JP7622976B2 - Positive and reverse fine rotation elastic bearing - Google Patents

Description

The present invention relates to a forward/reverse fine-motion elastic bearing that combines the function of supporting a shaft that repeatedly rotates in forward and reverse directions at a small angle and the function of returning the shaft to a fixed position using the restoring force of an elastic member.

General bearings are designed to support a shaft that rotates in a fixed direction, so they are not suitable for use in parts that support a shaft that rotates in small increments, and do not have the spring function to return the shaft to a fixed position. However, mechanisms for supporting a shaft that rotates in small increments and spring mechanisms are needed in various mechanical devices, so conventionally, bearings that use rolling elements (see, for example, Patent Documents 1 and 2) or bearings that use coil springs (see, for example, Patent Document 3) have been used.

The "rocking bearing" described in Patent Document 1 has a raceway ring whose outer diameter surface is formed in an arc shape and whose inner diameter surface is provided with a concave arc-shaped raceway surface, and a number of rollers that are arranged and roll on the raceway surface of the raceway ring. The outer diameter surface of the raceway ring is fixed by abutting it against the concave arc-shaped portion of the housing, and the rollers support the convex arc-shaped portion of the movable member so that it can rock freely. In this rocking bearing, a buffer means is provided on the outer diameter surface of the raceway ring that provides a buffering effect between the concave arc-shaped portion of the housing with which the outer diameter surface abuts.

The "forward and reverse fine rotation rolling bearing" described in Patent Document 2 is a forward and reverse fine rotation rolling bearing in which grease is sealed in a bearing space in which rolling elements are arranged between the raceway surfaces of the inner and outer rings, and which supports a shaft that rotates forward and reverse finely. The rolling elements are made of ceramic, a carbonitriding layer is formed on the raceway surfaces of the inner and outer rings, and a urea compound is used as a grease thickener.

The "elastic fulcrum bearing" described in Patent Document 3 is constructed by pressing a shaft body with a coil spring wound around a serration section on the outer periphery into a shaft hole with a serration section on the inner periphery.

JP 2008-64267 A JP 2006-316850 A Japanese Patent Publication No. 136633/1983

The "rocking bearing" described in Patent Document 1 and the "rolling bearing for forward and reverse fine rotation" described in Patent Document 2 have a complex structure, are noisy during operation, and require lubricants such as grease. In addition, when the bearings described in Patent Documents 1 and 2 are used in forward and reverse fine rotation parts, the multiple rolling elements equipped on each bearing repeatedly roll within a limited, minute range, which breaks the oil film of the grease used as a lubricant and causes solid contact, resulting in localized wear, which reduces the bearing's function and reduces durability. In particular, when the rolling elements are used under a heavy load or when used on a shaft that rotates forward and reverse finely at high speed, the aforementioned localized wear is likely to occur. Furthermore, the bearings described in Patent Documents 1 and 2 do not have the function of a spring to return the shaft to its fixed position.

In addition, when the "elastic fulcrum bearing" described in Patent Document 3 is used in the forward and reverse fine rotation part, minute sliding motion is repeated at the contact points between the coil spring and the shaft serration part and the shaft hole serration part, so it is impossible to avoid noise generation and fretting wear.

The problem that this invention aims to solve is to provide a forward/reverse fine-motion elastic rotary bearing that produces very little noise and vibration during operation, requires no maintenance, and can be made relatively easily compact and lightweight with a simplified structure.

The forward/reverse fine rotation elastic bearing according to the present invention has:
A support member disposed around a shaft body that rotates slightly in forward and reverse directions;
a plurality of elastic members each having a base end portion engaged with the support member and a tip end portion engaged with an outer periphery of the shaft body,
The present invention is characterized in that the base end and the tip end of the elastic member are engaged at positions where the elastic member can deform rotationally symmetrically about the axis of the shaft when a torsional moment is applied to the shaft.

In the forward/reverse fine rotation elastic bearing, it is preferable that the elastic members are plate-shaped elastic members having curved portions that are curved so as to surround a semicircular region around the shaft body.

In the forward/reverse fine rotation elastic bearing, the plate-shaped elastic member can have a portion in which the plate thickness of the plate-shaped elastic member decreases from the base end toward the tip end.

The present invention provides a forward/reverse fine-motion elastic rotary bearing that produces very little noise and vibration during operation, requires no maintenance, and can be made relatively easily compact and lightweight with a simplified structure.

1 is a partially omitted perspective view showing a forward/reverse fine-motion elastic rotation bearing according to an embodiment of the present invention. 2 is a partially omitted front view of the forward/reverse fine rotation elastic bearing as seen from the direction of the arrow A in FIG. 1 . 2 is a partially omitted side view of the forward/reverse fine-motion rotation elastic bearing as seen from the direction of the arrow B in FIG. 1 . 2 is a partially omitted plan view of a forward/reverse fine-motion rotation elastic bearing as seen from the direction of the arrow C in FIG. 1 . FIG. 2 is a partially omitted perspective view of a repeating moment generating device using the forward/reverse fine rotation elastic bearing shown in FIG. 1 . FIG. 6 is a partial enlarged view of the repeating moment generating device shown in FIG. 5 . FIG. 11 is a partially omitted perspective view showing a forward/reverse fine-motion rotation elastic bearing according to another embodiment of the present invention. FIG. 8 is a partially omitted front view of the forward/reverse fine rotation elastic bearing shown in FIG. 7 . FIG. 11 is a partially omitted perspective view showing a forward/reverse fine-motion rotation elastic bearing according to another embodiment of the present invention. FIG. 10 is a partially omitted front view of the forward/reverse fine rotation elastic bearing shown in FIG. FIG. 11 is a partially omitted perspective view showing a forward/reverse fine-motion rotation elastic bearing according to another embodiment of the present invention. FIG. 12 is a partially omitted front view of the forward/reverse fine rotation elastic bearing shown in FIG. 11 . FIG. 11 is a partially omitted perspective view showing a forward/reverse fine-motion rotation elastic bearing according to another embodiment of the present invention. FIG. 14 is a partially omitted front view of the fine-motion rotation elastic bearing shown in FIG. 13 .

Below, based on Figures 1 to 6, we will explain the forward/reverse fine-motion elastic rotation bearing 50, which is an embodiment of the present invention, and the repeating moment generating device 100 that uses the forward/reverse fine-motion elastic rotation bearing 50, and based on Figures 7 to 14, we will explain the forward/reverse fine-motion elastic rotation bearings 60, 70, 80, and 90, which are other embodiments of the present invention.

First, the structure and function of the forward/reverse fine rotation elastic bearing 50 will be described with reference to Figures 1 to 4. As shown in Figures 1 to 4, the forward/reverse fine rotation elastic bearing 50 comprises support members 51, 52 arranged around the shaft body 1 which rotates finely in forward and reverse directions, and a number of elastic members 53, 54 whose base ends 53b, 54b are engaged with the support members 51, 52, respectively, and whose tip ends 53a, 54a are engaged with the outer periphery of the shaft body 1, and the base end 53b (54b) side and the tip end 53a (54a) side of each of the elastic members 53, 54 are engaged at positions facing each other across the shaft body 1.

The multiple elastic members 53, 54 are plate-shaped elastic members of the same shape and dimensions, and the base end 53b (54b) and tip end 53a (54a) of each of the multiple elastic members 53, 54 are engaged in positions such that when a torsional moment is applied to the shaft body 1, the elastic members 53, 54 can deform rotationally symmetrically about the axis 1c of the shaft body 1.

The support members 51, 52 are integrally provided on a block body 55, and as shown in Fig. 2, the support members 51, 52 and the block body 55 have a concave shape when viewed from the front. As shown in Fig. 2, the support members 51, 52 have portions which are mirror symmetrical with respect to the shaft body 1. The support members 51, 52 are disposed at positions where the elastic members 53, 54 can deform rotationally symmetrically about the axis 1c of the shaft body 1 when a torsional moment is applied to the shaft body 1.

As described above, the elastic members 53, 54 are plate-like elastic members of the same shape and dimensions, and have curved portions 53c, 54c that are curved to surround a semicircular region around the shaft body 1. The plate thicknesses 53t, 54t of the plate-like elastic members 53, 53 decrease continuously from the base ends 53b, 54b of the plate-like elastic members 53, 54 to the tip ends 53a, 54a, respectively.

The base end 53b of the plate-shaped elastic member 53 is fixed to the support member 51 by a bolt 57b that passes through the support member 51 and the base end 53b from the left side surface 51s of the support member 51 toward the shaft body 1, and a nut 57n that is screwed onto the bolt 57b. Similarly, the base end 54b of the plate-shaped elastic member 54 is fixed to the support member 52 by a bolt 58b that passes through the support member 52 and the base end 54b from the right side surface 52s of the support member 52 toward the shaft body 1, and a nut 58n that is screwed onto the bolt 58b.

The tip 53a of the plate-shaped elastic member 53 is fixed to the outer circumferential surface of the shaft body 1 by a bolt 59, and the tip 54a of the plate-shaped elastic member 54 is fixed to the outer circumferential surface of the shaft body 1 by a bolt 56. As shown in Figures 1 and 2, the base end 53b and tip 53a of one plate-shaped elastic member 53 and the base end 54b and tip 54a of the other plate-shaped elastic member 54 are arranged in series on an imaginary straight line L that is perpendicular to the axis 1c of the shaft body 1.

In the forward/reverse fine rotation elastic bearing 50, the shaft body 1 is supported by a pair of plate-shaped elastic members 53, 54 arranged opposite each other on either side of the shaft body 1. This not only allows the shaft body 1, which rotates forward and reverse finely, to be stably supported in a fixed position, but also allows the shaft body 1 to be given a rotation angle proportional to the magnitude of the torsional moment loaded on the shaft body 1, and a restoring force can be applied that returns the shaft body 1 to a fixed position where the rotation angle is zero against the torsional moment.

In addition, the forward/reverse fine rotation elastic bearing 50 that supports the shaft 1 that rotates forward and reverse finely has no parts that come into contact with or separate from each other or slide in small areas, so noise and vibration during operation are extremely low and maintenance is unnecessary. Furthermore, because the forward/reverse fine rotation elastic bearing 50 has a small number of components, it is relatively easy to simplify the structure and make it smaller and lighter.

Next, a repeating moment generating device 100 using the forward/reverse fine rotation elastic bearing 50 shown in Figs. 1 to 4 will be described with reference to Figs. 5 and 6. Note that in Figs. 5 and 6, some of the components (e.g., the table 24 and the support legs 25) are shown as transparent to improve visibility.

As shown in Figures 5 and 6, the repeating moment generating device 100 can be used in a fatigue testing machine (not shown) that tests fatigue strength characteristics by applying a repeating moment to a test piece. In the repeating moment generating device 100, in order to hold the shaft body 1 that transmits the repeating moment to the test piece (not shown) set in the fatigue testing machine so that it can rotate in both directions, forward and reverse fine movement elastic bearings 50, 50 are arranged near both ends of the shaft body 1. The forward and reverse fine movement elastic bearings 50, 50 are arranged on the top surface of the table 24 at a predetermined distance in the direction of the axis 1c of the shaft body 1.

In the region between the forward and reverse fine rotation elastic bearings 50, 50, a pair of lever members 3a, 3b are attached to the shaft body 1 at positions spaced apart in the direction of the shaft center 1c of the shaft body 1, each perpendicular to the shaft body 1, and in the region where the lever members 3a, 3b face each other, shaft bodies 4, 5 that can rotate freely around axes 4c, 5c that are parallel to the shaft body 1 are provided at positions symmetrical with respect to the shaft body 1, and eccentric weight rotors 6, 7 that rotate together with the shaft bodies 4, 5 around the axes 4c, 5c are provided on parts of the shaft bodies 4, 5.

As shown in FIG. 6, the eccentric weight rotors 6, 7 each include an enlarged diameter portion 6b, 7b provided on a part of the shaft 4, 5, and an eccentric weight member 6c, 7c that is inserted into a through-hole 6h, 7h that is opened in the enlarged diameter portion 6b, 7b in a direction perpendicular to the axis 4c, 5c and is movable along the direction perpendicular to the shaft 4, 5.

The weight members 6c, 7c are provided with bolt members 6e, 7e screwed through the enlarged diameter portions 6b, 7b, weights 6g, 7g provided at one end of the bolt members 6e, 7e, and lock nuts 6d, 7d screwed onto the bolt members 6e, 7e to lock the bolt members 6e, 7e to the enlarged diameter portions 6b, 7b. A male thread is formed on the outer periphery of the bolt members 6e, 7e, and a short cylindrical stopper portion 6f, 7f with a larger diameter than the male thread portion is provided at the other end of the weight members 6c, 7c. In addition, a motor 14 is provided as a driving means for rotating the shaft bodies 4, 5 in synchronization.

The bolt members 6e, 7e, which have male threads on their outer circumference, are screwed into the enlarged diameter portions 6b, 7b, which have female threaded holes 6h, 7h, and the bolt members 6e, 7e are rotated around their axes to move them longitudinally, changing the distance between the weights 6g, 7g and the axes 4c, 5c of the shafts 4, 5, thereby changing the position of the center of gravity (not shown) of the weight members 6c, 7c away from or toward the axes 4c, 5c.

As shown in FIG. 5, the table 24 is a rectangular flat member, and is kept horizontal by four support legs 25 arranged on the underside of its four corners 24c. The support legs 25 have an L-shaped horizontal cross section, and a bottom plate 25b is provided on the underside. The four corners 24c of the table 24 are fixed while being placed on the upper surfaces 25a of the four support legs 25, and a rectangular flat under-table 26 is arranged on the bottom plates 25b located in four places.

On the under-table 26 below the table 24, there are provided a motor 14, medium timing pulleys 15, 16, large timing pulley 18, small timing pulleys 19a, 19b, and timing belts 21, 22 as driving means for synchronously rotating the two eccentric weight rotors 6, 7. When the motor 14 is operating, its rotational force is output to the rotating shaft 14a via the gear box 17.

A middle timing pulley 15 is attached to the rotating shaft 14a rotated by the motor 14, and a middle timing pulley 16 and a large timing pulley 18 are rotatably attached to the shaft body 1 via bearings. The rotating shaft 14a is parallel to the shaft body 1, and the middle timing pulley 15 on the motor 14 side is located directly below the middle timing pulley 16 on the shaft body 1 side, with the middle timing pulleys 15, 16 facing each other and vertically aligned in series.

Small timing pulleys 19a, 19b are attached to the shafts 4, 5. The small timing pulleys 19a, 19b are arranged in series with the large timing pulley 18 in between. The small timing pulleys 19a, 19b have the same size (outer diameter), and the medium timing pulleys 15, 16 also have the same size (outer diameter).

The middle timing pulley 15 and the middle timing pulley 16 are connected by a timing belt 21, and the small timing pulleys 19a, 19b and the large timing pulley 18 are connected by a timing belt 22.

When the motor 14 is operated, the middle timing pulley 15, which is attached integrally to the rotating shaft 14a, rotates, and the rotation of the middle timing pulley 15 is transmitted to the middle timing pulley 16 via the timing belt 21, so that the middle timing pulley 16 rotates in the same direction and at the same rotation speed as the rotating shaft 14a. The rotation of the middle timing pulley 16 is transmitted to the large timing pulley 18, which is integrated with the middle timing pulley 15, via the shaft body 1.

The rotation of the large timing pulley 18 is transmitted to the small timing pulleys 19a and 19b via the timing belt 22, so that the shafts 4 and 5 to which the small timing pulleys 19a and 19b are attached rotate in the same direction at the same rotational speed, and as a result, the two eccentric weight rotors 6 and 7 also rotate in the same direction at the same rotational speed in synchronization with each other. In the repeating moment generating device 100, the rotation center lines of the two eccentric weight rotors 6 and 7 are the same as the axes 4c and 5c of the shafts 4 and 5, respectively.

In the repeating moment generating device 100 shown in FIG. 5, the two eccentric weight rotors 6, 7 are arranged so that the eccentric directions of the centers of gravity of the weight members 6c, 7c (the directions of the centrifugal forces 6a, 7a shown in FIG. 6) differ by 180 degrees from each other about the axes 4c, 5c of the shafts 4, 5. Therefore, the two eccentric weight rotors 6, 7 rotate while maintaining a relationship in which the directions of the centrifugal forces 6a, 7a differ by 180 degrees from each other about the rotation center lines (axes 4c, 5c).

When the weight members 6c, 7c are in a state where their centers of gravity are eccentric from the axes 4c, 5c, and the eccentric weight rotors 6, 7 rotate with the rotation of the shafts 4, 5 driven by the driving force of the motor 14, the weight members 6c, 7c also rotate about the axes 4c, 5c, and centrifugal forces 6a, 7a of a magnitude determined by the amount of eccentricity of the centers of gravity of the weight members 6c, 7c and the number of rotations are generated in the axial direction of the bolt members 6e, 7e. The direction in which these centrifugal forces 6a, 7a act rotates around the axes 4c, 5c, so the direction of the centrifugal forces 6a, 7a changes up, down, left, and right with the rotation.

In this way, the two eccentric weight rotors 6, 7 rotate around their respective rotational centerlines (axis centers 4c, 5c), generating vibrations that alternately vibrate both ends of the lever members 3a, 3b up and down via the shafts 4, 5, causing the lever members 3a, 3b to repeat fine seesaw motions around the axis center 1c of the shaft 1, causing the shaft 1 integrated with the lever members 3a, 3b to repeat fine forward and reverse micro-rotations. Therefore, if a test piece (not shown) is set on the extension of the axis center 1c of the shaft 1, a repeated load (repeated moment) can be applied to the test piece.

In the repeating moment generating device 100, if the eccentricity of the center of gravity of the weight members 6c, 7c is set to the same amount, the centrifugal forces 6a, 7b will always be the same in magnitude and act in parallel and opposite directions, so that if the eccentric weight rotors 6, 7 are rotated at a constant speed, a sinusoidal repeating couple (moment) will be generated. This causes a repeating moment to be applied to the test material (not shown) set on the extension of the shaft 1, making it possible to perform fatigue testing on the test piece.

Furthermore, if the eccentricity of the centers of gravity of the weight members 6c, 7c is set to be the same, the centrifugal forces 6a, 7b will always be the same in magnitude and act in parallel and opposite directions, so that the force components that cause translational motion will always be offset and no vibration will occur no matter what position the eccentric weight rotors 6, 7 are in. As a result, only the moment that is rotationally symmetrical with respect to the axis 1c is always transmitted to the shaft body 1 and the forward/reverse fine rotation elastic bearing 50 that supports the shaft body, so the axis 1c of the shaft body 1 remains immobile.

In the forward/reverse fine rotation elastic bearing 50, which is part of the repeating moment generating device 100, the shaft body 1 is supported by a pair of plate-shaped elastic members 53, 54 arranged symmetrically on either side of the shaft body 1. This not only allows the shaft body 1, which rotates forward and reverse finely, to be stably supported in a fixed position, but also allows a rotation angle to be imparted to the shaft body 1 that is proportional to the magnitude of the torsional moment applied to the shaft body 1, and a restoring force can be imparted that returns the shaft body 1 to a fixed position where the rotation angle is zero against the torsional moment.

In addition, the forward/reverse fine-rotation elastic bearing 50 that supports the shaft 1 that rotates in a forward/reverse fine-rotation manner in the repeating moment generating device 100 does not have any parts that come into contact with or separate from each other or slide in a small area, so noise and vibration during operation are extremely low and maintenance is unnecessary.In addition, the forward/reverse fine-rotation elastic bearing 50 is made up of a small number of parts, so it is relatively easy to simplify the structure and make it smaller and lighter.

Next, forward and reverse fine-motion elastic rotary bearings 60, 70, 80, and 90, which are other embodiments of the present invention, will be described with reference to Figures 7 to 14. Note that, among the components constituting the forward and reverse fine-motion elastic rotary bearings 60, 70, 80, and 90 shown in Figures 7 to 14, some components that are common to the components of the forward and reverse fine-motion elastic rotary bearing 50 described above are given the same reference numerals as those shown in Figures 1 to 4, and descriptions thereof will be omitted.

The forward/reverse fine rotation elastic bearing 60 shown in Figures 7 and 8 comprises a plurality of support parts 61a, 61b protruding from the inner peripheral surface of a short cylindrical support member 61, and plate-shaped elastic members 53, 54 whose base ends 53b, 54b are engaged with the support parts 61a, 61b, respectively, and whose tip ends 53a, 54a are engaged with the outer periphery of a short cylindrical boss 62 that is detachable from the shaft body 1. The plate-shaped elastic members 53, 54 have the same shape and size, and are arranged so that the central axis (not shown) of the boss 62 coincides with the central axis of the support member 61. The shaft body 1 is inserted into the through hole 62a opened in the boss 62, and the key grooves 1b, 62b are aligned and a key (not shown) is inserted, and the boss 62 and the shaft body 1 are fixed together.

The support portions 61a and 61b formed on the inner peripheral surface of the support member 61 at 180 degree intervals are mirror symmetrical with the shaft body 1 (boss 62) in between. The base end portion 53b (54b) and the tip end portion 53a (54a) of the plate-shaped elastic members 53 and 54 having curved portions 53c and 54c are engaged at opposing positions with the shaft body 1 (boss 62) in between.

The forward/reverse fine rotation elastic bearing 60 has a boss 62 with a through hole 62a through which the shaft body 1 can be inserted and removed, so the forward/reverse fine rotation elastic bearing 60 can be distributed on the market as a single product. In addition, a key groove 61c is provided on a part of the outer circumferential surface of the support member 61. The forward/reverse fine rotation elastic bearing 60 can be used by attaching it to various devices such as a repeating moment generating device, for example, and exerts the same action and effect as the forward/reverse fine rotation elastic bearing 50 shown in FIG. 1.

Next, in the forward/reverse fine rotation elastic bearing 70 shown in Figures 9 and 10, three plate-shaped elastic members 73, 74, and 75 and a shaft body 1 are arranged inside a polygonal (hexagonal) ring-shaped support member 71. The plate-shaped elastic members 73, 74, and 75 have the same shape and dimensions, and have the same shape and function as the plate-shaped elastic members 51 and 52 shown in Figure 1.

The base ends 73b, 74b, and 75b of the three plate-shaped elastic members 73, 74, and 75 are arranged on the inner surface of the support member 71 at 60-degree intervals around the axis 1c of the shaft body 1, and are fixed to the support member 71 with multiple bolts and nuts 72. The tip ends 73a, 74a, and 75a of the plate-shaped elastic members 73, 74, and 75 are arranged on the outer surface of the shaft body 1 at 60-degree intervals around the axis 1c, and are fixed to the shaft body 1 with multiple bolts 76. The base ends 73b, 74b, and 75b and the tip ends 73a, 74a, and 75a of the plate-shaped elastic members 73, 74, and 75 are engaged at opposing positions across the shaft body 1.

The use or purpose of the forward/reverse fine rotation elastic bearing 70 is not limited, but it can be attached to various devices such as a repeating moment generating device and used, and exerts the same action and effect as the forward/reverse fine rotation elastic bearing 50 shown in FIG. 1. In the forward/reverse fine rotation elastic bearing 70, three plate-shaped elastic members 73, 74, and 75 are arranged inside the polygonal (hexagonal) ring-shaped support member 71, but this is not limited to this, and four or more plate-shaped elastic members can be arranged.

Next, the forward/reverse fine rotation elastic bearing 80 shown in Figures 11 and 12 includes support members 81, 82 arranged around the shaft body 1 that finely rotates in the forward and reverse directions, and multiple elastic members 53, 54 whose base ends 53b, 54b are engaged with the support members 81, 82, respectively, and whose tip ends 53a, 54a are engaged with the outer periphery of the shaft body 1, and the base ends 53b, 54b and tip ends 53a, 54a of the elastic members 53, 54 are engaged at positions facing each other across the shaft body 1. The multiple elastic members 53, 54 are plate-shaped elastic members of the same shape and size. The support members 81, 82 are integrally erected on a block body 85, and as shown in Figure 12, the support members 81, 82 and the block body 85 have a concave shape when viewed from the front.

As shown in Figures 11 and 12, the forward/reverse fine-motion elastic bearing 80 has the same function as a pair of forward/reverse fine-motion elastic bearings 50 shown in Figure 1 arranged symmetrically along the axial direction of the shaft body 1. By arranging multiple elastic members 53, 54 in parallel in this way, the elastic force supporting the shaft body 1, which repeatedly rotates in forward and reverse directions at a small angle, can be increased. The shape of the elastic members 53, 54 can be set arbitrarily, and the plate thickness and width do not need to be constant and can be freely changed from the base end to the tip end, but equivalent functions can be achieved by arranging elastic members of the same shape and dimensions at equal intervals.

Next, in the forward/reverse fine rotation elastic bearing 90 shown in Figures 13 and 14, two coil springs 93, 94 and a shaft body 1 are arranged inside a polygonal (square) ring-shaped support member 91. The coil springs 93, 94 have the same shape and dimensions, and the base ends 93b, 94b of the coil springs 93, 94 are respectively engaged with the inner peripheral surface of the support member 91, and the tip ends 93a, 94a of the coil springs 93, 94 are respectively engaged with the outer peripheral surface of the shaft body 1 via flat connecting members 95, 96.

The coil springs 93, 94 are arranged so that their respective expansion and contraction directions (longitudinal directions) 93s, 94s are parallel to each other across the shaft body 1, and the connecting members 95, 96 are fixed to the outer circumferential surface of the shaft body 1 at positions spaced 180 degrees apart. The connecting members 95, 96 are fixed so as to protrude in the radial direction of the shaft body 1 from the axis 1c of the shaft body 1, and the expansion and contraction directions (longitudinal directions) 93s, 94s of the coil springs 93, 94 are perpendicular to the surface direction of the connecting members 95, 96.

The forward/reverse fine rotation elastic bearing 90 can be used in the same way as the forward/reverse fine rotation elastic bearing 50 shown in FIG. 1, and can achieve the same effects. In addition, the coil springs 93 and 94 that make up the forward/reverse fine rotation elastic bearing 90 have a simple shape and are readily available general-purpose parts, so the forward/reverse fine rotation elastic bearing 90 can be simplified in structure and reduced in manufacturing costs.

Note that the forward/reverse fine-motion elastic bearings 50, 60, 70, 80, and 90 described based on Figures 1 to 14 are examples of forward/reverse fine-motion elastic bearings according to the present invention, and the forward/reverse fine-motion elastic bearings according to the present invention are not limited to the forward/reverse fine-motion elastic bearings 50, 60, 70, 80, and 90 described above.

The forward and reverse fine rotation elastic bearing of the present invention can be widely used in various mechanical devices as a mechanism for supporting a shaft that repeats forward and reverse fine rotation at a small angle.

Reference Signs List 1, 4, 5 shaft body 1b, 61c, 62b key groove 1c, 4c, 5c shaft center 3a, 3b lever member 6, 7 eccentric weight rotor 6a, 7a centrifugal force 6b, 7b enlarged diameter portion 6c, 7c weight member 6d, 7d lock nut 6e, 7e bolt member 6f, 7f stopper portion 6g, 7g weight 6h, 7h, 38 through hole 14 motor 14a rotating shaft 15, 16 middle timing pulley 17 gear box 18 large timing pulley 19a, 19b small timing pulley 21, 22 timing belt 24 table 24c corner portion 25 support leg 25a upper surface 25b bottom plate 26 under table 50, 60, 70, 80, 90 Positive and reverse fine rotation elastic bearing 51, 52, 61, 71, 81, 82, 91 Support member 51s Left side surface 52s Right side surface 53, 54, 73, 74, 75 Elastic member (plate-shaped elastic member)
53a, 54a, 73a, 74a, 75a Tip portion 53b, 54b, 73b, 74b, 75b Base portion 53c, 54c Curved portion 53t, 54t Plate thickness 55, 85 Block body 56, 57b, 58b, 59, 76 Bolt 57n, 58n Nut 61a, 61b Support portion 62 Boss 62a Through hole 72 Bolt nut 93, 94 Coil spring 93s, 94s Expanding/contracting direction (longitudinal direction)
95, 96 Connecting member 100 Repeating moment generating device

Claims (1)

A support member disposed around a shaft body that rotates slightly in forward and reverse directions;
a plurality of elastic members each having a base end side engaged with the support member and a tip end side engaged with an outer periphery of the shaft body,
In a forward/reverse fine rotation elastic bearing, a base end side and a tip end side of the elastic member are engaged at positions where the elastic member can deform rotationally symmetrically about an axis of the shaft when a torsional moment is applied to the shaft,
the plurality of elastic members are plate-shaped elastic members each having a curved portion curved so as to surround a semicircular region around the shaft body,
The plate-shaped elastic member has a portion where the plate thickness decreases from the base end toward the tip end .

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