B, which is connected to winding 3V1 in the reverse direction, is subjected to a reverse voltage. When inverter 20 applies a voltage to winding 3W1 of core 2A via terminal 20w, winding 3U2 of core 2B, which is connected to winding 3W1 in the reverse direction, is subjected to a reverse voltage.

[0030] In this way, cores 2A and 2B are spaced apart in the axial direction by half the slot pitch P, so the phase of the electrical angle between core 2A and the field 6 is shifted by 180 degrees from the phase of the electrical angle between core 2B and the field 6. Then, the windings 3 for each phase are mounted in the slots 2c of each core 2A and 2B sequentially, one phase at a time, and for adjacent cores 2A and 2B, the winding 3 of one core 2A and the one phase-shifted winding 3 of the other core 2B are connected in opposite directions. Therefore, when power is supplied from a single inverter 20 with a 120-degree phase switch, the armature E equipped with cores 2A and 2B can be driven synchronously in the same direction.

[0031] Furthermore, for adjacent cores 2A and 2B, the winding 3 of one core 2A and the winding 3 of the other core 2B, which is one phase offset, should be connected in opposite directions. For example, as shown in Figure 3, the first winding 3U1 from the left of core 2A and the third winding 3W2 from the left of core 2B may be connected in opposite directions, the second phase winding 3V1 from the left of core 2A and the first winding 3U2 from the left of core 2C may be connected in opposite directions, and the third winding 3W1 from the left of core 2A and the second winding 3V2 from the left of core 2C may be connected in opposite directions.

[0032] Furthermore, when using three-phase windings, the number of slots in each core 2A and 2B should be set to an integer multiple of 3, and the windings 3 for each phase should be mounted in the slots 2c of cores 2A and 2B, starting from one of the cores 2A or 2B and shifted by one phase at a time, facing the same direction. In addition, if there are six or more slots 2c for cores 2A and 2B, the windings for each phase may be arranged sequentially in each core 2A and 2B, such as U phase, U phase, V phase, V phase, W phase, W phase, with multiple windings 3 of the same phase mounted consecutively in adjacent slots 2c for each core 2A and 2B. Even in such cases, the axial spacing between cores 2A and 2B may be set to half the slot pitch P, and the U-phase winding 3 of one core 2A and the V-phase winding 3 of the other core 2B may be connected in opposite directions to adjacent cores 2A and 2B, the V-phase winding 3 of one core 2A and the W-phase winding 3 of the other core 2B may be connected in opposite directions, and the W-phase winding 3 of one core 2A and the U-phase winding of the other core 2A may be connected in opposite directions to each other.

[0033] Furthermore, as shown in Figures 4 and 5, even when three or more cores 2A, 2B, 2C are spaced axially by half the slot pitch P, for adjacent cores, it is sufficient that the windings of one core and the windings of the other core, which are one phase offset, are connected in opposite directions. Therefore, for example, if the winding 3 of the U phase of the third core 2C is 3U3, the winding 3 of the V phase of core 2C is 3V3, and the winding 3 of the W phase of core 2C is 3W3, then the first winding 3U2 from the left of the second core 2B and the second winding 3V3 from the left of core 2C are connected in opposite directions, the second phase winding 3V2 from the left of core 2B and the third winding 3W3 from the left of core 2C are connected in opposite directions, and the third winding 3W2 from the left of core 2B and the first winding 3U3 from the left of core 2C are connected in opposite directions. Furthermore, for adjacent cores 2B and 2C, it is sufficient that the winding 3 of one core 2B and the winding 3 of the other core 2C, which is one phase offset, are connected in opposite directions. For example, the first winding 3U2 from the left of the second core 2B and the third winding 3W3 from the left of the second core 2C may be connected in opposite directions, the second phase winding 3V2 from the left of the core 2B and the first winding 3U3 from the left of the core 2C may be connected in opposite directions, and the third winding 3W2 from the left of the core 2B and the second winding 3V3 from the left of the core 2C may be connected in opposite directions.

[0034] Furthermore, in this embodiment, the winding 3 is composed of three phases of windings U, V, and W. However, if multiple cores are spaced apart in the axial direction by half the slot pitch P, and the windings of each phase are mounted in the slots of each core sequentially from one side with a one-phase offset, and adjacent cores are connected in opposite directions to the windings of one core and the one-phase offset winding of the other core, then the windings may be composed of other windings such as two-phase or five-phase.

[0035] The armature E configured in this way is mounted on the outer circumference of the tip of the rod 11, which is the output shaft and is made of a non-magnetic material. Annular sliders 12, 13, and 14, whose outer circumferences slide against the inner circumference of the guide tube 9, are movably inserted into the field 6 together with the rod 11. The combination of the number of poles and the number of slots can be changed as appropriate. The axial length of the slider 13 is set to half the length of the slot pitch P. By inserting the slider 13 between the cores 2A and 2B and fitting the cores 2A, 2B and the slider 13 to the outer circumference of the rod 11, and then sandwiching the cores 2A, 2B and the slider 13 between the sliders 12 and 14 fixed to the outer circumference of the rod 11, the cores 2A and 2B can be fixed to the rod 11 at a distance of half the slot pitch P in the axial direction.

[0036] Rod 11 protrudes from the cylindrical linear motor 1 through a head cap 15 attached to the right end of barrel 7 in Figure 1. Sliders 12 and 13 are mounted on the left and right sides of the armature E of rod 11 in Figure 1, sliding against the inner circumference of guide tube 9. When slider 13 is in sliding contact with guide tube 9, even if a force is applied to move cores 2A and 2B radially, cores 2A and 2B can move smoothly in the axial direction without axial wobble relative to the field 6. Also, since sliders 12 and 14 slide against the inner circumference of guide tube 9 on both sides of the axial direction of cores 2A and 2B, they can move in the axial direction without interfering with guide tube 9.

[0037] Thus, the guide tube 9 forms a gap with high magnetic resistance between the outer circumference of the core 2 and the inner circumference of the field magnet 6, and also plays a role in cooperating with the sliders 12 and 13 to guide the axial movement of the armature E. The outer diameter of the core 2 is smaller than the inner diameter of the guide tube 9, so it does not interfere with the guide tube 9, and the cylindrical linear motor 1 can extend and retract smoothly, although it may slide against the inner circumference of the guide tube 9. The guide tube 9 may be made of a non-magnetic material, but it may also be made of synthetic resin or the like in addition to metal.

[0038] Although not shown in the diagram, the rod 11 is cylindrical, and power can be supplied to the winding 3 from the inverter 20 installed outside the cylindrical linear motor 1 through an external wire (not shown) passed through the rod 11. Specifically, the cap 16 is equipped with a connector 16a that connects the cable 17 connected to the winding 3 to the external inverter 20, allowing power to be supplied from the inverter 20 to the winding 3.

[0039] For example, by sensing the electrical angle of winding 3 with respect to the field 6, performing potential phase switching based on the electrical angle, and controlling the current amount of each winding 3 by PWM control, the thrust and the direction of movement of the armature E in the cylindrical linear motor 1 can be controlled. Note that the above control method is just one example and is not limited thereto. Furthermore, when an external force acts that causes relative axial displacement between the armature E and the field 6, the cylindrical linear motor 1 can be damped by generating a thrust that suppresses the relative displacement by energizing the winding 3 or by generating an induced electromotive force in the winding 3, thereby generating energy to produce power from the external force.

[0040] As described above, the cylindrical linear motor 1 of this embodiment has a field 6 in which N poles and S poles are alternately arranged in the axial direction, and a cylindrical shape with a gap in the axial direction. sky The armature E has multiple cores 2A and 2B arranged in a row, and multiple phase windings 3 mounted in the slots 2c of each core 2A and 2B, and one inverter 20 that can energize each of the windings 3, wherein the spacing between cores 2A and 2B is half the slot pitch P, and the windings 3 are mounted in the slots 2c of cores 2A and 2B with one phase offset from one of the cores 2A and 2B, and for adjacent cores 2A and 2B, the winding 3 of one core 2A and the one phase offset winding 3 of the other core 2B are connected in opposite directions.

[0041] When winding 3 is composed of three phase windings of U-phase, V-phase, and W-phase, the cylindrical linear motor 1 has a field 6 in which N poles and S poles are alternately arranged in the axial direction, and a cylindrical shape with a gap in the axial direction. skyThe armature E has a plurality of cores 2A, 2B arranged in a row, and three-phase windings 3 of U-phase, V-phase, and W-phase mounted in the slots 2c of each core 2A, 2B, and one inverter 20 capable of energizing each of the windings 3, wherein the spacing between cores 2A, 2B is half the slot pitch P, and between adjacent cores, the U-phase winding 3U1 of one core 2A and the V-phase winding 3V2 of the other core 2B are connected in opposite directions, the V-phase winding 3V1 of one core 2A and the W-phase winding 3W2 of the other core 2B are connected in opposite directions, and the W-phase winding 3W1 of one core 2A and the U-phase winding 3U2 of the other core 2B are connected in opposite directions.

[0042] In the cylindrical linear motor 1 configured in this way, cores 2A and 2B are spaced apart in the axial direction by half the slot pitch P, so the phase of the electrical angle between core 2A and the field 6 is shifted by 180 degrees from the phase of the electrical angle between core 2B and the field 6. The windings 3 for each phase are mounted in the slots 2c of each core 2A and 2B sequentially, one phase at a time, and for adjacent cores 2A and 2B, the winding 3 of one core 2A and the one-phase-shifted winding 3 of the other core 2B are connected in opposite directions. Therefore, when power is supplied from a single inverter 20 with a 120-degree phase switch, the armature E equipped with cores 2A and 2B can be driven synchronously in the same direction. As described above, the cylindrical linear motor 1 can be driven by supplying power to the windings 3 of each core 2A and 2B with a single inverter 20.

[0043] Thus, in the cylindrical linear motor 1 of this embodiment, all the windings 3 of the cores 2A and 2B can be energized with a single inverter 20. Therefore, there is no need to provide an inverter for each core 2A and 2B, and given that it can be driven with a single inverter 20, the distance between the cores 2A and 2B can be reduced to half of the slot pitch P, which is the minimum required, thus shortening the overall length in the axial direction. In summary, the cylindrical linear motor 1 of this embodiment can be miniaturized because it can be equipped with only one inverter 20 and have a minimum overall length in the axial direction.

[0044] Furthermore, the cylindrical linear motor 1 of this embodiment includes a non-magnetic guide tube 9 provided on the inner circumference of the field 6, and a slider 13 positioned between the cores 2A and 2B, sliding against the guide tube 9 to guide the movement of the armature E. With the cylindrical linear motor 1 configured in this way, it is possible to suppress axial runout of the armature E relative to the field 6 while ensuring smooth axial movement of the armature E. Note that if the axial length of the slider 13 is half the slot pitch P, interposing the slider 13 between the cores 2A and 2B allows the cores 2A and 2B to be positioned axially separated by half the slot pitch P, making assembly of the armature E easier.

[0045] In this embodiment, the cylindrical linear motor 1 has a structure in which the armature E is placed on the inner circumference of the field 6. However, it is also possible to adopt a structure in which the armature E is placed on the outer circumference of the field 6. In that case, teeth can be provided on the inner circumference side of the cores 2A and 2B, which are on the field side, and the windings 3 can be mounted in the slots formed between the teeth.

[0046] Although preferred embodiments of the present invention have been described in detail above, modifications, alterations, and changes are permitted as long as they do not deviate from the scope of the claims. [Explanation of Symbols]

[0047] 1...Cylindrical linear motor, 2A, 2B...Core, 2c...Slot, 3...Winding, 6...Field, 20...Inverter, E...Armature

Claims

1. A magnetic field in which north poles and south poles are arranged alternately in the axial direction, An armature having multiple cylindrical cores spaced apart in the axial direction, and multiple phase windings mounted in the slots of each core, Each of the windings is equipped with one inverter capable of supplying current, The aforementioned interval is half the slot pitch, The windings are mounted in the slots of the core, offset by one phase from one side of the core. In adjacent cores, the windings of one core and the windings of the other core, which are one phase offset, are connected in opposite directions. A cylindrical linear motor characterized by the following features.

2. A magnetic field in which north poles and south poles are arranged alternately in the axial direction, An armature having multiple cylindrical cores spaced apart in the axial direction, and three-phase windings of U-phase, V-phase, and W-phase mounted in the slots of each core, Each of the windings is equipped with one inverter capable of supplying current, The aforementioned interval is half the slot pitch, In adjacent cores, the U-phase winding of one core and the V-phase winding of the other core are connected in opposite directions, the V-phase winding of one core and the W-phase winding of the other core are connected in opposite directions, and the W-phase winding of one core and the U-phase winding of the other core are connected in opposite directions. A cylindrical linear motor characterized by the following features.

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