JP4048712B2 - Rotor connection structure of eddy current type speed reducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to an eddy current type reduction device as a retarder attached to an automobile, and relates to a connection structure for connecting a rotor to a rotating shaft member.
[0002]
[Prior art]
In the eddy current type speed reducer, an eddy current is generated in the rotor when the rotor connected to the rotating shaft member crosses the magnetic field, and thereby a braking force is applied to the rotor and the rotating shaft member. Finally, it is converted into heat and emitted.
[0003]
For example, in an eddy current type speed reducer used as a retarder in a large automobile, when the rotor is used severely, such as when used for a long time at a high speed when going down a long downhill, the temperature of the rotor will change to the inner surface. At 700 ° C or higher. For this reason, the diameter of the rotor is expanded by thermal expansion. For example, in a rotor having an inner diameter of about 400 mm, the diameter is increased by 2 to 3 mm.
[0004]
When the rotor is thermally expanded, it is conceivable that stress concentrates on a specific portion of the rotor and breaks, or the rotor does not uniformly expand in the circumferential direction and deforms abnormally. In order to prevent this, conventionally, as shown in FIG. 16, the support arm 41 attached to the rotor 40 is slidably fitted into the hole 43 provided in the outer peripheral portion of the rotary shaft member 42. In addition, a connection structure in which a spring 45 for urging the support arm 41 radially outward is provided in the hole 43 is used. According to this connection structure, the support arm 41 can slide outside in the radial direction, and thus thermal expansion of the rotor 40 can be allowed. Therefore, damage and abnormal deformation due to stress concentration of the rotor can be prevented. Further, since the spring 45 urges the rotor 40 in the direction of thermal expansion (in the direction of expanding the diameter), the thermal expansion of the rotor 40 can be promoted and the diameter can be increased uniformly in the circumferential direction.
[0005]
However, this connection structure has many parts and is complicated, and requires a heat-resistant O-ring 46 and heat-resistant grease to smoothly slide the arm 41 at a high temperature, resulting in a very high cost.
[0006]
In view of this, a rotor connection structure as shown in FIG.
[0007]
In this connection structure, the arm 50 provided on the outer periphery of the boss portion 49 connected to the rotating shaft 47 and the arm 52 provided on the inner periphery of the rotor 51 are connected to each other by the connection plate 53. According to this structure, the thermal expansion (expansion) of the rotor 51 can be allowed by bending the connecting plate 53 and can be manufactured at a low cost.
[0008]
[Problems to be solved by the invention]
However, the conventional rotor connecting structure as shown in FIG. 17 has a problem that rigidity is low and rotational strength is low.
[0009]
That is, when the rotation shaft 47 is accelerated in the rotation direction R with respect to the rotor 51, the connecting plate 53 receives a tensile stress. Therefore, the strength in the rotation direction R is relatively high, but the rotation shaft is decelerated, etc. When accelerating in the direction opposite to the rotation direction R with respect to 51, the connecting plate 53 receives compressive stress, and therefore the strength in the direction opposite to the rotation direction R is low. Further, when used as a retarder in a large automobile, the compressive stress applied to the connecting plate 53 is also received by rotational vibration generated from the intersection angle of the propeller shaft.
[0010]
Further, in the conventional rotor connecting structure as shown in FIG. 17, all connecting plates 53 are cantilevered, so that a large bending moment is applied to the connecting portion, which causes a problem in strength.
[0011]
Accordingly, an object of the present invention is to provide a rotor connection structure of an eddy current type speed reducer that solves the above-described problems and has sufficient rotational strength, and allows thermal expansion of the rotor to prevent breakage and deformation. is there.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a structure in which a rotor is connected to the outer peripheral side of a rotating shaft member to be braked, and the rotating shaft member is positioned at a radial intermediate position between the rotating shaft member and the rotor. A plate-like metal spring extending in the circumferential direction is arranged, and the metal spring is formed in a ring shape over the entire circumference in the circumferential direction of the rotary shaft member, and the rotary shaft member and the rotor are wound around the metal spring. While alternately fastening in the direction, at least one of them is fastened at a plurality of locations.
[0013]
According to this configuration, since at least one of the rotating shaft member and the rotor is fastened to the metal spring at a plurality of points, the rotational strength can be increased. Moreover, since the rotating shaft member and the rotor are connected via a metal spring, the metal spring is deformed, so that thermal expansion of the rotor is allowed, and damage and abnormal deformation can be prevented. Further, since the metal spring is formed in a ring shape over the entire circumference of the rotating shaft member, the rotating shaft member is accelerated in the opposite rotating direction even when the rotating shaft member is accelerated in one rotating direction with respect to the rotor. In both cases, tensile stress is applied, and sufficient rotational strength can be obtained.
[0014]
Further, the rotating shaft member and the rotor may be fastened to the metal spring at a plurality of locations. According to this, the rotational strength of the rotor can be further increased.
[0015]
Further, the metal spring is formed into a corrugated shape having a convex portion bent radially outward and a concave portion bent radially inward, and the rotary shaft member or the rotor is fastened to the top of the convex portion and the bottom of the concave portion. You may be made to do. According to this, the deformation amount of the metal spring in the circumferential direction can be increased.
[0017]
Further, the metal spring may be fastened to the rotating shaft member and the rotor in a state compressed from the natural state in the diameter reducing direction or expanded in the diameter increasing direction. According to this, since a uniform urging force is always applied over the entire circumference of the rotor, the rotor can be thermally expanded evenly in the circumferential direction. Further, when the metal spring is compressed in the diameter reducing direction and fastened, the metal spring urges the rotor in the diameter increasing direction, so that the thermal expansion of the rotor can be promoted. As a result, the effect that the rotor can be thermally expanded uniformly can be further increased, and the stress generated during expansion can be further reduced.
[0019]
The rotating shaft member includes first spokes that extend radially outward, the rotor includes second spokes that extend radially inward, and the top of the convex portion of the metal spring is the first spoke. Alternatively, it may be fastened to one of the second spokes, and the bottom of the concave portion of the metal spring may be fastened to the other spoke. According to this, it becomes difficult for the heat of a rotor to be transmitted to a fastening part, and the force concerning a fastening part can be made small.
[0020]
Furthermore, the first spoke and the second spoke may be provided offset in the axial direction. According to this, the space can be effectively used by shifting the position of the metal spring in the axial direction.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0022]
FIG. 1 is a front view of an eddy current type speed reducer using a rotor connecting structure according to an embodiment of the present invention, and FIG. 2 is a side sectional view thereof.
[0023]
This embodiment shows a rotor connecting structure in an eddy current type speed reducer used as a retarder in an automobile. First, an outline of the retarder will be described with reference to FIG.
[0024]
As shown in the figure, a rotating shaft 55 (here, a propeller shaft provided on the output side of the transmission), a mounting flange 56 fixed to the rotating shaft 55, and a wheel 15 fixed to the mounting flange 56 by bolts 54. The rotor 12 is coupled to the outer peripheral side of the rotary shaft member 11 configured by Inside the rotor 12, a fixed frame 59 having a large number of ferromagnetic plates (pole pieces) 57 on the outer peripheral portion is provided. Inside the fixed frame 59, a magnet support wheel 60 is rotatably provided, and a plurality of permanent magnets 61 are provided on the outer peripheral portion of the magnet support wheel 60 at equal intervals in the circumferential direction. Further, the fixed frame 59 is provided with an actuator 62 for rotating the magnet support wheel 60.
[0025]
During braking, an eddy current is generated in the rotor 12 by rotating the magnet support wheel 60 by a predetermined angle by the actuator 62 to generate a magnetic circuit between the permanent magnet 61, the ferromagnetic plate 57, and the rotor 12. A braking force is applied.
[0026]
Now, a connection structure for connecting the wheel 15 forming a part of the rotating shaft member 11 and the rotor 12 will be described with reference to FIGS. 1 and 2.
[0027]
A plurality of wheel spokes (first spokes) 16 extending outward in the radial direction are provided on the outer peripheral portion of the wheel 15 at equal intervals in the circumferential direction.
[0028]
A plurality of radiating fins 17 are provided on the outer peripheral portion of the rotor 12 at predetermined intervals in the circumferential direction. A plurality of rotor spokes (second spokes) 19 extending radially inward are provided at equal intervals in the circumferential direction at the axial end portion (right end portion in FIG. 2) of the rotor 12.
[0029]
The wheel spokes 16 and the rotor spokes 19 described above are alternately arranged at predetermined intervals in the circumferential direction. Further, the wheel spoke 16 and the rotor spoke 19 are formed integrally with the wheel 15 and the rotor 12, respectively.
[0030]
A metal spring 13 extending in the circumferential direction is disposed between the wheel spoke 16 and the rotor spoke 19, and the wheel 15 and the rotor 12 are connected via the metal spring 13.
[0031]
The metal spring 13 is made of plate-shaped spring steel, and in the present embodiment, is formed in a ring shape integrally with the circumferential direction.
[0032]
The metal spring 13 is formed in a waveform in which convex portions 20 bent radially outward and concave portions 21 bent radially inward are alternately provided. The convex portion 20 and the concave portion 21 are formed in a substantially trapezoidal shape composed of slope portions 22 and 22 on both sides and a top portion 20a and a bottom portion 21a located between the slope portions 22 and 22, respectively. Therefore, the inclined surface portion 22 of the metal spring 13 also serves as a part of both the convex portion 20 and the concave portion 21 adjacent to each other. Moreover, although the slope part 22 is a linear shape in this embodiment, the curved shape may be sufficient.
[0033]
The top portion 20a of the convex portion 20 of the metal spring 13 is overlaid on the end surface 19a of the rotor spoke 19, and the bottom portion 21a of the concave portion 21 is overlaid on the end surface 16a of the wheel spoke 16 and is fastened to each other by a bolt 23. .
[0034]
Here, the assembly method of the metal spring 13 of this embodiment is demonstrated using FIG.
[0035]
In the drawing, the state indicated by the dotted line a indicates the natural state, that is, the state before being fastened to the wheel spoke 16 and the rotor spoke 19, and the state indicated by the solid line b indicates the state after assembly. .
[0036]
As shown in the drawing, when the metal spring 13 is fastened to the wheel spoke 16 and the rotor spoke 19, the metal spring 13 is fastened in a state compressed from the natural state in the diameter reducing direction. Therefore, the metal spring 13 always urges the rotor 12 radially outward, that is, in the direction of expanding the diameter.
[0037]
Next, the operation of this embodiment will be described.
[0038]
When the wheel 15 connected to the rotation shaft rotates, the rotation is transmitted to the rotor 12 via the metal spring 13.
[0039]
When the wheel 15 is accelerated in the rotation direction R with respect to the rotor 12, the metal spring 13 receives a tensile stress. On the other hand, when the wheel 15 is accelerated in the direction opposite to the rotation direction R with respect to the rotor 12, the metal spring 13 is similarly subjected to tensile stress.
[0040]
Thus, when acceleration acts in the rotation direction R and the opposite direction, the metal spring 13 receives a tensile stress in any case, so that sufficient rotation strength can be obtained.
[0041]
When the rotor 12 generates heat due to the eddy current flowing through the rotor 12 during braking, the diameter of the rotor 12 is expanded by thermal expansion. At this time, as shown by a dotted line a in FIG. 3, the metal spring 13 is deformed and expanded in diameter so that the height of each convex portion 20 is high and the length of the top portion 20a is short (to return to the natural state). To do). Thereby, the thermal expansion of the rotor 12 is allowed.
[0042]
Thus, since the metal spring 13 allows thermal expansion of the rotor 12, stress is not concentrated inside the rotor 12, and damage and abnormal deformation are prevented.
[0043]
Further, since the metal spring 13 urges the rotor 12 with a uniform force in the circumferential direction, the urging force of the metal spring 13 promotes the diameter expansion of the rotor 12, and the rotor 12 can be expanded evenly in the circumferential direction.
[0044]
Furthermore, by forming the metal spring 13 in a waveform, the deformation stroke of the metal spring 13 in the circumferential direction can be increased. That is, the diameter of the rotor 12 can be sufficiently increased.
[0045]
Further, since the rotor spoke 19 is provided on the rotor 12 and the metal spring 13 is fastened to the rotor spoke 19, the heat capacity of the rotor 12 is increased and the rotor spoke 19 serves as a radiation fin. 12 thermal expansion can be suppressed. As a result, the force applied to the fastening portion between the metal spring 13 and the rotor spoke 19 and the wheel spoke 16 can be reduced. Further, since the fastening portion of the bolt 23 can be moved away from the inner peripheral surface of the rotor 12, the temperature rise of the fastening portion due to heat transmitted from the rotor 12 can be suppressed. These have the effect of preventing the bolt 23 from loosening.
[0046]
In the present embodiment, ten wheel spokes 16 and ten rotor spokes 19 are provided, but the present invention is not limited in this respect, and more or less may be provided as necessary. In this case, of course, the rotational strength of the rotor 12 can be increased by increasing the number of the spokes 19 and 16.
[0047]
In the present embodiment, the metal spring 13 has been described as being assembled with the diameter reduced inward in the radial direction. However, the present invention is not limited in this respect, and the metal spring 13 is expanded outwardly in the radial direction. Or may be assembled in a natural state. In either case, the metal spring 13 can be deformed to allow thermal expansion of the rotor 12 and thus prevent damage and abnormal deformation. Further, when the diameter of the rotor 12 is increased, the metal spring 13 is uniformly biased in the circumferential direction, so that the rotor 12 can be uniformly expanded in the circumferential direction.
[0048]
Further, in the present embodiment, the fastening method between the metal spring 13 and the spokes 16 and 19 has been described as bolting, but the present invention is not limited in this respect, and other fastening methods such as riveting may be used. . Moreover, although it was supposed that it fastened with the one volt | bolt 23 in each fastening position, you may fasten with the several volt | bolt 23. FIG.
[0049]
Various modifications of the present invention can be considered, and other embodiments of the present invention will be described with reference to FIGS.
[0050]
First, the form shown in FIGS. 4 and 5 is a modified example of the rotor spoke 19. In the embodiment shown in FIG. 1, the rotor spoke 19 is formed integrally with the rotor 12, whereas FIG. In the embodiment shown in FIG. 2, the rotor spoke 19 and the rotor 12 are formed separately and attached to the rotor 12 by bolts 26. In the form shown in FIG. 5, the rotor spoke 19 and the rotor 12 are formed separately, and the rotor spoke 19 is welded to the rotor 12.
[0051]
Needless to say, these attachment methods of the rotor spokes 19 can also be applied to the wheel spokes 16.
[0052]
Next, in the form shown in FIG. 6, the length of the rotor spoke 19 is formed longer than the form shown in FIG. 1, and the end face 19 a is positioned radially inward from the end face 16 a of the wheel spoke 16. It is a thing. In this form, contrary to the form shown in FIG. 1, the top part 20 a of the convex part 20 of the metal spring 13 is overlapped with the end face 16 a of the wheel spoke 16, and the bottom part 21 a of the concave part 21 is the end face 19 a of the rotor spoke 19. Are overlaid on each other and fastened. According to this embodiment, since the length of the rotor spoke 19 is long, the above-described loosening prevention effect of the bolt 23 can be made remarkable.
[0053]
In the form shown in FIG. 7, the rotor spoke 19 is provided, but the wheel spoke 16 is not provided, and the bottom portion 21 a of the concave portion 21 of the metal spring 13 is directly fastened to the wheel 15. According to this configuration, similarly to the embodiment shown in FIG. 6, the bolt 23 can be reliably prevented from loosening.
[0054]
In the form shown in FIG. 8, contrary to the form shown in FIG. 7, the wheel spoke 19 is provided, but the rotor spoke 16 is not provided, and the top 20a of the convex part 20 of the metal spring 13 is directly connected to the rotor. 12 is fastened to the inner peripheral surface. In the embodiment shown in FIG. 9, the metal spring 13 is directly fastened to the inner peripheral surface of the rotor 12 and the outer peripheral surface of the wheel 15 without providing either the rotor spoke 16 or the wheel spoke 19. .
[0055]
Thus, the manufacturing cost of the rotor 12 and the wheel 15 can be kept low by setting it as the structure which does not provide either the rotor spoke 16 or the wheel spoke 19, or both.
[0056]
Next, FIGS. 10 to 12 show modifications of the metal spring 13, and the form shown in FIG. 10 is formed by stacking metal springs 13a and 13b having a thickness smaller than that of the metal spring 13 shown in FIG. It is what was used. According to this structure, the internal stress generated in the metal springs 13a and 13b when the metal springs 13a and 13b are deformed as the diameter of the rotor 12 is increased can be reduced. In addition, there is an effect of suppressing the vibration of the rotor 12 by a damping effect due to friction between the overlapping leaf springs 13a and 13b. In the embodiment shown in FIG. 10, two leaf springs 13a and 13b are stacked, but it is needless to say that more leaf springs may be stacked.
[0057]
In the form shown in FIG. 11, the metal spring 13 is formed in a cylindrical shape instead of a waveform.
[0058]
In the form shown in FIG. 12, the metal spring 13 is formed by dividing a plurality of metal springs 13 in the circumferential direction, and the end portions 27 and 29 are overlapped and fastened to form a ring shape integrated in the circumferential direction as a whole. Formed. The connecting portion between the end portions 27 and 29 may be fixed by welding.
[0059]
The form shown in FIG. 13 is not an embodiment of the present invention but a reference example. To explain, the metal spring 13 is divided into a plurality of parts in the circumferential direction, and these are separately fastened to the spokes 16 and 19. It is a thing. In this case, the rotor 12 and the wheel 15 are fastened alternately to the metal spring 13 in the circumferential direction, and at least one of them is fastened to the metal spring 13 at a plurality of points. It is. By doing so, the metal spring 13 receives a tensile stress in any case where acceleration is applied in the rotation direction R and the opposite direction, so that sufficient rotation strength can be obtained. Preferably, when one of the rotor 12 and the wheel 15 is fastened to the metal spring 13 at n places, the other is fastened at n + 1 places. By doing so, the strength in the rotation direction R is equal to the strength in the reverse direction, and a balance can be achieved.
[0060]
Moreover, when the metal spring 13 is formed by dividing a plurality of metal springs 13 at equal intervals in the circumferential direction, the same shape can be produced in large quantities, and thus the manufacturing cost can be kept low.
[0061]
In the embodiment of the present invention shown in FIGS. 14 and 15, the wheel spokes 16 and the rotor spokes 19 are offset from each other in the axial direction. The form shown in FIG. The pork 19 is offset to the outside (right side in the drawing) of the rotor 12 in the axial direction. In the form shown in FIG. 15, contrary to FIG. 14, the wheel spoke 16 is offset with respect to the rotor spoke 19 inside the rotor 12 (left side in the drawing) in the axial direction. Thus, by offsetting the wheel spoke 16 and the rotor spoke 19 in the axial direction with respect to each other, the axial position of the metal spring 13 can be shifted to effectively use the space. For example, by shifting the axial position of the metal spring 13 to the outside of the rotor 12, the permanent magnet 61 disposed in the rotor 12 can be made larger and the retarder braking force can be increased.
[0062]
Here, in the conventional connecting structure as shown in FIG. 17, when the arm 50 and the arm 52 are offset in the axial direction, the connecting plate 53 is twisted when the diameter of the rotor 51 is increased, and the rotor 51 is displaced in the axial direction. There is a risk that.
[0063]
However, since the metal spring 13 of the present invention has an elastic force in the radial direction, even when the spokes 16 and 19 are offset, the diameter of the rotor 12 can be accommodated only by deformation in the radial direction. The rotor 12 is not twisted and the rotor 12 is not displaced in the axial direction. In particular, if the metal spring 13 is compressed and assembled in the diameter reducing direction, when the rotor 12 is expanded in diameter, the metal spring 13 is expanded in diameter by its own elastic return force, so that the effect is higher.
[0064]
It should be noted that the modification examples described so far can be configured in combination.
[0065]
Furthermore, the present invention can be applied to the rotor connecting structure of all types of eddy current type reduction gears, such as those using permanent magnets, those using electromagnets, and those using both.
[0066]
【The invention's effect】
In short, according to the present invention, excellent effects are exhibited as described below.
1) A sufficient rotational strength can be obtained.
2) The rotor is not damaged or abnormally deformed when thermally expanded.
[Brief description of the drawings]
FIG. 1 is a front view of an eddy current reduction device using a rotor connecting structure according to an embodiment of the present invention.
FIG. 2 is a side cross-sectional view of an eddy current speed reducer using a rotor coupling structure according to an embodiment of the present invention.
FIG. 3 is a diagram showing a natural state and an assembled state of a metal spring.
FIG. 4 is a partially enlarged view showing another embodiment of a spoke attachment structure.
FIG. 5 is a partially enlarged view showing another embodiment of a spoke attachment structure.
FIG. 6 is a front view of a rotor connecting structure according to another embodiment.
FIG. 7 is a front view showing a form in which wheel spokes are not provided.
FIG. 8 is a front view showing a form in which a rotor spoke is not provided.
FIG. 9 is a front view showing a form in which wheel spokes and rotor spokes are not provided.
FIG. 10 is a partially enlarged view showing a configuration in which metal springs are stacked.
FIG. 11 is a partially enlarged view showing a form in which a metal spring is divided in the circumferential direction and the ends thereof are overlapped and fastened.
FIG. 12 is a front view showing a form in which metal springs are formed in the circumferential direction and are separately fastened.
13 is a front view showing a form in which a metal spring is divided into a plurality of parts in the circumferential direction (not an embodiment of the present invention but a reference example) .
FIG. 14 is a cross-sectional view showing a form in which wheel spokes and rotor spokes are offset in the axial direction.
FIG. 15 is a cross-sectional view showing a form in which wheel spokes and rotor spokes are offset in the axial direction.
FIG. 16 is a side sectional view showing a conventional rotor connecting structure;
FIG. 17 is a front view showing another conventional rotor connecting structure;
[Explanation of symbols]
11 Rotating shaft member 12 Rotor 13 Metal spring 16 Wheel spoke 19 Rotor spoke

Claims (6)

The rotor is connected to the outer peripheral side of the rotating shaft member to be braked,
A plate-like metal spring extending in the circumferential direction of the rotating shaft member is disposed at a radial intermediate position between the rotating shaft member and the rotor,
The metal spring is formed in a ring shape over the entire circumference of the rotating shaft member,
The rotating shaft member and the rotor are alternately fastened to the metal spring in the circumferential direction, and at least one of them is fastened at a plurality of locations. Construction.   The rotor connection structure of an eddy current type reduction gear according to claim 1, wherein the rotating shaft member and the rotor are fastened to the metal spring at a plurality of locations.   The metal spring is formed in a corrugated shape having a convex portion bent radially outward and a concave portion bent radially inward, and the rotating shaft member or the rotor is fastened to the top of the convex portion and the bottom of the concave portion. The rotor connection structure of the eddy current type speed reducer according to claim 1 or 2. The rotor connection structure of an eddy current type speed reducer according to claim 1, wherein the metal spring is fastened to the rotary shaft member and the rotor in a state where the metal spring is compressed in the diameter reducing direction or expanded in the diameter increasing direction. . The rotating shaft member includes a first spoke that extends radially outward, the rotor includes a second spoke that extends radially inward, and the top of the convex portion of the metal spring is the first spoke or the first spoke. The rotor connection structure of an eddy current type speed reducer according to claim 3 or 4 , wherein the rotor is fastened to either one of the two spokes and the bottom of the concave portion of the metal spring is fastened to the other spoke . The rotor connection structure for an eddy current type reduction gear according to claim 5, wherein the first spoke and the second spoke are provided to be offset in the axial direction .

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