JP6602582B2 - Nut detent mechanism - Google Patents

Description

  The present invention relates to a nut detent mechanism.

  Conventionally, for example, an eccentric rocking type speed reducer is known as a speed reducer. Such a speed reducer is generally inserted into a case in which internal teeth are formed on the inner peripheral side, an external gear having external teeth meshing with the internal teeth, and a through-hole formed in the external gear. A crankshaft that swings the external gear by rotation and a carrier that holds the external gear via the crankshaft are provided. The crankshaft is rotatably held by the carrier, and an eccentric body is provided on the crankshaft. The eccentric body is inserted into the through hole of the external gear. Thus, the carrier holds the external gear via the crankshaft.

  In such a reducer, when the crankshaft rotates around its central axis by external input, the eccentric body swings the external gear, and the external gear meshes the external teeth with the internal teeth of the case. Rotate while. Thereby, a crankshaft revolves while rotating, and a carrier rotates by this revolving operation (for example, refer to patent documents 1).

JP 2014-211204 A

  By the way, such a reduction gear is provided with a pair of output shaft bearings that rotate and hold the output shaft. Each output shaft bearing is attached to the output shaft between the carrier and the pinion. Each output shaft bearing is sandwiched and held in the axial direction between a nut and a case disposed below the carrier (on the pinion side of the carrier in the axial direction). Thereby, the preload is applied to the output shaft bearing. However, in the conventional speed reducer, if the nut that fastens the carrier and the output shaft is loosened, the preload applied to the output shaft bearing may change.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a nut detent mechanism capable of preventing the nut from being loosened.

  The present invention includes a shaft member that rotates about a central axis, a nut that is screwed to the shaft member, and at least one plate that is fixed to the shaft member and restricts rotation of the nut relative to the shaft member. The nut is provided with a locking portion, and the rotation of the nut is restricted by the plate being locked to the locking portion of the nut.

  In the nut detent mechanism, the plate is fixed to the shaft member by a bolt, a long hole through which the bolt passes is formed in the plate, and a bolt hole into which the bolt is screwed is formed in the shaft member. It may be formed.

  In the nut detent mechanism, the nut is formed with four locking portions every 90 ° centered on the central axis, and the elongated hole of the plate is 40 ° centered on the central axis. It may be formed at an angle.

  In the nut detent mechanism, the nut is formed with eight locking portions every 45 ° centered on the central axis, and the elongated hole of the plate is 45 ° centered on the central axis. It may be formed at an angle.

In the nut detent mechanism, the number of the bolts of the plate per one and N _B, the number of the locking portion and N _F, the number of the plate and N _P, around the said central axis said when the angle of the elongated hole of the plate was alpha °, the total number _{N T} of the bolt _holes, with N T = [360 ° / α / N F × N B + (N B -1)] × N P In addition, the number of bolt holes may be N _T / N _P at every phase number N _P and α / N _B ° around the central axis.

In the nut detent mechanism, the plate is provided N _P sheets, wherein the shaft member has a plurality of bolt holes group including one or more of the bolt holes are formed respectively, the plurality of bolts Anagun, the may be arranged in the position where the rotational symmetry by 360 ° / N _P with respect to the central axis.

  In the nut detent mechanism, the shaft member is formed with a plurality of bolt holes, and the angle of the elongated hole with respect to the central axis is such that the adjacent bolt holes are in relation to the central axis. It may be more than twice the angle formed.

  According to the present invention, it is possible to prevent the nut from being loosened.

It is sectional drawing which shows the nut rotation prevention mechanism which concerns on one embodiment of this invention. It is a top view which shows the nut rotation prevention mechanism which concerns on one embodiment of this invention, and is a II direction arrow line view of FIG. It is a top view which shows the nut rotation prevention mechanism which concerns on a modification, and is a figure corresponding to FIG. It is a top view for demonstrating the meaning which the term of (N _B -1) has in Formula (X). It is a top view for demonstrating the meaning which the term of (N _B -1) has in Formula (X). It is a top view for demonstrating the meaning which the term of (N _B -1) has in Formula (X).

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Configuration of Nut Detent Mechanism FIG. 1 shows a nut detent mechanism 10 according to this embodiment. As shown in FIG. 1, the nut detent mechanism 10 includes a case 11 that is formed in a cylindrical shape, and a shaft member 20 that is rotatably accommodated in the case 11.

  Such a nut detent mechanism 10 constitutes a part of a speed reducer, for example. In this case, in the nut detent mechanism 10, the shaft member 20 is connected to, for example, a speed reduction unit (not shown). The rotation input from a motor (not shown) is decelerated by the decelerating unit and output from the shaft member 20. The shaft member 20 has an end surface 20a located on one end side (the upper end side in FIG. 1). On the other end side (the lower end side in FIG. 1) of the shaft member 20, for example, a drive gear (not shown) that outputs rotation from the shaft member 20 is provided. In the present embodiment, in the axial direction, the side on which the nut 21 (described later) is provided (upper side in FIG. 1) is referred to as one end side, and the side opposite to the side on which the nut 21 is provided (lower side in FIG. 1). It is called the other end side.

  In the figure, the symbol L1 indicates the central axis of the shaft member 20. The shaft member 20 rotates around the central axis L1. In the present specification, when simply referred to as “axial direction”, this direction means a direction extending on the central axis L1 or a direction parallel to the central axis L1. A direction orthogonal to the central axis L1 is referred to as a “radial direction”, and a direction around the central axis L1 is referred to as a “circumferential direction”.

  The case 11 is formed in a substantially cylindrical shape and has an inner wall surface 11a facing the shaft member 20 side. The inner wall surface 11 a of the case 11 is provided with an annular convex portion 12 that projects radially inward. The convex portion 12 is formed over the entire circumferential direction of the inner wall surface 11a.

  A first bearing housing portion 14 is formed on the surface on one end side of the convex portion 12 (upper surface in FIG. 1). A first bearing 15 is disposed in the first bearing housing portion 14. The illustrated first bearing 15 is a tapered roller bearing. The first bearing 15 causes the outer ring to abut against the bottom surface of the first bearing housing portion 14 (the surface on one end side of the convex portion 12) in the axial direction and to abut against the inner wall surface 11a of the case 11 in the radial direction. ing. Accordingly, the first bearing 15 is attached to the first bearing housing portion 14.

  In addition, a second bearing housing portion 16 is formed on the surface on the other end side of the convex portion 12 (the lower surface in FIG. 1). A second bearing 17 is disposed in the second bearing housing portion 16. The illustrated second bearing 17 is a tapered roller bearing. The second bearing 17 abuts the outer ring on the top surface of the second bearing housing 16 (the surface on the other end side of the convex portion 12) in the axial direction, and also contacts the inner wall surface 11a of the case 11 in the radial direction. Touching. Thus, the second bearing 17 is attached to the second bearing housing portion 16.

  The shaft member 20 is inserted into the inner peripheral side of the inner ring of the first bearing 15 and the inner peripheral side of the inner ring of the second bearing 17. Thereby, the shaft member 20 is rotatably held by the case 11. The shaft member 20 has a second bearing support surface 20b. The surface on the other end side of the inner ring of the second bearing 17 (the lower surface in FIG. 1) is in contact with the second bearing support surface 20b.

  As shown in FIGS. 1 and 2, the shaft member 20 is provided with a nut (fixing member) 21 that is screwed into the shaft member 20 while being pressed against the first bearing 15. That is, a screw portion 20c is formed on the outer peripheral portion on one end side of the shaft member 20, and a nut 21 is screwed to the screw portion 20c. The nut 21 has a planar ring shape, and is in contact with a surface (one upper surface in FIG. 1) on one end side of the inner ring of the first bearing 15. The nut 21 is rotatable with respect to the shaft member 20 about the central axis L1. A washer (not shown) may be interposed between the nut 21 and the first bearing 15.

  As described above, the nut 21 is in contact with the inner ring of the first bearing 15 in the axial direction. By tightening the nut 21 to the other end side, the axial position of the shaft member 20 is positioned. That is, by pretightening the nut 21 with respect to the shaft member 20, preload is applied to the first bearing 15 and the second bearing 17. The preload is a pressure applied to both bearings by assembling a pair of bearings so as to press each other. Specifically, by tightening the nut 21 with respect to the shaft member 20, the first bearing 15, the convex portion 12, and the second bearing 17 are located between the nut 21 and the second bearing support surface 20 b of the shaft member 20. It is sandwiched between. In this way, pre-load acts on the first bearing 15 and the second bearing 17 by tightening the nut 21 with respect to the shaft member 20.

  In the present embodiment, a locking portion 22 is provided on the outer periphery of the nut 21. As shown in FIG. 2, the locking portion 22 includes a chamfered portion obtained by cutting a circular outer periphery of the nut 21 in a straight line when viewed from the plane. In this case, the locking portions 22 are formed at four locations for each angle β of 90 ° with the central axis L1 as the center, and are each formed of a plane perpendicular to the paper surface of FIG. Note that the angle β formed by the locking portions 22 refers to an angle formed by normal lines of the locking portions 22 adjacent to each other (lines perpendicular to the plane constituting the locking portion 22).

  A plate 23 that restricts the rotation of the nut 21 relative to the shaft member 20 is fixed to the shaft member 20. The plate 23 plays a role of regulating the rotation of the nut 21 by being locked to the locking portion 22 of the nut 21. In this case, two plates 23 are provided and have the same shape. As shown in FIG. 1, each plate 23 has a substantially L-shaped cross section, a horizontal fixing portion 23 a fixed to the shaft member 20, and extends vertically from the fixing portion 23 a and contacts the locking portion 22. A contact portion 23b. Note that the number of the plates 23 may be at least one, and is not limited to two.

  Further, a plurality of (12) bolt holes 25 into which bolts (fastening members) 24 are inserted and screwed are formed in one end surface 20a of the shaft member 20. The plurality of bolt holes 25 are arranged on a circumference C around the central axis L1. In this case, the shaft member 20 is formed with a plurality (two places) of bolt hole groups 25 </ b> A each including six bolt holes 25. These bolt hole groups 25A are arranged at two locations (two phases) and are arranged at positions that are rotationally symmetric by 180 ° with respect to the central axis L1. In each bolt hole group 25A, the six bolt holes 25 are arranged at equal intervals with an angle θ around the central axis L1. In this case, the angle θ is 20 °. Note that the angle θ formed by the bolt holes 25 refers to an angle formed by the centers of the bolt holes 25 adjacent to each other with respect to the central axis L1 when viewed from the axial direction.

Incidentally, when the number of plates 23 and the _{N P,} the bolt hole group 25A of the _{N P} portion _{(N P} phase) is provided, the bolt hole group 25A of the _{N P} point, with respect to the central axis L1, respectively 360 ° / it is preferably disposed at a position to be rotationally symmetric by N _P. For example, in FIG. 2, the number of plates 23 is N _P = 2, and the two bolt hole groups 25A are arranged at positions that are rotationally symmetric by 360 ° / 2 = 180 ° with respect to the central axis L1. . Thereby, the number of the bolt holes 25 can be reduced, and the man-hour for processing the bolt holes 25 with respect to the shaft member 20 can be suppressed.

  Each plate 23 is fixed to the shaft member 20 by bolts 24 screwed into bolt holes 25, respectively. In addition, a long hole 26 through which the bolt 24 passes is formed in the plate 23. Two bolts 24 are inserted into each of the long holes 26. However, the present invention is not limited to this, and each plate 23 may be fixed to the shaft member 20 by one or three or more bolts 24. The long hole 26 of each plate 23 is formed in an arc shape along a circumference C centered on the central axis L1. The long hole 26 is formed at an angle α about the central axis L1. In this case, the angle α is 40 °. The angle α of the long hole 26 is defined by the centers of the bolts 24 at both ends with respect to the central axis L1 when viewed from the axial direction when the bolts 24 are disposed at both ends in the length direction of the long hole 26, respectively. Say the corner.

  In addition, it is preferable that the angle α of the long hole 26 is not less than twice the angle θ formed by the adjacent bolt holes 25 (α ≧ 2θ). In this case, since two or more bolt holes 25 are opened in the long hole 26, each plate 23 can be fixed to the shaft member 20 by two or more bolts 24.

  In the nut detent mechanism 10, the abutment portion 23 b of the plate 23 abuts on the locking portion 22 of the nut 21, thereby preventing the nut 21 from being loosened. Thereby, the malfunction which the value of the preload added to the 1st bearing 15 and the 2nd bearing 17 changes can be prevented. That is, it can be prevented that the preload applied to the output shaft bearings 15 and 17 is changed, thereby causing a decrease in the life and strength of the output bearing and a reduction in the rigidity of the speed reducer. Also, even when using a mechanical detent to prevent loosening, it is difficult to manage the preload because the phase of the nut 21 that applies an appropriate preload to the bearing during assembly differs depending on the product. With the above configuration, the preload can be easily adjusted steplessly. Therefore, it is possible to prevent a decrease in output bearing life / strength and a reduction in the reduction gear rigidity.

  Further, a locking portion 22 is provided on the outer peripheral portion of the nut 21, and the nut 21 is prevented from rotating by fixing the plate 23 to the shaft member 20 with bolts 24. Further, the plate 23 is fixed to the shaft member 20 by providing a long hole 26 in the plate 23 and inserting a bolt 24 into the long hole 26. As a result, regardless of the phase of the nut 21 (that is, whatever the locking portion 22 of the nut 21 is in any rotational position with respect to the central axis L1), the plate 23 is attached to the shaft member 20 by the bolt 24 It is possible to fix and regulate the rotation of the nut 21. For this reason, after tightening the nut 21 so that an appropriate preload is applied between the first bearing 15 and the second bearing 17, the nut 21 is further rotated to align the plate 23 with the position of the locking portion 22. Therefore, the preload can be held at an appropriate set value. As a result, it is possible to prevent a problem that the strength of the first bearing 15 and the second bearing 17 is reduced, and to improve the service life thereof.

  The nut detent mechanism 10 described above may constitute, for example, a part of an eccentric oscillating speed reducer. In this case, the speed reducer is, for example, a yaw driving device that yaw-drives the nacelle with respect to the tower of the windmill, or a pitch that drives the shaft of the blade with respect to the hub on the nacelle side. A reduction gear used for the driving device may be used. The speed reducer is not limited to the wind turbine, but may be used in various industrial machines or construction machines. In addition to the eccentric swing type, the speed reducer may be a speed reducer configured as a planetary gear mechanism or a speed reducer configured as a spur gear mechanism. Alternatively, the nut detent mechanism 10 may be used in various speed change mechanisms including gears, such as a speed increaser.

Next, the operation of the present embodiment will be described.

  In the speed reducer including the nut detent mechanism 10 described above, the rotational driving force from a motor (not shown) is decelerated by a speed reduction unit (not shown) and transmitted to the shaft member 20. As a result, the shaft member 20 rotates and torque can be transmitted from the shaft member 20 to an external mechanism.

  According to the nut detent mechanism 10 according to the present embodiment, the nut 21 that is screwed to the shaft member 20 while being pressed against the first bearing 15 side is provided. A plate 23 that restricts the rotation of the nut 21 relative to the shaft member 20 is fixed to the shaft member 20. Thereby, it is possible to prevent the nut 21 from being loosened, and to prevent a problem that the value of the preload applied to the first bearing 15 and the second bearing 17 changes.

  That is, the nut 21 is tightened with respect to the shaft member 20, and an appropriate preload is applied between the first bearing 15 and the second bearing 17 by fixing the nut 21 at an appropriate position. Yes. According to the present embodiment, as described above, the plate 23 is locked to the locking portion 22 of the nut 21 to restrict the rotation of the nut 21 and prevent the nut 21 from rising and rotating. Thereby, the nut 21 does not loosen with respect to the shaft member 20, and it is possible to prevent a problem that the value of the preload applied to the first bearing 15 and the second bearing 17 changes.

  In addition, according to the present embodiment, the plate 23 is fixed to the shaft member 20 by the bolt 24, and the plate 23 is formed with the long hole 26 through which the bolt 24 passes. The shaft member 20 has a bolt hole 25 into which the bolt 24 is screwed. As a result, the rotation of the nut 21 can be restricted regardless of the rotational position of the nut 21 relative to the central axis L1. For this reason, after tightening the nut 21 so that an appropriate preload is applied between the first bearing 15 and the second bearing 17, the nut 21 is further rotated to align the plate 23 with the position of the locking portion 22. Therefore, the preload can be maintained at an appropriate value. Thereby, the strength reduction of the 1st bearing 15 and the 2nd bearing 17 can be prevented, and the lifetime can be improved.

  On the other hand, as a comparative example, it is also conceivable to place a star washer (toothed washer) between the nut 21 and the shaft member 20 in place of the plate 23 as a rotation stop of the nut 21. In this case, it is also conceivable that when the nut 21 comes to a predetermined position, the tooth of the star washer is bent and locked in the notch of the nut 21 to fix the nut 21. However, when the preload between the first bearing 15 and the second bearing 17 is set to a certain set value, the phase of the nut 21 varies depending on the product (which phase the nut 21 stops at is uncertain). For this reason, the rotation stop phase does not match, and the phase of the nut 21 needs to be shifted (rotated) to the rotation stop phase. For example, it is necessary to rotate the nut 21 to a position where the tooth of the star washer and the notch of the nut 21 coincide. In this case, the preload setting may not be constant depending on the product. On the other hand, according to the present embodiment, as described above, the rotation of the nut 21 can be regulated by the plate 23 fixed to the shaft member 20 regardless of the phase of the nut 21. Become.

  Further, according to the present embodiment, the nut 21 is formed with the four locking portions 22 every 90 ° around the central axis L1, and the long hole 26 of the plate 23 is centered on the central axis L1. It is formed at an angle of 40 °. Thereby, the number of the bolt holes 25 can be suppressed, and the man-hour for processing the bolt holes 25 with respect to the shaft member 20 can be suppressed.

Next, a modified example of the nut detent mechanism will be described with reference to FIG. FIG. 3 is a plan view (a diagram corresponding to FIG. 2) showing a nut detent mechanism according to a modification. The modification shown in FIG. 3 is mainly different in the configuration of nuts and bolt holes, and the other configuration is substantially the same as the embodiment shown in FIGS. 1 and 2. 3, the same parts as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 3, eight locking portions 22 are provided on the outer periphery of the nut 21. The locking portions 22 are formed at eight locations for each angle β of 45 ° around the central axis L1. A plurality of (six) bolt holes 25 into which bolts 24 are inserted and screwed are formed in one end surface 20a of the shaft member 20. In this case, the shaft member 20 is formed with bolt hole groups 25 </ b> A each including three bolt holes 25. These bolt hole groups 25A are arranged at two locations (two phases) and are arranged at positions that are rotationally symmetric by 180 ° with respect to the central axis L1. In each bolt hole group 25A, the three bolt holes 25 are arranged at equal intervals at an angle θ of 22.5 ° with the central axis L1 as the center. Further, two plates 23 are provided, and the long holes 26 of each plate 23 are formed at an angle α of 45 ° with the central axis L1 as the center.

  According to this modification, the nut 21 is formed with eight locking portions 22 every 45 ° centered on the central axis L1, and the long holes 26 of the plate 23 are 45 ° centered on the central axis L1. It is formed at an angle. As a result, the rotation of the nut 21 can be restricted regardless of the rotational position of the nut 21 with respect to the central axis L1. For this reason, after tightening the nut 21 so that an appropriate preload is applied between the first bearing 15 and the second bearing 17, it is not necessary to further rotate the nut 21, and the preload is maintained at an appropriate value. be able to. Moreover, according to this modification, the number of the bolt holes 25 can be further suppressed, and the man-hour for processing the bolt holes 25 with respect to the shaft member 20 can be suppressed.

Number and Arrangement of Bolt Holes Next, how to arrange the bolt holes 25 with respect to the shaft member 20 in order to reduce the total number of bolt holes 25 for each shaft member 20 will be described.

  Generally, (i) the number of locking portions 22 formed on each nut 21, (ii) the number of bolts 24 per plate 23, (iii) the number of plates 23, and (iv) the long hole 26 Is determined in advance in consideration of various factors when designing the nut detent mechanism 10. Specifically, these numerical values (i) to (iv) are determined in advance according to the degree of freedom of the dimensions where the nut 21 and the plate 23 are installed, the load acting on the nut 21 and the plate 23, and the like.

When the numerical values (i) to (iv) are determined in advance, the present inventors determine the total number _NT of the bolt holes 25 on the basis of the following mathematical formula (X). It was found that the total number of bolt holes 25 can be minimized.
N _T = [360 ° / α ° / N _F × N _B + (N _B −1)] × N _P (X)

Here, _{N B} is the number of bolts 24 per one plate 23 (the numerical value (ii)), _{N F} is the number of the locking portion 22 (the numerical value (i)), _{N P} is the plate 23 is the number of sheets (the above numerical value (iii)), and α is the angle (the above numerical value (iv)) of the long hole 26 of the plate 23 around the central axis L1. If the value of [360 ° / α ° / N _F × N _B + (N _B −1)] is not a natural number, the decimal part is rounded up.

In this case, the locking portion 22 are equally spaced apart by an angle β of 360 ° / _{N F.} Further, _{N T} number of bolt holes _25, N T / _{N P} pieces each, with the number of phases _{N P, α} / _{N B} ° around the central axis L1 is positioned (above angle theta) intervals.

For example, in the embodiment shown in FIG. 2, (i) the number of locking portions 22 is four (N _F = 4), and (ii) the number of bolts 24 per one plate 23 is two. Yes (N _B = 2), (iii) The number of plates 23 is two (N _P = 2), and (iv) The angle α of the long hole 26 is 40 ° (α = 40 °). In this case, the total number N _T of the bolt holes 25 is N _T = [360 ° / 40 ° / 4 × 2 + (2-1)] × 2 = 12, from the above formula (X). The locking portions 22 are arranged at equal intervals by an angle β of 360 ° / 4 = 90 °. Further, twelve bolt holes 25 are arranged at 12/2 = 6 pieces each at an angle θ of 2 phases and 40 ° / 2 = 20 ° around the central axis L1.

In the modification shown in FIG. 3, (i) the number of locking portions 22 is eight (N _F = 8), and (ii) the number of bolts 24 per one plate 23 is two. (N _B = 2), (iii) The number of plates 23 is two (N _P = 2), and (iv) the angle α of the long hole 26 is 45 ° (α = 45 °). In this case, the total number _NT of the bolt holes 25 is _NT = [360 ° / 45 ° / 8 × 2 + (2-1)] × 2 = 6 from the above formula (X). The locking portions 22 are arranged at equal intervals by an angle β of 360 ° / 8 = 45 °. The six bolt holes 25 are arranged at 6/2 = 3 pieces, each having two phases and an angle θ of 45 ° / 2 = 22.5 ° around the central axis L1.

  By arranging the bolt holes 25 with respect to the shaft member 20 in this way, the plate 23 can be fixed to the shaft member 20 by the bolts 24 regardless of the phase of the nut 21, and the rotation of the nut 21 is ensured. Can be regulated. Further, the number of bolt holes 25 can be minimized, and the number of man-hours for processing the bolt holes 25 in the shaft member 20 can be reduced.

(N _B −1) term Next, the meaning of the term (N _B −1) in the above formula (X) will be described with reference to FIGS.

First, consider the case where the number of bolts 24 per plate 23 is one as shown in FIG. 4A (N _B = 1). At this time, N _B = 1, N _F = 4, N _P = 2 and α = 45 °, and N _T = [360 ° / 45 ° / 4 × 1 + (1-1)] × 2 = 4. . The four bolt holes 25 are arranged two by two around the central axis L1 and at two angles and at an angle θ of 45 °. In FIG. 4A, one bolt hole 25 is disposed at the center of each long hole 26.

  Next, as shown in FIG. 4B, a case is assumed in which the nut 21 and the plate 23 are integrally rotated with respect to the shaft member 20 in the clockwise direction. At this time, the nut 21 and the plate 23 are rotated by 67.5 ° in the clockwise direction with reference to the state shown in FIG.

  When the nut 21 and the plate 23 are further rotated in the clockwise direction in the state shown in FIG. 4B, no bolt holes 25 are disposed inside the elongated hole 26. Therefore, by moving the plate 23 to the adjacent locking portion 22 in the counterclockwise direction (see the arrow in FIG. 4B), one bolt hole 25 is arranged inside the elongated hole 26. Become. Therefore, the plate 23 can be fixed to the shaft member 20 using the bolts 24 regardless of the phase of the nut 21 and the plate 23.

Thus, when the number of bolts 24 per one plate 23 is one, it is not necessary to consider the term (N _B −1), and N _B −1 = 0.

Subsequently, as shown in FIG. 5A, the number of bolts 24 per plate 23 is two (N _B = 2), and the case where the term (N _B −1) is ignored is assumed. Think. At this time, N _B = 2, N _F = 4, N _P = 2 and α = 45 °, and N _T = [360 ° / 45 ° / 4 × 2] × 2 = 8. The eight bolt holes 25 are arranged four by four around the central axis L1 at an angle θ of 2 phases and 22.5 °. In FIG. 5A, a total of two bolt holes 25 are arranged at the center and end of each elongated hole 26.

  Next, as shown in FIG. 5B, a case is assumed in which the nut 21 and the plate 23 are integrally rotated with respect to the shaft member 20 in the clockwise direction. At this time, the nut 21 and the plate 23 are rotated 67.5 ° clockwise with reference to the state shown in FIG.

  When the nut 21 and the plate 23 are further rotated in the clockwise direction in the state shown in FIG. 5B, only one bolt hole 25 is disposed inside the elongated hole 26. Here, even if the plate 23 is moved to the adjacent locking portion 22 in the counterclockwise direction (see the arrow in FIG. 5B), only one bolt hole 25 is disposed inside the elongated hole 26. Not. Therefore, depending on the phases of the nut 21 and the plate 23, it becomes impossible to fix the single plate 23 to the shaft member 20 using the two bolts 24.

For this reason, when the number of bolts 24 per one plate 23 is two, it is necessary to consider the term (N _B −1).

Subsequently, as shown in FIG. 6A, the number of bolts 24 per one plate 23 is two (N _B = 2), and the case of considering the term (N _B −1) is considered. . At this time, N _B = 2, N _F = 4, N _P = 2 and α = 45 °, and N _T = [360 ° / 45 ° / 4 × 2 + (2-1)] × 2 = 10. . The ten bolt holes 25 are arranged in groups of two, two phases and at an angle θ of 22.5 °, with the center axis L1 as the center. In FIG. 6A, a total of two bolt holes 25 are arranged at the center and end of each elongated hole 26.

  Next, as shown in FIG. 6B, a case is assumed in which the nut 21 and the plate 23 are integrally rotated with respect to the shaft member 20 in the clockwise direction. At this time, the nut 21 and the plate 23 are rotated 90 ° in the clockwise direction on the basis of the state shown in FIG.

  If the nut 21 and the plate 23 are further rotated in the clockwise direction in the state shown in FIG. 6B, only one bolt hole 25 is disposed inside the elongated hole 26. Therefore, by moving the plate 23 to the locking portion 22 adjacent in the counterclockwise direction (see the arrow in FIG. 6B), the two bolt holes 25 are arranged inside the elongated hole 26. Become. Therefore, regardless of the phase of the nut 21 and the plate 23, the plate 23 can be fixed to the shaft member 20 using the two bolts 24.

As described above, when the number of the bolts 24 per one plate 23 is two, it is necessary to consider the term (N _B −1). That is, for each bolt hole group 25A, it is necessary to increase the number of bolt holes 25 by (N _B −1) = (2-1) = 1. Similarly, when the number of bolts 24 per plate 23 is 3, the number of bolt holes 25 for each bolt hole group 25A is (N _B −1) = (3-1) = 2. There is a need to increase them one by one.

DESCRIPTION OF SYMBOLS 10 Nut detent mechanism 11 Case 14 1st bearing accommodating part 15 1st bearing 16 2nd bearing accommodating part 17 2nd bearing 20 Shaft member 21 Nut 22 Locking part 23 Plate 24 Bolt 25 Bolt hole 25A Bolt hole group 26 Long hole

Claims (6)

A shaft member that rotates about a central axis;
A nut screwed into the shaft member;
Including at least one plate fixed to the shaft member and restricting rotation of the nut relative to the shaft member;
A locking portion is provided on the nut, and the rotation of the nut is restricted by the plate locking to the locking portion of the nut ,
The plate is fixed to the shaft member by a bolt at a radially outer side than the central shaft,
The plate is formed with an elongated hole that penetrates the bolt and extends in the circumferential direction.
A nut detent mechanism in which a bolt hole into which the bolt is screwed is formed at a position radially outside of the central shaft of the shaft member . In the nut, the four locking portions are formed every 90 ° around the central axis, and the elongated hole of the plate is formed at an angle of 40 ° around the central axis. The nut detent mechanism according to claim 1 . The nut is formed with eight locking portions every 45 ° around the central axis, and the elongated hole of the plate is formed at an angle of 45 ° around the central axis. The nut detent mechanism according to claim 1 . The number of the bolts of the plate per one and N _B, the number of the locking portion and N _F, the angle of the long hole of the plate a number of the plate and N _P, around the said central axis Is α °,
The total number _NT of the bolt holes is
N _T = [360 ° / α / N _F × N _B + (N _B −1)] × N _P
If the value of [360 ° / α / N _F × N _B + (N _B −1)] does not become a natural number, the decimal part is rounded up to a natural number,
The nut hole according to any one of claims 1 to 3 , wherein the bolt holes are arranged in N _T / N _P increments around the central axis at a phase number N _P and every α / N _B °. Stop mechanism. The plate is provided N _P sheets, wherein the shaft member, a plurality of bolt holes groups each comprising one or more of the bolt holes is formed, the plurality of bolts Anagun is 360 ° with respect to the central axis / N _P by being arranged in a position where the rotational symmetry, nut Lock mechanism according to any one of claims 1 to 4. The shaft member is formed with a plurality of bolt holes, and the angle of the elongated hole with the central axis as the center is at least twice the angle between the adjacent bolt holes with respect to the central axis. The nut detent mechanism according to any one of claims 1 to 5 .

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