WO2004044444A1 - Movement guide device, ball screw, and method of producing ball raceway groove - Google Patents

Movement guide device, ball screw, and method of producing ball raceway groove Download PDF

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Publication number
WO2004044444A1
WO2004044444A1 PCT/JP2003/014253 JP0314253W WO2004044444A1 WO 2004044444 A1 WO2004044444 A1 WO 2004044444A1 JP 0314253 W JP0314253 W JP 0314253W WO 2004044444 A1 WO2004044444 A1 WO 2004044444A1
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WO
WIPO (PCT)
Prior art keywords
ball
rolling groove
ball rolling
pole
guide device
Prior art date
Application number
PCT/JP2003/014253
Other languages
French (fr)
Japanese (ja)
Inventor
Takeki Shirai
Yuuji Tachikake
Original Assignee
Thk Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thk Co., Ltd. filed Critical Thk Co., Ltd.
Priority to DE10393641T priority Critical patent/DE10393641T5/en
Publication of WO2004044444A1 publication Critical patent/WO2004044444A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C29/00—Bearings for parts moving only linearly
    • F16C29/005—Guide rails or tracks for a linear bearing, i.e. adapted for movement of a carriage or bearing body there along
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/02—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements
    • B24B19/06—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements for grinding races, e.g. roller races
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C29/00—Bearings for parts moving only linearly
    • F16C29/04—Ball or roller bearings
    • F16C29/06—Ball or roller bearings in which the rolling bodies circulate partly without carrying load
    • F16C29/0633—Ball or roller bearings in which the rolling bodies circulate partly without carrying load with a bearing body defining a U-shaped carriage, i.e. surrounding a guide rail or track on three sides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/583—Details of specific parts of races
    • F16C33/585—Details of specific parts of races of raceways, e.g. ribs to guide the rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/64—Special methods of manufacture
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • F16C2240/70—Diameters; Radii
    • F16C2240/76—Osculation, i.e. relation between radii of balls and raceway groove

Definitions

  • the present invention relates to a method for manufacturing a motion guide device, a pole screw and a ball rolling groove.
  • the present invention relates to a motion guide device that guides a linear motion or a rotary motion of a guided object, in which a plurality of poles that perform rolling motion are interposed between a track member and a moving member, or between a screw shaft and a nut.
  • the present invention relates to a ball screw in which a plurality of rolling balls are interposed.
  • a pole rolling groove is formed on a track member and a moving member of the motion guide device so as to be a track of a rolling ball.
  • Various forms are applied to the ball rolling grooves depending on the intended load receiving method.
  • FIG. 12 shows a cross section of the ball rolling groove.
  • the two main types of ball rolling grooves are circular arc grooves and gothic arch grooves.
  • the cross section of one circular groove is made of one circular arc.
  • the contact point of the ball It is called two-point contact because there are two points.
  • the cross-sectional shape of the Gothic arch groove is composed of two arcs, so that the ball contacts usually have four four-point contact structures (for example, see Non-Patent Document 1). .
  • each contact is a point contact where the ball and the smooth curved surface come into contact.
  • the load capacity of each ball is uniquely determined by the geometrical shape and material of the ball and the ball rolling groove. Therefore, in order to increase the load capacity by using balls of the same material and dimensions, a method has been adopted in which the radius of curvature of the ball rolling groove approaches the radius of the ball.
  • reducing the radius of curvature between the ball and the pole rolling groove increased the precision required for machining, and also caused industrial disadvantages such as increased costs.
  • an object of the present invention is to provide a motion guide device, a ball screw, and a method of manufacturing the same, which can increase the load capacity without making the radius of curvature of the pole rolling groove close to the radius of the ball. I do.
  • the present inventor has formed a plurality of convex portions which can be deformed in the direction in which the ball rolling grooves extend in the vicinity of the contact points of the pole rolling grooves, thereby forming a plurality of poles receiving the load.
  • the projections of the strip were in contact with each other. That is, the invention according to claim 1 is a movement in which a ball rolling groove is formed on at least one of the track member and the moving member, the ball rolling groove being a track when a ball interposed between the track member and the moving member rolls.
  • the ball rolling groove is formed with a plurality of elastically deformable protrusions extending uniformly in a direction in which the pole rolling groove extends, and a load is applied between the track member and the moving member.
  • the contact point between the ball and the ball rolling groove comes into contact at a plurality of points instead of at one point, the load on the ball is distributed at each point, and the ball is loaded at a specific point. High stress concentration can be suppressed.
  • the plurality of convex portions extend uniformly in the direction in which the pole rolling groove extends, when the pole rolls, the direction of the rotation axis of the ball is changed and the rotation of the ball is changed. Does not work. Therefore, whether the ball touches at one point or many points has little effect on the ball's rolling resistance.
  • the ⁇ portion is elastically deformed by the load so that the ball comes into contact with the depression.
  • the convex portion is elastically deformed, and a wide contact area between the pole and the ball rolling groove is ensured, so that the ball rolling groove has a wide rail load area.
  • the motion guide device of the present invention is a linear or curved motion guide device in which a moving member is slidably attached to a track member that extends linearly or in a curved line, or an annular track member in which an annular moving member is rotatable. It can be suitably used for the found rolling bearing.
  • the present invention also provides a ball screw in which a helical ball rolling groove is formed on a screw shaft and a nut, the helical ball rolling groove serving as a trajectory when the ball interposed between the screw shaft and the nut is rolled.
  • the rolling groove is formed with a plurality of elastically deformable convex portions that extend uniformly in the direction in which the spiral pole rolling groove extends, and receives a load between the track member and the moving member.
  • the pole may be configured as a ball screw that comes into contact with the plurality of protrusions before contacting the depression between the plurality of protrusions.
  • the present invention provides a method of manufacturing a ball rolling groove, wherein at least one of a track member and a moving member forms a ball rolling groove which becomes a track when a ball interposed between the track member and the moving member rolls.
  • a disk-shaped blade or grindstone having a smaller radius than the ball is moved in a direction in which the ball rolling groove extends, and the outer peripheral shape of the blade or grinding wheel is transferred to the pole rolling groove.
  • the depression between the plurality of protrusions has a radius of curvature smaller than the radius of the ball, so that the contact point between the ball and the ball rolling groove is not at one point but at a plurality of points.
  • FIG. 1 A perspective view of the motion guide device (linear guide) according to the first embodiment of the present invention. Figure (including partial cross section).
  • Fig. 2 is a cross-sectional view of the endless circuit along the direction in which the endless circuit of the motion guide device extends.
  • FIG. 3 Cross-sectional view of the ball rolling groove in a plane perpendicular to the direction in which the ball rolling groove extends.
  • Fig. 4 Diagram showing the distribution of generated stress (Von Mses stress) (when the pole and the smooth surface are in contact at one point).
  • Fig. 5 Diagram showing the distribution of generated stress (Von Mses stress) (when the ball and the smooth surface come in contact at two points).
  • Fig. 6 Diagram showing the distribution of the generated shearing force (XY shear) (when the ball and the smooth surface make contact at one point).
  • Fig. 7 Diagram showing the distribution of the generated shear force (XY shear) (when the ball and the smooth surface come in contact at two points).
  • Figure 8 Diagram showing the manufacturing method of the pole rolling groove (cross-sectional view in a direction perpendicular to the pole rolling groove).
  • FIG. 9 is a perspective view of a motion guide device (ball spline) according to a second embodiment of the present invention.
  • FIG. 10 is a perspective view of a ball screw according to a third embodiment of the present invention.
  • FIG. 11 is a cross-sectional view of a radial rolling bearing according to a fourth embodiment of the present invention.
  • Fig. 12 Cross-sectional view of a conventional general ball rolling groove ((A) in the figure shows the circuit groove, and (B) shows the Gothic arch groove).
  • FIG. 1 is a perspective view of a motion guide device according to a first embodiment of the present invention.
  • the lower guide includes a track rail 1 as a track member, and a moving block 3 as a moving member slidably mounted on the track rail 1 via a number of poles 2.
  • the track rail 1 is a long member whose cross section orthogonal to the longitudinal direction is formed in a substantially rectangular shape, and has a ball rolling groove 1a on its upper surface and both side surfaces which is a track for rolling the ball. Are formed over the entire length of the orbital rail 1.
  • the track rail 1 may be formed to extend linearly or may be formed to extend in a curved line.
  • the number of pole rolling grooves 1a is four in total, two on each side, but the number can be variously changed depending on the application of the linear guide.
  • the moving block 3 is also provided with pole rolling grooves 3a, which oppose the ball rolling grooves 1a, respectively.
  • Load rolling paths 1 2 are formed between the pole rolling grooves 1 a of the track rail 1 and the pole rolling grooves 3 a of the moving block 3, and a plurality of balls 2 are sandwiched therebetween.
  • the moving block 3 is provided with four return paths 13 extending in parallel with each ball rolling groove 1a, and a direction change path connecting each return path 13 and each load rolling path 1 2 ... ing.
  • One infinite circulation path is composed of a combination of one turning path 5 and return path 13 and a pair of turning paths 5 connecting them (see Fig. 2).
  • FIG. 2 shows a cross-sectional view of the infinite circuit along the extending direction of the infinite circuit.
  • Each of the infinite circulation paths is loaded with a large number of balls 2.
  • the connecting body 8 has a large number of spacers 4 provided at predetermined intervals, and a pair of belt portions 10, 10 connecting the spacers 4 on both sides thereof.
  • the pole 2 is housed and held between the parts 4,4.
  • the surface of the spacer 4 facing the ball 2 is spherically concave in accordance with the pole 2. This prevents contact between the poles 2 and 2 and enables smooth circulation of the poles 2 in the infinite circulation path.
  • the ponole 2 rolls on the load rolling path 12 from one end to the other while receiving a load, and then moves to one of the direction changing paths 5. It is scooped up, guided to the return path 13, and further returned to one end of the load rolling path 12 via the direction change path 5 on the opposite side.
  • FIG. 3 shows a sectional view of the pole rolling groove 1a in a plane perpendicular to the direction in which the pole rolling groove 1a extends.
  • the ball rolling groove 1a which is a track on which the ball 2 normally rolls, has a smooth surface and has a shape as close as possible to a geometric arc.
  • a plurality of protrusions 7 extending in the direction in which the pole rolling groove 1a extends are formed near the contact point between the ball 2 and the ball rolling groove 1a.
  • the projections 7 are not random irregularities such as roughness, but the direction in which the ball 2 travels (the direction perpendicular to the paper surface).
  • the outline of the ball rolling groove 1a on which the convex portions 7 are formed may be formed in a circular arc groove, may be formed in a Gothic arch groove, or may be formed in a smooth plane. .
  • a load acts on the pole 2 interposed between the track rail 1 and the moving block 3.
  • the pole receiving the load contacts a plurality of protrusions 7 before contacting the depression 39 between the protrusions 7.
  • the ball 2 contacts only the pair of projections 7, 7 and the depression between the projections 7, 3.
  • the plurality of protrusions 7, 7 are elastically deformed, and the ball 2 also comes into contact with the depression 39 between the protrusions 7, 7.
  • the pole 2 contacts the depression 13 between the projections 7, 7, the projections 7 are elastically deformed but not plastically deformed. Therefore, when the load is removed from the ball 2, the convex portions 7 are restored as shown in FIG.
  • the pitch of the convex portions 7 is determined, for example, as follows. There is a contact area between the ball 2 and the ball rolling groove 1a which is expected in the assumed load, for example, the basic static load rating. The pitch of the projections 7 is set such that the three or four projections 7 contact the ball 2 in this contact area.
  • the basic static load rating is the sum of the permanent deformation amount of the pole 2 and the permanent deformation amount of the ball rolling groove 1a at the contact part where the maximum stress is applied. A static load with a fixed direction and magnitude that increases by a factor of 0.00.
  • the plurality of convex portions 7 play a role like a rail, and the ball 2 rolls on the rail.
  • the ball 2 rolls in the ball rolling groove 1a
  • the ball 2 has a rotation axis 14 in a direction orthogonal to the moving direction.
  • friction acts on the contact point between the ball 2 and the ball rolling groove 1a.
  • the ball 2 comes into contact with the pair of projections 7 at two points, Does the force that binds 14 work? Therefore, even if the projections 7 are provided, the influence on the resistance in the rolling direction of the pole 2 is small.
  • the load applied to the ball 2 is received at multiple points rather than at one point, the contact area expands faster for the load, and the load capacity is proportional to the increase in the contact area. Can be larger.
  • Figures 4 to 7 show the results of FEM (finite element method) analysis of the stress and shear force generated when the pole and the smooth surface make contact at one point and when they make contact at two points.
  • FEM finite element method
  • Figures 4 and 5 show the distribution of the generated stress (Von Mses stress).
  • Fig. 4 shows a normal case where the pole and the smooth surface make contact at one point
  • Fig. 5 shows a case where the ball and the projection make contact at two points. The same hatching is applied to portions where the magnitude of the stress is equal.
  • Figures 6 and 7 show the distribution of the generated shear force (XY shear).
  • Fig. 6 shows the case where the ball and the smooth surface make contact at one point, as usual, and
  • Fig. 7 shows the case where the ball and the projection make contact at two points. The same hatching is applied to the parts with the same shear force.
  • FIG. 8 shows a method of manufacturing the ball rolling groove 1a.
  • a disk-shaped grindstone 15 having a smaller radius than the radius of the ball 2 is prepared.
  • roll the ball while rotating whetstone 15 Move in the direction in which the groove la extends (in the direction perpendicular to the paper surface), and make the ball rolling groove 1a on the outer peripheral surface of the grindstone 15; Grind from the ffiil opening surface to the rolling surface, and form the outer peripheral shape of the grindstone 15 Is transferred to the ball rolling groove 1a.
  • a certain interval is set in a plane orthogonal to the direction in which the ball rolling groove 1a extends so that the position of the grinding wheel 15 is aligned with the grinding wheel position of No. 10 from the grinding wheel position of No.
  • FIG. 9 is a perspective view of a motion guide device according to a second embodiment of the present invention. This figure shows a pole spline as a linear motion guide device.
  • the ball spline has a spline shaft 21 as a track member, and an outer cylinder 23 as a moving member movably attached to the spline shaft 21 via a number of balls 22.
  • ball rolling grooves 21 a Extending in the axial direction of the spline shaft 21.
  • a pole rolling groove corresponding to the pole rolling groove 21 a is formed in the outer cylinder 23 attached to the spline shaft 21.
  • a plurality of convex portions extending in the direction in which the ball rolling grooves 21a ... extend.
  • FIG. 10 is a perspective view of a pole screw according to the third embodiment of the present invention.
  • the screw shaft 31 is formed with a ball rolling groove 31a having a substantially semicircular cross section and a constant spiral lead around the screw shaft 31.
  • a pole rolling groove 32a having a substantially semicircular cross section is formed to face the ball rolling groove 31a of the screw shaft 31.
  • a plurality of spiral convex portions extending in the direction in which the ball rolling grooves 31 a and 32 a extend are formed.
  • a plurality of balls 34 are accommodated in the pole rolling path between the ball rolling groove 31 a of the screw shaft 31 and the ball rolling groove 32 a of the nut 32.
  • Circulation parts 33, 33 are attached to the nut 32.
  • the circulating parts 3 3, 3 3 form a no-load return passage connecting one end of the ball rolling path to the other end, and allow a plurality of balls 3 4... to move relative to the nut 3 2 with respect to the screw shaft 3 1. Circulate together.
  • FIG. 11 is a sectional view of a radial type rolling bearing according to a fourth embodiment of the present invention.
  • An inner race 42 as an annular moving member is rotatably mounted on the outer race 41 as an annular race member.
  • Ball rolling grooves 41a and 42a are formed on the outer ring 41 and the inner ring 42, respectively.
  • the ball 43 is sandwiched between the ball rolling grooves 41a and 42a.
  • a plurality of annular convex portions extending in the direction in which the ball rolling grooves extend are formed in these pole rolling grooves 41a and 42a.
  • the radial type rolling bearing has been described.
  • the ball rolling groove in which a plurality of convex portions are formed may be used for a thrust type rolling bearing.
  • the present invention is not limited to the above-described embodiment, and can be variously changed without changing the gist of the present invention.
  • the ball rolling groove in which a plurality of convex portions are formed may not be formed in both the track member and the moving member, or may be formed in either one.
  • a plurality of protrusions extending in the direction in which the ball rolling groove extends are formed near the contact point of the pole rolling groove, and the ball and the plurality of protrusions are formed by the load acting on the ball. Since the protruding portions are in contact with each other, the load on the ball is distributed and applied to each point, and high stress concentration at a specific point can be suppressed. Therefore, the load capacity can be increased without making the radius of curvature of the ball rolling groove close to the radius of the pole.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Bearings For Parts Moving Linearly (AREA)
  • Transmission Devices (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
  • Rolling Contact Bearings (AREA)

Abstract

A movement guide device whose load capacity is increased without nearing a curvature radius of ball rolling grooves to a radius of balls. Ball rolling grooves are formed in a raceway rail and moving block of a linear guide, the ball rolling grooves serving as raceways where balls interposed between a raceway member and a moving member roll. Elastically deformable lines of ridges extending in the direction in which the ball rolling grooves extend are formed in the vicinity of contact points of the ball rolling grooves with which points the balls are in contact. This results that the balls and the lines of ridges are in contact by a load acting on the balls. The load to the balls is distributed to each point of the ridges so that high stress concentration at a specific point can be prevented from occurring. As a result, load capacity of the device can be increased without nearing a curvature radius of ball rolling grooves to a radius of the balls.

Description

明細書 運動案内装置、 ポールねじ及びボール転走溝の製造方法 技術分野  TECHNICAL FIELD The present invention relates to a method for manufacturing a motion guide device, a pole screw and a ball rolling groove.
本発明は、 軌道部材と移動部材との間に転がり運動する複数のポールが介在さ れ、 案内対象の直線運動又は回転運動を案内する運動案内装置、 又はねじ軸とナ ットとの間に転がり運動する複数のボールが介在されるボールねじに関する。 背景技術  The present invention relates to a motion guide device that guides a linear motion or a rotary motion of a guided object, in which a plurality of poles that perform rolling motion are interposed between a track member and a moving member, or between a screw shaft and a nut. The present invention relates to a ball screw in which a plurality of rolling balls are interposed. Background art
運動案内装置の軌道部材及ぴ移動部材には、 転がり運動するボールの軌道とな るポール転走溝が形成される。 ボール転走溝には目的とする荷重の受け方によつ て様々な形態が適用されている。  A pole rolling groove is formed on a track member and a moving member of the motion guide device so as to be a track of a rolling ball. Various forms are applied to the ball rolling grooves depending on the intended load receiving method.
図 1 2はボール転走溝の断面を示す。 ボール転走溝の二大形状には、 サーキュ ラーアーク溝とゴシックアーチ溝がある。 図中 （A) に示すように、 サーキユラ. 一アーク溝の断面形状は 1つの円弧でできていて、 サーキユラ一アーク溝を持つ た軌道部材と移動部材とでボールを挟むと、 ボールの接点が 2点になるので 2点 接触と呼ばれる。 図中 （B) に示すように、 ゴシックアーチ溝の断面形状は、 2 つの円弧でできているため、 通常ボールの接点が 4つの 4点接触構造になる （例 えば、 非特許文献 1参照)。  FIG. 12 shows a cross section of the ball rolling groove. The two main types of ball rolling grooves are circular arc grooves and gothic arch grooves. As shown in (A) in the figure, the cross section of one circular groove is made of one circular arc. When the ball is sandwiched between a track member and a moving member having a circular groove, the contact point of the ball It is called two-point contact because there are two points. As shown in (B) in the figure, the cross-sectional shape of the Gothic arch groove is composed of two arcs, so that the ball contacts usually have four four-point contact structures (for example, see Non-Patent Document 1). .
2点接触では、 ポールとボール転走溝との接点がボールを挟んで対峙し、 4点 接触では、 ボール中心に対して概ね 9 0 ° ずれた方向に合計 4つの接点が形成さ れる。 また、 まれに 3点で接触させる場合にも、 ボール中心に対して概ね等間隔 に配置されるのが常である。 これらいずれの場合でも、 それぞれの接点ではボー ルと平滑な曲面とが接する点接触になる。  In the two-point contact, the contact point between the pole and the ball rolling groove faces each other across the ball, and in the four-point contact, a total of four contact points are formed in a direction shifted by about 90 ° from the center of the ball. Also, in the rare case of contact at three points, they are usually arranged at approximately equal intervals with respect to the center of the ball. In each case, each contact is a point contact where the ball and the smooth curved surface come into contact.
【非特許文献 1】  [Non-Patent Document 1]
清水、他 9名、 「リニアシステム事始め」、リニアシステム編集委員会、 2 0 0 0年 6月 1 5日発行、 p . 4 0 発明の開示 Shimizu, and 9 others, "Beginning with Linear Systems", Linear Systems Editorial Committee, published on June 15, 2000, p. 40 Disclosure of the invention
従来の平滑なポール転走溝を有する運動案内装置では、各ボールの負荷容量は、 ボール及ぴボール転走溝の幾何学的形状と材質とで一義的に定まる。 そのため同 一材質及び同一寸法のボールを用いて負荷容量の増大を図るには、 ボール転走溝 の曲率半径をボールの半径に近づける方法が採られてきた。 しかしながら、 ボー ルとポール転走溝の曲率半径を近づけることは加工での要求精度を高めることに つながり、 コスト増等の産業上の不利益を併発した。  In a conventional motion guide device having a smooth pole rolling groove, the load capacity of each ball is uniquely determined by the geometrical shape and material of the ball and the ball rolling groove. Therefore, in order to increase the load capacity by using balls of the same material and dimensions, a method has been adopted in which the radius of curvature of the ball rolling groove approaches the radius of the ball. However, reducing the radius of curvature between the ball and the pole rolling groove increased the precision required for machining, and also caused industrial disadvantages such as increased costs.
そこで本発明は、ポール転走溝の曲率半径をボールの半径に近づけることなく、 負荷容量の増大を図ることができる運動案内装置、 ボールねじ、 及びそれらの製 造方法を提供することを目的とする。  Therefore, an object of the present invention is to provide a motion guide device, a ball screw, and a method of manufacturing the same, which can increase the load capacity without making the radius of curvature of the pole rolling groove close to the radius of the ball. I do.
以下、 本発明について説明する。 上記課題を解決するために本発明者は、 ポー ル転走溝の接点付近にボール転走溝が伸びる方向に伸びる複数条の弹性変形がで きる凸部を形成し、荷重を受けるポールと複数条の凸部とが接触するようにした。 すなわち請求項 1の発明は、 軌道部材及び移動部材の少なくとも一方に、 前記 軌道部材と前記移動部材との間に介在されるボールが転がる際の軌道となるボー ル転走溝が形成される運動案内装置において、 前記ボール転走溝には、 ポール転 走溝が伸びる方向に一様に伸びる複数条の弾性変形ができる凸部が形成され、 前 記軌道部材と前記移動部材との間で荷重を受ける前記ポールは、 前記複数条の凸 部間の窪みに接触する前に前記複数条の凸部に接触することを特徴とする運動案 内装置により、 上述した課題を解決する。  Hereinafter, the present invention will be described. In order to solve the above-mentioned problem, the present inventor has formed a plurality of convex portions which can be deformed in the direction in which the ball rolling grooves extend in the vicinity of the contact points of the pole rolling grooves, thereby forming a plurality of poles receiving the load. The projections of the strip were in contact with each other. That is, the invention according to claim 1 is a movement in which a ball rolling groove is formed on at least one of the track member and the moving member, the ball rolling groove being a track when a ball interposed between the track member and the moving member rolls. In the guide device, the ball rolling groove is formed with a plurality of elastically deformable protrusions extending uniformly in a direction in which the pole rolling groove extends, and a load is applied between the track member and the moving member. The above-mentioned subject is solved by the exercise planning device, wherein the pole that receives the contact comes into contact with the plurality of protrusions before contacting the depression between the plurality of protrusions.
この発明によれば、 ボールとボール転走溝との接点が一点ではなく、 複数の点 で接触するようになるので、ボールへの負荷はそれぞれの点に分散して負荷され、 特定の一点での高い応力集中を抑制することができる。 また複数状の凸部は、 ポ 一ル転走溝の伸びる方向に一様に伸びているので、 ポールが転がる際にボールの 回転軸の方向を変ィ匕させ、 ボールの回転を変えてしまうような力が働かない。 し たがつて一点で接触しても多数点で接触しても、 ボールが転がる際の抵抗には影 響が少ない。  According to the present invention, since the contact point between the ball and the ball rolling groove comes into contact at a plurality of points instead of at one point, the load on the ball is distributed at each point, and the ball is loaded at a specific point. High stress concentration can be suppressed. In addition, since the plurality of convex portions extend uniformly in the direction in which the pole rolling groove extends, when the pole rolls, the direction of the rotation axis of the ball is changed and the rotation of the ball is changed. Does not work. Therefore, whether the ball touches at one point or many points has little effect on the ball's rolling resistance.
前記荷重によって、 前記 ώ部が弾性変形して前記ボールが前記窪みに接触する のが望ましい。 この発明によれば、 凸部が弾性変形して、 ポールとボール転走溝との広い接触 面積が確保されるので、 ボール転走溝に広レヽ負荷領域が確保される。 It is preferable that the ώ portion is elastically deformed by the load so that the ball comes into contact with the depression. According to the present invention, the convex portion is elastically deformed, and a wide contact area between the pole and the ball rolling groove is ensured, so that the ball rolling groove has a wide rail load area.
本発明の運動案内装置は、 直線的若しくは曲線的に伸びる軌道部材に移動部材 がスライド可能に取り付けられた直線若しくは曲線運動案内装置、 又は環状の軌 道部材に環状の移動部材が回転可能に組みつけられた転がり軸受けに好適に用い ることができる。  The motion guide device of the present invention is a linear or curved motion guide device in which a moving member is slidably attached to a track member that extends linearly or in a curved line, or an annular track member in which an annular moving member is rotatable. It can be suitably used for the found rolling bearing.
また本発明は、 ねじ軸及びナットに、 前記ねじ軸と前記ナットとの間に介在さ れるボールが転がる際の軌道となる螺旋状のボール転走溝が形成されるボールね じにおいて、 前記ボール転走溝には、 螺旋状のポール転走溝が伸びる方向に一様 に伸びる複数条の弾性変形ができる凸部が形成され、 前記軌道部材と前記移動部 材との間で荷重を受ける前記ポールは、 前記複数条の凸部間の窪みに接触する前 に前記複数条の凸部に接触することを特徴とするボールねじとして構成してもよ い。  The present invention also provides a ball screw in which a helical ball rolling groove is formed on a screw shaft and a nut, the helical ball rolling groove serving as a trajectory when the ball interposed between the screw shaft and the nut is rolled. The rolling groove is formed with a plurality of elastically deformable convex portions that extend uniformly in the direction in which the spiral pole rolling groove extends, and receives a load between the track member and the moving member. The pole may be configured as a ball screw that comes into contact with the plurality of protrusions before contacting the depression between the plurality of protrusions.
さらに本発明は、 軌道部材及ぴ移動部材の少なくとも一方に、 軌道部材と移動 部材との間に介在されるボールが転がる際の軌道となるボール転走溝を形成する ボール転走溝の製造方法にぉレ、て、 前記ボールの半径よりも半径が小さな円盤状 の刃物又は砥石を前記ボール転走溝の伸びる方向に移動させ、 前記刃物又は砥石 の外周形状を前記ポール転走溝に転写する工程と、 前記刃物又は砥石を前記ボー ル転走溝が伸びる方向と直交する面内で移動させる工程と、 前記刃物又は砥石を 前記ポール転走溝の伸びる方向に移動させ、 前記刃物又は砥石の外周形状を前記 ボール転走溝に転写する工程とを備え、 前記ボール転走溝には、 前記ボール転走 溝が伸びる方向に伸びる複数条の弾性変形ができる凸部が形成されることを特徴 とするボール転走溝の製造方法により、 上述する課題を解決する。  Further, the present invention provides a method of manufacturing a ball rolling groove, wherein at least one of a track member and a moving member forms a ball rolling groove which becomes a track when a ball interposed between the track member and the moving member rolls. A disk-shaped blade or grindstone having a smaller radius than the ball is moved in a direction in which the ball rolling groove extends, and the outer peripheral shape of the blade or grinding wheel is transferred to the pole rolling groove. Moving the blade or the grindstone in a direction perpendicular to the direction in which the ball rolling groove extends; moving the blade or the grinding stone in the direction in which the pole rolling groove extends; Transferring the outer peripheral shape to the ball rolling groove, wherein the ball rolling groove is formed with a plurality of elastically deformable convex portions extending in a direction in which the ball rolling groove extends. To be The method for producing Lumpur rolling groove, to solve the problem of above.
この発明によれば、 複数条の凸部間の窪みがボールの半径よりも小さな曲率半 径になるので、 ボールとボール転走溝との接点が一点ではなく、 複数の点で接触 するようになる。 図面の簡単な説明  According to the present invention, the depression between the plurality of protrusions has a radius of curvature smaller than the radius of the ball, so that the contact point between the ball and the ball rolling groove is not at one point but at a plurality of points. Become. BRIEF DESCRIPTION OF THE FIGURES
図 1 本発明の第 1の実施形態における運動案内装置 （リニアガイド） の斜視 図 （一部断面を含む)。 FIG. 1 A perspective view of the motion guide device (linear guide) according to the first embodiment of the present invention. Figure (including partial cross section).
図 2 上記運動案内装置の無限循環路の伸びる方向に沿った無限循環路の断面 図。  Fig. 2 is a cross-sectional view of the endless circuit along the direction in which the endless circuit of the motion guide device extends.
図 3 ボール転走溝の伸びる方向と垂直な面内におけるボール転走溝の断面図。 図 4 発生する応力 （Von Mses応力） の分布を示す図 （ポールと平滑面が一 点で接触する場合)。  Figure 3 Cross-sectional view of the ball rolling groove in a plane perpendicular to the direction in which the ball rolling groove extends. Fig. 4 Diagram showing the distribution of generated stress (Von Mses stress) (when the pole and the smooth surface are in contact at one point).
図 5 発生する応力 （Von Mses応力） の分布を示す図 （ボールと平滑面が二 点で接触する場合)。  Fig. 5 Diagram showing the distribution of generated stress (Von Mses stress) (when the ball and the smooth surface come in contact at two points).
図 6 発生するせん断力 (XY shear) の分布を示す図 （ボールと平滑面が一点 で接触する場合)。  Fig. 6 Diagram showing the distribution of the generated shearing force (XY shear) (when the ball and the smooth surface make contact at one point).
図 7 発生するせん断力 (XY shear) の分布を示す図 （ボールと平滑面が二点 で接触する場合 )。  Fig. 7 Diagram showing the distribution of the generated shear force (XY shear) (when the ball and the smooth surface come in contact at two points).
図 8 ポール転走溝の製造方法を示す図 （ポール転走溝と直交する方向の断面 図)。  Figure 8 Diagram showing the manufacturing method of the pole rolling groove (cross-sectional view in a direction perpendicular to the pole rolling groove).
図 9 本発明の第 2の実施形態における運動案内装置 （ボールスプライン） の 斜視図。  FIG. 9 is a perspective view of a motion guide device (ball spline) according to a second embodiment of the present invention.
図 1 0 本発明の第 3の実施形態におけるボールねじの斜視図。  FIG. 10 is a perspective view of a ball screw according to a third embodiment of the present invention.
図 1 1 本発明の第 4の実施形態におけるラジアル型の転がり軸受けの断面図。 図 1 2 従来の一般的なボール転走溝の断面図 （図中 （A) はサーキユラーァ 一ク溝を示し、 図中 （B ) はゴシックアーチ溝を示す)。 発明を実施するための最良の形態  FIG. 11 is a cross-sectional view of a radial rolling bearing according to a fourth embodiment of the present invention. Fig. 12 Cross-sectional view of a conventional general ball rolling groove ((A) in the figure shows the circuit groove, and (B) shows the Gothic arch groove). BEST MODE FOR CARRYING OUT THE INVENTION
図 1は本発明の第 1の実施形態における運動案内装置の斜視図を示す。 この図 は直線運動案内装置としてリニァガイドを示している。 リユアガイドは軌道部材 としての軌道レール 1と、 軌道レール 1に多数のポール 2…を介してスライド可 能に取り付けられた移動部材としての移動プロック 3とを備えている。 軌道レー ル 1はその長手方向と直交する断面が概略矩形状に形成された長尺の部材であり、 その上面及ぴ両側面にはボールが転がる際の軌道になるボール転走溝 1 a…が軌 道レール 1の全長に渡って形成されている。 ここで軌道レール 1は、 直線的に伸びるように形成されることもあるし、 曲線 的に伸びるように形成されることもある。 またポール転走溝 1 a…の本数は左右 で 2条ずつ合計 4条設けられているが、 その条数はリニアガイドの用途等に応じ て種々変更され得る。 FIG. 1 is a perspective view of a motion guide device according to a first embodiment of the present invention. This figure shows a linear guide as a linear motion guide device. The lower guide includes a track rail 1 as a track member, and a moving block 3 as a moving member slidably mounted on the track rail 1 via a number of poles 2. The track rail 1 is a long member whose cross section orthogonal to the longitudinal direction is formed in a substantially rectangular shape, and has a ball rolling groove 1a on its upper surface and both side surfaces which is a track for rolling the ball. Are formed over the entire length of the orbital rail 1. Here, the track rail 1 may be formed to extend linearly or may be formed to extend in a curved line. The number of pole rolling grooves 1a is four in total, two on each side, but the number can be variously changed depending on the application of the linear guide.
移動プロック 3にも、 ボール転走溝 1 a…とそれぞれ対向するポール転走溝 3 a…が設けられている。 軌道レール 1のポール転走溝 1 a…と移動ブロック 3の ポール転走溝 3 a…との間で負荷転走路 1 2…が形成され、 複数のボール 2…が 挟まれている。 さらに移動ブロック 3には、 各ボール転走溝 1 aと平行に伸びる 4条の戻し路 1 3…と、 各戻し路 1 3…と各負荷転走路 1 2…を結ぶ方向転換路 が設けられている。 1つの方向転換路 5及び戻し路 1 3と、 それらを結ぶ一対の 方向転換路 5との組合せによって 1つの無限循環路が構成される （図 2参照)。 図 2は無限循環路の伸びる方向に沿った無限循環路の断面図を示す。 各無限循 環路には、 多数のボール 2…が連結体 8により相互に連鎖した状態で装填されて いる。 連結体 8は、 所定間隔で設けられた多数の間座部 4…と、 それらの間座部 4…をその両側で結ぶ一対のベルト部 1 0 , 1 0とを有しており、 間座部 4， 4 同士の間にポール 2が収容 ·保持される。 間座部 4のボール 2との対向面はポー ル 2に合わせて球面状に凹んでいる。 これにより、 ポール 2， 2同士の接触を防 止することができるとともに、 無限循環路内でのポール 2…のスムーズな循環が 可能になる。  The moving block 3 is also provided with pole rolling grooves 3a, which oppose the ball rolling grooves 1a, respectively. Load rolling paths 1 2 are formed between the pole rolling grooves 1 a of the track rail 1 and the pole rolling grooves 3 a of the moving block 3, and a plurality of balls 2 are sandwiched therebetween. Further, the moving block 3 is provided with four return paths 13 extending in parallel with each ball rolling groove 1a, and a direction change path connecting each return path 13 and each load rolling path 1 2 ... ing. One infinite circulation path is composed of a combination of one turning path 5 and return path 13 and a pair of turning paths 5 connecting them (see Fig. 2). FIG. 2 shows a cross-sectional view of the infinite circuit along the extending direction of the infinite circuit. Each of the infinite circulation paths is loaded with a large number of balls 2. The connecting body 8 has a large number of spacers 4 provided at predetermined intervals, and a pair of belt portions 10, 10 connecting the spacers 4 on both sides thereof. The pole 2 is housed and held between the parts 4,4. The surface of the spacer 4 facing the ball 2 is spherically concave in accordance with the pole 2. This prevents contact between the poles 2 and 2 and enables smooth circulation of the poles 2 in the infinite circulation path.
移動ブロック 3が軌道レール 1に沿って移動するのに伴って、 ポーノレ 2…は荷 重を受けつつ負荷転走路 1 2をその一端から他端まで転がり運動し、 その後一方 の方向転換路 5に掬い上げられて戻し路 1 3へ導かれ、 さらに反対側の方向転換 路 5を経由して負荷転走路 1 2の一端に戻される。  As the moving block 3 moves along the track rail 1, the ponole 2 ... rolls on the load rolling path 12 from one end to the other while receiving a load, and then moves to one of the direction changing paths 5. It is scooped up, guided to the return path 13, and further returned to one end of the load rolling path 12 via the direction change path 5 on the opposite side.
図 3はポール転走溝 1 aの伸びる方向と垂直な面内におけるポール転走溝 1 a の断面図を示す。 通常ボール 2が転がる際の軌道となるボール転走溝 1 aは、 滑 らかな表面であり、 限りなく幾何学的な円弧に近い形状にされる。 これに対して 本実施形態では、 ボール 2とボール転走溝 1 aとの接点付近において、 ポール転 走溝 1 aが伸びる方向に伸びる複数条の凸部 7…が形成される。 この凸部 7…は 粗さのようにランダムな凹凸ではなく、 ボール 2が進む方向 （紙面と直交する方 向） に対しては一様な形状をなし、 ボール 2が進む方向と直交する面内において ボール 2と複数点で接触する。 凸部 7…が形成されるボール転走溝 1 aのアウト ラインは、 サーキユラ一アーク溝に形成されてもよく、 ゴシックアーチ溝に形成 されてもよく、 また平滑な平面に形成されてもよい。 FIG. 3 shows a sectional view of the pole rolling groove 1a in a plane perpendicular to the direction in which the pole rolling groove 1a extends. The ball rolling groove 1a, which is a track on which the ball 2 normally rolls, has a smooth surface and has a shape as close as possible to a geometric arc. On the other hand, in the present embodiment, a plurality of protrusions 7 extending in the direction in which the pole rolling groove 1a extends are formed near the contact point between the ball 2 and the ball rolling groove 1a. The projections 7 are not random irregularities such as roughness, but the direction in which the ball 2 travels (the direction perpendicular to the paper surface). Direction), has a uniform shape, and contacts the ball 2 at multiple points in a plane perpendicular to the direction in which the ball 2 travels. The outline of the ball rolling groove 1a on which the convex portions 7 are formed may be formed in a circular arc groove, may be formed in a Gothic arch groove, or may be formed in a smooth plane. .
軌道レール 1と移動ブロック 3との間に介在されるポール 2には荷重が作用す る。 荷重を受けるポールは図中 （A) に示すように、 凸部 7 , 7間の窪み 3 9に 接触する前に複数条の凸部 7…に接触する。 すなわちポール転走溝にポールを載 せただけの状態 （すなわち荷重が作用していない状態） では、 ボール 2は一対の 凸部 7， 7のみに接触して凸部 7， 7間の窪み 3 9に接触することがない。 ボー ルに荷重が加わると、 図中 （B ) に示すように、 複数条の凸部 7， 7が弾性変形 してボール 2が凸部 7， 7間の窪み 3 9にも接触する。 ポール 2が凸部 7， 7間 の窪み 1 3に接触するとき、 凸部 7…は弾性変形するが、 塑性変形することがな い。 このため、 ボール 2から荷重が取り除力れると、 再ぴ凸部 7…は図中 （A) に示すように復元する。  A load acts on the pole 2 interposed between the track rail 1 and the moving block 3. As shown in (A) in the figure, the pole receiving the load contacts a plurality of protrusions 7 before contacting the depression 39 between the protrusions 7. In other words, in a state where the pole is merely placed on the pole rolling groove (ie, in a state where no load is applied), the ball 2 contacts only the pair of projections 7, 7 and the depression between the projections 7, 3. Never touch 9 When a load is applied to the ball, as shown in (B) in the figure, the plurality of protrusions 7, 7 are elastically deformed, and the ball 2 also comes into contact with the depression 39 between the protrusions 7, 7. When the pole 2 contacts the depression 13 between the projections 7, 7, the projections 7 are elastically deformed but not plastically deformed. Therefore, when the load is removed from the ball 2, the convex portions 7 are restored as shown in FIG.
凸部 7…のピッチは例えば以下のように決定される。 想定された負荷、 例えば 基本静定格荷重の中で予想されるボール 2とボール転走溝 1 aとの接触領域があ る。 この接触領域において 3〜4条の凸部 7…とボール 2とが接触するように凸 部 7…のピッチが設定される。 ここで基本静定格荷重とは、 最大応力を受けてい る接触部において、 ポール 2の永久変形量とボール転走溝 1 aの永久変形量との 和が、 ポール 2の直径の 1 Z 1 0 0 0 0倍になるような方向と大きさの一定した 静止荷重をいう。  The pitch of the convex portions 7 is determined, for example, as follows. There is a contact area between the ball 2 and the ball rolling groove 1a which is expected in the assumed load, for example, the basic static load rating. The pitch of the projections 7 is set such that the three or four projections 7 contact the ball 2 in this contact area. Here, the basic static load rating is the sum of the permanent deformation amount of the pole 2 and the permanent deformation amount of the ball rolling groove 1a at the contact part where the maximum stress is applied. A static load with a fixed direction and magnitude that increases by a factor of 0.00.
複数条の凸部 7…がレールのような役割をなし、 ボール 2がレールの上を転が つていくようになる。 ボール 2がボール転走溝 1 aを転がる際、 ボール 2は移動 する方向と直交する方向に回転軸 1 4を持つ。 この回転軸 1 4を拘束するような 力が掛かつたときにボール 2とボール転走溝 1 aの接触点に摩擦が働く。 ボール 2が完全な円弧状のボール転走溝 1 aと一点で接触する場合でも、 本実施形態の ように一対の凸部 7， 7と二点で接触する場合であっても、 その回転軸 1 4を拘 束するような力は働かなレ、。 したがって、 凸部 7…があったとしてもポール 2が 転がる方向における抵抗に与える影響は少なレ、。 またボール 2にカ卩わる荷重に対しては一点で受けるよりも多数点で受けるよう になるので、 荷重の割には接触面積の拡大が早くなり、 負荷容量を接触面積の拡 大に見合う分大きくすることができる。 The plurality of convex portions 7 play a role like a rail, and the ball 2 rolls on the rail. When the ball 2 rolls in the ball rolling groove 1a, the ball 2 has a rotation axis 14 in a direction orthogonal to the moving direction. When a force that restrains the rotating shaft 14 is applied, friction acts on the contact point between the ball 2 and the ball rolling groove 1a. Regardless of whether the ball 2 comes into contact with the complete arc-shaped ball rolling groove 1a at one point or as in the present embodiment, the ball 2 comes into contact with the pair of projections 7 at two points, Does the force that binds 14 work? Therefore, even if the projections 7 are provided, the influence on the resistance in the rolling direction of the pole 2 is small. Also, since the load applied to the ball 2 is received at multiple points rather than at one point, the contact area expands faster for the load, and the load capacity is proportional to the increase in the contact area. Can be larger.
図 4乃至図 7はポールと平滑面が一点で接触する場合と、 二点で接触する場合 とで発生する応力及びせん断力を F EM (有限要素法） で解析した結果を示す。 ここでは、 1 2 . 7 mmのボールにある荷重をかけて 5 μ πι強制的に平滑面ある いは 3 μ πι〜5 μ πι程度の高さの凸部に押し付けている。 またこれらの図はボー ル及ぴ平滑面の接触部分を拡大して示している。  Figures 4 to 7 show the results of FEM (finite element method) analysis of the stress and shear force generated when the pole and the smooth surface make contact at one point and when they make contact at two points. Here, a 12.7 mm ball is pressed against a smooth surface or a convex portion with a height of about 3 μπι to 5 μπι by applying a certain load to the ball. These figures also show the contact area between the ball and the smooth surface in an enlarged manner.
図 4及び図 5は発生する応力 （Von Mses応力） の分布を示す。 図 4は通常ど おり、 ポールと平滑面が一点で接触する場合を示し、 図 5はボールと凸部が二点 で接触する場合を示す。 応力の大きさが等しい部分には同一のハッチングが施し てある。  Figures 4 and 5 show the distribution of the generated stress (Von Mses stress). Fig. 4 shows a normal case where the pole and the smooth surface make contact at one point, and Fig. 5 shows a case where the ball and the projection make contact at two points. The same hatching is applied to portions where the magnitude of the stress is equal.
図 5に示すように、二点で接触する場合、少し離れている二点で接触しはじめ、 二点の中間部分は空いている状態になっている。 ボール 2に荷重を加えると離れ た二点で荷重を受けはじめ、 ボールと平滑面との接触領域が凸部の内側にも外側 にも広がっていくのがわかる。 このため応力も全体に分散していき、 大きな応力 も発生しにくくなる。  As shown in Fig. 5, when two points touch each other, they start touching at two points slightly apart from each other, and the middle part of the two points is empty. It can be seen that when a load is applied to ball 2, the load begins to be applied at two separate points, and the contact area between the ball and the smooth surface spreads both inside and outside the projection. For this reason, stress is also dispersed throughout, and large stress is unlikely to occur.
図 6及ぴ図 7.は発生するせん断力 (XY shear) の分布を示す。 図 6は通常どお り、 ボールと平滑面が一点で接触する場合を示し、 図 7はボールと凸部が二点で 接触する場合を示す。 せん断力の大きさが等しい部分には同一のハツチングが施 してある。  Figures 6 and 7 show the distribution of the generated shear force (XY shear). Fig. 6 shows the case where the ball and the smooth surface make contact at one point, as usual, and Fig. 7 shows the case where the ball and the projection make contact at two points. The same hatching is applied to the parts with the same shear force.
ポールの破壌を考慮するときに一番問題になるのは、 最大せん断応力である。 ポールが荷重を受けたときに、 最大せん断応力が働く部分はボールの接触点より もわずか内側であり、 最大せん断応力が働く部分ですベりを生じさせる力が働く ために材料が破壌する。  The biggest issue when considering pole rupture is the maximum shear stress. When the pole is loaded, the part where the maximum shear stress is applied is slightly inside the point of contact of the ball, and the material where the maximum shear stress is applied breaks down due to the slipping force.
図 7に示すように、 二点で接触する場合は、 せん断力が大きくなる範囲も少な くなるし、 またせん断力も全体に分散するのがわかる。  As shown in Fig. 7, when contact is made at two points, the range in which the shearing force increases is small, and the shearing force is also dispersed throughout.
図 8はボール転走溝 1 aの製造方法を示す。 まずボール 2の半径よりも半径が 小さな円盤状の砥石 1 5を用意する。 次に砥石 1 5を回転させつつ、 ボール転走 溝 l aが伸びる方向 （紙面と直交する方向） に移動させ、 砥石 1 5の外周面でボ 一ル転走溝 1 aを; ffiil口工面から転走面まで研削し、 砥石 1 5の外周形状をボール 転走溝 1 aに転写する。 次に砥石 1 5の位置を例えば N o . 9の砥石位置から N o . 1 0の砥石位置とレヽうように、 ボール転走溝 1 aが伸びる方向と直交する面 内で一定の間隔を保って移動させる。 再び砥石 1 5をポール転走溝 1 aの伸びる 方向に移動させ、 砥石 1 5の外周形状を前記ボール転走溝 1 aに転写する。 これ により例えば、 N o . 9の砥石の円弧と N o . 1 0の砥石の円弧との境目に凸部 7が形成される。 この図では凸部 7の形状を実際のものより大きく示している。 なお砥石 1 5をボール転走溝 1 aが伸びる方向に直線的に移動させれば、 直線 運動案内装置用のボール転走溝を形成でき、 円形に移動させれば転がり軸受け用 のボール転走溝を形成でき、 螺旋状に移動させればボールねじ用のボール転走溝 を形成できる。 FIG. 8 shows a method of manufacturing the ball rolling groove 1a. First, a disk-shaped grindstone 15 having a smaller radius than the radius of the ball 2 is prepared. Next, roll the ball while rotating whetstone 15 Move in the direction in which the groove la extends (in the direction perpendicular to the paper surface), and make the ball rolling groove 1a on the outer peripheral surface of the grindstone 15; Grind from the ffiil opening surface to the rolling surface, and form the outer peripheral shape of the grindstone 15 Is transferred to the ball rolling groove 1a. Next, a certain interval is set in a plane orthogonal to the direction in which the ball rolling groove 1a extends so that the position of the grinding wheel 15 is aligned with the grinding wheel position of No. 10 from the grinding wheel position of No. 9 for example. Keep and move. The grindstone 15 is moved again in the direction in which the pole rolling groove 1a extends, and the outer peripheral shape of the grinding stone 15 is transferred to the ball rolling groove 1a. Thereby, for example, the convex portion 7 is formed at the boundary between the arc of the No. 9 grindstone and the arc of the No. 10 grindstone. In this figure, the shape of the projection 7 is shown larger than the actual shape. If the grindstone 15 is moved linearly in the direction in which the ball rolling groove 1a extends, a ball rolling groove for a linear motion guide device can be formed, and if it is moved circularly, the ball rolling for a rolling bearing will occur. A groove can be formed, and a ball rolling groove for a ball screw can be formed by spirally moving the groove.
またこのボール転走溝の製造方法の他に、 N C (数値制御） 技術によって砥石 の外周面に凹凸を形成し、 この砥石をポール転走溝の伸びる方向に移動させ、 凹 凸の砥石の外周形状をボール転走溝に転写し、 これによりボール転走溝に複数条 の凸部を形成してもよい。 さらに砥石の代わりに切削用の刃物を用いてもよい。 図 9は本発明の第 2の実施形態における運動案内装置の斜視図を示す。 この図 は、 直線運動案内装置としてポールスプラインを示している。 ボールスプライン は軌道部材としてのスプライン軸 2 1と、 そのスプライン軸 2 1に多数のボール 2 2…を介して移動自在に取り付けられた移動部材としての外筒 2 3とを有して いる。  In addition to the method of manufacturing the ball rolling groove, irregularities are formed on the outer peripheral surface of the grinding wheel by NC (numerical control) technology. The shape may be transferred to a ball rolling groove, whereby a plurality of convex portions may be formed in the ball rolling groove. Further, a cutting tool may be used in place of the grindstone. FIG. 9 is a perspective view of a motion guide device according to a second embodiment of the present invention. This figure shows a pole spline as a linear motion guide device. The ball spline has a spline shaft 21 as a track member, and an outer cylinder 23 as a moving member movably attached to the spline shaft 21 via a number of balls 22.
スプライン軸 2 1の表面には、 ボール 2 2の軌道となり、 スプライン軸 2 1の 軸線方向に延びるポール転走溝 2 1 a…が形成される。 スプライン軸 2 1に取り 付けられる外筒 2 3には、 ポール転走溝 2 1 aに対応するポール転走溝が形成さ れる。 これらのボール転走溝 2 1 a…に、 ボール転走溝 2 1 a…が伸びる方向に 伸びる複数条の凸部が形成される。  On the surface of the spline shaft 21, there are formed ball rolling grooves 21 a... Extending in the axial direction of the spline shaft 21. A pole rolling groove corresponding to the pole rolling groove 21 a is formed in the outer cylinder 23 attached to the spline shaft 21. In these ball rolling grooves 21a ..., a plurality of convex portions extending in the direction in which the ball rolling grooves 21a ... extend.
外筒 2 3に形成したボール転走溝とスプライン軸 2 1に形成したボール転走溝 2 1 aとの間でボール転走路が形成される。 ボール転走路の隣には荷重から解放 されたボール 2 2…が移動する無負荷戻し通路が形成されている。外筒 2 3には、 複数のボール 2 2…をサーキット状に整列'保持する保持器 2 4が組み込まれる。 図 1 0は本発明の第 3の実施形態におけるポールねじの斜視図を示す。 ねじ軸 3 1には、 その周囲に螺旋状の一定のリ一ドを備えた略断面半円状のボール転走 溝 3 1 aが形成される。 ナツト 3 2の内周面には、 ねじ軸 3 1のボール転走溝 3 1 aに対向する略断面半円状のポール転走溝 3 2 aが形成される。 これらのボー ル転走溝 3 l a , 3 2 aに、 ボール転走溝 3 1 a , 3 2 aが伸びる方向に伸びる 螺旋状の複数条の凸部が形成される。 A ball rolling path is formed between the ball rolling groove formed in the outer cylinder 23 and the ball rolling groove 21 a formed in the spline shaft 21. Next to the ball rolling path, there is formed a no-load return path through which the balls 22 released from the load move. The outer cylinder 23 A retainer 24 for holding a plurality of balls 22 in a circuit shape is incorporated. FIG. 10 is a perspective view of a pole screw according to the third embodiment of the present invention. The screw shaft 31 is formed with a ball rolling groove 31a having a substantially semicircular cross section and a constant spiral lead around the screw shaft 31. On the inner peripheral surface of the nut 32, a pole rolling groove 32a having a substantially semicircular cross section is formed to face the ball rolling groove 31a of the screw shaft 31. In these ball rolling grooves 3 la and 32 a, a plurality of spiral convex portions extending in the direction in which the ball rolling grooves 31 a and 32 a extend are formed.
. ねじ軸 3 1のボール転走溝 3 1 aとナット 3 2のボール転走溝 3 2 aとの間の ポール転走路には、 複数のボール 3 4…が収容される。 ナット 3 2には循環部品 3 3， 3 3が取り付けられる。 循環部品 3 3 , 3 3は、 ボール転走路の一端と他 端を連結する無負荷戻し通路を棒成し、 複数のボール 3 4…をねじ軸 3 1に対す るナット 3 2の相対運動に併せて循環させる。  A plurality of balls 34 are accommodated in the pole rolling path between the ball rolling groove 31 a of the screw shaft 31 and the ball rolling groove 32 a of the nut 32. Circulation parts 33, 33 are attached to the nut 32. The circulating parts 3 3, 3 3 form a no-load return passage connecting one end of the ball rolling path to the other end, and allow a plurality of balls 3 4… to move relative to the nut 3 2 with respect to the screw shaft 3 1. Circulate together.
図 1 1は本発明の第 4の実施形態におけるラジアル型の転がり軸受けの断面図 を示す。 環状の軌道部材としての外輪 4 1には環状の移動部材としての内輪 4 2 が回転可能に組み付けられている。 外輪 4 1及び内輪 4 2それぞれにはボール転 走溝 4 1 a , 4 2 aが形成され、 これらのボール転走溝 4 1 a , 4 2 aの間にボ ール 4 3が挟まれている。 これらのポール転走溝 4 1 a ,. 4 2 aに、 ボール転走 溝が伸びる方向に伸びる環状の複数条の凸部が形成される。 なおこの実施形態で' は、 ラジアル型の転がり軸受について説明したが、 複数条の凸部が形成されるボ 一ル転走溝はスラスト型の転がり軸受に用いられてもよい。  FIG. 11 is a sectional view of a radial type rolling bearing according to a fourth embodiment of the present invention. An inner race 42 as an annular moving member is rotatably mounted on the outer race 41 as an annular race member. Ball rolling grooves 41a and 42a are formed on the outer ring 41 and the inner ring 42, respectively.The ball 43 is sandwiched between the ball rolling grooves 41a and 42a. I have. A plurality of annular convex portions extending in the direction in which the ball rolling grooves extend are formed in these pole rolling grooves 41a and 42a. In this embodiment, the radial type rolling bearing has been described. However, the ball rolling groove in which a plurality of convex portions are formed may be used for a thrust type rolling bearing.
なお本発明は上記実施形態に限られることなく、 本発明の要旨を変更しない範 囲で種々変更可能である。 例えば複数条の凸部が形成されるボール転走溝は、 軌 道部材と移動部材の双方に形成されなくても、どちらか一方に形成されてもよレ、。 以上説明したように本発明によれば、 ポール転走溝の接点付近にボール転走溝 が伸びる方向に伸びる複数条の凸部を形成し、 ボールに作用する荷重によってボ ールと複数条の凸部とが接触するようにしたので、 ボールへの負荷はそれぞれの 点に分散して負荷され、 特定の一点での高い応力集中を抑制することができる。 したがって、 ボール転走溝の曲率半径をポールの半径に近づけることなく、 負荷 容量の増大を図ることができる。  The present invention is not limited to the above-described embodiment, and can be variously changed without changing the gist of the present invention. For example, the ball rolling groove in which a plurality of convex portions are formed may not be formed in both the track member and the moving member, or may be formed in either one. As described above, according to the present invention, a plurality of protrusions extending in the direction in which the ball rolling groove extends are formed near the contact point of the pole rolling groove, and the ball and the plurality of protrusions are formed by the load acting on the ball. Since the protruding portions are in contact with each other, the load on the ball is distributed and applied to each point, and high stress concentration at a specific point can be suppressed. Therefore, the load capacity can be increased without making the radius of curvature of the ball rolling groove close to the radius of the pole.

Claims

請求の範囲 The scope of the claims
1 軌道部材及ぴ移動部材の少なくとも一方に、 前記軌道部材と前記移動部材 との間に介在されるボールが転がる際の軌道となるボール転走溝が形成される運 動案内装置において、  (1) In a motion guide device, at least one of a track member and a moving member is formed with a ball rolling groove serving as a track when a ball interposed between the track member and the moving member rolls.
前記ボール転走溝には、 ポール転走溝が伸びる方向に一様に伸びる複数条の弾 性変形ができる凸部が形成され、  The ball rolling groove has a plurality of elastically deformable protrusions extending uniformly in the direction in which the pole rolling groove extends,
前記軌道部材と前記移動部材との間で荷重を受ける前記ボールは、 前記複数条 の凸部間の窪みに接触する前に前記複数条の凸部に接触することを特徴とする運 動案内装置。  The ball bearing, which receives a load between the track member and the moving member, comes into contact with the plurality of protrusions before contacting the depression between the plurality of protrusions. .
2 前記荷重によって、 前記凸部が弾性変形して前記ボールが前記窪みに接触 することを特徴とする請求項 1に記載の運動案内装置。  2. The motion guide device according to claim 1, wherein the convex portion is elastically deformed by the load so that the ball comes into contact with the depression.
3 前記運動案内装置は、 直線的若しくは曲線的に伸びる軌道部材に移動部材 がスライド可能に取り付けられた直線若しくは曲線運動案内装置、 又は環状の軌 道部材に環状の移動部材が回転可能に組みつけられた転がり軸受けであることを 特徴とする請求項 1又は 2に記載の運動案内装置。  (3) The motion guide device is a linear or curved motion guide device in which a moving member is slidably mounted on a track member extending linearly or curvedly, or an annular moving member is rotatably assembled to an annular track member. The motion guide device according to claim 1 or 2, wherein the motion guide device is a rolling bearing.
4 ねじ軸及ぴナツトに、 前記ねじ軸と前記ナツトとの間に介在されるポール が転がる際の軌道となる螺旋状のボール転走溝が形成されるボールねじにおいて, 前記ポール転走溝には、 螺旋状のボール転走溝が伸ぴる方向に一様に伸びる複 数条の弾性変形ができる凸部が形成され、  (4) In a ball screw in which a helical ball rolling groove is formed on a screw shaft and a nut as a trajectory when a pole interposed between the screw shaft and the nut rolls, Is formed with a plurality of elastically deformable protrusions extending uniformly in the direction in which the spiral ball rolling groove extends,
前記軌道部材と前記移動部材との間で荷重を受ける前記ボールは、 前記複数条 の凸部間の窪みに接触する前に前記複数条の凸部に接触することを特徴とするポ ールねじ。  The ball screw, which receives a load between the track member and the moving member, comes into contact with the plurality of protrusions before contacting the depression between the plurality of protrusions. .
5 軌道部材及び移動部材の少なくとも一方に、 軌道部材と移動部材との間に 介在されるボールが転がる際の軌道となるボール転走溝を形成するポール転走溝 の製造方法において、  (5) A method of manufacturing a pole rolling groove for forming a ball rolling groove on at least one of a track member and a moving member, the ball rolling groove serving as a track when a ball interposed between the track member and the moving member rolls.
前記ポールの半径よりも半径が小さな円盤状の刃物又は砥石を前記ポール転走 溝の伸びる方向に移動させ、 前記刃物又は砥石の外周形状を前記ボール転走溝に 転写する工程と、  A step of moving a disk-shaped blade or grindstone having a radius smaller than the radius of the pole in a direction in which the pole rolling groove extends, and transferring an outer peripheral shape of the blade or grindstone to the ball rolling groove;
前記刃物又は砥石を前記ポール転走溝が伸びる方向と直交する面内で移動させ る工程と、 Move the blade or grindstone in a plane perpendicular to the direction in which the pole rolling groove extends Process
前記刃物又は砥石を前記ボール転走溝の伸びる方向に移動させ、 前記刃物又は 砥石の外周形状を前記ボール転走溝に転写する工程とを備え、  Moving the blade or whetstone in the direction in which the ball rolling groove extends, and transferring the outer peripheral shape of the blade or whetstone to the ball rolling groove,
前記ボール転走溝には、 前記ボール転走溝が伸びる方向に伸びる複数条の弾性 変形ができる凸部が形成されることを特徴とするボール転走溝の製造方法。  A method of manufacturing a ball rolling groove, wherein a plurality of elastically deformable convex portions extending in a direction in which the ball rolling groove extends are formed in the ball rolling groove.
PCT/JP2003/014253 2002-11-11 2003-11-10 Movement guide device, ball screw, and method of producing ball raceway groove WO2004044444A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE10393641T DE10393641T5 (en) 2002-11-11 2003-11-10 Motion guide device, ball screw and method of forming a ball track groove

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JP2002326800A JP2004162748A (en) 2002-11-11 2002-11-11 Movement guiding device, ball screw, and manufacturing method for ball rolling channel
JP2002-326800 2002-11-11

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0388653U (en) * 1989-12-28 1991-09-10
JPH03107518U (en) * 1990-02-22 1991-11-06
JPH0647729U (en) * 1992-10-14 1994-06-28 日本トムソン株式会社 Rolling guide unit
JP2002039190A (en) * 2000-07-28 2002-02-06 Koyo Seiko Co Ltd Four-point contact ball bearing
JP2002276765A (en) * 2001-03-21 2002-09-25 Ntn Corp Double nut preloading type ball screw

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0388653U (en) * 1989-12-28 1991-09-10
JPH03107518U (en) * 1990-02-22 1991-11-06
JPH0647729U (en) * 1992-10-14 1994-06-28 日本トムソン株式会社 Rolling guide unit
JP2002039190A (en) * 2000-07-28 2002-02-06 Koyo Seiko Co Ltd Four-point contact ball bearing
JP2002276765A (en) * 2001-03-21 2002-09-25 Ntn Corp Double nut preloading type ball screw

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JP2004162748A (en) 2004-06-10

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