JP2019168010A - Magnetic gear - Google Patents

Abstract

To provide a magnetic gear capable of increasing transmittable 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 and 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 and having a plurality of outer magnets 26b aligned in the circumferential direction of an outer yoke 26a. The outer magnet 26b is embedded in the outer yoke 26a so that adjacent same poles face each other in the circumferential direction. The outer yoke 26a has an outer magnet hole 26c in which the outer magnet 26b is embedded. The outer magnet hole 26c has an opening 26f on the inner peripheral surface of the outer yoke 26a.SELECTED DRAWING: Figure 3

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 can be 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. An outer gear arranged with magnets, and the outer magnets are embedded in the outer yoke so that the adjacent magnets face each other in the circumferential direction.

  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.

  The outer yoke has a circumferential surface shape in which the inner circumferential surface or the outer circumferential surface where the opening is opened has a rotation axis center, and an edge of one end of the outer magnet coincides with an edge of the opening. Also good.

  The inner magnets may be embedded in the inner yoke so that adjacent poles face each other in the circumferential direction.

  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.

  The inner yoke has a circumferential surface shape in which the inner circumferential surface or the outer circumferential surface where the opening is opened has a rotation axis center, and an edge of one end of the inner magnet coincides with an edge of the opening. Also good.

  An inner gear in which a plurality of inner magnets are arranged in the circumferential direction of the inner yoke, and a center in which a plurality of soft magnetic bodies are arranged in the circumferential direction of the non-magnetic cylindrical body provided to be relatively rotatable on the outer circumferential side with respect to the inner gear. A ring, and an outer gear that is provided on the outer peripheral side of the center ring so as to be rotatable relative to the outer periphery, and in which a plurality of outer magnets are arranged in the circumferential direction of the outer yoke. The inner yoke is embedded in the inner yoke so that the same pole faces in the direction, and the inner yoke has an inner magnet hole in which the inner magnet is embedded, and the inner magnet hole is an inner peripheral surface or an outer peripheral surface of the inner yoke. It has an opening part in at least one of these.

  The inner yoke has a circumferential surface shape in which the inner circumferential surface or the outer circumferential surface where the opening is opened has a rotation axis center, and an edge of one end of the inner magnet coincides with an edge of the opening. Also good.

  In the magnetic gear according to the present invention, the outer magnets are embedded in the outer yoke so that the same poles face each other in the circumferential direction, or the inner poles face each other so that the same poles face each other in the circumferential direction. It is embedded in the inner yoke, and the magnetic force can be efficiently transmitted to the respective magnetic pole portions to increase the transmittable torque.

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 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. 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 second 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 third embodiment.

  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 NL = 31 pole pairs (62 pieces) of outer magnets 26b. 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 includes an inner yoke 14a and NH = 3 pole pairs (six) inner magnets 14b. 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 FIG.

  As shown in FIG. 3, 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 circumferential surface of the inner yoke 14a and the inner circumferential surface of the center ring 30 is sufficiently narrow, and the gap between the inner circumferential surface of the outer yoke 26a and the outer circumferential surface of the center ring 30 is sufficiently narrow. Easy to apply force.

  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 portion 26d, and a bridge 26e. The outer magnet hole 26c is a hole in which the outer magnet 26b is embedded and accommodated, and has an opening 26f 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 26f are in contact with the outer magnet hole 26c without a gap, and the inner end thereof coincides with the edge 26g of the opening 26f. . 3 to 5, the N pole is identified as a dot background 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 26b and the outer magnet hole 26c are rectangular and have a radial shape that is long in the radial direction with respect to the outer yoke 26a and equiangularly spaced. Of the three sides forming the outer magnet hole 26c, the two sides in the longitudinal direction are parallel lines, and open inward while remaining parallel, and the opening 26f has no irregularities. The outer magnet 26b 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 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 magnetic pole portion 26d has a substantially rectangular shape sandwiched between two outer magnet holes 26c on both sides in the circumferential direction. The magnetic pole portions 26d are elongated in the radial direction with respect to the outer yoke 26a and have a radial arrangement at equal angular intervals. The magnetic pole portion 26d acts as a pseudo magnetic pole for directing the magnetic flux in the radial direction, with the portions sandwiched between the S poles of the outer magnet 26b on both sides being the S poles and the portions sandwiched between the N poles being the N poles. To do.

  The bridge 26e is a narrow portion that connects adjacent magnetic pole portions 26d with the outer peripheral portion of the outer yoke 26a. The magnetic pole portions 26d are connected to each other by the bridge 26e, and the outer yoke 26a has an integrated configuration and ensures strength. Since the bridge 26e is sufficiently thin, 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 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, and a bridge 14e. The inner magnet hole 14c is a hole in which the inner magnet 14b is embedded and accommodated, and has an opening 14f 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, and the three sides other than the opening 14f are in contact with the inner magnet hole 14c without any gap, and the outer end thereof coincides with the edge 14g of the opening 14f. .

  The inner magnets 14b and the inner magnet holes 14c are rectangular and are long in the radial direction with respect to the inner yoke 14a, and are radially arranged at equal angular intervals. 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 14f has no irregularities. The inner magnet 14b 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 inner gear 14 in which the inner magnet 14b is embedded in the inner yoke 14a in this way is an IPM type.

  The magnetic pole portion 14d is a portion sandwiched between two inner magnet holes 14c on both sides in the circumferential direction, and has a fan shape with a narrow inner diameter side and a wider outer diameter side. The magnetic pole portion 14d acts as a pseudo magnetic pole for directing the magnetic flux in the radial direction, with the portions sandwiched between the S poles of the inner magnet 14b on both sides serving as the S poles and the portions sandwiched between the N poles serving as the N poles. To do.

  The bridge 14e is a narrow portion that connects adjacent magnetic pole portions 14d with the inner peripheral portion of the inner yoke 14a. Each magnetic pole part 14d is mutually connected by the bridge | bridging 14e, and the inner yoke 14a becomes integral structure and intensity | strength is ensured. Since the bridge 14e is formed to be sufficiently thin, 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.

  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 26f 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 26g of 26f and is very close to the outer peripheral surface of the center ring 30. Further, since the opening 26f is provided, the magnetic pole portions 26d are not interconnected on the inner peripheral side of the outer gear 26, and there is no short-circuit conduction of the magnetic flux from the N pole to the S pole in this portion. . 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 14f on the outer peripheral side, the inner magnet 14b can be arranged as far as possible outside, and the outer end of the inner magnet 14b has an opening 14f. Which coincides with the edge 14g of the center ring 30 and is very close to the inner peripheral surface of the center ring 30. Further, since the opening 14f is provided, the magnetic pole portions 14d are not interconnected on the outer peripheral side of the inner gear 14, and there is no short-circuit conduction of the magnetic flux from the N pole to the S pole in this portion. 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 26g of the opening portion 26f, and the outer end portion of the inner magnet 14b coincides with the edge 14g of the opening portion 14f. 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.

  In the magnetic gear 10a configured as described above, since the outer gear 26 and the inner gear 14 are each IPM type, the transmittable torque is increased. Further, the outer magnet hole 26c has a shape that opens to the inner peripheral side, and the outer magnet 26b can be enlarged by the volume of the outer magnet hole 26c, thereby obtaining a strong magnetic force. Similarly, the inner magnet hole 14c opens to the outer peripheral side, and the inner magnet 14b can be enlarged by the volume of the inner magnet hole 14c, and a strong magnetic force can be obtained. As a result, the transmission torque can be increased.

  The magnetic gear 10a has such characteristics, and the analysis results confirmed that the maximum transmission torque is 21% higher and the efficiency is slightly higher than the magnetic gear 10b according to the second embodiment described below.

  Next, a magnetic gear 10b according to a second embodiment will be described with reference to FIG. About the magnetic gear 10b and the magnetic gear 10c mentioned later, the same code | symbol is attached | subjected about the component similar to said magnetic gear 10a, and the detailed description is abbreviate | omitted.

  As shown in FIG. 4, the magnetic gear 10 b is provided with an outer gear 42 instead of the outer gear 26, and with an inner gear 44 instead of the inner gear 14. The outer gear 42 has an outer yoke 42a and an outer magnet 42b. The outer magnets 42b are the same as the outer magnets 26b described above, and are arranged in the same number and at the same angle. The outer yoke 42a has the same material, inner diameter, outer diameter, and axial width as the outer yoke 26a. The outer yoke 42a has an outer magnet hole 42c, a magnetic pole part 42d, and a bridge 42e. The magnetic pole part 42d has the same shape as the magnetic pole part 26d. The outer magnet hole 42c is a hole in which the outer magnet 42b is embedded and accommodated, and has an opening 42f on the outer peripheral surface side of the outer yoke 42a. The outer magnet 42b has the same shape as the outer magnet hole 42c, and the three sides other than the opening 42f are in contact with the outer magnet hole 42c without a gap, and the outer end thereof coincides with the edge 42g of the opening 42f. . With such a configuration, the outer magnet 42b can be enlarged, a strong magnetic force can be obtained, and the transmission torque can be increased. Further, since the opening 42f is provided, the magnetic pole portions 26d are not interconnected on the outer peripheral side of the outer gear 42, and there is no short-circuit conduction of the magnetic flux from the N pole to the S pole in this portion.

  The bridge 42e is a thin portion that connects the adjacent magnetic pole portions 42d with the inner peripheral portion of the outer yoke 42a. The magnetic pole portions 42d 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 intensity of the magnetic pole part 42d 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 44b. The inner magnets 44b are the same as the inner magnets 14b described above, and are arranged in the same number and at the same angle. The inner yoke 44a has the same material, inner diameter, outer diameter, and axial width as the inner yoke 14a. The inner yoke 44a has an inner magnet hole 44c, a magnetic pole portion 44d, and a bridge 44e. The magnetic pole part 44d has the same shape as the magnetic pole part 14d. The inner magnet hole 44c is a hole in which the inner magnet 44b is embedded and accommodated, and has an opening 44f and a pair of retaining protrusions 44h on the inner peripheral surface side of the inner yoke 44a. The inner magnet 44b has the same shape as the inner magnet hole 44c, and the three sides other than the opening 44f are in contact with the inner magnet hole 44c without a gap. With such a configuration, the inner magnet 44b can be enlarged, and a strong magnetic force can be obtained to increase the transmission torque. Further, since the opening 44f is provided, the magnetic pole portions 44d are not interconnected on the inner peripheral side of the inner gear 44, and there is no short-circuit conduction of the magnetic flux from the N pole to the S pole in this portion. .

  The retaining protrusions 44h are small protrusions provided at both ends in the circumferential direction so as to slightly narrow the opening 44f, and stably hold the inner magnet 44b by contacting from the inner peripheral end. The inner magnet 44b is larger than the outer magnet 42b, but is securely held by the retaining protrusion 44h. Further, by providing the retaining protrusion 44h, the inner diameter side of the inner magnet 44b 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 face of the inner magnet 44b is formed in a linear shape, interference with the core 46 provided on the inner peripheral side of the inner yoke 44a can be avoided.

  Depending on conditions, the retaining protrusion 44h may be omitted, the inner magnet 44b may be set slightly larger toward the inner diameter side, and the inner end 44j may be aligned with the edge 44g of the opening 44f as indicated by the phantom line. . With such a configuration, the inner magnet 44b can be further enlarged, and a strong magnetic force can be obtained. In this case, in order to avoid interference with the core 46, the inner diameter side end surface of the inner magnet 44b is preferably an arc surface along the outer peripheral surface of the core 46.

  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, a configuration like the magnetic gear 10c according to the third embodiment diameter shown in FIG. In the magnetic gear 10c, the outer magnet hole 48c is closed by the bridge 48e on the outer diameter side and closed by the bridge 48f on the inner diameter side. The inner magnet hole 50c is closed on the outer diameter side with a bridge 50e and closed on the inner diameter side with a bridge 50f. In the magnetic gear 10c, the outer gear 48, the outer yoke 48a, the outer magnet 48b, the outer magnet hole 48c, the magnetic pole portion 48d, the inner gear 50, the inner yoke 50a, the inner magnet 50b, the inner magnet hole 50c, and the magnetic pole portion 50d The gear 26, the outer yoke 26a, the outer magnet 26b, the outer magnet hole 26c, the magnetic pole portion 26d, the inner gear 14, the inner yoke 14a, the inner magnet 14b, the inner magnet hole 14c, and the magnetic pole portion 14d are equivalent. In such a magnetic gear 10c, four surfaces of the outer magnet 48b and the inner magnet 50b are in contact with the outer magnet hole 48c and the inner magnet hole 50c and are stabilized. Further, the outer yoke 48a and the inner yoke 50a have a strong strength because the outer peripheral surface and the inner peripheral surface are circumferential surfaces without deep notches, respectively.

  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 in the circumferential direction, the magnetic pole portions may be connected and fixed at the end portions in the axial direction.

  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 Magnetic gear 12 Outer gear body 14, 44, 50 Inner gears 14a, 44a, 50a Inner yokes 14b, 44b, 50b Inner magnets 14c, 44c, 50c Inner magnet holes 14d, 44d, 50d Magnetic pole portions 14e, 44e , 26e, 42e, 48e, 50e, 50f Bridges 14f, 26f, 44f Openings 14g, 26g, 44g Edge 16 Center body 24 Casing 26, 42, 48 Outer gears 26a, 42a, 48a, outer yokes 26b, 42b, 48b, Outer magnets 26c, 42c, 48c, outer magnet holes 26d, 42d, 48d, magnetic pole part 30, center ring 30a, pole holder (non-magnetic cylinder)
30b Pole piece (soft magnetic material)
44h Stop projection 46 Core

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 magnetic gear, wherein the outer magnet is embedded in the outer yoke such that adjacent poles face each other in the circumferential direction. 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 outer yoke has a circumferential surface shape in which the inner peripheral surface or the outer peripheral surface where the opening opens is a center of a rotation axis,
The magnetic gear according to claim 1, wherein an edge of one end of the outer magnet coincides with an edge of the opening. The magnetic gear according to any one of claims 1 to 3,
The magnetic gear, wherein the inner magnet is embedded in the inner yoke so that adjacent poles face each other in the circumferential direction. 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 inner yoke has a circumferential surface shape in which the inner peripheral surface or the outer peripheral surface where the opening opens is a center of a rotation axis,
The magnetic gear according to claim 1, wherein an edge of one end 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 magnet is embedded in the inner yoke so that the same poles face each other in the circumferential direction between adjacent magnets,
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 inner yoke has a circumferential surface shape in which the inner peripheral surface or the outer peripheral surface where the opening opens is a center of a rotation axis,
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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