JP2019167972A - Magnetic gear - Google Patents

Abstract

To provide a magnetic gear capable of increasing the transmission possible torque.SOLUTION: A magnetic gear 10a comprises: an inner gear 14 having a plurality of inner magnets 14b aligned in the circumferential direction of an inner yoke 14a; a center ring 30 relatively-rotatably provided on the outer peripheral side of the inner gear 14 having a plurality of pole pieces 30b aligned in the circumferential direction of a pole holder 30a; and an outer gear relatively-rotatably provided on the outer peripheral side of the center ring 30 having a plurality of outer magnets 26b aligned in the circumferential direction of an outer yoke 26a. A plurality of magnetic pole parts 26d sandwiched between the pair of outer magnets 26b adjacent in opposite orientation are formed in the outer gear 26. A pair of outer magnets 26b sandwiching a magnetic pole part 26d are disposed so that the interval is wider than the outer diameter side. An outer magnet hole 26c has an opening 26g on the inner peripheral surface of the outer yoke 26a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a magnetic gear that transmits torque in a non-contact manner by a gear that uses magnetism.

  A general gear mechanism uses a plurality of gears, and gears are changed according to the ratio of the number of teeth. Vibration and noise are generated by contact between teeth, mechanical life is due to wear, and maintenance such as lubrication is possible. Necessary. On the other hand, magnetic gears that transmit torque in a non-contact manner using magnetism have been developed and put into practical use. The magnetic gear does not have the above-mentioned disadvantages because it transmits torque without contact.

  As a general configuration of the magnetic gear, for example, as shown in Patent Document 1, an inner gear and an outer gear in which a plurality of magnets are arranged in the circumferential direction, and a center ring in which a plurality of pole pieces are arranged in the circumferential direction are provided. The inner gear, the center ring, and the outer gear are concentrically and relatively rotatable in this order from the inner diameter side to the outer diameter side. Any one of the inner gear, the center ring, and the outer gear is used as an input unit, and any one of them is used as an output unit, and the rotation is transmitted by transmission.

  Non-Patent Document 1 discloses that different gear ratios are obtained when the center rotor of the magnetic gear is fixed and when the outer gear is fixed, and a calculation formula for those gear ratios.

JP 2017-225209 A

Ando, “Development Trend of Magnetic Gears”, Journal of AEM Society of Japan, Vol 24, No. 2, 2016, p. 15-20

  Since such a magnetic gear has a structure in which torque is transmitted in a magnetically non-contact manner, there is a limit to the transmission torque, and further improvement of the transmittable torque is desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic gear capable of increasing the transmittable torque.

  In order to solve the above-described problems and achieve the object, a magnetic gear according to the present invention includes an inner gear in which a plurality of inner magnets are arranged in the circumferential direction of an inner yoke, and a relative rotation on the outer circumferential side with respect to the inner gear. A center ring in which a plurality of soft magnetic bodies are arranged in the circumferential direction of the non-magnetic cylinder, and a plurality of outer outer rings in the circumferential direction of the outer yoke. A plurality of magnetic pole portions sandwiched between a pair of adjacent outer magnets in a direction in which the same poles face each other, and the pair of the outer gears sandwiching the magnetic pole portions. The outer magnet is arranged such that the gap on the inner diameter side is wider than the outer diameter side.

  The outer yoke may have an outer magnet hole in which the outer magnet is embedded, and the outer magnet hole may have an opening on at least one of an inner peripheral surface and an outer peripheral surface of the outer yoke.

  At least a part of one edge of the outer magnet may coincide with the edge of the opening.

  The inner gear is formed with a plurality of magnetic pole portions sandwiched between a pair of adjacent inner magnets in the direction in which the same poles face each other, and the pair of inner magnets sandwiching the magnetic pole portions has an outer diameter larger than the inner diameter side. You may arrange | position so that the side may become wide.

  The inner yoke may have an inner magnet hole in which the inner magnet is embedded, and the inner magnet hole may have an opening on at least one of an inner peripheral surface or an outer peripheral surface of the inner yoke.

  At least a part of one edge of the inner magnet may coincide with the edge of the opening.

  The magnetic gear according to the present invention is provided with an inner gear in which a plurality of inner magnets are arranged in the circumferential direction of the inner yoke, and a relatively rotatable outer peripheral side with respect to the inner gear. A center ring in which a plurality of soft magnetic bodies are arranged, and an outer gear that is provided so as to be relatively rotatable on the outer peripheral side with respect to the center ring, and in which a plurality of outer magnets are arranged in the circumferential direction of the outer yoke, The inner gear is formed with a plurality of magnetic pole portions sandwiched between a pair of adjacent inner magnets, and the pair of inner magnets sandwiching the magnetic pole portions in a direction in which the same poles face each other has an outer diameter larger than the inner diameter side. The inner yoke has an inner magnet hole in which the inner magnet is embedded, and the inner magnet hole has the inner yaw. It characterized in that it has on at least one opening in the inner peripheral surface or an outer peripheral surface of the.

  An edge of one end of the inner magnet may coincide with an edge of the opening.

  In the magnetic gear according to the present invention, the pair of outer magnets sandwiching the magnetic pole part are arranged so that the same poles face each other and the inner diameter side is wider than the outer diameter side. The pair of inner magnets sandwiched are arranged in such a manner that the same poles face each other and the gap is wider on the outer diameter side than on the inner diameter side. Thereby, the magnetic force of the magnetic pole part is easily directed to the center ring, the magnetic action between the outer gear, the center ring and the inner gear is strengthened, and the transmittable torque can be increased.

FIG. 1 is an exploded perspective view showing a magnetic gear according to the first embodiment. FIG. 2-1 is a magnetic gear according to the first embodiment, and is a cross-sectional view showing a state where the inner shaft is assembled so as to protrude from the left side surface. FIG. 2B is a cross-sectional view illustrating the magnetic gear according to the first embodiment, which is assembled so that the inner shaft protrudes from the right side surface. FIG. 3 is a front view of the outer gear, the inner gear, and the center ring of the magnetic gear according to the first embodiment. FIG. 4 is a partially enlarged front view of the outer gear, the inner gear, and the center ring of the magnetic gear according to the first embodiment. FIG. 5 is a partially enlarged front view of the outer gear, the inner gear, and the center ring of the magnetic gear according to the second embodiment. FIG. 6 is a front view of the outer gear, the inner gear, and the center ring of the magnetic gear according to the third embodiment. FIG. 7 is a front view of an outer gear, an inner gear, and a center ring of a magnetic gear that are comparison targets for analysis.

  Embodiments of a magnetic gear according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. Hereinafter, in order to identify the direction, the upper right direction is the X1 direction and the lower left direction is the X2 direction with the axial direction in FIG. 1 as a reference, and an arrow indicating the direction is shown in each figure. The inner and inner diameter directions are directions facing the center of the rotation axis, and are opposite to the outer or outer diameter direction. Further, the bolts are all called bolts B regardless of their sizes and types.

  As shown in FIGS. 1 and 2-1, a magnetic gear 10a according to the first embodiment includes an outer gear body 12, an inner gear 14, a center body 16, an outer shaft 18, an inner shaft 20, And a base 22.

  The outer gear body 12 includes a casing 24, an outer gear 26, and an outer side surface portion 28. The casing 24 is a cylinder and forms an outer frame of the main body portion excluding the base 22 in the magnetic gear 10a.

  The outer gear 26 includes an outer yoke 26a and an outer magnet 26b corresponding to NL = 31 pole pairs. In the outer gear 26, four magnets are used per pole pair, and a total of 124 (= 31 × 4) outer magnets 26b are used (see FIG. 3). That is, the number of outer magnets 26b is a multiple of four. The outer gear 26 is also called a low speed rotor. A more detailed configuration of the outer gear 26 will be described later.

  The outer side surface portion 28 is a lid that covers the X1 direction side of the magnetic gear 10a, is fixed to the end surface of the casing 24 in the X1 direction by a plurality of bolts B, and rotates integrally with the outer gear 26 without being rotatable. The outer side surface portion 28 has a center hole 28a through which the inner shaft 20 can be inserted, a shaft fixing portion 28b that is six bolt holes arranged at equal angles, and a base fixing portion 28c that is six bolt holes. The shaft fixing portion 28 b can fix the outer shaft 18 with a bolt B. The base fixing portion 28c is disposed on the outer diameter side of the shaft fixing portion 28b and can be fixed to the base 22 with a bolt B (see FIG. 2-2). An annular protrusion 28d protruding in the X1 direction is provided between the shaft fixing part 28b and the base fixing part 28c, and a fitting groove 28e shallower on the inner diameter side than the annular protrusion 28d is formed. The shaft fixing portion 28b is provided at the bottom of the fitting groove 28e.

  The inner gear 14 has an inner yoke 14a and an inner magnet 14b corresponding to NH = 3 pole pairs. In the inner gear 14, four magnets are used per one pole pair, and a total of 12 (= 3 × 4) inner magnets 14b are used (see FIG. 3). That is, the number of inner magnets 14b is a multiple of four. An inner shaft fixing hole 15 into which the inner shaft 20 is inserted and fixed is provided at the center of the inner gear 14. The inner gear 14 is also called a high speed rotor. A more detailed configuration of the inner gear 14 will be described later.

  The center body 16 has a center ring 30 and a center side surface portion 32. The center ring 30 has a pole holder 30a and NS = 34 pole pieces 30b. The pole holder 30a is a non-magnetic cylinder. The pole piece 30b is a soft magnetic material, and is arranged at an equal angle in the circumferential direction with respect to the pole holder 30a. The inner yoke 14a, the inner magnet 14b, the outer yoke 26a, the outer magnet 26b, and the pole piece 30b are set so that the axial position and the axial length are substantially equal to each other (see FIG. 2-1).

The number of pole pairs NL of the outer magnet 26b in the outer gear 26, the number NH of the inner magnet 14b in the inner gear 14 and the number NS of the pole pieces 30b in the center ring 30 are:
NS = NL ± NH
Is selected so that the relationship is established.
In the magnetic gear 10a, NS = 34, NL = 31, NH = 3,
34 = 31 + 3
The relationship is established.

  The center side surface portion 32 is a lid that covers the X2 direction side of the magnetic gear 10a. The center ring 30 and the center side surface portion 32 are integrally formed and are not relatively rotatable, and the outer peripheral portion of the center side surface portion 32 is connected to the end surface of the center ring 30 in the X2 direction. The center side surface portion 32 includes a center hole 32a through which the inner shaft 20 can be inserted, a shaft fixing portion 32b that is six bolt holes arranged at equal angles, and a base fixing portion that is six bolt holes arranged at equal angles. 32c. The shaft fixing portion 32 b can fix the outer shaft 18 with a bolt B. The base fixing portion 32c is disposed on the outer diameter side of the shaft fixing portion 32b and is fixed to the base 22 by the bolt B. An annular protrusion 32d protruding in the X2 direction is provided between the shaft fixing part 32b and the base fixing part 32c, and a fitting groove 32e shallower on the inner diameter side than the annular protrusion 32d is formed. The shaft fixing portion 32b is provided at the bottom of the fitting groove 32e.

  The six shaft fixing portions 32b and the six shaft fixing portions 28b have the same shape and the same arrangement when viewed from the axial direction, and the outer shaft 18 can be fixed thereto. The six base fixing portions 32c and the six base fixing portions 28c have the same shape and the same arrangement when viewed from the axial direction, and the base 22 can be fixed thereto.

  The center side surface portion 32 has the same symmetrical structure as the inner diameter side portion excluding the outer periphery of the outer side surface portion 28, and includes a center hole 28a, a center hole 32a, a shaft fixing portion 28b, a shaft fixing portion 32b, and a base fixing portion 28c. The base fixing portion 32c, the annular protrusion 28d and the annular protrusion 32d, and the fitting groove 28e and the fitting groove 32e are the same shape and are arranged in the same manner.

  The outer shaft 18 and the inner shaft 20 are input / output units to which a driving mechanism and a driven mechanism are connected. The outer shaft 18 has a flange 18a, a shaft portion 18b protruding from the flange 18a to one side, and six holes 18c provided at equal intervals on the flange 18a. When the bolt B is screwed into the shaft fixing portion 28b through the hole 18c, the outer shaft 18 is fixed to the outer side surface portion 28, and the shaft portion 18b protrudes in the X1 direction. The flange 18a is fitted into the fitting groove 28e and stabilized. The outer shaft 18 can be fixed to both the outer side surface portion 28 and the center side surface portion 32 and can be referred to as an outer / center combined shaft or a low speed shaft.

  The inner shaft 20 has a long cylindrical shaft shape and is mechanically connected to the inner shaft fixing hole 15 (for example, a key, a spline, a D-cut structure), and cannot rotate with respect to the inner gear 14 and is integrated. Rotate to. The inner shaft 20 can be attached to and detached from the inner shaft fixing hole 15 and can be rearranged in the opposite axial direction. The vicinity of the end portion in the X1 direction of the inner shaft 20 is pivotally supported by a bearing 34a with respect to the center hole 28a of the outer side surface portion 28. A substantially central portion of the inner shaft 20 is pivotally supported by a bearing 34 b with respect to a central hole 32 a of the center side surface portion 32. Spacers 36a and 36b are interposed between the inner rings of the bearings 34a and 34b and the inner gear 14, respectively. The bearings 34a and 34b are prevented from coming off by snap rings 38a and 38b. The inner gear 14 is rotatable relative to the outer gear body 12 and the center body 16 by bearings 34a and 34b. The inner shaft 20 can also be called a high speed shaft.

  A bearing 40 a is provided between a part of the outer side surface portion 28 and the inner circumferential surface of the center ring 30 in the X1 direction end. A bearing 40 b is provided between the X2 direction end outer peripheral surface of the center side surface portion 32 and the X2 direction end inner peripheral surface of the casing 24. The outer gear body 12 and the center body 16 can be rotated relative to each other by the bearings 40a and 40b.

  The base 22 has a function as a fixed base, is L-shaped in a side view, and has a side plate 22a and a base plate 22b. The side plate 22a is erected perpendicularly to the base plate 22b. The side plate 22a has a shaft insertion hole 22c provided at the center and six holes 22d provided at equal angles around the shaft insertion hole 22c. When the bolt B is screwed into the base fixing portion 32c through the hole 22d, the base 22 is fixed to the center side surface portion 32. The shaft insertion hole 22c has a diameter through which the outer shaft 18, the flange 18a, and the inner shaft 20 can be inserted. A shallow annular notch 22e is provided at one end of the shaft insertion hole 22c, and an annular protrusion 28d or an annular protrusion 32d can be fitted into the annular notch 22e. The shaft insertion hole 22c and the fitting grooves 28e and 32e have the same diameter.

  As shown in FIG. 2A, the outer shaft 18 is fixed to the outer side surface portion 28 of the outer gear body 12, and the shaft portion 18 b protrudes in the X1 direction. The inner shaft 20 is fixed to the inner shaft fixing hole 15 of the inner gear 14, and is assembled so as to protrude in the X2 direction through the center hole 32a and the shaft insertion hole 22c. The outer shaft 18 and the inner shaft 20 have a coaxial structure. The base 22 is fixed to the center side surface portion 32 of the center body 16. By assembling the magnetic gear 10a in this way, the outer gear body 12 to which the outer shaft 18 is integrally fixed serves as the low speed side input / output portion, and the inner gear 14 to which the inner shaft 20 is integrally fixed is connected to the high speed side input / output portion. Become. The outer shaft 18 and the inner shaft 20 are shifted by the magnetic action of the outer gear body 12, the inner gear 14, and the center ring 30 to transmit rotational torque.

At this time, the gear ratio Gr when the outer shaft 18 is the input side and the inner shaft 20 is the output side is obtained by the following equation.
Gr = −NL / NH = −31 / 3 = −10.33
In other words, the absolute value of the transmission gear ratio Gr is 10.33, which is a minus sign, so that the rotation direction is reversed.

  On the other hand, as shown in FIG. 2-2, the outer shaft 18 can be fixed to the center side surface portion 32 of the center body 16, and in this case, the shaft portion 18b protrudes in the X2 direction. The inner shaft 20 is fixed to the inner shaft fixing hole 15 of the inner gear 14, and is assembled so as to protrude in the X1 direction through the center hole 28a and the shaft insertion hole 22c. Also in this case, the outer shaft 18 and the inner shaft 20 have a coaxial structure. The base 22 is fixed to the outer side surface portion 28 of the outer gear body 12. By assembling the magnetic gear 10a in this way, the center body 16 to which the outer shaft 18 is integrally fixed becomes the low speed side input / output portion, and the inner gear 14 to which the inner shaft 20 is integrally fixed becomes the high speed side input / output portion. . The outer shaft 18 and the inner shaft 20 are shifted by the magnetic action of the outer gear body 12, the inner gear 14, and the center ring 30 to transmit rotational torque.

At this time, the gear ratio Gr is obtained by the following equation.
Gr = NS / NH = 34/3 = + 11.33
That is, the absolute value of the transmission gear ratio Gr is 11.33, which is a plus sign, so that the rotation direction is forward. In addition, since the principle by which the speed change operation | movement is obtained by the magnetic effect | action of the magnetic gears 10a-10c is well-known as shown, for example in patent document 1 or nonpatent literature 1, description is abbreviate | omitted here.

  The structure of the inner gear 14 and the outer gear 26 will be described in more detail with reference to FIGS. 3 and 4.

  As shown in FIGS. 3 and 4, since the outer yoke 26a and the inner yoke 14a are cylindrical bodies, the inner peripheral surface and the outer peripheral surface are circumferential surfaces around the rotation axis, and there is no useless unevenness. Therefore, the gap between the outer peripheral surface of the inner yoke 14a and the inner peripheral surface of the center ring 30 is sufficiently narrow, and the gap between the inner peripheral surface of the outer yoke 26a and the outer peripheral surface of the center ring 30 is sufficiently narrow. Particularly, gaps between the magnetic pole part 26d and the magnetic pole part 14d, which will be described later, and the center ring 30 are narrow, and magnetic forces are easily applied to the respective parts.

  The outer yoke 26 a of the outer gear 26 is a soft magnetic body and is a cylindrical body fixed to the inner peripheral surface of the casing 24. The outer yoke 26a has an outer magnet hole 26c, a magnetic pole part 26d, a bridge 26e, and a clamping part 26f.

  The magnetic pole part 26d is a part that acts as a pseudo magnetic pole for directing the magnetic flux toward the center ring 30 on the inner diameter side, and is provided at 62 locations corresponding to NL = 31 pole pairs. Of these, every other 32 locations are N poles and the other 32 locations are S poles. In FIG. 4, the portion of the magnetic pole part 26 d that is the N pole is identified by the symbol 26 dn and the portion that is the S pole is identified by the symbol 26 ds. In FIG. 4 and FIG. 5, the N pole is identified as a dot ground and the S pole is identified as a white background in the outer magnet 26b and the inner magnet 14b for easy understanding.

  The outer magnet hole 26c is a hole in which the outer magnet 26b is embedded and accommodated, and has an opening 26g on the inner peripheral surface side of the outer yoke 26a. The outer magnet 26b has the same shape as the outer magnet hole 26c, and the three sides other than the opening 26g are in contact with the outer magnet hole 26c without a gap, and the inner end thereof coincides with the edge 26h of the opening 26g. .

  The outer magnet 26b and the outer magnet hole 26c are rectangular, are long in a direction slightly inclined with respect to the radial direction with respect to the outer yoke 26a, and have a substantially larger interval on the inner diameter side than on the outer diameter side. It is arranged in a V shape. The individual magnetic pole portions 26d are sandwiched between outer magnets 26b on both sides in the circumferential direction, and have a substantially fan-shaped shape that is narrower on the inner diameter side than on the outer diameter side.

  The outer magnet 26b is magnetized in the short direction, and the same polarity is opposed to the magnetic pole portion 26d. In FIG. 4, the N pole side portion of the outer magnet 26b sandwiching the N pole magnetic pole portion 26dn is identified by reference numeral 26bn, and the S pole side portion of the outer magnet 26b sandwiching the S pole magnetic pole portion 26ds is denoted by reference symbol 26bs. Identifying. That is, the pair of outer magnets 26bn has the N poles facing each other with the magnetic pole portion 26dn interposed therebetween, and the pair of outer magnets 26bs has the S poles opposed to each other with the magnetic pole portion 26ds interposed therebetween.

  A portion sandwiched between the outer magnets 26bn or the outer magnets 26bs is a magnetic pole portion 26d, and a triangular portion sandwiched between the outer magnet 26bn and the outer magnet 26bs is a sandwiching portion 26f. Adjacent magnetic pole part 26d and clamping part 26f are mutually connected by a bridge 26e on the outside.

  In this way, the magnetic pole portion 26d is sandwiched between the outer magnets 26b of the same polarity on both sides and has a shape in which the inner diameter side expands, so that a strong magnetic force can be applied to the center ring 30, and the transmission torque can be increased. Increase. Further, the magnetic pole portion 26d is formed to be sufficiently narrow on the outer diameter side, there is little leakage of the magnetic force to the outside, and the magnetic force acting on the inner diameter side can be increased.

  As described above, the outer magnet hole 26c has the opening 26g on the inner peripheral surface side. Of the three sides forming the outer magnet hole 26c, the two sides in the longitudinal direction are parallel lines, and open inward as the parallel lines, and the opening 26g has no irregularities. Further, since the outer magnet hole 26c is slightly inclined with respect to the radial direction, the opening 26g is also slightly inclined with respect to the circumferential direction. As a result, on the inner peripheral surface of the outer yoke 26a, a portion other than the magnetic pole portion 26d is formed with a concave portion 26i having a substantially isosceles triangle shape having two openings 26g as two sides.

  The bridge 26e is a narrow portion that connects the adjacent magnetic pole portion 26d and the sandwiching portion 26f at the outer peripheral portion of the outer yoke 26a. The magnetic pole portions 26d and the clamping portions 26f are connected to each other by the bridge 26e, and the outer yoke 26a has an integrated configuration and ensures strength. Since the width of the bridge 26e is sufficiently narrow, the short-circuit conduction of the magnetic flux from the N pole to the S pole is suppressed, and the magnetic flux strength of the magnetic pole portion 26d is maintained. The outer gear 26 in which the outer magnet 26b is embedded in the outer yoke 26a in this way is an IPM type (Internal Permanent Magnet).

  The inner yoke 14a of the inner gear 14 is a soft magnetic material and has a disk shape. The inner yoke 14a has an inner magnet hole 14c, a magnetic pole part 14d, a bridge 14e, and a clamping part 14f.

  The magnetic pole part 14d is a part that acts as a pseudo magnetic pole for directing the magnetic flux to the center ring 30 on the outer diameter side, and is provided at six locations corresponding to NH = 3 pole pairs. Of these, every other three locations are N poles and the other three locations are S poles. In FIG. 4, the portion of the magnetic pole portion 14 d that is the N pole is identified by a symbol 14 dn and the portion that is the S pole is identified by a symbol 14 ds.

  The inner magnet hole 14c is a hole in which the inner magnet 14b is embedded and accommodated, and has an opening 14g on the outer peripheral surface side of the inner yoke 14a. The inner magnet 14b has the same shape as the inner magnet hole 14c, the three sides other than the opening 14g are in contact with the inner magnet hole 14c without any gap, and the outer end thereof coincides with the edge 14h of the opening 14g. .

  The inner magnet 14b and the inner magnet hole 14c are rectangular, are long in a direction inclined by 45 ° with respect to the radial direction with respect to the inner yoke 14a, and have a larger interval on the outer diameter side than on the inner diameter side. It is arranged in a substantially V shape. Each magnetic pole part 14d is sandwiched between inner magnets 14b on both sides in the circumferential direction, and has a substantially wide fan shape with a wider interval on the outer diameter side than on the inner diameter side.

  The inner magnet 14b is magnetized in the short direction, and the same polarity is opposed to the magnetic pole portion 14d. In FIG. 4, the N pole side portion of the inner magnet 14b sandwiching the N pole magnetic pole portion 14dn is identified by reference numeral 14bn, and the S pole side portion of the inner magnet 14b sandwiching the S pole magnetic pole portion 14ds is denoted by reference numeral 14bs. Identifying. That is, the pair of inner magnets 14bn has the N poles facing each other with the magnetic pole part 14dn interposed therebetween, and the pair of inner magnets 14bs has the S poles opposed to each other with the magnetic pole part 14ds interposed therebetween.

  The pair of inner magnets 14bn are orthogonal to each other, and similarly, the pair of inner magnets 14bs are orthogonal to each other. Thus, by arranging the pair of inner magnets 14bn and 14bs in the orthogonal direction, the volume of the inner magnets 14bn and 14bs can be maximized while directing the magnetic flux to the magnetic pole portion 14d.

  The portion sandwiched between the inner magnets 14bn or between the inner magnets 14bs is the magnetic pole portion 14d, and the triangular portion sandwiched between the inner magnet 14bn and the inner magnet 14bs is the sandwiching portion 14f. The adjacent magnetic pole part 14d and the clamping part 14f are mutually connected by the bridge 14e inside.

  In this way, the magnetic pole portion 14d is sandwiched between the inner magnets 14b of the same polarity on both sides and has a shape in which the outer diameter side spreads, so that a strong magnetic force can be applied to the center ring 30, and the transmission torque Will increase. Further, the magnetic pole portion 14d is formed with a sufficiently narrow inner diameter side, so that there is little leakage of the magnetic force inward, and the magnetic force acting on the outer diameter side can be increased.

  As described above, the inner magnet hole 14c has the opening 14g on the outer peripheral surface side. Of the three sides forming the inner magnet hole 14c, two sides in the longitudinal direction are parallel lines, and open to the outside while being parallel lines, and the opening 14g has no irregularities. Further, since the inner magnet hole 14c is inclined with respect to the radial direction, the opening 14g is also slightly inclined with respect to the circumferential direction. As a result, on the outer peripheral surface of the inner yoke 14a, a low substantially trapezoidal concave portion 14i is formed in the portion other than the magnetic pole portion 14d with the two opening portions 14g being inclined opposite sides.

  The bridge 14e is a narrow portion that connects the adjacent magnetic pole portion 14d and the sandwiching portion 14f to each other at the inner peripheral portion of the inner yoke 14a. The magnetic pole portion 14d and the sandwiching portion 14f are connected to each other by the bridge 14e, and the inner yoke 14a has an integrated structure and ensures strength. Since the width of the bridge 14e is sufficiently narrow, the short-circuit conduction of the magnetic flux from the N pole to the S pole is suppressed, and the magnetic flux strength of the magnetic pole portion 14d is maintained. The inner gear 14 in which the inner magnet 14b is embedded in the inner yoke 14a in this way is an IPM type.

  Thus, each of the magnetic gears 10a has the outer gear 26 and the inner gear 14 having an IPM type structure. In the IPM type structure, a magnet is arranged on the surface of each rotor, and a high torque can be obtained as compared with an SPM type (Surface Permanent Magnet, surface magnet type) in which the magnet is magnetized in the radial direction. In addition, since the eddy current loss is small, the efficiency is high. Furthermore, since the inner magnet 14b and the outer magnet 26b have an embedded structure, there is no concern that the inner magnet 14b and the outer magnet 26b will be peeled outside due to the action of centrifugal force, which is suitable for high-speed rotation. Further, if at least one of the inner gear 14 and the outer gear 26 has an IPM structure, the above-described effects can be obtained accordingly.

  In the outer gear 26, since the outer magnet hole 26c has an opening 26g on the inner peripheral side, the outer magnet 26b can be arranged as far as possible inward, and the inner end of the outer gear 26b is an opening. It coincides with the edge 26h of 26g and is very close to the outer peripheral surface of the center ring 30. In addition, since the opening 26g is provided, the magnetic pole part 26d of the outer magnet 26b or the magnetic pole part 26ds that are in contact with the magnetic pole part 26ds and the clamping part 26f are not connected to each other on the inner peripheral side of the outer gear 26. There is no short-circuit conduction of the magnetic flux from the N pole to the S pole. Therefore, the magnetic pole portion 26d can direct a particularly strong magnetic flux in the inner direction.

  In the inner gear 14, since the inner magnet hole 14c has the opening 14g on the outer peripheral side, the inner magnet 14b can be arranged as far as possible outward, and the outer end thereof is the opening 14g. Which coincides with the edge 14h of the center ring 30 and is very close to the inner peripheral surface of the center ring 30. In addition, since the opening 14g is provided, the magnetic pole part 14dn of the inner magnet 14b or the magnetic pole part 14ds that are in contact with the magnetic pole part 14ds and the clamping part 14f are not connected to each other on the outer peripheral side of the inner gear 14, and this part is not connected. There is no short-circuit conduction of the magnetic flux from the N pole to the S pole. Therefore, the magnetic pole portion 14d can direct a particularly strong magnetic flux in the outward direction. With such a configuration, the inner gear 14 and the outer gear 26 can exert a strong magnetic force on the other side via the center ring 30.

  Further, when the outer magnet 26b is inserted into the outer magnet hole 26c, the outer magnet 26b may be inserted from the axial direction or may be inserted from the opening 26g in the radial direction. Similarly, when inserting the inner magnet 14b into the inner magnet hole 14c, the inner magnet 14b may be inserted from the axial direction, or may be inserted from the opening 14g in the radial direction.

  The inner end portion of the outer magnet 26b coincides with the edge 26h of the opening portion 26g, and the outer end portion of the inner magnet 14b coincides with the edge 14h of the opening portion 14g. Instead, it should be in approximately the same position. For example, the outer magnet 26b and the inner magnet 14b may interfere with the center ring 30 if they protrude from the inner peripheral surface of the outer yoke 26a and the outer peripheral surface of the inner yoke 14a. Setting a little shorter for a margin is also synonymous with the agreement here. For example, as shown by the phantom line in FIG. 4, when the inner magnet hole 14c is not rectangular, it is only necessary that a part of the end portion of the inner magnet 14b coincides with the edge 14h. The same applies to the outer magnet hole 26c, the outer magnet 26b, and the edge 26h.

  Next, a magnetic gear 10b according to a second embodiment will be described with reference to FIG. Regarding the magnetic gear 10b and the magnetic gears 10c and 100 described later, the same components as those of the magnetic gear 10a are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the magnetic gear 10 b includes an outer gear 42 instead of the outer gear 26 and an inner gear 44 instead of the inner gear 14. The outer gear 42 has an outer yoke 42a and an outer magnet 26b. The outer magnet 26b is the same as that in the magnetic gear 10a, and the magnetic pole part 26d and the clamping part 26f are formed by the arrangement of the outer magnet 26b. The outer yoke 42a is provided with an outer magnet hole 42c and a bridge 42e instead of the outer magnet hole 26c and the bridge 26e in the outer yoke 26a. The outer magnet hole 42c is a hole in which the outer magnet 26b is embedded and accommodated, and has an opening 42g on the outer peripheral surface side of the outer yoke 42a. The outer magnet 26b has the same shape as the outer magnet hole 42c, and the three sides other than the opening 42g are in contact with the outer magnet hole 42c without a gap, and the outer end thereof coincides with the edge 42h of the opening 42g. . With such a configuration, the outer magnet 26b can be enlarged, a strong magnetic force can be obtained, and the transmission torque can be increased. In addition, since the opening 42g is provided, the magnetic pole part 26dn or the magnetic pole part 26ds of the outer magnet 26b on the outer peripheral side of the outer gear 42 are not connected to the magnetic pole part 26d and the clamping part 26f, respectively. There is no short-circuit conduction of the magnetic flux from the N pole to the S pole.

  The bridge 42e is a narrow portion that connects the adjacent magnetic pole portion 26d and the sandwiching portion 26f at the inner peripheral portion of the outer yoke 42a. The magnetic pole portions 26d and the clamping portions 26f are connected to each other by the bridge 42e, and the outer yoke 42a has an integrated configuration and ensures strength. Since the width of the bridge 42e is sufficiently narrow, the short-circuit conduction of the magnetic flux from the N pole to the S pole is suppressed, and the magnetic flux strength of the magnetic pole portion 26d is maintained.

  Further, since the outer peripheral surface of the outer yoke 42a is fixed to the inner peripheral surface of the casing 24, the strength is ensured. Therefore, the outer yoke 42a is secured by the bridge 42e with strength on the inner circumferential surface side and secured with the casing 24 on the outer circumferential surface side, and is suitable for high-speed rotation and excellent in vibration resistance.

  The inner gear 44 has an inner yoke 44a and an inner magnet 14b. The inner magnet 14b is the same as that in the magnetic gear 10a, and the magnetic pole part 14d and the clamping part 14f are formed by the arrangement of the inner magnet 14b. The inner yoke 44a is provided with an inner magnet hole 44c and a bridge 44e instead of the inner magnet hole 14c and the bridge 14e in the inner yoke 14a. The inner magnet hole 44c is a hole in which the inner magnet 14b is embedded and accommodated, and has an opening 44g on the inner peripheral surface side of the inner yoke 44a. The inner magnet 14b has the same shape as the inner magnet hole 44c, and the three sides other than the opening 44g are in contact with the inner magnet hole 44c without a gap. With such a configuration, the inner magnet 14b can be enlarged, a strong magnetic force can be obtained, and the transmission torque can be increased. Further, since the opening 42g is provided, the magnetic pole part 14d of the inner magnet 14b or the magnetic pole part 14ds that are in contact with the magnetic pole part 14ds and the clamping part 14f are not connected to each other on the inner peripheral side of the inner gear 44. There is no short-circuit conduction of the magnetic flux from the N pole to the S pole. The inner diameter side of the inner magnet 14b is set at a position slightly closer to the outer diameter side than the inner peripheral surface of the inner yoke 44a. Thereby, even if the inner diameter side end surface of the inner magnet 14b is linear, interference with the core 46 provided on the inner peripheral side of the inner yoke 44a can be avoided.

  In the magnetic gear 10a and the magnetic gear 10b described above, the magnet hole in which the magnet is embedded is provided with an opening on either the inner diameter side or the outer diameter side, but such an opening may not be provided depending on conditions. . That is, in the outer gears 26 and 42, both the outer peripheral side bridge 26e (see FIG. 4) and the inner peripheral side bridge 42e (see FIG. 5) may be provided. Further, in the inner gears 14 and 44, both the inner peripheral bridge 14e (see FIG. 4) and the outer peripheral bridge 42e (see FIG. 5) may be provided.

  In the magnetic gear 10a and the magnetic gear 10b described above, the magnet hole in which the magnet is embedded is provided with an opening on either the inner diameter side or the outer diameter side. It may be provided on both sides of the side. Although illustration is omitted, the outer and inner magnets can be made larger by providing the openings of the magnet holes on both the outside and inside of each yoke. In this case, since there is no member for connecting the magnetic pole portions and the sandwiching portions in the circumferential direction, it is preferable to connect and fix the magnetic pole portions at the end portions in the axial direction.

  Further, only one of the outer gears 26 and 42 and the inner gears 14 and 44 may be used to form the fan-shaped magnetic pole portion by arranging the embedded magnets in a V-shape. For example, as shown in FIG. A form like the magnetic gear 10c according to the embodiment may be employed.

  In the magnetic gear 10 c, the inner gear 14 and the center ring 30 are the same as those in the magnetic gear 10 a described above, and an outer gear 50 is provided instead of the outer gear 26. Similar to the magnetic gear 10a, the magnetic gear 10c has a configuration of NS = 34, NL = 31, and NH = 3. The outer gear 50 includes an outer yoke 50a and NL = 31 pole pairs (62 pieces) of outer magnets 50b. The outer magnet 50b is embedded in the outer magnet hole 50c. Sixty-two outer magnets 50b are radially arranged at equal intervals in a radial direction. The outer magnet 50b is magnetized in the circumferential tangential direction, that is, in the short direction, and adjacent magnets are arranged in the direction in which the magnetization direction is reversed, and the S poles face each other and the N poles face each other in the circumferential direction. The total volume of the outer magnet 50b is substantially equal to the total volume of the outer magnet 26b. In the outer gear 50, a region sandwiched between the pair of outer magnets 50b becomes a magnetic pole portion 50d, which acts as a pseudo magnetic pole. Although the outer gear 50 is an IPM type, the outer magnet 26b is not V-shaped and the fan-shaped magnetic pole portion 26d is not formed as in the outer gear 26 described above.

  Such an outer gear 50 has a reasonably large outer magnet 50b and outer magnet hole 50c and a relatively small number, so that it is easy to manufacture and assemble and is low in cost. Further, since the magnetic gear 10c includes the inner gear 14 similar to the magnetic gear 10a, a corresponding transmission torque increasing effect can be obtained.

  As an example, the inventor of the present application conducted comparative analysis on the magnetic gear 100 shown in FIG. 7 in order to examine the V-shaped arrangement characteristics of the outer magnet 26b and the inner magnet 14b in the magnetic gear 10a and the magnetic gear 10c. In the magnetic gear 100, the center ring 30 is the same as that in the magnetic gear 10 a described above, an outer gear 50 is provided instead of the outer gear 26, and an inner gear 52 is provided instead of the inner gear 14. The outer gear 50 is the same as that in the magnetic gear 10c (see FIG. 6).

  The magnetic gear 100 has a configuration of NS = 34, NL = 31, and NH = 3 similarly to the magnetic gear 10a. The inner gear 52 includes an inner yoke 52a and NH = 3 pole pairs (six) inner magnets 52b. The inner magnet 52b is embedded in the inner magnet hole 52c. Six of the inner magnets 52b are radially arranged at equal intervals in a direction elongated in the radial direction. The inner magnet 52b is magnetized in the circumferential tangential direction, that is, the short direction, and the adjacent magnets are arranged in the direction in which the magnetization direction is reversed, and the S poles face each other and the N poles face each other in the circumferential direction. The total volume of the inner magnet 52b is substantially equal to the total volume of the inner magnet 14b. In the inner gear 52, a region sandwiched between the pair of inner magnets 52b becomes a magnetic pole portion 52d, which acts as a pseudo magnetic pole. Although the inner gear 52 is of the IPM type, it is not in the form of forming the fan-shaped magnetic pole portion 14d by arranging the inner magnets 14b in a V shape like the inner gear 14 described above.

  According to the result of the comparative analysis, the magnetic gear 10a according to the first embodiment (see FIG. 3) has a maximum transmission torque 24% larger than that of the magnetic gear 100, and the magnetic gear 10c according to the third embodiment ( 6), it was confirmed that the maximum transmission torque was 17% larger than that of the magnetic gear 100.

  The present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be freely changed without departing from the gist of the present invention.

10a, 10b, 10c, 100 Magnetic gear 12 Outer gear body 14, 44, 52 Inner gears 14a, 44a, 52a Inner yokes 14b, 14bn, 14bs, 52b Inner magnets 14c, 44c, 52c Inner magnet holes 14d, 14dn, 14ds, 26d, 26dn, 26ds, 50d, 52d Magnetic pole portions 14e, 26e, 42e Bridges 14f, 26f Holding portions 14g, 26g, 42g, 44g Openings 14h, 26h, 42h Edges 14i, 26i Recess 16 Center body 24 Casings 26, 42, 50 Outer gears 26a, 42a, 50a Outer yokes 26b, 26bn, 26bs, 50b Outer magnets 26c, 42c, 50c Outer magnet hole 30 Center ring 30a Pole holder (non-magnetic cylinder)
30b Pole piece (soft magnetic material)

Claims (8)

An inner gear in which a plurality of inner magnets are arranged in the circumferential direction of the inner yoke;
A center ring provided on the outer peripheral side relative to the inner gear so as to be relatively rotatable, and a plurality of soft magnetic bodies arranged in the circumferential direction of the non-magnetic cylindrical body,
An outer gear that is provided on the outer peripheral side relative to the center ring so as to be relatively rotatable, and in which a plurality of outer magnets are arranged in the circumferential direction of the outer yoke;
Have
The outer gear is formed with a plurality of magnetic pole portions sandwiched between a pair of adjacent outer magnets in a direction in which the same poles face each other,
The pair of outer magnets sandwiching the magnetic pole part are arranged such that the gap on the inner diameter side is wider than the outer diameter side. The magnetic gear according to claim 1, wherein
The outer yoke has an outer magnet hole in which the outer magnet is embedded,
The outer gear hole has an opening on at least one of an inner peripheral surface and an outer peripheral surface of the outer yoke. The magnetic gear according to claim 2,
The magnetic gear according to claim 1, wherein at least a part of one edge of the outer magnet coincides with an edge of the opening. The magnetic gear according to any one of claims 1 to 3,
The inner gear is formed with a plurality of magnetic pole portions sandwiched between a pair of adjacent inner magnets in a direction in which the same poles face each other,
The pair of inner magnets sandwiching the magnetic pole part are arranged so that the interval is wider on the outer diameter side than on the inner diameter side. The magnetic gear according to claim 4, wherein
The inner yoke has an inner magnet hole in which the inner magnet is embedded,
The magnetic gear according to claim 1, wherein the inner magnet hole has an opening on at least one of an inner peripheral surface and an outer peripheral surface of the inner yoke. The magnetic gear according to claim 5,
The magnetic gear according to claim 1, wherein at least a part of one edge of the inner magnet coincides with an edge of the opening. An inner gear in which a plurality of inner magnets are arranged in the circumferential direction of the inner yoke;
A center ring provided on the outer peripheral side relative to the inner gear so as to be relatively rotatable, and a plurality of soft magnetic bodies arranged in the circumferential direction of the non-magnetic cylindrical body,
An outer gear that is provided on the outer peripheral side relative to the center ring so as to be relatively rotatable, and in which a plurality of outer magnets are arranged in the circumferential direction of the outer yoke;
Have
The inner gear is formed with a plurality of magnetic pole portions sandwiched between a pair of adjacent inner magnets in a direction in which the same poles face each other,
The pair of inner magnets sandwiching the magnetic pole part are arranged so that the interval on the outer diameter side is wider than the inner diameter side,
The inner yoke has an inner magnet hole in which the inner magnet is embedded,
The magnetic gear according to claim 1, wherein the inner magnet hole has an opening on at least one of an inner peripheral surface and an outer peripheral surface of the inner yoke. The magnetic gear according to claim 7,
The magnetic gear according to claim 1, wherein an edge of one end of the inner magnet coincides with an edge of the opening.

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