JP4696708B2 - Eddy current reducer - Google Patents

Description

  The present invention relates to an eddy current reduction device, and more particularly to an eddy current reduction device that can improve braking force without increasing the amount of magnets.

  An eddy current type speed reducer (hereinafter referred to as a retarder) generates a eddy current by applying a magnetic field to a rotor connected to a rotating shaft, and uses a force generated by the interaction between the eddy current and the magnetic field. It brakes the rotating shaft and is used as an auxiliary brake for large vehicles.

  This retarder is roughly classified into a type using a permanent magnet as a magnetic source that generates a magnetic force (magnetic field) acting on the rotor and a type using an electromagnet. The types using a permanent magnet are as follows. It has been known.

  For example, the retarder shown in FIGS. 9 to 11 includes a bottomed cylindrical brake drum (rotor) 2 that is connected to a rotary shaft 1 (for example, a transmission output shaft of a vehicle) in a relatively non-rotatable manner, and the brake drum. 2 and an annular protective case 3 arranged on the inner side of 2.

  The brake drum 2 includes a wheel 5 connected to the rotating shaft 1, a plurality of arms 6 that radially extend from the wheel 5 radially outward, and a drum 7 connected to the outer end of the arm 6. Have.

  The protective case 3 has an outer cylinder portion 40 made of a nonmagnetic material, and a plurality of pole pieces 41 made of a ferromagnetic material are embedded in the outer cylinder portion 40 at equal intervals in the circumferential direction. A magnet ring 42 is accommodated inside the protective case 3 so as to be slidable in the axial direction of the rotary shaft 1. The magnet ring 42 includes a magnet support cylinder (yoke) 43 made of a magnetic material and a plurality of permanent magnets 45 arranged on the outer peripheral surface of the magnet support cylinder 43. The same number of permanent magnets 45 as the pole pieces 41 described above are arranged along the circumferential direction of the magnet support cylinder 43 and the rotating shaft 1. Each permanent magnet 45 has magnetic pole faces at both ends in the radial direction, and is arranged so that the polarities of the magnetic pole faces facing the pole pieces 41 are alternately different between the permanent magnets 45 adjacent in the circumferential direction (FIG. 11). reference).

  The magnet support cylinder 43 of the magnet ring 42 is connected to an actuator (not shown) via a rod 46 (see FIG. 9), and the permanent magnet 45 does not face the pole piece 41 and the braking position where the permanent magnet 45 faces the pole piece 41. It can move between the non-braking position.

  When braking the rotating shaft 1, the magnet ring 42 is moved to the braking position by an actuator (not shown), and the permanent magnet 45 is opposed to the pole piece 41. Then, as shown in FIG. 11, since the magnetic flux from each permanent magnet 45 acts on the brake drum 2 rotating through the pole piece 41, an eddy current is generated in the brake drum 2 and a braking torque for the rotating shaft 1 is generated. To do.

  At the time of non-braking, the magnet ring 42 is moved to a non-braking position where the permanent magnet 45 does not face the pole piece 41. As a result, since the magnetic flux from the permanent magnet 45 does not act on the braking drum 2, no braking torque is generated for the rotating shaft 1.

  On the other hand, in the type of retarder shown in FIGS. 12 and 13, two magnet rings 50 and 51 are arranged inside the protective case 3. These magnet rings 50 and 51, like the magnet ring 42 of the retarder shown in FIG. 11, are magnet support cylinders 52 and 53 made of a ferromagnetic material and a plurality of magnet support cylinders 52 and 53 arranged on the outer peripheral surface. Permanent magnets 55 and 56 are provided. One (the left side in FIG. 13) magnet ring 50 is fixed so as not to rotate relative to the protective case 3, and the other (the right side in FIG. 13) magnet ring 51 is a protective case. 3 is provided so as to be relatively rotatable in the circumferential direction. Therefore, hereinafter, the magnet ring 50 is referred to as a stationary magnet ring, and the magnet ring 51 is referred to as a movable magnet ring.

  The movable magnet ring 51 is connected to an actuator 57 (see FIG. 12), and each permanent magnet 56 of the movable magnet ring 51 and each permanent magnet 55 of the stationary magnet ring 50 are adjacent to each other with the same magnetic pole (see FIG. 12). And a non-braking position (see FIG. 13) adjacent to each other with different magnetic poles.

  When braking a rotating shaft (not shown) to which the braking drum 2 is connected, the movable magnet ring 51 is rotated to the braking position by the actuator 57, and each permanent magnet of the movable magnet ring 51 is rotated as shown in FIG. 56 and each permanent magnet 55 of the stationary magnet ring 50 are adjacent to each other with the same polarity. Then, like the retarder shown in FIG. 11, the magnetic flux from the permanent magnets 56 and 55 of the movable magnet ring 51 and the stationary magnet ring 50 acts on the brake drum 2 rotating through the pole piece 41. An eddy current is generated in the shaft, and a braking torque for the rotating shaft is generated.

  At the time of non-braking, the movable magnet ring 51 is moved to the non-braking position, and the permanent magnets 56 of the movable magnet ring 51 and the permanent magnets 55 of the stationary magnet ring 50 are adjacent to each other with different polarities as shown in FIG. . As a result, the magnetic fluxes from the permanent magnets 56 and 55 of the movable magnet ring 51 and the stationary magnet ring 50 are short-circuited by the pole piece 41 to the permanent magnets 55 and 56 of the other magnet ring 50 and 51 adjacent in the axial direction. Therefore, the braking torque for the rotating shaft is not generated.

  As described above, since all of the conventional retarders are configured to form a magnetic circuit via the pole piece 41, the braking drum (rotor) 2 and the magnet support cylinders 43, 52, and 53 during braking, the magnetic flux is supported by the magnet. The length of the magnetic circuit is unnecessarily increased by passing through the cylinders 43, 52, 53, leading to a decrease in magnetic force acting on the brake drum 2, and a decrease in braking torque.

  Therefore, the present applicant has developed a retarder as shown in Patent Document 1.

  As shown in FIG. 14, this retarder forms magnetic pole surfaces of the permanent magnets 61 of the magnet ring 60 at both ends in the circumferential direction so that the permanent magnets 61 adjacent in the circumferential direction face each other with the same magnetic pole. A pole piece 62 made of a ferromagnetic material is interposed between the permanent magnets 61. Moreover, in this retarder, the outer peripheral part of the protective case 63 is opened, and the outer cylinder part 40 and the pole piece 41 as shown in FIGS. 11 and 13 are omitted. In this retarder, the magnet support cylinder 65 that supports the permanent magnet 61 is formed of a nonmagnetic material.

  According to this retarder, as shown in FIG. 14, a magnetic circuit can be formed between the braking drum 2 and the pole piece 62 during braking, so that the magnetic flux does not pass through the magnet support cylinder 65 and the magnetic circuit length is increased. 11 or shorter than that shown in FIG. Accordingly, the braking force is improved.

  This concept is based on the type using one magnet ring 42 that slides in the axial direction as shown in FIGS. 9 to 11, and the movable magnet ring 51 and the stationary magnet ring 50 as shown in FIGS. It is applicable to any of the types using the two magnet rings.

JP 2000-184690 A

  However, the demand for improving the braking force for the retarder is increasing year by year, and further improvement is desired.

  Here, if the number and volume of permanent magnets, that is, the amount of magnets is increased, the magnetic force acting on the rotor is increased, so that the braking force can naturally be increased. Therefore, it is required to improve the braking force without increasing the magnet amount.

  Accordingly, an object of the present invention is to provide an eddy current type reduction device that can improve the braking force without increasing the amount of magnets in the eddy current type reduction device that solves the above problems and uses a permanent magnet as a magnetic source. is there.

To achieve the above object, the present invention provides a rotor coupled to a rotating shaft, a plurality of permanent magnets for applying a magnetic force to the rotor, and opposing magnetic pole surfaces of adjacent permanent magnets among the plurality of permanent magnets. And a magnet ring having a magnetic ring composed of a magnetic body disposed between each of the permanent magnets, wherein a plurality of the permanent magnets are disposed at intervals in the circumferential direction of the rotating shaft, The magnet has magnetic pole surfaces at both circumferential ends, and the magnetic body is arranged so as to fill in the circumferential direction between the opposing magnetic pole surfaces of adjacent permanent magnets among the plurality of permanent magnets. At least one of the peripheral surfaces of the outer peripheral surface and the inner peripheral surface is formed by the peripheral end surface of the permanent magnet, and the magnetic ring is in contact with the air gap or the nonmagnetic material on the peripheral surface, The magnetic pole surface is the radial direction of the rotating shaft It is formed to be inclined with respect to the line extending, pole face facing the two adjacent permanent magnets, respectively inclined in the same direction with respect to the line extending in the radial direction of the rotary shaft, and that The adjacent magnetic pole surfaces of two adjacent permanent magnets have the same polarity .

The present invention is also directed to an eddy current reduction device comprising: a rotor coupled to a rotating shaft; and a magnet ring having a permanent magnet for causing a magnetic force to act on the rotor. A plurality of permanent magnets are arranged at intervals in the circumferential direction, and each permanent magnet has a magnetic pole surface at both ends in the circumferential direction, and the magnetic pole surface is inclined with respect to a line extending in the radial direction of the rotating shaft. In addition, the magnetic pole surfaces of the plurality of permanent magnets are all inclined at the same angle in the same direction with respect to the line extending in the radial direction of the rotating shaft.

  Further, the inclination direction of the magnetic pole surface of the permanent magnet may be the rotation direction of the rotation shaft or the opposite direction.

  The rotor comprises a bottomed cylindrical brake drum, and the magnet ring is disposed inside the brake drum, and is arranged around an annular magnet support cylinder made of a non-magnetic material and an outer peripheral surface of the magnet support cylinder. A plurality of the permanent magnets arranged at intervals in the direction, and a pole piece made of a magnetic material arranged between the permanent magnets may be provided.

The present invention is also directed to an eddy current reduction device comprising: a rotor coupled to a rotating shaft; and a magnet ring having a permanent magnet for causing a magnetic force to act on the rotor. A plurality of permanent magnets are arranged at intervals in the circumferential direction, and each permanent magnet has a magnetic pole surface at both ends in the circumferential direction, and the magnetic pole surface is inclined with respect to a line extending in the radial direction of the rotating shaft. The rotor comprises a bottomed cylindrical brake drum, and the magnet ring is disposed inside the brake drum, and is arranged around an annular magnet support cylinder made of a non-magnetic material and an outer peripheral surface of the magnet support cylinder. A plurality of the permanent magnets arranged at intervals in the direction, and a pole piece made of a magnetic material arranged between the permanent magnets, and movable as a magnet ring that can rotate in the circumferential direction of the rotating shaft Axial to magnet ring and its movable magnet ring And a stationary magnet ring that is non-rotatable in the circumferential direction of the rotating shaft, and adjusts the phase of the movable magnet ring so that the magnetic force of the permanent magnet of the movable magnet ring and the stationary magnet ring is adjusted to the braking drum. a braking position for applying a, in which an actuator for switching between a non-braking position which does not act on the magnetic force of the permanent magnets of the movable magnet ring and stationary magnet ring to the brake drum.

  According to the present invention, an excellent effect that the braking force can be improved without increasing the magnet amount is exhibited.

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

  1 is a side sectional view of the upper half of the eddy current type speed reducer (hereinafter referred to as a retarder) of the present embodiment, FIG. 2 is a partial front sectional view of the rotor and magnet ring of the retarder of FIG. 1, and FIG. It is a partial top view. In these drawings, the same components as those shown in FIGS. 9 to 14 are denoted by the same reference numerals.

  As shown in the figure, the retarder of this embodiment includes a bottomed cylindrical brake drum (rotor) 2 integrally connected to a rotary shaft 1 such as a transmission output shaft of a vehicle, and the brake drum 2. And an annular protective case 3 disposed on the inside of the.

  The brake drum 2 is connected to a wheel 5 connected to the rotary shaft 1 so as not to rotate relatively, a plurality of arms 6 extending radially outward from the wheel 5, and an outer end of the arm 6. And a plurality of cooling fins 9 are formed on the outer peripheral surface of the drum 7.

  The protective case 3 is made of a nonmagnetic material such as aluminum and has a shape in which the outer peripheral portion is open. Two magnet rings 10 and 11 are arranged inside the protective case 3 so as to be adjacent to each other in the axial direction of the rotary shaft 1. Each of the magnet rings 10 and 11 includes a magnet support tube (yoke) 12 and 13 made of a non-magnetic material (for example, aluminum), and a plurality of permanent magnets 15 disposed on the outer peripheral surface of the magnet support tube 12 and 13. 16 and pole pieces 17 and 18 interposed between the permanent magnets 15 and 16, and one (the left side in FIG. 1) magnet ring 10 is circumferential (rotating shaft) with respect to the protective case 3. The other magnet ring 11 is fixed to the protective case 3 so as not to rotate relative to the protective case 3. Therefore, hereinafter, the magnet ring 10 is also referred to as a movable magnet ring, and the magnet ring 11 is also referred to as a stationary magnet ring.

  As shown in FIG. 2, a plurality of permanent magnets 15, 16 of both magnet rings 10, 11 are arranged at equal intervals in the circumferential direction of the magnet support cylinders 12, 13 (the same direction as the circumferential direction of the rotating shaft 1). Each has a magnetic pole surface at both ends in the circumferential direction. The permanent magnets 15 and 16 are disposed so that the permanent magnets 15 and 16 adjacent in the circumferential direction face each other with the same polarity in the circumferential direction. Moreover, the coating for countermeasures, such as a heat | fever, dust, a water | moisture content, is given to the radial direction outer end surface of each permanent magnet 15 and 16. The retarder of this embodiment is characterized by the shape of these permanent magnets 15 and 16, which will be described in detail later.

  The pole pieces 17 and 18 are made of a ferromagnetic material such as iron, and the radially outer end surfaces thereof are located outward from the radially outer end surfaces of the permanent magnets 15 and 16. Therefore, the radially outer end surfaces of the pole pieces 17 and 18 are closer to the braking drum 2 than the radially outer end surfaces of the permanent magnets 15 and 16.

  The movable magnet ring 10 has a magnet support cylinder 12 connected to an actuator 20 (see FIG. 1) such as an air cylinder, and each permanent magnet 15 is adjacent to each permanent magnet 16 of the stationary magnet ring 11 with the same polarity. It can move between a braking position (state shown in FIG. 1) and a non-braking position (state shown in FIG. 3) adjacent to each other with different magnetic poles.

  When the rotating shaft 1 is braked, the actuator 20 rotates the movable magnet ring 10 to the braking position (adjusts the phase), and as shown in FIG. 1, the permanent magnet 15 and the stationary magnet ring of the movable magnet ring 10. 11 permanent magnets 16 are adjacent to each other with the same polarity. Then, as shown in FIG. 2, the magnetic flux from one magnetic pole surface of each of the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11 acts on the braking drum 2 rotating through the pole pieces 17 and 18. Since it flows to the other magnetic pole surface, an eddy current is generated in the braking drum 2 and a braking torque for the rotating shaft 1 is generated. Thus, in the retarder of this embodiment, since the magnetic flux from the permanent magnets 15 and 16 does not pass through the magnet support cylinders 12 and 13 during braking, the magnetic circuit length is short and the braking torque can be improved.

  At the time of non-braking, the movable magnet ring 10 is moved to the non-braking position, and the permanent magnet 15 of the movable magnet ring 10 and the permanent magnet 16 of the stationary magnet ring 11 are adjacent to each other with different polarities as shown in FIG. As a result, the magnetic fluxes from the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11 are short-circuited by the pole pieces 17 and 18, and the permanent magnets 16 of the other magnet rings 11 and 10 adjacent in the axial direction are connected. Since no magnetic flux acts on the brake drum 2, no eddy current is generated on the brake drum 2, and no braking torque is generated on the rotating shaft 1.

  Now, since the retarder of this embodiment is characterized by the shapes of the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11, the characteristic parts will be described below with reference to FIGS.

  As can be seen from the figure, each of the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11 has magnetic pole surfaces 15a and 16a at both ends in the circumferential direction, and the magnetic pole surfaces 15a and 16a are rotating shafts. 1 is inclined at a predetermined angle θ with respect to a line L extending in the radial direction (hereinafter referred to as a radial line). More specifically, as the magnetic pole surfaces 15a and 16a of all the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11 move from the radially inner end to the radially outer end, the braking drum 2 It is formed so as to be inclined with respect to the radial line L (radiation line) so as to recede in the direction opposite to the rotation direction of the (rotating shaft 1). Thus, when magnetizing the permanent magnets 15 and 16 whose magnetic pole surfaces 15a and 16a are inclined, the magnetization direction is made perpendicular to the magnetic pole surfaces 15a and 16a. It should be noted that both end surfaces in the circumferential direction of the pole pieces 17 and 18 disposed between the permanent magnets 15 and 16 are also formed so as to be inclined at the same angle in the same direction together with the magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16. Is done.

  Thus, by inclining the magnetic pole surfaces 15a, 16a of the permanent magnets 15, 16 with respect to the radial line L of the rotating shaft 1 (braking drum 2), the volume (magnet amount) of the permanent magnets 15, 16 is reduced. The area of the magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16 can be increased without increasing.

This will be described with reference to FIG. 4. If the radial lengths of the magnetic pole faces 15'a, 16'a of the permanent magnets 15 ', 16' parallel to the radial line L are L2, the permanent magnets 15 ', The magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16 have the same volume as that of 16 '(the same magnet amount) and the magnetic pole surfaces 15a and 16a are inclined with respect to the radial line L at an angle θ (excluding θ = zero). The length L1 in the radial direction is L2 / cos θ, which is longer than L2. For example, when the inclination angle θ of the magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16 is 30 °, L1 = L2 × 2 / (3 ^1/2 ), and the radial length L1 of the magnetic pole surfaces 15a and 16a is This is about 1.15 times the radial length L2 of the magnetic pole faces 15′a, 16′a parallel to the radial line L.

  Thus, by inclining the magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16 with respect to the radial line L of the rotating shaft 1, the magnetic pole surfaces 15a and 16a of the permanent magnets 15 and 16 without increasing the magnet amount. Can be increased, that is, the areas of the magnetic pole surfaces 15a and 16a can be increased. Thereby, the magnetic force of each of the permanent magnets 15 and 16 is increased, and the magnetic flux entering the braking drum 2 during braking increases, so that the braking torque acting on the braking drum 2 and the rotary shaft 1 becomes larger than before.

  In order to confirm the braking torque improvement effect of the retarder of the present embodiment, the inventor of the present invention has a retarder braking torque in which the magnetic pole surfaces 15a, 16a of the permanent magnets 15, 16 are inclined with respect to the radial line L of the rotating shaft 1. Was measured. The result is shown in FIG. Here, the inclination angle of the magnetic pole surfaces 15a and 16a is 30 °.

  The line connecting the triangular points in the figure is the result of the retarder of this embodiment. The line connecting the square points shows the result of a conventional retarder in which the magnetic pole surface of the permanent magnet is parallel to the radial line L of the rotating shaft for comparison. Note that the number and volume of permanent magnets, that is, the amount of magnets are the same in the retarder of this embodiment and the conventional retarder.

  As can be seen from the figure, the braking torque of the retarder of this embodiment in which the magnetic pole surfaces 15a, 16a of the permanent magnets 15, 16 are inclined with respect to the radial line L of the rotary shaft 1 The braking torque of the retarder was exceeded.

  From this result, according to the retarder of this embodiment, it was confirmed that the braking force can be improved without increasing the number and volume of expensive magnets, that is, the amount of magnets. Therefore, according to the retarder of the present embodiment, the braking force can be improved without increasing the size and cost of the device.

  In the above embodiment, the magnetic pole surfaces 15 a and 16 a of the permanent magnets 15 and 16 of the movable magnet ring 10 and the stationary magnet ring 11 are opposite to the rotational direction of the brake drum 2 with respect to the radial line L of the rotating shaft 1. However, the present invention is not limited in this respect, and may be inclined in the same direction as the rotation direction of the brake drum 2.

  Moreover, in the said embodiment, although the inclination direction and inclination angle of the magnetic pole surfaces 15a and 16a of all the permanent magnets 15 and 16 were made the same, this invention is not limited in this point, An inclination direction and / or an inclination angle are set. Different permanent magnets 15 and 16 may be used.

  In the above embodiment, it has been described that the outer peripheral portion of the protective case 3 is released. However, the present invention is not limited in this respect, and a cover made of a nonmagnetic material may be provided on the outer peripheral portion of the protective case 3. good.

  Furthermore, the present invention can be applied to various types of retarders in addition to the above-described embodiments.

  For example, the present invention can also be applied to a type using a single magnet ring that can slide in the axial direction of the rotating shaft, as described in the “Background Art” section with reference to FIGS. That is, instead of the magnet ring 42 shown in FIGS. 9 to 11, one magnet ring having the same structure as the magnet rings 10 and 11 shown in FIG. 2 is provided in the protective case 3 so as to be slidable in the axial direction, The outer cylinder part 40 and the pole piece 41 of the protective case 3 may be omitted and the outer peripheral part may be open.

  The present invention can also be applied to a type of retarder in which two magnet rings 22 and 23 are arranged adjacent to each other in the radial direction of the rotating shaft 1 as shown in FIGS.

  In this retarder, the outer cylindrical portion 24 of the protective case 3 is formed of a magnetic material, and a plurality of permanent magnets 25 are embedded in the outer cylindrical portion 24 at equal intervals in the circumferential direction. And the permanent magnet 25 constitute a stationary magnet ring (outer magnet ring) 22. That is, in this stationary magnet ring 22, the outer cylinder part 24 has a role of a pole piece.

  On the other hand, a movable magnet ring (inner magnet ring) 23 that is rotatable in the circumferential direction is disposed inside the protective case 3 so as to oppose the radially inner side of the stationary magnet ring 22. The movable magnet ring 23 is provided so as to be relatively rotatable with respect to the protective case 3, and is disposed on the outer peripheral surface of the magnet support cylinder 26 at a circumferential interval with a magnet support cylinder 26 made of a nonmagnetic material. A plurality of permanent magnets 27 and a pole piece 29 made of a magnetic material are provided between the permanent magnets 27. The movable magnet ring 23 is connected to the actuator 20 (see FIG. 6) and can rotate relative to the protective case 3 and the stationary magnet ring 22 in the circumferential direction.

  Also in such a retarder, as shown in FIGS. 7A and 7B, the magnetic pole surfaces formed at the circumferential ends of the permanent magnets 25 and 27 of the magnet rings 22 and 23 are arranged on the rotating shaft. Since the magnetic force of the permanent magnets 25 and 27 can be increased without increasing the magnet amount by inclining at a predetermined angle with respect to the radial line L of 1 (see FIG. 6), the braking drum 2 and the rotary shaft 1 The braking torque with respect to can be improved.

  In this retarder, the movable magnet ring 23 is rotated so that the permanent magnets 27 of the movable magnet ring 23 and the permanent magnets 25 of the stationary magnet ring 22 are adjacent to each other with the same polarity as shown in FIG. If it is (adjacent in the radial direction), the magnetic fluxes of the permanent magnets 27 and 25 of the movable magnet ring 23 and the stationary magnet ring 22 act on the brake drum 2 via the pole pieces 29 and 24. When a braking torque is generated for the shaft 1 and the permanent magnets 27 of the movable magnet ring 23 and the permanent magnets 25 of the stationary magnet ring 22 are adjacent to each other with different polarities as shown in FIG. Since a short circuit magnetic circuit is formed between the permanent magnet 27 of the ring 23 and the permanent magnet 25 of the stationary magnet ring 22, no magnetic flux acts on the braking drum 2 and no braking torque is generated.

  Further, as shown in FIG. 8, each permanent magnet 27 'of the movable magnet ring 23' has a magnetic pole surface at both ends in the radial direction, and the magnet support cylinder 26 'of the movable magnet ring 23' is made of a magnetic material. Even in the type of retarder, the braking torque can be improved by inclining the magnetic pole surface of each permanent magnet 25 of the stationary magnet ring 22 with respect to the radial line L of the rotating shaft (not shown).

  As described above, the present invention can be applied to a retarder having any structure as long as the type includes a permanent magnet having magnetic pole faces at both ends in the circumferential direction.

It is an upper half side sectional view of an eddy current type reduction gear concerning one embodiment of the present invention. It is a fragmentary front sectional view showing a rotor (braking drum) and a magnet ring of an eddy current type reduction gear concerning one embodiment of the present invention. It is a fragmentary top view of the magnet ring of the eddy current type reduction gear which concerns on one Embodiment of this invention. It is a figure for demonstrating the difference in the magnetic pole surface length of a permanent magnet. It is a figure which shows the analysis result of the braking torque which acts on a rotating shaft. It is upper half side surface sectional drawing of the eddy current type speed reducer which concerns on other embodiment of this invention. It is a partial front sectional view showing a rotor (braking drum) and a magnet ring of an eddy current type speed reducer according to another embodiment of the present invention, where (a) shows a state at the time of braking and (b) shows a state at the time of non-braking. Indicates the state. It is a partial front sectional view showing a rotor (braking drum) and a magnet ring of an eddy current type speed reducer according to another embodiment of the present invention, where (a) shows a state at the time of braking and (b) shows a state at the time of non-braking. Indicates the state. It is upper half side surface sectional drawing of the conventional eddy current type reduction gear. It is a partially broken perspective view which shows the protective case and magnet ring of the conventional eddy current type reduction gear. It is a partial front sectional view of a conventional eddy current type reduction gear. It is a partial fracture perspective view of the conventional eddy current type reduction gear. It is a partial side sectional view of a conventional eddy current type reduction gear. It is a partial front cross section of the eddy current type reduction device which the present applicant proposed previously.

Explanation of symbols

1 Rotating shaft 2 Brake drum (rotor)
3 Protective case 10 Magnet ring (movable magnet ring)
11 Magnet ring (Fixed magnet ring)
12 Magnet support tube (yoke)
13 Magnet support tube (yoke)
DESCRIPTION OF SYMBOLS 15 Permanent magnet 15a Magnetic pole surface 16 Permanent magnet 16a Magnetic pole surface 17 Pole piece 18 Pole piece L The line extended to the radial direction of a rotating shaft

Claims (5)

A rotor coupled to a rotating shaft, a plurality of permanent magnets for applying a magnetic force to the rotor, and magnetic bodies respectively disposed between opposing magnetic pole faces of adjacent permanent magnets among the plurality of permanent magnets In an eddy current type speed reducer provided with a magnet ring having a magnetic ring,
A plurality of the permanent magnets are arranged at intervals in the circumferential direction of the rotating shaft, each permanent magnet has a magnetic pole surface at both ends in the circumferential direction, and the magnetic body is an adjacent permanent magnet among the plurality of permanent magnets Are arranged so as to fill in the circumferential direction between the opposing magnetic pole faces
Of the peripheral surfaces of the magnetic ring, at least one peripheral surface of the outer peripheral surface and the inner peripheral surface is formed by the peripheral end surface of the permanent magnet,
The magnetic ring is in contact with a void or a non-magnetic material on the peripheral surface,
The magnetic pole surface is formed to be inclined with respect to a line extending in the radial direction of the rotating shaft, and the opposing magnetic pole surfaces of two adjacent permanent magnets are respectively lines extending in the radial direction of the rotating shaft. An eddy current type speed reducer characterized by tilting in the same direction and facing pole faces of two adjacent permanent magnets having the same polarity . In an eddy current reduction device comprising: a rotor coupled to a rotating shaft; and a magnet ring having a permanent magnet for applying a magnetic force to the rotor.
A plurality of the permanent magnets are arranged at intervals in the circumferential direction of the rotating shaft, each permanent magnet has a magnetic pole surface at both ends in the circumferential direction, and the magnetic pole surface extends in the radial direction of the rotating shaft. Formed inclined with respect to the line, and
The magnetic pole surfaces of the plurality of permanent magnets are all formed so as to be inclined at the same angle in the same direction with respect to a line extending in the radial direction of the rotating shaft. The eddy current reduction device according to claim 1 or 2, wherein an inclination direction of the magnetic pole surface of the permanent magnet is a rotation direction of the rotation shaft or an opposite direction thereof. The rotor comprises a bottomed cylindrical brake drum,
The magnet ring is disposed inside the brake drum, and is an annular magnet support cylinder made of a non-magnetic material, and a plurality of the permanent magnets arranged on the outer peripheral surface of the magnet support cylinder at intervals in the circumferential direction, The eddy current type reduction device according to any one of claims 1 to 3, further comprising a pole piece arranged between the permanent magnets and made of a magnetic material. In an eddy current reduction device comprising: a rotor coupled to a rotating shaft; and a magnet ring having a permanent magnet for applying a magnetic force to the rotor.
A plurality of the permanent magnets are arranged at intervals in the circumferential direction of the rotating shaft, each permanent magnet has a magnetic pole surface at both ends in the circumferential direction, and the magnetic pole surface extends in the radial direction of the rotating shaft. Formed inclined to the line,
The rotor comprises a bottomed cylindrical brake drum,
The magnet ring is disposed inside the brake drum, and is an annular magnet support cylinder made of a non-magnetic material, and a plurality of the permanent magnets arranged on the outer peripheral surface of the magnet support cylinder at intervals in the circumferential direction, Arranged between these permanent magnets, with a pole piece made of magnetic material,
The magnet ring includes a movable magnet ring that can rotate in the circumferential direction of the rotating shaft, and a stationary magnet ring that is adjacent to the movable magnet ring from the axial direction and cannot rotate in the circumferential direction of the rotating shaft,
A braking position that adjusts the phase of the movable magnet ring to apply the magnetic force of the permanent magnet of the movable magnet ring and the stationary magnet ring to the braking drum, and the movable magnet ring and the stationary magnet ring of the stationary magnet ring. An eddy current reduction device comprising an actuator for switching between a non-braking position where a magnetic force of a permanent magnet does not act.

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