JP6211294B2 - Method for maintaining the position of the drive shaft of a spiral motor - Google Patents

Description

  The present invention includes a drive shaft, a spiral rotor, and a spiral stator, and the spiral rotor is screwed into the spiral stator while maintaining a predetermined gap. When driven, the drive shaft rotates and rotates in the axial direction. The present invention relates to a method of maintaining the position of the drive shaft in a spiral motor that is adapted to slide.

  There are various types of motors, such as rotary motors and linear motors. A rotary motor is provided with a rotor inside a circularly arranged stator, and this rotor rotates. A mover provided with a plurality of permanent magnets is arranged through a predetermined gap with respect to a stator in which a plurality of coils are arranged in a straight line, and the mover is slid linearly. As another type of such a motor, a so-called spiral motor has been proposed by the present applicant and has attracted attention in recent years due to its excellent characteristics. For example, as shown in Patent Documents 1 to 3, the spiral motor includes a drive shaft, a spiral rotor provided on the drive shaft, and a spiral stator. The spiral rotor is composed of a flight spirally provided along the drive shaft and a plurality of permanent magnets provided on both sides of the flight, and the spiral stator is formed with a spiral groove. And a plurality of coils provided on both sides of the groove. The helical rotor is screwed to the helical stator so that a predetermined gap is maintained between the permanent magnet and the coil. Therefore, when the current supplied to the coil is controlled, the spiral rotor moves in the axial direction while rotating. That is, the drive shaft can be slid in the axial direction while rotating. As described above, the spiral motor can drive the drive shaft in the axial direction without using mechanical parts such as a ball screw mechanism, and the permanent magnet and the coil are arranged in a spiral shape so that the number of the linear motor is large. Compared to application fields, it is being studied because a large driving force can be obtained.

Japanese Patent No. 3712073 Japanese Patent No. 4543165 JP 2009-17711 A

  As described above, the spiral motor is excellent because it can be driven with a strong driving force in the axial direction. However, there is a problem to be solved as follows. When a predetermined machine is driven by the spiral motor, an axial force may act on the drive shaft of the spiral motor due to an external force received by the machine when the spiral motor is stopped. As described above, when an axial force is applied from the outside, there is a problem with respect to maintaining the position of the drive shaft against the axial force. More specifically, the spiral motor is controlled in a state where a predetermined gap is maintained between the permanent magnet and the coil. When an axial force is applied from the outside to the drive shaft of the spiral motor controlled in this way, the gap changes momentarily, and the control unit of the spiral motor detects this by a sensor and instantaneously turns the coil. The current supplied to the is changed. Then, the change of the gap is eliminated and the drive shaft returns to the original position. That is, the position can be held. However, it is impossible to prevent a slight change in the position instantaneously. In addition, power is required to control the gap appropriately, and when the axial force from the outside is large, the power consumed to maintain the position is large. Furthermore, when the external force acting in the axial direction changes greatly in a short time, it is difficult to control the gap and the position of the drive shaft may not be maintained.

  Therefore, according to the present invention, when the position of the drive shaft is held in the spiral motor, the control of the drive shaft of the spiral motor capable of reliably holding the position is simple even though the control is simple and requires minimal power. The object is to provide a position holding method.

In order to achieve the above object, the present invention is configured to hold the position of the drive shaft by seating the permanent magnet of the rotor constituting the spiral motor on the coil of the stator by magnetic force . That is, the spiral motor includes a drive shaft, a spiral rotor, and a spiral stator, and the spiral rotor is provided with a flight spirally provided along the drive shaft and a plurality of permanents provided on both sides of the flight. The helical stator is composed of an iron core in which a spiral groove is formed and a plurality of coils provided on both sides of the groove. The helical rotor is screwed to the helical stator so that a predetermined gap is maintained between the permanent magnet and the coil. In such a spiral motor, a permanent magnet is provided on one surface of the flight, to maintain the current supply to Rutotomoni coil seated in the coil provided on one surface of the groove of the iron core magnetic force Thus, the seating state is maintained, so that the position of the drive shaft is maintained.

That is, in order to achieve the above object, the invention according to claim 1 includes a drive shaft, a spiral rotor, and a spiral stator, and the spiral rotor is spirally provided along the drive shaft. And a plurality of permanent magnets provided on both sides of the flight, and the helical stator has an iron core in which a helical groove is formed and a plurality of pieces provided on both sides in the groove. The helical rotor is screwed into the helical stator so that a predetermined gap is maintained between the permanent magnet and the coil, and when driven, the drive shaft rotates and rotates in the axial direction. in the spiral motor adapted to slide, when the magnet is provided on one surface of the flight, Ru is seated in the coil provided on one surface of the groove of the core To maintain the current supply to the coil to keep the sitting state by magnetic force, and as a position retaining method of the drive shaft of the spiral motor, characterized in that to hold the position of the drive shaft thereby.
According to a second aspect of the present invention, in the method of the first aspect, when the drive shaft is held at a predetermined target stop position, the spiral motor is driven to stop the drive shaft at the target stop position. Then, the position of the drive shaft of the spiral motor is configured to rotate the spiral rotor while seating the magnet on the coil while restricting the axial movement of the drive shaft.
The method according to claim 3 is the method according to claim 1, wherein when the drive shaft is held at a predetermined target stop position, the spiral motor is driven to move the drive shaft from the target stop position to the gap. Is stopped at a position shifted by an amount, and then the drive shaft is driven in the axial direction while restricting the rotation of the spiral rotor to seat the magnet on the coil, whereby the drive shaft is at the target stop position. It is comprised as a position holding method of the drive shaft of the spiral motor characterized by holding.

As described above, the present invention includes the drive shaft, the spiral rotor, and the spiral stator, and the spiral rotor is provided in a spiral shape along the drive shaft and a plurality of surfaces provided on both sides of the flight. The helical stator is composed of an iron core in which a spiral groove is formed and a plurality of coils provided on both sides of the groove, and between the permanent magnet and the coil. The spiral rotor is screwed into the spiral stator so that a predetermined gap is maintained, and when driven, the drive shaft rotates with the drive shaft rotating in the axial direction. It is configured as a position holding method. The present invention, a magnet is provided on one surface of the flight, the seating state by the magnetic force to maintain the current supply to Rutotomoni coil seated in the coil provided on one surface of the groove of the core And thereby maintaining the position of the drive shaft. Since the drive shaft is held in this way, even if an axial force in one direction acts on the drive shaft by an external force, the position of the drive shaft does not change simply by pressing the magnet against the coil on which the magnet is seated. At this time, a frictional force acts between the magnet and the coil, preventing the drive shaft from sliding and rotating. On the other hand, when the axial force acting on the drive shaft by the external force is in the opposite direction, the magnet tends to be separated from the seated coil. However, the position of the drive shaft is maintained because a predetermined current is passed through the coil and the magnet is kept seated on the coil by the magnetic force. That is, the position of the drive shaft can be maintained even when an axial force in the opposite direction is applied. When the position of the drive shaft is held by seating the magnet on the coil in this way, a small amount of electric power is required, no complicated control is required, and the position can be reliably held.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the spiral motor which concerns on embodiment of this invention, The (a) is a perspective view which shows the state which cut | disconnected the principal part of the spiral motor, ((I) is the front of a spiral motor. It is sectional drawing. It is a figure which shows operation | movement of the spiral motor which concerns on embodiment of this invention, The (a) is operation | movement at the time of normal, (b), (c) is operation | movement in the holding | maintenance method which concerns on embodiment of this invention, respectively FIG. 3 is a front sectional view of a part of the spiral motor. It is a graph which shows the relationship between the position in the axial direction of a drive shaft, and a rotation angle in the spiral motor which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. The present invention relates to a method for maintaining the position of a drive shaft of a spiral motor. First, the spiral motor 1 according to the present embodiment will be described. The spiral motor 1 according to the present embodiment is provided in a cylindrical casing 2 having a predetermined length in the axial direction, as shown in FIGS. A drive shaft 4 supported by a predetermined bearing mechanism 3, 3 with respect to the casing 2, a spiral rotor 6 provided on the drive shaft 4, and a spiral fixed to the inner peripheral surface of the casing 2. And a stator 7.

  The spiral rotor 6 includes a flight 9 provided in a spiral shape with a predetermined pitch along the axial direction of the drive shaft 4, and a plurality of permanent magnets 10, 10,. It consists of and. In this embodiment, the permanent magnets 10, 10,... Are arranged so as to be equally spaced by 60 degrees around the axis, and the S poles and the N poles are alternately arranged, and the flight 9 is arranged in the axial direction. , It appears that six permanent magnets 10, 10,... Are arranged in the circumferential direction. That is, when considered as a rotary motor, the number of poles of the rotor can be said to be six. However, in actuality, the permanent magnets 10, 10,... Are also provided on the back surface of the flight 9, and are provided in a spiral shape, so that the number of permanent magnets 10, 10,.

  The helical stator 7 includes an iron core 12 or a yoke fixed to the inner peripheral surface of the casing 2 and a plurality of coils 13, 13,... Provided on the iron core 12. The iron core 12 is formed with an axial hole through which the drive shaft 4 gently passes, and a spiral groove 14 having a predetermined width is formed at the same pitch as the flight 9 of the spiral rotor 6. The plurality of coils 13, 13,... Are provided at equal intervals on both surfaces in the groove 14 of the iron core 12. The helical rotor 6 is screwed into such a helical stator 7, but between the permanent magnets 10, 10,... Of the helical rotor 6 and the coils 13, 13,. A predetermined gap, that is, gaps 16, 16,... Are maintained. In other words, the controller for controlling the spiral motor 1 controls the gaps 16, 16,. Note that the controller and sensor are not shown in FIG.

  In the spiral motor 1 according to the present embodiment, when the current supplied to the coils 13, 13,... Is appropriately controlled, the spiral rotor 6 is moved relative to the spiral stator 7 while the gaps 16 are maintained. Driven in a spiral. Then, the drive shaft 4 can be driven in the axial direction while rotating. When the spiral motor 1 is stopped, when an axial force is applied to the drive shaft 4 by an external force, the position of the drive shaft 4 is conventionally held as follows. That is, as shown in FIG. 2A, when the axial force Y1 is applied to the drive shaft 4 from the outside, the position of the drive shaft 4 is momentarily shifted due to the axial force, so that the spiral rotor 6 becomes permanent. The gaps 16, 16,... Between the magnets 10, 10,... And the coils 13, 13,. A sensor detects the change of the gaps 16, 16,. The controller controls the current supplied to the coils 13, 13,... To quickly return the gaps 16, 16,. That is, the position of the drive shaft 4 is restored.

  In the method for holding the position of the drive shaft 4 according to the present embodiment, the permanent magnets 10, 10, which are levitated or separated from the coils 13, 13,... So that the predetermined gaps 16, 16,. .. Of the permanent magnets 10, 10... Provided on one surface of the flight 9 are touched down or seated on the facing cores 13, 13. In the state of being seated in this way, it receives an axial force due to an external force. ... of the permanent magnets 10, 10,... To be seated have two methods for seating the permanent magnets 10, 10,. That is, as shown in FIG. 2 (a), the permanent magnets 10, 10,... , 13,... And, as shown in FIG. 2C, the permanent magnets 10, 10,... On the surface opposite to the expected direction of the axial force Y1 from the outside. This is a method of sitting on the coils 13, 13,. When the former method is adopted, the permanent magnets 10, 10,... Are strongly pressed against the coils 13, 13,... By the axial force Y1, so that the frictional force acts so strongly that the drive shaft 4 does not rotate efficiently. Can be held. In this case, only the minimum current necessary for maintaining the permanent magnets 10, 10,... Seated on the coils 13, 13,. On the other hand, when the latter method is adopted, the axial force Y1 acts in the direction in which the permanent magnets 10, 10,... Seated on the coils 13, 13,. Therefore, a certain amount of current is required to maintain the seated state, but the position of the drive shaft 4 is maintained in the same manner as the former. Even if the latter method is adopted, the permanent magnets 10, 10,... Are seated on the coils 13, 13,... By a predetermined attractive force, so that the friction force acts and the drive shaft 4 does not rotate.

  In the spiral motor 1 according to the present embodiment, a method for holding the position of the drive shaft 4 at a desired target stop position will be described. The drive shaft 4 of the spiral motor 1 is driven in the axial direction in the driveable ranges 21 to 22, but is driven while rotating. That is, the rotation angle and position of the drive shaft 4 are in a proportional relationship as shown by the graph 20 in FIG. Consider two graphs 24 and 25 drawn by moving the graph 20 of the drive shaft 4 parallel to the gap 16 and 16 in the horizontal axis direction. Then, graph 24 shows when permanent magnets 10, 10,... On one side of flight 9 are seated on coils 13, 13,..., And graph 25 shows permanent magnets 10, 10,. Are graphs showing the relationship between the position of the drive shaft 4 and the rotation angle when seated on the coils 13, 13,.

  Consider a case where the drive shaft 4 is held at the target stop position 28. However, the permanent magnets 10, 10,... On one surface of the flight 9 are seated on the coils 13, 13,. In this embodiment, there are two methods. In the first method, first, the drive shaft 4 is driven to reach the target stop position 28 in a state where the predetermined gaps 16, 16 are maintained between the permanent magnets 10, 10,. To control. This position is indicated by reference numeral 31 in the graph. Next, the position of the drive shaft 4 in the axial direction is kept constant, the spiral rotor 6 is rotated, and the permanent magnets 10, 10,... On one surface of the flight 9 are seated on the coils 13, 13,. This position is indicated by reference numeral 32. That is, the drive shaft 4 can be held at the target stop position 28. In the second method, first, the drive shaft 4 is driven in a state where the predetermined gaps 16 and 16 are maintained between the permanent magnets 10, 10,... And the coils 13, 13,. It stops at a position larger than the position 28 by the gap 16. This is indicated by reference numeral 33 in the graph. Next, the position of the drive shaft 4 is moved backward by the gap 16 while the rotation of the drive shaft 4 is restricted. Then, the position indicated by reference numeral 32 is reached. That is, the drive shaft 4 can be held at the target stop position 28. As can be easily understood by those skilled in the art, there are two methods in the same manner even when the permanent magnets 10, 10,... On the other surface of the flight 9 are seated on the coils 13, 13,. That is, in the first method, the permanent magnets 10, 10,... And the coils 13, 13,... Drive the drive shaft 4 in a state where the predetermined gaps 16, 16 are maintained, and reach the target stop position 28. , And then the position of the drive shaft 4 in the axial direction is kept constant, and the spiral rotor 6 is rotated so that the permanent magnets 10, 10,. Sit on. This position is indicated by reference numeral 34. In the second method, the drive shaft 4 is driven in a state where the predetermined gaps 16, 16 between the permanent magnets 10, 10,... And the coils 13, 13,. Stop at a position that is 16 smaller, i.e., at the position indicated by 35. Next, in a state where the rotation of the drive shaft 4 is restricted, the position of the drive shaft 4 is advanced by the gap 16 and seated at the position of reference numeral 34. Thus, the drive shaft 4 can be held at the target stop position 28 by any method.

  The method for holding the position of the drive shaft 4 of the spiral motor 1 according to the present embodiment can be variously modified. For example, when the permanent magnets 10, 10,... Are seated on the coils 13, 13,... So as to hold the drive shaft 4 at the target stop position 28, the position in the axial direction is changed while restricting the rotation of the drive shaft 4. Or rotating the drive shaft 4 while keeping the axial position of the drive shaft 4 constant, the position of the drive shaft 4 is changed while changing the axial position of the permanent magnets 10, 10,. It may be seated on 13,. In addition, when the permanent magnets 10, 10,... Are seated on the coils 13, 13,..., The permanent magnets 10, 10,. And the coils 13, 13,... May be controlled so as to gradually approach each other over two or three or more stages, and may be seated last.

DESCRIPTION OF SYMBOLS 1 Spiral motor 2 Casing 3 Bearing mechanism 4 Drive shaft 6 Helical rotor 7 Helical stator 9 Flight 10 Permanent magnet 12 Iron core 13 Coil 14 Groove 16 Gap 28 Target stop position

Claims (3)

It comprises a drive shaft, a spiral rotor and a spiral stator, and the spiral rotor comprises a flight spirally provided along the drive shaft and a plurality of permanent magnets provided on both sides of the flight. The helical stator includes an iron core in which a spiral groove is formed and a plurality of coils provided on both surfaces of the groove, and a predetermined gap is provided between the permanent magnet and the coil. In the spiral motor in which the spiral rotor is screwed to the spiral stator so that the gap is maintained and the drive shaft rotates when driven to slide in the axial direction.
Said magnet is provided on one surface of the flight, seating state by the magnetic force to maintain the current supply to one of Rutotomoni said coil said seated in the coil provided on a surface of the groove of the core Maintaining the position of the drive shaft , thereby maintaining the position of the drive shaft of the spiral motor.   2. The method according to claim 1, wherein when the drive shaft is held at a predetermined target stop position, the spiral motor is driven to stop the drive shaft at the target stop position, and then the axial direction of the drive shaft is increased. A method for holding a position of a drive shaft of a spiral motor, wherein the magnet is seated on the coil by rotating the spiral rotor while restricting movement.   The method according to claim 1, wherein when the drive shaft is held at a predetermined target stop position, the spiral motor is driven to stop the drive shaft at a position shifted from the target stop position by the gap, Thereafter, the drive shaft is driven in the axial direction while restricting the rotation of the spiral rotor to seat the magnet on the coil, thereby holding the drive shaft at the target stop position. Method for maintaining the position of the drive shaft.

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