JP2008017579A - Eddy current decelerating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eddy current decelerating apparatus which can generate power while braking a rotating shaft by an eddy current. <P>SOLUTION: The eddy current decelerating apparatus comprises an annular body provided on the fixed side concentrically with respect to the rotating shaft, a plurality of cores provided at the annular body along the circumferential direction thereof at predetermined intervals, a conductive coil wound around these cores, a ring-shaped yoke located at the radial inside or outside of the annular body and provided at the fixed side, a plurality of permanent magnets provided at the yoke along the circumferential direction thereof while alternating the N pole and the S pole so that each magnetic pole opposes each core of the annular body, a ring-shaped rotor composed of nonmagnetic conductors provided at the rotating shaft between the annular body and the yoke, and a plurality of pole pieces of a magnetic body provided at the rotor to oppose the cores of the annular body and the permanent magnets of the yoke, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an eddy current reduction device capable of braking a rotating shaft with an eddy current.

  Conventionally, an eddy current brake (eddy current reduction device) using an eddy current is known.

  As shown in FIG. 7, the eddy current brake uses a braking force 85 generated by the interaction between the eddy current 83 generated by the mutual movement of the magnet 81 and the conductor (rotor) 82 and the magnetic field 84 from the magnet 81. The conductor is decelerated. Here, the magnet 81 for generating the magnetic field 84 includes a permanent magnet and an electromagnet.

  A retarder as shown in FIG. 8 is one in which an eddy current brake using the principle of FIG. 7 is used as an auxiliary brake for an automobile brake.

  As shown in FIG. 8, the stator 92 of the retarder 91 is casing with aluminum to protect the magnet 93, and in order to suppress a decrease in magnetic flux due to an increase in the air gap, a pole piece (P / P) A magnetic material (iron material) called 94 is attached.

  As an ON-OFF mechanism for switching between retarding and non-braking of the retarder, as shown in FIG. 9, slide switching is performed in which a yoke 102 to which a magnet 101 is fixed is slid in the rotation axis direction by an air cylinder (not shown). The mechanism 106 is proposed in Patent Document 1, for example.

  In the mechanism of FIG. 9, the magnet 101 is moved in the axial direction so that the magnet 101 faces the pole piece (P / P) 104 in the casing 103, and the magnet 101 is connected to the magnet 101 via the pole piece (P / P) 104. By switching to the braking side (ON) by forming a magnetic circuit with a rotor (not shown).

  Further, as shown in FIG. 10, two rows of yokes 112 in which a plurality of magnets 111 are fixed so that N poles and S poles are alternately arranged along the circumferential direction are arranged in the axial direction, and one yoke 112 is arranged. For example, Patent Document 2 proposes a rotation switching mechanism 117 that rotates in the circumferential direction using an air cylinder (not shown) or the like.

  In the mechanism of FIG. 10, one yoke 112 is rotated so that the magnetic poles of adjacent rows of magnets are different, thereby creating a closed circuit in a pole piece (P / P) 115 in the casing 114, and a rotor (not shown). In this case, the magnetic flux is not passed through the non-braking side (OFF).

JP 2002-291224 A JP 2002-291226 A

  However, since the retarder 81 described above obtains a braking force due to eddy current loss, all of the braking energy is released into the atmosphere as heat, and there is a problem that the effective use of energy cannot be sufficiently achieved.

  Accordingly, an object of the present invention is to provide an eddy current reduction device capable of generating power while solving the above-described problems and braking a rotating shaft with an eddy current.

  In order to achieve the above object, the present invention provides an annular body that is positioned concentrically with respect to a rotating shaft and provided on a fixed side, and a predetermined interval along the circumferential direction of the annular body. A plurality of provided iron cores, a conductive coil wound around the iron cores, a ring-shaped yoke provided on the fixed side and positioned inside or outside in the radial direction of the annular body, A plurality of permanent magnets provided so that N poles and S poles alternate along the circumferential direction, and each magnetic pole faces each iron core of the annular body, and the annular body and the yoke And a ring-shaped rotor made of a non-magnetic conductor provided between and a magnetic body provided on the rotor so as to face the iron core of the annular body and the permanent magnet of the yoke, respectively. The above rotating shaft rotates In this case, an eddy current is generated in the non-magnetic part of the rotor to decelerate the rotating shaft, and the pole piece of the rotor or the non-magnetic substance is interposed between the iron core of the annular body and the permanent magnet of the yoke. By positioning the portion and increasing or decreasing the amount of magnetic flux, an electromotive force is generated in the coil of the annular body to generate power.

  In order to achieve the above object, the present invention provides an annular body that is positioned concentrically with respect to a rotating shaft and provided on a fixed side, and a predetermined interval along the circumferential direction of the annular body. A plurality of provided iron cores, conductive coils wound around these iron cores, a ring-shaped yoke arranged on the fixed side in the axial direction with respect to the annular body, and a circumferential direction in the yoke A plurality of permanent magnets provided so that N poles and S poles alternate along each other, and each magnetic pole faces each iron core of the annular body, and between the annular body and the yoke on the rotating shaft A ring-shaped rotor made of a non-magnetic conductor provided on the rotor, and a plurality of poles made of a magnetic material provided on the rotor so as to face the iron core of the annular body and the permanent magnet of the yoke, respectively. And when the rotary shaft rotates, An eddy current is generated in the non-magnetic part of the rotor to decelerate the rotation shaft, and the pole piece or non-magnetic part of the rotor is positioned between the iron core of the annular body and the permanent magnet of the yoke. By increasing or decreasing the amount, the electromotive force is generated in the annular coil to generate power.

  Preferably, the pole pieces of the rotor are provided in the same number as the iron core of the annular body.

  According to the present invention, an excellent effect that power can be generated while the rotating shaft is braked by eddy current is exhibited.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  The eddy current reduction device of this embodiment is used as an auxiliary brake of a vehicle, for example, and is configured to apply a braking force to an output shaft (hereinafter referred to as a rotating shaft) of a vehicle transmission.

  First, a schematic structure of the eddy current reduction device will be described with reference to FIGS.

  As shown in FIG. 1 to FIG. 3, the eddy current reduction device 1 of the present embodiment includes a rotating shaft 2 and an annular body 3 that is positioned concentrically with the rotating shaft 2 and provided on the fixed side. The ring-shaped yoke 4 provided on the fixed side and positioned on the inner side in the radial direction of the annular body 3, and the ring-shaped yoke provided on the rotary shaft 2 positioned between the annular body 3 and the yoke 4. The rotor 5 is provided. The annular body 3, the yoke 4 and the rotor 5 are basically arranged concentrically with the rotary shaft 2 and at the same axial position during braking.

  The annular body 3 is attached to a casing (not shown). The annular body 3 is made of a magnetic material.

  The annular body 3 includes a plurality of cores (hereinafter referred to as coil cores) 31 (hereinafter referred to as coil cores) 31 at predetermined intervals along the circumferential direction, and these coil cores. A coil 32 (conductive coil) wound around 31 is provided.

  Specifically, the coil core 31 is formed at equal intervals along the inner peripheral surface of the annular body 3 and protrudes radially inward from the inner peripheral surface. For example, the coil 32 is formed by winding all the coil cores 31 with a single electric wire, and the coil 32 is connected to a vehicle battery or the like.

  The yoke 4 is positioned concentrically with the rotating shaft 2 and attached to a casing (not shown). The yoke 4 is made of a magnetic material such as low carbon steel, for example.

  The yoke 4 has a plurality of permanent magnets 41 (12 poles in the example shown, only 4 poles shown in FIGS. 1 and 2), and N poles and S poles are alternately arranged along the circumferential direction. Is provided so as to face each coil core 31 of the annular body 3.

  Specifically, the permanent magnet 41 is attached to the yoke 4 at equal intervals so that one magnetic pole protrudes radially outward (iron core side) and the other magnetic pole contacts the outer peripheral surface of the yoke 4. It is done. In the present embodiment, the same number of permanent magnets 41 as the coil cores 31 are provided, and are arranged and fixed at circumferential positions corresponding to the coil cores 31.

  In the present embodiment, a switching device for reciprocating the yoke 4 and the permanent magnet 41 along the axial direction of the rotary shaft 2 is provided.

  The switching device includes a yoke support member 421 that slidably contacts the inner peripheral surface of the yoke 4 and supports the yoke 4 so as to be movable in the axial direction, and an air that is attached to one end of the yoke 4 in the axial direction and can expand and contract in the axial direction. A cylinder (not shown), and the air cylinder is expanded and contracted so that the permanent magnet 41 faces the coil iron core 31 (substantially the same axial position) (braking ON position) and the axis with respect to the coil iron core 31 The position of the yoke 4 is switched between a position separated in the direction (braking OFF position).

  The rotor 5 is disposed with a predetermined gap in the radial direction with respect to the annular body 3 and the yoke 4, and is attached to the rotary shaft 2 by a support material (not shown) (for example, a spoke-shaped support material). The gap between the rotor 5 and the annular body 3 and the yoke 4 is set in consideration of the magnetic force of the permanent magnet 41, for example.

  The rotor 5 is made of a nonmagnetic conductor. Specifically, the material of the rotor 5 is a material (good conductor) having a strength that can withstand rotation and a low electrical resistance so that eddy currents are easily generated. As the non-magnetic material of the rotor 5, for example, copper or aluminum can be considered.

  The rotor 5 is provided with a plurality of pole pieces 51 made of a magnetic material (magnetic material) (for example, iron).

  The pole pieces 51 are embedded in the rotor 5 at equal intervals in the circumferential direction, and are provided so as to face the coil core 31 of the annular body 3 and the permanent magnet 41 of the yoke 4, respectively. Further, between the pole pieces 51 of the rotor 5, a nonmagnetic part 52 made of a nonmagnetic material constituting the rotor 5 itself is located.

  In the present embodiment, the same number of pole pieces 51 of the rotor 5 as the coil cores 31 of the annular body 3 (and the permanent magnets 41 of the yoke 4) are provided.

  The magnetic material of the pole piece 51 is desirably a material having a high magnetic permeability so that the magnetic flux of the permanent magnet 41 passes through the coil core 31 as much as possible, and a material having a large electric resistance (insulator or semiconductor) so that eddy currents are not easily generated. Etc.) is preferable. For example, as the magnetic material of the pole piece 51, a laminated steel plate can be considered.

  As will be described in detail later, the pole piece 51 or the non-magnetic part 52 of the rotor 5 is interposed between the coil core 31 of the annular body 3 and the permanent magnet 41 of the yoke 4 by the rotation of the rotating shaft 2 (rotor 5) during braking. Are alternately positioned and the amount of magnetic flux increases or decreases, so that an electromotive force is generated in the coil 32 of the annular body 3 to generate power.

  Next, the operation of the eddy current reduction device 1 of this embodiment will be described.

  First, a magnetic circuit formed between the coil iron core 31, the pole piece 51, and the permanent magnet 41 will be described with reference to FIGS. 1, 2, 4, and 5. FIG. 4 and 5 schematically show a rotary engine having a permanent magnet and a power generation coil having 8 poles in a linear model.

  As shown in FIGS. 1 and 4, when the pole piece 51 of the rotor 5 is located at the same circumferential position as the coil core 31 of the annular body 3 and the permanent magnet 41 of the yoke 4, the N pole of the permanent magnet 41 A magnetic circuit C <b> 1 is formed that passes through the pole piece 51 and the coil core 31 and reaches the yoke 4, the adjacent coil core 31, the pole piece 51, and the S pole of the permanent magnet 41. At this time, the magnetic flux passing through the coil core 31 is maximized.

  When the rotor 5 rotates from the position shown in FIG. 1, the amount of magnetic flux passing through the pole piece 51 and passing through the coil iron core 31 gradually decreases.

  As shown in FIGS. 2 and 5, when the nonmagnetic portion 52 of the rotor 5 is located at the same circumferential position as the coil core 31 of the annular body 3 and the permanent magnet 41 of the yoke 4, the nonmagnetic portion The magnetic flux from the permanent magnet 41 to the coil core 31 is interrupted by 52, and a magnetic circuit C2 is formed from the N pole of the permanent magnet 41 to the S pole of the adjacent permanent magnet 41 through the pole piece 51. At this time, the magnetic flux passing through the coil iron core 31 is minimum (almost 0).

  When the rotor 5 rotates from the position shown in FIG. 2, the amount of magnetic flux passing through the coil core 31 through the pole piece 51 gradually increases.

  As described above, in the present embodiment, the rotating shaft 2 and the rotor 5 are rotated, and the amount of magnetic flux entering the coil core 31 is increased or decreased to generate an electromotive force in the coil 32.

  Next, the relationship between the rotation angle of the rotating shaft 2 (rotor 5), the voltage of the coil 32, and the magnetic flux in the coil iron core 31 will be described with reference to FIG.

  6 shows, as an example, magnetic flux (indicated by a broken line M in FIG. 6) and electromotive force (voltage) (voltage in FIG. 6) in the coil core 31 due to the rotation angle of the rotor 5 in the eddy current reduction device 1 having 12 poles. , Indicated by a solid line E). Here, the rotation angle when the pole piece 51 is located at the same circumferential position as the coil core 31 and the permanent magnet 41 is 0 degree, and shows up to 60 degrees.

  As shown in FIG. 6, at the rotation angles 0, 30 and 60 degrees (indicated by reference sign H in FIG. 6) where the pole piece 51 is located at the same circumferential position as the coil core 31 and the permanent magnet 41, the coil core 31. The magnetic flux inside becomes the maximum.

  On the other hand, at the rotation angle of 15 and 45 degrees (indicated by symbol L in FIG. 6) where the pole piece 51 is located at the intermediate position of the pole (permanent magnet 41), the magnetic flux in the coil core 31 is minimized.

  As described above, the magnetic flux in the coil core 31 changes depending on the rotation angle, and an electromotive force corresponding to the amount of change is generated in the coil 32 to generate power.

  Next, braking of the rotating shaft 2 will be described.

  In the present embodiment, since the non-magnetic part 52 of the rotor 5 is formed of a non-magnetic conductor, the rotor 5 moves across the magnetic circuit C1 by rotation, and the non-magnetic part 52 An eddy current is generated inside. Due to the eddy current and the magnetic circuit C1, a force in the direction opposite to the rotation direction acts on the rotor 5, and the rotating shaft 2 is braked.

  When the braking force is unnecessary, the magnetic flux entering the rotor 5 (magnetic flux between the permanent magnet 41 and the coil iron core 31) is reduced by separating the permanent magnet 41 from the coil iron core 31 by the switching device described above. Power can be reduced.

  Thus, in this embodiment, since the rotor 5 rotates on the outer peripheral side of the magnetic flux generated from the permanent magnet 41 when the rotor 5 rotates, a non-magnetic good conductor portion (non-magnetic portion 52). Since an eddy current is generated and a braking force can be obtained, and the magnetic flux in the coil iron core 31 changes, power can be generated.

  That is, in the present embodiment, an eddy current braking device having a power generation function can be obtained using the arranged magnets.

  As a result, since it is possible to generate electric power using a part of the braking energy without releasing all the braking energy as heat into the atmosphere, it is possible to effectively use the energy.

  In addition, this invention is not limited to the above-mentioned embodiment, Various modifications and application examples can be considered.

  For example, in the above-described embodiment, the annular body 3 (coil core 31 and coil 32) is disposed on the outer peripheral side in the radial direction with respect to the rotors 5 and 7, and the yoke 4 (permanent magnet 41) is disposed on the inner peripheral side. The arrangement of the annular body 3 and the yoke 4 may be reversed on the inner and outer periphery.

  Moreover, you may make it arrange | position a yoke (magnet), a rotor (pole piece), and a cyclic | annular body (a coil iron core and a coil) in order in a rotating shaft direction.

  That is, a ring-shaped yoke is arranged on the fixed side in an axial direction with respect to the annular body, and is located between the annular body and the yoke, and is made of a non-magnetic material (or made of a non-magnetic conductor). ) A ring-shaped rotor may be provided on the rotating shaft. At this time, the annular body, the yoke, and the rotor are preferably formed in a ring shape having substantially the same diameter.

  Further, the switching device is not limited to the above-described one that moves the yoke 4 in the axial direction. For example, as shown in FIG. 10, a plurality of magnets 101 have alternating N poles and S poles along the circumferential direction. Such a fixed yoke 102 may be arranged in two rows in the axial direction, and a rotary switching mechanism 117 for rotating one yoke 102 in the circumferential direction by an air cylinder (not shown) or the like may be used.

FIG. 1 is a cross-sectional view of an eddy current reduction device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the eddy current reduction device of the present embodiment, and shows a state where the rotor is rotated by a predetermined angle from FIG. FIG. 3 is a partial perspective view of the eddy current reduction device of the present embodiment. FIG. 4 is a linear model diagram for explaining the operation of the eddy current reduction device of the present embodiment. FIG. 5 is a linear model diagram for explaining the operation of the eddy current reduction device of the present embodiment, and shows a state in which the rotor is rotated by a predetermined angle from FIG. FIG. 6 is a diagram for explaining the relationship between the rotation angle of the rotor, the magnetic flux in the iron core, and the voltage of the coil. FIG. 7 is a diagram for explaining the braking force due to the eddy current. FIG. 8 shows a conventional eddy current reduction device. FIG. 9 shows a conventional eddy current reduction device. FIG. 10 shows a conventional eddy current reduction device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eddy current reduction device 2 Rotating shaft 3 Annulus 31 Iron core (coil core)
32 Coil 4 Yoke 41 Permanent magnet 5 Rotor 51 Pole piece 52 Non-magnetic part

Claims (3)

An annular body provided concentrically with the rotation axis and provided on the fixed side;
A plurality of iron cores provided at predetermined intervals along the circumferential direction of the annular body;
A conductive coil wound around these iron cores;
A ring-shaped yoke provided on the fixed side and positioned on the radially inner side or outer side of the annular body;
A plurality of permanent magnets provided on the yoke such that N poles and S poles alternate along the circumferential direction, and each magnetic pole faces each iron core of the annular body;
A ring-shaped rotor made of a non-magnetic conductor provided on the rotating shaft between the annular body and the yoke;
The rotor includes a plurality of pole pieces made of a magnetic body provided to face the iron core of the annular body and the permanent magnet of the yoke, respectively.
When the rotating shaft rotates, an eddy current is generated in the nonmagnetic portion of the rotor to decelerate the rotating shaft, and the rotor pole is interposed between the iron core of the annular body and the permanent magnet of the yoke. An eddy current reduction device configured to generate electricity by generating an electromotive force in a coil of the annular body by positioning a piece or a non-magnetic part and increasing or decreasing the amount of magnetic flux. An annular body provided concentrically with the rotation axis and provided on the fixed side;
A plurality of iron cores provided at predetermined intervals along the circumferential direction of the annular body;
A conductive coil wound around these iron cores;
A ring-shaped yoke provided on the fixed side in the axial direction with respect to the annular body;
A plurality of permanent magnets provided on the yoke such that N poles and S poles alternate along the circumferential direction, and each magnetic pole faces each iron core of the annular body;
A ring-shaped rotor made of a non-magnetic conductor provided on the rotating shaft between the annular body and the yoke;
The rotor includes a plurality of pole pieces made of a magnetic body provided to face the iron core of the annular body and the permanent magnet of the yoke, respectively.
When the rotating shaft rotates, an eddy current is generated in the nonmagnetic portion of the rotor to decelerate the rotating shaft, and the rotor pole is interposed between the iron core of the annular body and the permanent magnet of the yoke. An eddy current reduction device configured to generate electricity by generating an electromotive force in a coil of the annular body by positioning a piece or a non-magnetic part and increasing or decreasing the amount of magnetic flux. The eddy current reduction device according to claim 1 or 2, wherein pole pieces of the rotor are provided in the same number as the iron core of the annular body.

Images