Curved guide

Abstract

To provide a curved guide in which rolling elements circulate smoothly. This curved guide comprises: an arc-shaped rail; a block movable relative to the rail; and a plurality of rolling elements that are arranged in a circulation path including a rolling path (13a) provided between a rolling part of the rail and a rolling part of the block, a return path, and a turn path (10a) connected to the rolling path (13a) and the return path. The turn path (10a) is curved starting from a curvature center (O) of the arc-shaped rolling path (13a).

Description

Curve Guide

[0001] The present invention relates to a curved guide in which a block moves along an arc-shaped rail.

[0002] A curved guide is used to guide the arcuate motion of a movable body such as a table (see Patent Document 1). The curved guide includes an arcuate rail and a block that can move relatively along the rail. A circulation path for the rolling elements is formed by a rolling path between the rolling portion of the rail and the rolling portion of the block, a return path, and a turning path connecting the rolling path and the return path. Multiple rolling elements are arranged in the circulation path. When the block moves relatively to the rail, the rolling elements move while rolling along the rolling path. After moving along the rolling path, the rolling elements enter the turning path, move along the return path in the opposite direction to the rolling path, and re-enter the rolling path from another turning path.

[0003] In conventional curved guideways, the rails are arc-shaped. The rolling paths are arc-shaped along the arc-shaped rails. The return paths are arc-shaped or linear. The turning paths of linear guideways are used, and are semicircular.

[0004] JP 2017-089772 A

[0005] In order for rolling elements to circulate smoothly in a curved guide, it is necessary to smoothly connect the arc-shaped rolling path and the turning path with a tangent. However, if the turning path of a linear guide is applied to a curved guide and the arc-shaped rolling path and the semicircular turning path are smoothly connected with a tangent, as in conventional curved guides, there are problems in that because the rail is curved in an arc, the turning path becomes narrow on the inner side of the curved guide, making it difficult for the rolling elements to pass through, and the turning path becomes wide on the outer side of the curved guide, making it easy for the rolling elements to meander.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a curved guide in which rolling elements circulate smoothly.

[0007] In order to solve the above problems, one aspect of the present invention is a curved guide comprising an arc-shaped rail, a block that can move relative to the rail, a rolling path between the rolling portion of the rail and the rolling portion of the block, a return path, and a plurality of rolling elements arranged in a circulation path that includes a turning path connected to the rolling path and the return path, wherein the turning path is curved starting from the center of curvature of the arc-shaped rolling path.

[0008] According to the present invention, it is possible to prevent the turning path from narrowing on the inner periphery side of the curved guide and widening on the outer periphery side of the curved guide, thereby allowing the rolling elements to circulate smoothly.

[0009]

[0033] FIG. 2(a) is a perspective view of a curved guide according to an embodiment of the present invention. FIG. 2(b) is a side view, and FIG. 2(c) is a front view of the curved guide according to this embodiment. FIG. 3(a) is a perspective view showing the circulation path on the inner periphery of the curved guide according to this embodiment, and FIG. 3(b) is a perspective view showing the circulation path on the outer periphery. FIG. 4(a) shows the track of the circulation path of the linear guide, and FIG. 4(b) shows the track of the circulation path of the curved guide according to this embodiment. FIG. 5(a) shows the track of the turning path on the inner periphery of the curved guide according to this embodiment, and FIG. 5(b) shows the track of the turning path on the outer periphery.

[0034] FIG. 2(a) is a perspective view of a linear guide in which the curved guide according to this embodiment is linearly developed. FIG. 8(a) is a conceptual diagram of a cross-sectional track curve of the linear guide, and FIG. 8(b) is a conceptual diagram of a longitudinal track curve of the linear guide. FIG. 9(a) is a diagram showing a specific example of a cross-sectional track curve of the linear guide, and FIG. 9(b) is a diagram showing a specific example of a longitudinal track curve of the linear guide.

[0010] Hereinafter, a curved guide according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, the curved guide according to the present invention can be embodied in various forms and is not limited to the embodiments described in this specification. The present embodiment is provided with the intention that those skilled in the art will be able to fully understand the invention by fully disclosing the specification. (Curved Guide)

[0011] 1 and 2, the curved guide 1 of this embodiment is an R guide including an arc-shaped rail 2 and a block 4 that is movable relative to the rail 2. The block 4 moves in an arc along the arc-shaped rail 2. The block 4 is fan-shaped. In a plan view, an extension line of an end face 4d of the block 4 passes through the center of curvature of the rail 2. A movable body to be guided, such as a table, is attached to the block 4.

[0012] Reference numeral 13 denotes a rolling path, reference numeral 9 denotes a return path, and reference numeral 10 denotes a turn path. The rolling path 13 is formed between the rolling portion 7 of the rail 2 and the rolling portion 8 of the block 4 (see also FIG. 3 ). A circulation path 5 is formed by the rolling path 13, the return path 9, and the turn path 10. The circulation paths 5 include an inner circulation path 5 and an outer circulation path 5. The number of circulation paths 5 is not particularly limited and may be, for example, 2 or 4. A plurality of balls are arranged as rolling elements 3 in the circulation path 5. When the block 4 moves relative to the rail 2, the rolling elements 3 move while rolling on the rolling path 13. After moving on the rolling path 13, the rolling elements 3 enter the turn path 10, move on the return path 9 in the opposite direction to the rolling path 13, and re-enter the rolling path 13 from another turn path 10. The dashed lines in FIG. 1 represent the tracks (rolling element center tracks) 13 a , 9 a , and 10 a of the rolling path 13 , the return path 9 , and the turning path 10 , respectively.

[0013] The rolling path 13 is arc-shaped. As shown in FIG. 6 , in a plan view of the curved guide 1, the center of curvature O of the rolling path 13 is substantially the same as the center of curvature O of the rail 2 (see FIG. 6 ). The return path 9 is arc-shaped. In a plan view of the curved guide 1, the return path 9 is concentric with the rolling path 13, and the center of curvature O of the return path 9 is substantially the same as the center of curvature O of the rolling path 13. As shown in FIGS. 1 and 2 , the turning path 10 has a three-dimensional shape resembling a curved U. Symbol A indicates the start point of the turning path 10, and symbol C indicates the end point of the turning path 10. As shown in FIG. 6 , in a plan view of the curved guide 1, the center of curvature O of the track 10a of the turning path 10 at the start point A of the turning is inside circles D and D' extending the track 13a of the arc-shaped rolling path 13 (see FIG. 6 ). The turning path 10 will be described later.

[0014] As shown in Figures 1 and 2, the rail 2 extends in an arc shape. The rail 2 has a top surface 2a, a pair of left and right side surfaces 2b, and a bottom surface 2c. An inner rolling portion 7 and an outer rolling portion 7 extending in the longitudinal direction are formed on the side surface 2b of the rail 2. The rolling portions 7 are groove-shaped (rolling grooves), and the cross-sectional shape of the rolling portions 7 is a Gothic arch or circular arc. A plurality of mounting holes 6 for mounting the rail 2 to a base are formed on the top surface 2a of the rail 2.

[0015] The block 4 has a generally U-shaped cross section and is disposed so as to straddle the rail 2. As shown in Figures 3(a) and 3(b), the block 4 has a web portion 4a facing the upper surface 2a of the rail 2, and a pair of sleeve portions 4b hanging down from both left and right ends of the web portion 4a and facing the side surfaces 2b of the rail 2. The block 4 is a single structure.

[0016] As shown in Figure 3(a), a rolling section 8, a return section 19, and a turn section 20 are formed on the inner peripheral side of the block 4. As shown in Figure 3(b), a rolling section 8, a return section 19, and a turn section 20 are also formed on the outer peripheral side of the block 4. The rolling section 8 is formed in the sleeve section 4b of the block 4. The rolling section 8 is groove-shaped (rolling groove), and the cross-sectional shape of the rolling section 8 is a Gothic arch or circular arc. The rolling section 8 faces the rolling section 7 of the rail 2. A rolling element 3 is sandwiched between the rolling section 7 and the rolling section 8. When the block 4 moves relative to the rail 2, the rolling element 3 rolls in the rolling path 13 between the rolling section 7 and the rolling section 8.

[0017] 3(a) and 3(b), the return section 19 is formed in the web section 4a of the block 4. The return section 19 is groove-shaped and opens toward the rail 2. A return path 9 is formed between the return section 19 and the rail 2. In the return path 9, a small gap exists between the rolling element 3 and the wall surface of the return path 9. The rolling element 3 moves along the return path 9 while being pushed by the following rolling element 3. The return section 19 may be tunnel-shaped so that the block 4 alone can form the return path 9, or the return section 19 may be closed with a lid (not shown), and the return path 9 may be formed by the return section 19 and the lid (not shown).

[0018] As shown in Figures 3(a) and (b), the turn section 20 is formed so as to straddle the sleeve section 4b and web section 4a of the block 4. The turn section 20 is groove-shaped and opens toward the rail 2. A turn path 10 is formed between the turn section 20 and the rail 2. In the side view shown in Figure 2(b), the upper part of the turn path 10 protrudes most in the longitudinal direction. In the front view shown in Figure 2(c), the turn path 10 is roughly J-shaped, combining an arc along the side surface of the rail 2 and a straight line along the top surface of the rail 2.

[0019] On the rolling path 13 side of the turn path 10, the rolling element 3 is sandwiched between the turn section 20 and the rail 2. On the return path 9 side of the turn path 10, there is a small gap between the rolling element 3 and the wall surface of the turn path 10. When the block 4 moves relative to the rail 2, the rolling element 3 rolls between the turn section 20 and the rail 2 on the rolling path 13 side of the turn path 10, and on the return path 9 side of the turn path 10, the rolling element 3 moves along the turn path 10 while being pushed by the following rolling element 3. The turn section 20 may be tunnel-shaped so that the block 4 alone constitutes the turn path 10, or part of the turn section 20 may be closed with a lid (not shown), and part of the turn path 10 may be constituted by part of the turn section 20 and the lid (not shown).

[0020] As shown in Figures 3(a) and 3(b), the rolling section 8, return section 19, and turn section 20 of the block 4 are seamlessly formed on the block 4 using a cutting tool such as an end mill. In the above embodiment, the rolling section 8, return section 19, and turn section 20 are formed on the block 4 of a single structure, but the block 4 may be composed of a block body and an end plate attached to the end face of the block body, with the rolling section 8 and return path 9 formed on the block body and the turn path 10 formed on the end plate. (Trajectory of the turn path of the curved guide (F Ｘ ', F Ｙ ', F Ｚ ´))

[0021] The turning path 10 of the curved guide 1 of this embodiment will be described below. As shown in Figure 1, the longitudinal direction of the rail 2, i.e., the direction of movement of the block 4, is defined as the Y axis, the height direction as the Z axis, and the horizontal direction (the normal direction of the rail 2) as the X axis.

[0022] In order for the rolling elements 3 to circulate smoothly, it is necessary to smoothly connect the arc-shaped rolling path 13 and the turning path 10 with a tangent. In a conventional curved guide, the track 40a of the turning path of the linear guide 31 (see FIG. 7) shown in FIG. 4(a) was applied to the track 40a of the turning path of the curved guide 1, as shown by the dashed line in FIG. 4(b). In FIG. 4(a), reference numeral 43a denotes the track of the rolling path of the linear guide 31, reference numeral 39a denotes the track of the return path of the linear guide 31, and reference numeral 40a denotes the track of the turning path of the linear guide 31 (see also FIG. 7).

[0023] However, as shown in Figure 4(b), if the track 40a of the turning path of the linear guide 31 is applied to the track 40a of the turning path of the curved guide 1 and the arc-shaped rolling path 13 and the turning path 10 are smoothly connected by a tangent, because the rail 2 of the curved guide 1 is curved in an arc, the turning path 10 will be narrow on the inner side of the curved guide 1, making it difficult for the rolling elements 3 to pass, and the turning path 10 will be wide on the outer side of the curved guide 1, making it easier for the rolling elements 3 to meander. Therefore, the turning path 10 of the curved guide 1 is curved starting from the center of curvature O of the arc-shaped rolling path 13.

[0024] Figure 5(a) shows the track 10a of the turning path 10 of the circulation path 5 on the inner periphery side of the curved guide 1, and Figure 5(b) shows the track 10a of the turning path 10 on the outer periphery side of the curved guide 1. On the inner periphery side of Figure 5(a), the sign of the X-axis is set to + from point A toward the center of the arc of the rolling path 13, and on the outer periphery side of Figure 5(b), the sign of the X-axis is set to + from point A toward the outside of the arc of the rolling path 13. The dashed lines in Figures 5(a) and (b) indicate the track 40a of the turning path 40 of the linear guide 31.

[0025] As shown in FIG. 5(a), the track 10a (F Ｘ ´ ｉ , F Ｙ ´ ｉ , F ｚ ´ ｉ ) is the track 40a (F Ｘ , F Ｙ , F Ｚ ), the radius of curvature R of the raceway 13a of the rolling path 13 on the inner periphery side of the curved guide 1 shown in FIG. ｉUsing the above, it is expressed as follows: (Equation 1) F Ｘ ´ ｉ =R ｉ (1-cos γ)+F Ｘ ・cosγ F Ｙ ´ ｉ =R ｉ ・sinγ-F Ｘ ・sinγ F Ｚ ´ ｉ =F Ｚ Here, γ is the arc angle from the turn start point A, and γ = F Ｙ / R ｉ is.

[0026] Formula 1 is the arc length F from the turn start point A on the track 13a of the arc-shaped rolling path 13 of the curved guide 1. Ｙ Point P is taken at the point where the distance has advanced by F. Ｘ The points separated by a distance of 100 m are the trajectory 10a (F Ｘ ´ ｉ , F Ｙ ´ ｉ , F ｚ ´ ｉ ) The Z coordinate of the track 10a of the turning path 10 of the curved guide 1 is the same as the Z coordinate of the track 40a of the turning path 40 of the linear guide 31. By gradually increasing γ using Equation 1, the track 10a of the entire length of the turning path 10 of the curved guide 1 can be obtained.

[0027] As shown in Equation 1, when the turning path 10 of the curved guide 1 is curved starting from the center of curvature O of the arc-shaped rolling path 13, it is possible to prevent the turning path 10 from narrowing on the inner periphery of the curved guide 1 and widening on the outer periphery of the curved guide 1. It is also ensured that the tangents of the rolling path 13 of the curved guide 1 and the turning path 10 are continuous at the turning start point A. Note that, although it is desirable that the curvatures of the rolling path 13 of the curved guide 1 and the turning path 10 are continuous at the turning start point A, they may be discontinuous.

[0028] Similarly, as shown in FIG. 5(b), the track 10a (F Ｘ ´ Ｏ , F Ｙ ´ Ｏ , F Ｚ ´Ｏ ) is the track 40a (F Ｘ , F Ｙ , F Ｚ ), the radius of curvature R of the raceway 13a of the rolling path 13 on the outer periphery of the curved guide 1 shown in FIG. Ｏ Using the above, it is expressed as follows: (Equation 2) F Ｘ ´ Ｏ =-R Ｏ (1-cos γ)+F Ｘ ・cosγ F Ｙ ´ Ｏ =R ｉ sinγ+F Ｘ ・sinγ F Ｚ ´ Ｏ =F Ｚ Here, γ is the arc angle from the turn start point A, and γ = F Ｙ / R Ｏ is.

[0029] It is also possible to exchange the start point A of the turn with the end point C of the turn, and use the radius of curvature of the return path 9 of the curved guide 1 instead of the radius of curvature of the rolling path 13 of the curved guide 1. (Trajectory of the turning path of the linear guide (F Ｘ , F Ｙ , F Ｚ ))

[0030] As described above, the turning path 10 of the curved guide 1 is curved starting from the center of curvature O of the arc-shaped rolling path 13, and is formed by deforming the turning path 40 of the linear guide 31 as shown in Equations 1 and 2. An example of the turning path 40 of the linear guide 31 will be described below.

[0031] Consider a linear guide 31 shown in Fig. 7. This linear guide 31 includes a linear rail 32 and a block 34 that is movable relative to the rail 32. In the following description, the longitudinal direction of the rail 32, i.e., the direction of movement of the block 34, is defined as the Y axis, the height direction as the Z axis, and the horizontal direction as the X axis.

[0032] Reference numeral 43 denotes a rolling path, reference numeral 39 denotes a return path, and reference numeral 40 denotes a turning path. The dashed dotted lines in FIG. 7 indicate tracks 43a, 39a, and 40a of the circulation path 35 (rolling path 43, return path 39, turning path 40). The rolling path 43 is formed between the rolling portion 37 of the rail 32 and the rolling portion 38 of the block 34. The rolling path 43 is linear. The returning path 39 is linear and parallel to the rolling path 43. The turning path 40 has a three-dimensional shape.

[0033] The trajectory 40a of the turning path 40 of the linear guide 31 is formed based on a cross-sectional trajectory curve 44 (see FIG. 8(a)) in the XZ cross section of the linear guide 31 and a longitudinal trajectory curve 45 (see FIG. 8(b)) drawn on an imaginary plane VP in which the longitudinal direction of the linear guide 31 is the Y-axis and the length ω of the cross-sectional trajectory curve 44 is the length ω of the W-axis.

[0034] As shown in FIG. 8A , the cross-sectional orbit curve 44 is a curve that indicates the actual trajectory of the track along which the rolling elements 3 circulate in the XZ cross section of the linear guide 31. A is the start point of the turn, and C is the end point of the turn. The cross-sectional orbit curve 44 is determined in advance based on the constraints of the shape of the rail 32 and the shape of the turning path 40. For example, in this embodiment, the cross-sectional orbit curve 44 is determined in advance based on the constraints of the shape of the rail 32 and is formed by connecting a single arc and a straight line so that the rolling elements 3 can move along the arc portion 41 of the side surface 32 b and the top surface 32 a of the rail 32. Of course, the cross-sectional orbit curve 44 is not limited to this, and instead of a single arc, it may be formed by connecting multiple arcs with different curvatures. Furthermore, instead of connecting arcs and straight lines, the cross-sectional orbit curve 44 may be formed using only arcs, ellipses, clothoid curves, spline curves, or the like.

[0035] As shown in FIG. 8( b), the longitudinal track curve 45 is a curve that reverses the track direction by 180°. A is the start point of the turn, and C is the end point of the turn. The longitudinal track curve 45 is connected to the track 43 a of the rolling path 43 and the track 39 a of the return path 39. The track 43 a of the rolling path 43 and the track 39 a of the return path 39 are straight lines parallel to the Y axis. The turn track width α of the longitudinal track curve 45, i.e., the distance between the track 43 a of the rolling path 43 and the track 39 a of the return path 39, is equal to the total track length α of the cross-sectional track curve 44 (see FIG. 8( a)).

[0036] The Y axis of the virtual plane VP is the longitudinal direction of the linear guide 31, i.e., the direction of relative movement of the block 34. The W axis of the virtual plane VP is different from the Z axis of the linear guide 31. The variable ω of the W axis is not the length of the linear guide 31 in the Z axis direction, but the trajectory length ω from the turn start point A of the cross-sectional trajectory curve 44 (see FIG. 8A). For example, if the cross-sectional trajectory curve 44 is an arc, the trajectory length ω is the arc length.

[0037] The longitudinal trajectory curve 45 is a curve with continuous tangents, such as a single circular arc, or may be a curve with continuous tangents, such as an ellipse, a clothoid curve, or a spline curve.

[0038] The longitudinal track curve 45 is connected to the track 43a of the rolling path 43 at the turn start point A so as to have a substantially continuous tangent. Also, the longitudinal track curve 45 is connected to the track 39a of the return path 39 at the turn end point C so as to have a substantially continuous tangent. Note that it is preferable that the longitudinal track curve 45 is connected to both the track 43a of the rolling path 43 and the track 39a of the return path 39 so as to have a continuous tangent, but it may also be connected to only the track 43a of the rolling path 43 so as to have a continuous tangent.

[0039] When the horizontal direction of the linear guide 31 is the X coordinate, the height direction is the Z coordinate, and the longitudinal direction is the Y coordinate, the coordinates of the track 40a of the turning path 40 are expressed by the following continuous X, Y, and Z coordinates using the track length ω from the turn start point A of the cross-sectional track curve 44. (Equation 3) (X, Y, Z) = (F Ｘ (ω), F Ｙ (ω), F Ｚ (ω)) where the X and Z coordinates of the trajectory 40a are the X and Z coordinates of the cross-sectional trajectory curve 44 (F Ｘ (ω), F Ｚ The Y coordinate of the orbit 40a is the Y coordinate (F (ω)) of the longitudinal orbit curve 45 with ω of the W axis of the virtual plane VP as a variable. Ｙ (ω)).

[0040] An example of the trajectory 40a will be described below. The X and Z coordinates of the trajectory 40a are calculated by the coordinates (F Ｘ (ω), F Ｚ (ω)).

[0041] As shown in FIG. 9A, when the cross-sectional trajectory curve 44 is formed by connecting a circular arc and a straight line, the X and Z coordinates of the cross-sectional trajectory curve 44 are expressed as follows: (X, Z)=(F Ｘ (ω), F Ｚ (ω)) In the section A to B, In the section B to C, Here, A is the start point of the turn, B is the curvature change point within the cross-sectional trajectory curve, and C is the end point of the turn. ω is the trajectory length from the start point A of the turn, and is a variable that changes from 0 to α. θ is the turn start angle, R １ is the cross-sectional orbit radius, and α is the cross-sectional orbit total length.

[0042] As shown in FIG. 8B, the Y coordinate of the trajectory 40a is the Y coordinate (F Ｙ (ω)).

[0043] As shown in FIG. 9B, when the longitudinal trajectory curve 45 is formed from a single arc, the Y coordinate of the trajectory 40a is expressed as follows: Y=F (Equation 5) Ｙ (ω) In the section A to C, Here, R ２ is the longitudinal orbital radius, and R ２ = α / 2.

[0044] F in Equation 4 Ｘ (ω), F Ｚ (ω), F in Eq. Ｙ From (ω), the X, Y, and Z coordinates of the trajectory 40a can be calculated with the trajectory length ω from the turn start point A as a variable. Ｗ is not used to find the coordinates of the trajectory 40a, but is listed here for reference.

[0045] 7 shows the track 40a of the turning path 40 formed based on the cross-sectional track curve 44 and the longitudinal track curve 45. By forming the track 40a in this manner, even if the track 40a is a three-dimensional, complex track, it can be connected at the turn start point A to the track 43a of the rolling path 43 so as to be substantially tangent to the track 43a. Also, it can be connected at the turn end point C to the track 39a of the return path 39 so as to be substantially tangent to the track 43a.

[0046] The trajectory 40a of the turning path 40 of the linear guide 31 is not limited to the three-dimensional trajectory described above. For example, it may be a two-dimensional trajectory such as a circular arc, an ellipse, a clothoid curve, or a spline curve drawn in a plane. (Effect)

[0047] The effects of the curved guide 1 of this embodiment will be described below.

[0048] Since the turning path 10 is curved starting from the center of curvature O of the arc-shaped rolling path 13, it is possible to prevent the turning path 10 from narrowing on the inner periphery side of the curved guide 1 and widening on the outer periphery side of the curved guide 1. Therefore, the rolling elements 3 circulate smoothly.

[0049] The rolling path 13 and the turning path 10 are connected so that the tangents are substantially continuous, so that the rolling elements 3 circulate more smoothly.

[0050] The track 10a (F) of the turning path 10 on the inner periphery of the curved guide 1 Ｘ ´ ｉ , F Ｙ ´ ｉ , F Ｚ ´ ｉ ) and / or the track 10a of the outer turning path 10 (F Ｘ ´ Ｏ , F Ｙ ´ Ｏ , F Ｚ ´ Ｏ ) on the track 40a (F Ｘ , F Ｙ , F Ｚ ), and the radius of curvature of the rolling path 13 or the return path 9 of the curved guide 1 is used to express it as in Equation 1 and / or Equation 2, so that it is possible to ensure that the tangents of the arc-shaped rolling path 13 of the curved guide 1 and the turning path 10 are continuous at the turning start point A.

[0051] The track 40a (F Ｘ , F Ｙ , F Ｚ) is formed based on a cross-sectional trajectory curve 44 in the XZ cross section of the linear guide 31 and a longitudinal trajectory curve 45 drawn on an imaginary plane VP in which the longitudinal direction of the linear guide 31 is the Y axis and the trajectory length ω from the turning start point A of the cross-sectional trajectory curve 44 is the length ω of the W axis.Therefore, even if the turning path 40 of the linear guide 31 is a complex three-dimensional trajectory, the tangents of the turning path 40 of the linear guide 31 and the rolling path 43 can be made continuous.

[0052] The present invention is not limited to the above-described embodiment, and can be embodied in other embodiments without departing from the spirit of the present invention.

[0053] In the above embodiment, the rolling elements are balls, but the rolling elements may be rollers. Also, spacers may be interposed between the rolling elements.

[0054] In the above embodiment, an example of an outer block type curved guide in which a block with a substantially U-shaped cross section straddles a rail has been described, but an inner block type curved guide in which an inner block is placed inside an outer rail with a substantially U-shaped cross section may also be used. Also, arc-shaped rails may be connected to form a ring shape.

[0055] The curved guide of this embodiment is a mechanical element that guides the arcuate motion of a movable body, and its uses are not particularly limited, and it can be used, for example, in automobile steering devices, machine tools, conveying devices, industrial robots, semiconductor manufacturing devices, liquid crystal manufacturing devices, wind power generation devices, truck cranes, slewing bearings in astronomical observatories, etc.

[0056] This specification is based on Japanese Patent Application No. 2024-001944, filed on January 10, 2024, the entire contents of which are incorporated herein by reference.

[0057] 1... curved guide, 2... rail, 3... rolling element, 4... block, 7... rolling portion of rail, 8... rolling portion of block, 9... return path of curved guide, 13... rolling path of curved guide, 10... turning path of curved guide, 31... linear guide, 40... turning path of linear guide, 44... cross-sectional track curve of linear guide, 45... longitudinal track curve of linear guide

Claims

1. A curved guide comprising an arcuate rail, a block movable relative to the rail, and a plurality of rolling elements disposed in a circulation path including a rolling path, a return path between a rolling portion of the rail and a rolling portion of the block, and a turn path connecting the rolling path and the return path, wherein the turn path is curved starting from the center of curvature of the arcuate rolling path.

2. The curved guide according to claim 1, wherein the rolling path and the turn path are connected such that the tangents are substantially continuous.

3. The orbit (F Ｘ ´ ｉ ,F Ｙ ´ ｉ ,F Ｚ ´ ｉ ) of the turning path of the inner - peripheral - side circulation path of the curved guide is represented by Equation 1 using the orbit (F Ｘ ,F Ｙ ,F Ｚ ) of the turning path of the linear guide and the radius of curvature R ｉ of the orbit of the rolling path or the return path of the inner - peripheral - side circulation path of the curved guide, and / or, the orbit (F Ｘ ´ Ｏ ,F Ｙ ´ Ｏ ,F Ｚ ´ Ｏ ) of the turning path of the outer - peripheral - side circulation path of the curved guide is represented by Equation 2 using the orbit (F Ｘ ,F Ｙ ,F Ｚ ) of the turning path of the linear guide and the radius of curvature R Ｏ of the orbit of the rolling path or the return path of the outer - peripheral - side circulation path of the curved guide. The curved guide according to claim 1 or 2 is characterized in that. (Equation 1) F Ｘ ´ ｉ =R ｉ (1 - cosγ)+ F Ｘ ・cosγ F Ｙ ´ ｉ =R ｉ ・sinγ - F Ｘ ・sinγ F Ｚ ´ ｉ =F Ｚ Here, γ is the arc angle from the start point of the turn, and γ = F Ｙ / R ｉ . (Equation 2) F Ｘ ´ Ｏ = - R Ｏ (1 - cosγ)+ F Ｘ ・cosγ F Ｙ ´ Ｏ =R Ｏ ・sinγ + F Ｘ ・sinγ F Ｚ ´ Ｏ =F Ｚ Here, γ is the arc angle from the start point of the turn, and γ = F Ｙ / R Ｏ It is.

4. The orbit (F Ｘ , F Ｙ , F Ｚ ) of the turning path of the linear guide is formed based on the cross-sectional orbit curve in the XZ cross-section of the linear guide and the longitudinal orbit curve drawn on a virtual plane with the longitudinal direction of the linear guide as the Y-axis and the orbit length ω from the turn start point of the cross-sectional orbit curve as the length ω of the W-axis. (F Ｘ , F Ｚ ) are the X and Z coordinates of the cross-sectional orbit curve, and F Ｙ is the Y coordinate of the longitudinal orbit curve with the ω of the W-axis of the virtual plane as a variable, and the curve guide according to claim 3, characterized in that.

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