JP2017118072A - Noncontact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a noncontact power supply device in which change in the efficiency, due to change in the size of a gap in the axial direction, is less likely to occur.SOLUTION: A noncontact power supply device includes a first core, a second core, a first coil, a second coil, a protrusion formed in the first plane part of the first core or the second plane part of the second core, circumferentially around the axis, a housing section formed in the first plane part of the first core or the second plane part of the second core, and housing the protrusion, and a lap part that is the duplication part of the opposite surfaces of the protrusion and housing section, having two faces opposing with a clearance in the radial direction of the shaft.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a non-contact power feeding apparatus.

  2. Description of the Related Art Conventionally, a non-contact power feeding device that can transmit an electric signal or power in a non-contact manner between two relatively rotatable cores is known.

JP 2006-128397 A

  In this type of technology, when the size of the axial gap generated between the cores varies, the magnetic coupling varies, and the power transmission efficiency may vary.

  Then, one of the subjects of this invention is obtaining the non-contact electric power feeder which suppresses the fluctuation | variation of the transmission efficiency by the fluctuation | variation of the magnitude | size of the clearance gap of an axial direction, for example.

  A non-contact power feeding device according to an embodiment of the present invention is a non-contact power feeding device that feeds electric power by rotating a core arranged in a non-contact state about the center of an axis, and is a plane orthogonal to the axis center. A magnetic body having a first planar portion and a magnetic body having a second planar portion that is disposed opposite to the first core and that forms a gap with the first planar portion. A second core, a first coil fixed to the first core, wound in the circumferential direction of the shaft of the first core, and generating a magnetic field when an alternating current is passed; and the second core A second coil that is wound in the circumferential direction of the shaft of the first core and disposed at a position facing the first coil, and generates an electromotive force upon receiving the magnetic field change, Formed on the first plane portion of the first core or the second plane portion of the second core, and And a housing portion that is formed on the first flat surface portion of the first core or the second flat surface portion of the second core and that houses the projecting portion. And a lap portion which is an overlapping portion of the facing surfaces of the protrusion and the housing portion and has two surfaces facing each other with a gap in the radial direction of the shaft.

  In the above configuration, the size of the gap in the radial direction does not change even when the core and the core move relative to each other in the axial direction. In addition, the change in the magnetoresistance of the gap due to the change in the area of the side surfaces facing each other with a gap in the radial direction, that is, the area where the lap portion overlaps in the radial direction is proportional to the overlapping area, and is due to the gap in the axial direction. It is gradual compared to the magnetoresistance change. Therefore, according to the present embodiment, the axial gap between the cores even when there is a change in the relative position in the axial direction between the cores, that is, when the relative proximity or separation in the axial direction occurs. As compared with the configuration in which only the circuit is provided, it is possible to suppress the change in the magnetic resistance, and hence the fluctuation in the transmission efficiency of the electric signal or power.

  Moreover, in the non-contact power feeding device, for example, the wrap portion is positioned outside the radial direction of the first coil and the second coil. In such a configuration, the wrap portion is a place where the magnetic flux density is relatively large. Therefore, according to such a configuration, for example, an effect due to the provision of the radial gap is easily obtained.

  Moreover, in the non-contact power feeding device, for example, the wrap portion is positioned inside the radial direction of the first coil and the second coil. In such a configuration, the wrap portion is a place where the magnetic flux density is relatively large. Therefore, according to such a configuration, for example, the above-described effect due to the provision of the radial gap is easily obtained.

  Moreover, in the non-contact power feeding device, for example, the wrap portion is positioned closer to the radially inner ends of the first coil and the second coil than the center of the shaft. In such a configuration, the position closer to the radially inner ends of the first coil and the second coil than the center of rotation is a place where the magnetic flux density is relatively large. Therefore, according to such a configuration, for example, the above-described effect due to the provision of the radial gap is easily obtained.

  In the non-contact power feeding device, for example, the wrap portion includes a first end portion of the first coil opposite to the second coil, and the first coil of the second coil. And the second end on the opposite side. In such a configuration, between the first end of the first coil opposite to the second coil and the second end of the second coil opposite to the first coil. The position of is a place where the magnetic flux density is relatively large. Therefore, according to such a configuration, for example, the above-described effect due to the provision of the radial gap is easily obtained.

FIG. 1 is an exemplary schematic perspective view of a contactless power supply device according to an embodiment. FIG. 2 is an exemplary cross-sectional view of the contactless power supply device of the embodiment, and is a view showing one side of the rotation center. FIG. 3 is an exemplary cross-sectional view of a non-contact power feeding device according to a modification of the embodiment, in which one side of the rotation center is shown.

  Hereinafter, exemplary embodiments of the present invention are disclosed. The configuration of the embodiment shown below and the operations, results, and effects brought about by the configuration are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments, and at least one of various effects based on the basic configuration and derivative effects can be obtained. .

  As shown in FIGS. 1 and 2, the non-contact power feeding apparatus 100 includes two elements 1 (core 12) and 2 (core 22) facing each other with a gap in the axial direction of the rotation center Ax. The non-contact power supply apparatus 100 transmits an electric signal, electric power, and the like between the two elements 1 and 2 using electromagnetic induction in a non-contact manner. The rotation center Ax is an example of an axis center.

  The non-contact power feeding apparatus 100 includes a primary side, that is, a feeding-side element 1 and a secondary side, that is, a receiving-side element 2. At least one of the primary side element 1 and the secondary side element 2, that is, one or both, is configured to be rotatable around the rotation center Ax. The non-contact power supply apparatus 100 can also be referred to as a rotary transformer. In the present embodiment, for convenience of explanation, a configuration in which the primary element 1 is arranged below each figure and the secondary element 2 is arranged above each figure is exemplified. The arrangement is not limited. Further, the non-contact power supply apparatus 100 can be configured such that the element 2 becomes the primary side and the element 1 becomes the secondary side depending on an electric signal from a circuit (not shown) or switching of power supply. .

  Element 1 has a coil 11 and a core 12. Element 1 (core 12) has a short columnar or disk-like appearance in the axial direction of rotation center Ax. The coil 11 is an example of a first coil, and the core 12 is an example of a first core.

  The coil 11 is wound around the rotation center Ax and has an annular shape. The coil 11 has a winding 11a and a bobbin 11b as a guide for winding the winding 11a. The coil 11 included in the element 1 on the primary side is supplied with an input signal and feed power.

  The core 12 includes a planar portion 1f (first planar portion) that is a surface facing the core 22, and an annular and groove-shaped recess 1d (accommodating portion) centering on a rotation center Ax provided on the planar portion 1f. It consists of and. The core 12 is provided with a plurality of concave portions 1d having different sizes (radius) in a concentric manner, and a plurality of flat portions 1f having different sizes (radius) are provided in a concentric manner. In the present embodiment, the planar portions 1f and the recesses 1d are alternately provided from the rotation center Ax toward the outside in the radial direction. The cross-sectional shape in a plane including the rotation center Ax of the recess 1d is a quadrangle. The concave portion 1d is composed of two peripheral surfaces 1c that form side surfaces and are spaced apart in the radial direction, and an end surface 1e that is a bottom surface orthogonal to the axial direction. Each of the peripheral surfaces 1c has a cylindrical surface shape around the rotation center Ax. In addition, the flat portion 1 f of the core 12 is provided with a coil housing portion 1 i for housing the coil 11 as one annular concave shape. On both sides of the coil housing portion 1i in the radial direction, flat portions 1f are arranged. The core 12 can be made of a ferromagnetic material such as nickel-manganese ferrite.

  The element 2 has a coil 21 and a core 22. The element 2 (core 22) has a short cylindrical or disk-like appearance in the axial direction of the rotation center Ax. The coil 21 is an example of a second coil, and the core 22 is an example of a second core.

  The coil 21 is wound around the rotation center Ax and is formed in an annular shape. The coil 21 includes a winding 21a and a bobbin 21b as a guide for winding the winding 21a. The coil 11 and the coil 21 face each other with a gap in the axial direction without the cores 12 and 22 interposed therebetween. An output signal or received power is output from the coil 21 included in the secondary element 2.

  The core 22 has an annular and wall-like shape centered on a plane portion 2f (second plane portion) provided opposite to the plane portion 1f of the core 12 and a rotation center Ax provided on the plane portion 2f. It is comprised by the convex part 2p (projection part). The core 22 is provided with a plurality of flat portions 2f having different sizes (radius) concentrically, and a plurality of convex portions 2p having different sizes (radius) are provided concentrically. In this embodiment, the convex part 2p and the plane part 2f are alternately provided as it goes to the outer side of radial direction from the rotation center Ax. The cross-sectional shape in a plane including the rotation center Ax of the plane part 2f is a quadrangle shape, and the convex part 2p constitutes two peripheral surfaces 2c that form side surfaces and are spaced apart in the radial direction, and a top surface. And an end surface 2e perpendicular to the axial direction. Each of the peripheral surfaces 2c has a cylindrical surface shape around the rotation center Ax. Further, in the planar portion 2 f of the core 22, a coil housing portion 2 i that houses the coil 21 is provided in one annular concave shape. Convex portions 2p are arranged on both sides in the radial direction of the coil housing portion 2i. The core 22 can be made of a ferromagnetic material such as nickel-manganese ferrite.

  A convex portion 2 p of the core 22 is accommodated in the concave portion 1 d of the core 12. The core 12 and the core 22 face each other with a space (space) therebetween. The flat portion 1f of the core 12 faces the flat portion 2f of the core 22 with a gap ga. The end surface 1e as the bottom surface of the concave portion 1d of the core 12 faces the end surface 2e as the top surface of the convex portion 2p of the core 22 with a gap ga. The inner peripheral surface 1c as the side surface of the concave portion 1d of the core 12 faces the inner peripheral surface 2c as the side surface of the convex portion 2p of the core 22 with a gap gr therebetween. The outer peripheral surface 1c as the side surface of the concave portion 1d of the core 12 faces the outer peripheral surface 2c as the side surface of the convex portion 2p of the core 22 with a gap gr therebetween. Moreover, since the convex part 2p is an example of a protrusion and the recessed part 1d is an example of an accommodating part, it is not restricted to this, For example, a convex part is formed in the core 12, and a recessed part is formed in the core 22. May be. Further, the wrap portion includes a peripheral surface 1c and a peripheral surface 2c. The wrap portion may also be referred to as an overlapping portion or an opposing portion.

  In such a configuration, when a current flows through the primary coil 11, a magnetic field (not shown) surrounding the coil 11 and the coil 21 is generated in the cores 12 and 22. The magnetic flux generated by the magnetic field travels from the inner peripheral portions 12i and 22i of the cores 12 and 22 to the outer peripheral portions 12o and 22o of the cores 12 and 22 through the gaps ga and gr along the one side in the axial direction of the rotation center Ax. From the portions 12o and 22o, the other side in the axial direction of the cores 12 and 22 is returned to the inner peripheral portions 12i and 22i through the gaps ga and gr. That is, the magnetic flux generated by the magnetic field rotates around the coils 11 and 21 substantially along a plane including the rotation center Ax. When an alternating current is passed through the coil 11, the flow of magnetic flux due to the magnetic field flows in an alternating manner along the path. Due to the time variation of the magnetic flux, the magnetic flux generated by the magnetic field generates an electromotive force in the secondary coil 21 and a current flows. In this way, an electrical signal or power is transmitted in a non-contact manner between the coil 11 and the coil 21. The outer peripheral portion 12o is an example of a first outer peripheral portion, the outer peripheral portion 22o is an example of a second outer peripheral portion, the inner peripheral portion 12i is an example of a first inner peripheral portion, and an inner peripheral portion 22i is an example of the second inner periphery.

  In such a configuration, when the relative position change in the axial direction between the cores 12 and 22 occurs, that is, the proximity or separation occurs, the size of the axial gap ga changes, and the magnetoresistance in the gap ga is changed. Is greatly changed, and as a result, the phenomenon that the transmission efficiency of electric signals or electric power changes is observed.

  Therefore, in the present embodiment, a concave and convex structure that fits each other is provided on the surfaces of the cores 12 and 22 that face each other, and a radial gap gr is provided between the cores 12 and 22 in addition to the axial gap ga. Thus, the non-contact power feeding apparatus 100 is configured. The radial gap gr does not change even when the cores 12 and 22 move relative to each other in the axial direction, and the gap due to the change in the area of the region where the circumferential surfaces 1c and 2c facing each other overlap in the radial direction. The change in magnetoresistance is proportional to the overlapping area and is gradual compared to the change in magnetoresistance due to the axial gap.

  As described above, according to the present embodiment, the cores 12 and 22 are provided with the peripheral surfaces 1c and 2c (lap portions) facing each other via the gap gr in the radial direction. And in this embodiment, even if the relative position change of the axial direction of the cores 12 and 22 arises, the surrounding surfaces 1c and 2c are comprised so that the state which mutually opposes via the clearance gap gr may be maintained. Yes. Therefore, according to this embodiment, there is a change in the relative position in the axial direction between the elements 1 and 2, that is, between the cores 12 and 22, that is, when relative proximity or separation in the axial direction occurs. However, as compared with the configuration in which only the axial gap ga is provided between the cores 12 and 22, it is possible to suppress the change in the magnetic resistance, and thus the change in the transmission efficiency of the electric signal or power.

  It is more effective to provide the radial gap gr in a place where the magnetic flux density is higher. Therefore, in the present embodiment, [1] the radial gap gr, that is, the peripheral surfaces 1c and 2c (wrapped portions) are the outer peripheral portions 12o and 22o of the cores 12 and 22, and the inner peripheral portions 12i and 22i of the cores 12 and 22, respectively. Is provided.

  Further, in the present embodiment, [2] the radial gap gr, that is, the peripheral surfaces 1c and 2c (wrapped portions), in the inner peripheral portions 12i and 22i, is more in the radial direction of the coils 11 and 21 than the rotation center Ax. It is provided so that at least a part is included in a position near the inner ends 11c and 21c, that is, the range S1 in FIG. In the outer peripheral portions 12o and 22o of the cores 12 and 22, a radial gap is provided in a section from a radially outer end of the coils 11 and 21 to a position having a radial width substantially equal to the range S1. It is preferable to provide gr (circumferential surfaces 1c and 2c).

  Further, in the present embodiment, [3] the radial gap gr, that is, the peripheral surfaces 1c and 2c (wrapped portions) of the coil 11 in the axial direction of the outer peripheral portions 12o and 22o and the inner peripheral portions 12i and 22i. At least a part of the range between the end 11e in the axial direction opposite to the coil 21 and the end 21e in the axial direction opposite to the coil 11 of the coil 21, that is, the range S2 in FIG. It is provided to be included.

  According to the above [1] to [3] alone or in combination, the above-described effects due to the provision of the radial gap gr, that is, the peripheral surfaces 1c and 2c (lap portions) are more likely to increase. Further, in the present embodiment, the radial gap gr, that is, the peripheral surfaces 1c and 2c (wrapped portion) is included in the range within the range S1 and within the range S2. Therefore, according to the present embodiment, the effect of providing the radial gap gr (circumferential surfaces 1c, 2c) can be further enhanced.

  As mentioned above, although embodiment of this invention was illustrated, the said embodiment is an example and is not intending limiting the range of invention. The embodiment can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the scope of the invention. In addition, the configuration and shape of each example can be partially exchanged. In addition, the specifications (structure, type, direction, shape, size, length, width, height, number, arrangement, position, etc.) of each configuration and shape can be changed as appropriate.

  For example, as shown in FIG. 3, the same effect can be obtained even in the modification in which the through holes 12 h and 22 h are provided in the central portions of the cores 12 and 22. This is because the magnetic field is relatively weak at the center of the cores 12 and 22. In addition, the radial gap gr, that is, the position where the peripheral surfaces 1c and 2c (lap portions) are provided can be changed as appropriate. In addition, the arrangement of the convex portions and the concave portions can be changed as appropriate, such as one core having a convex portion (a concave portion in the other core) provided outside the radial direction of the convex portion (the concave portion in the other core). it can.

  DESCRIPTION OF SYMBOLS 100 ... Non-contact electric power feeder, 1c ... Peripheral surface (surface, lap | wrap part), 1d ... Recessed part (accommodating part), 1e ... End surface, 1f ... Planar part (1st plane part), 2c ... Peripheral surface (surface, lap | wrap) Part), 2f ... plane part (second plane part), 2e ... end face, 2p ... convex part (projection part), 11 ... coil (first coil), 11c ... (inner side in the radial direction of the coil) 11e ... end (first end), 12 ... core (first core), 21 ... coil (second coil), 21c ... end (inside the radial direction of the coil), 21e ... End (second end), 22 ... core (second core), Ax ... rotation center (shaft center), ga, gr ... gap.

Claims (6)

A non-contact power feeding device that feeds power by rotating a core arranged in a non-contact state around the center of an axis,
A first core of a magnetic body having a first plane portion that is a plane orthogonal to the axis center;
A second core of a magnetic body having a second planar portion disposed opposite to the first core and forming a gap with the first planar portion;
A first coil fixed to the first core, wound in the circumferential direction of the axis of the first core, and generating a magnetic field when an alternating current is passed;
A second core fixed to the second core, wound in the circumferential direction of the shaft of the first core and disposed at a position facing the first coil, and generates an electromotive force in response to the magnetic field change. Coil of
Protrusions formed on the first plane portion of the first core or the second plane portion of the second core, and provided circumferentially around the axis;
An accommodating portion that is formed on the first planar portion of the first core or the second planar portion of the second core, and accommodates the protrusion;
A lap portion having two surfaces facing each other with a gap in the radial direction of the shaft, which is an overlapping portion of opposing surfaces of the protrusion and the accommodating portion,
A non-contact power feeding device.   2. The non-contact power feeding device according to claim 1, wherein a state in which the two surfaces face each other with a gap in the radial direction is maintained at the wrap portion with respect to the variation in the gap in the axial direction.   3. The non-contact power feeding device according to claim 1, wherein the wrap portion is positioned outside the radial direction of the first coil and the second coil.   The non-contact power feeding device according to any one of claims 1 to 3, wherein the wrap portion is positioned inside the radial direction of the first coil and the second coil.   5. The non-contact power feeding device according to claim 4, wherein the wrap portion is positioned closer to the radially inner ends of the first coil and the second coil than a center of the shaft.   The wrap portion includes a first end portion of the first coil opposite to the second coil, and a second end portion of the second coil opposite to the first coil. The non-contact power feeding device according to claim 1, which is located between the first and second devices.

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