JP2022088755A

JP2022088755A - Support shaft for toroidal-type continuously variable transmission and manufacturing method of support shaft

Info

Publication number: JP2022088755A
Application number: JP2020200756A
Authority: JP
Inventors: 保雄伊東; Yasuo Ito; 昌大喜多; Masahiro Kita
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2022-06-15
Anticipated expiration: 2040-12-03
Also published as: JP7517121B2

Abstract

To provide a support shaft for a toroidal-type continuously variable transmission which can simultaneously perform the removal of an excess thickness of a male screw part arranged at an end part of the support shaft, and the finish processing of the male screw part, and a manufacturing method of the support shaft.SOLUTION: A support shaft 100 has a male screw part 102 which is applied with carburetion quenching, and not applied with the carburetion quenching at an end part, and an escape part 103 coaxial with the male screw part 102 at an end face 102a of the male screw part 102. Since the escape part 103 is smaller than a trough diameter D of the male screw part 102 in a diameter, and longer than a depth d of a carburetion-quenched hardening layer 101b from an end face of the escape part 103 in a length L in an axial direction, the removal of an excess thickness of the male screw part 102 arranged at an end part of the support shaft 100, and the finish processing of the male screw part can be simultaneously performed.SELECTED DRAWING: Figure 1

Description

本発明は、自動車、航空機の発電機または各種産業機械の変速機などに利用可能なトロイダル型無段変速機用の支持軸および支持軸の製造方法に関する。 The present invention relates to a support shaft and a method for manufacturing a support shaft for a toroidal continuously variable transmission that can be used for a generator of an automobile, an aircraft, a transmission of various industrial machines, and the like.

例えば自動車用変速機として用いるダブルキャビティ式トロイダル型無段変速機は、図５および図６に示すように構成されている。図５に示すように、ケーシング５０の内側には入力軸１が回転自在に支持されており、この入力軸１の外周には、二つの入力側ディスク２，２と二つの出力側ディスク３，３とが取り付けられている。また、入力軸１の中間部の外周には出力歯車４が回転自在に支持されている。この出力歯車４の中心部に設けられた円筒状のフランジ部４ａ，４ａには、出力側ディスク３，３がスプライン結合によって連結されている。 For example, a double-cavity toroidal continuously variable transmission used as an automobile transmission is configured as shown in FIGS. 5 and 6. As shown in FIG. 5, an input shaft 1 is rotatably supported inside the casing 50, and two input-side discs 2 and 2 and two output-side discs 3 are on the outer periphery of the input shaft 1. 3 and are attached. Further, the output gear 4 is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1. The output side disks 3 and 3 are connected to the cylindrical flange portions 4a and 4a provided at the center of the output gear 4 by spline coupling.

入力軸１は、図中左側に位置する入力側ディスク２とカム板（ローディングカム）７との間に設けられたローディングカム式の押圧装置１２を介して、駆動軸２２により回転駆動されるようになっている。また、出力歯車４は、二つの部材の結合によって構成された仕切壁１３を介してケーシング５０内に支持されており、これにより、入力軸１の軸線Ｏを中心に回転できる一方で、軸線Ｏ方向の変位が阻止されている。 The input shaft 1 is rotationally driven by the drive shaft 22 via a loading cam type pressing device 12 provided between the input side disk 2 located on the left side in the drawing and the cam plate (loading cam) 7. It has become. Further, the output gear 4 is supported in the casing 50 via a partition wall 13 formed by connecting two members, whereby the output gear 4 can rotate about the axis O of the input shaft 1 while the axis O Directional displacement is blocked.

出力側ディスク３，３は、入力軸１との間に介在されたニードル軸受５，５によって、入力軸１の軸線Ｏを中心に回転自在に支持されている。また、図中左側の入力側ディスク２は、入力軸１にボールスプライン６を介して支持され、図中右側の入力側ディスク２は、入力軸１にスプライン結合されており、これら入力側ディスク２は入力軸１と共に回転するようになっている。また、入力側ディスク２，２の内側面（凹面；トラクション面とも言う）２ａ，２ａと出力ディスク３，３の内側面（凹面；トラクション面とも言う）３ａ，３ａとの間には、パワーローラ１１（図６参照）が回転自在に挟持されている。 The output-side discs 3 and 3 are rotatably supported around the axis O of the input shaft 1 by needle bearings 5 and 5 interposed between the output-side discs 3 and 3. Further, the input side disc 2 on the left side in the figure is supported by the input shaft 1 via the ball spline 6, and the input side disc 2 on the right side in the figure is spline-coupled to the input shaft 1, and these input side discs 2 Is designed to rotate with the input shaft 1. Further, between the inner side surfaces (concave surface; also referred to as traction surface) 2a and 2a of the input side discs 2 and 2 and the inner side surfaces (concave surface; also referred to as traction surface) 3a and 3a of the output discs 3 and 3, a power roller is used. 11 (see FIG. 6) is rotatably sandwiched.

図５中右側に位置する入力側ディスク２の内周面２ｃには、段差部２ｂが設けられ、この段差部２ｂに、入力軸１の外周面１ａに設けられた段差部１ｂが突き当てられるとともに、入力側ディスク２の背面（図５の右面）は、入力軸１の外周面に形成されたネジ部に螺合されたローディングナット９に突き当てられている。これによって、入力側ディスク２の入力軸１に対する軸線Ｏ方向の変位が実質的に阻止されている。また、カム板７と入力軸１の鍔部１ｄとの間には、皿ばね８が設けられており、この皿ばね８は、各ディスク２，２，３，３の凹面２ａ，２ａ，３ａ，３ａとパワーローラ１１，１１の周面１１ａ，１１ａとの当接部に押圧力（予圧）を付与する。 A step portion 2b is provided on the inner peripheral surface 2c of the input side disk 2 located on the right side in FIG. 5, and the step portion 1b provided on the outer peripheral surface 1a of the input shaft 1 is abutted against the step portion 2b. At the same time, the back surface (right surface of FIG. 5) of the input side disk 2 is abutted against the loading nut 9 screwed into the screw portion formed on the outer peripheral surface of the input shaft 1. As a result, the displacement of the input side disk 2 in the axis O direction with respect to the input shaft 1 is substantially prevented. Further, a disc spring 8 is provided between the cam plate 7 and the flange portion 1d of the input shaft 1, and the disc spring 8 has concave surfaces 2a, 2a, 3a of the discs 2, 2, 3, 3 respectively. , 3a and the peripheral surfaces 11a and 11a of the power rollers 11 and 11 are subjected to a pressing force (preload).

図６は、図５のＡ－Ａ線に沿う断面図である。図６に示すように、ケーシング５０の内側には、入力軸１に対し捻れの位置にある一対の枢軸１４，１４を中心として揺動する一対のトラニオン１５，１５が設けられている。なお、図６においては、入力軸１の図示は省略している。各トラニオン１５，１５は、支持板部１６の長手方向(図６の上下方向)の両端部に、この支持板部１６の内側面側に折れ曲がる状態で形成された一対の折れ曲がり壁部２０，２０を有している。そして、この折れ曲がり壁部２０，２０によって、各トラニオン１５，１５には、パワーローラ１１を収容するための凹状のポケット部Ｐが形成される。また、各折れ曲がり壁部２０，２０の外側面には、各枢軸１４，１４が互いに同心的に設けられている。 FIG. 6 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 6, inside the casing 50, a pair of trunnions 15 and 15 swinging around a pair of pivots 14 and 14 at a twisted position with respect to the input shaft 1 are provided. In FIG. 6, the input shaft 1 is not shown. Each trunnion 15, 15 is a pair of bent wall portions 20, 20 formed in a state of being bent toward the inner side surface side of the support plate portion 16 at both ends in the longitudinal direction (vertical direction in FIG. 6) of the support plate portion 16. have. Then, the bent wall portions 20 and 20 form a concave pocket portion P for accommodating the power roller 11 in each trunnion 15 and 15. Further, on the outer surface of each of the bent wall portions 20, 20, the pivot axes 14, 14 are provided concentrically with each other.

支持板部１６の中央部には円孔２１が形成され、この円孔２１には変位軸（支持軸）２３の基端部２３ａが支持されている。そして、各枢軸１４，１４を中心として各トラニオン１５，１５を揺動（傾転）させることにより、これら各トラニオン１５，１５の中央部に支持された変位軸２３の傾斜角度を調節できるようになっている。また、各トラニオン１５，１５の内側面から突出する変位軸２３の先端部２３ｂの周囲には、各パワーローラ１１が回転自在に支持されており、各パワーローラ１１，１１は、各入力側ディスク２，２および各出力側ディスク３，３の間に挟持されている。なお、各変位軸２３，２３の基端部２３ａと先端部２３ｂとは、互いに偏心している。 A circular hole 21 is formed in the central portion of the support plate portion 16, and the proximal end portion 23a of the displacement shaft (support shaft) 23 is supported in the circular hole 21. Then, by swinging (tilting) the trunnions 15 and 15 around the pivots 14 and 14, the tilt angle of the displacement shaft 23 supported by the central portion of the trunnions 15 and 15 can be adjusted. It has become. Further, each power roller 11 is rotatably supported around the tip portion 23b of the displacement shaft 23 protruding from the inner side surface of each trunnion 15, and each power roller 11, 11 is a disk on each input side. It is sandwiched between 2, 2 and each output side disk 3, 3. The base end portions 23a and the tip end portions 23b of the displacement shafts 23 and 23 are eccentric to each other.

また、各トラニオン１５，１５の枢軸１４，１４はそれぞれ、一対のヨーク２３Ａ，２３Ｂに対して揺動自在および軸方向(図６の上下方向)に変位自在に支持されており、各ヨーク２３Ａ，２３Ｂにより、トラニオン１５，１５はその水平方向の移動を規制されている。各ヨーク２３Ａ，２３Ｂは鋼等の金属のプレス加工あるいは鍛造加工により矩形状に形成されている。各ヨーク２３Ａ，２３Ｂの四隅には円形の支持孔１８が４つ設けられており、これら支持孔１８にはそれぞれ、トラニオン１５の両端部に設けた枢軸１４がラジアルニードル軸受３０を介して揺動自在に支持されている。また、ヨーク２３Ａ，２３Ｂの幅方向（図６の左右方向）の中央部には、円形の係止孔１９が設けられており、この係止孔１９の内周面は円筒面として、球面ポスト６４，６８を内嵌している。すなわち、上側のヨーク２３Ａは、ケーシング５０に固定部材５２を介して支持されている球面ポスト６４によって揺動自在に支持されており、下側のヨーク２３Ｂは、球面ポスト６８およびこれを支持する駆動シリンダ３１の上側シリンダボディ６１によって揺動自在に支持されている。 Further, the pivots 14 and 14 of the trunnions 15 and 15 are supported swingably and axially (up and down in FIG. 6) with respect to the pair of yokes 23A and 23B, respectively. By 23B, trunnions 15 and 15 are restricted from their horizontal movement. The yokes 23A and 23B are formed into a rectangular shape by pressing or forging a metal such as steel. Four circular support holes 18 are provided at the four corners of the yokes 23A and 23B, and the pivots 14 provided at both ends of the trunnion 15 swing in each of these support holes 18 via the radial needle bearing 30. It is supported freely. Further, a circular locking hole 19 is provided at the center of the yokes 23A and 23B in the width direction (horizontal direction in FIG. 6), and the inner peripheral surface of the locking hole 19 is a cylindrical surface and is a spherical post. 64 and 68 are internally fitted. That is, the upper yoke 23A is swingably supported by the spherical post 64 supported by the casing 50 via the fixing member 52, and the lower yoke 23B is the spherical post 68 and the drive supporting the spherical post 68. It is swingably supported by the upper cylinder body 61 of the cylinder 31.

なお、各トラニオン１５，１５に設けられた各変位軸２３，２３は、入力軸１に対し、互いに１８０度反対側の位置に設けられている。また、これらの各変位軸２３，２３の先端部２３ｂが基端部２３ａに対して偏心している方向は、両ディスク２，２，３，３の回転方向に対して同方向(図６で上下逆方向)となっている。また、偏心方向は、入力軸１の配設方向に対して略直交する方向となっている。したがって、各パワーローラ１１，１１は、入力軸１の長手方向に若干変位できるように支持される。その結果、押圧装置１２が発生するスラスト荷重に基づく各構成部材の弾性変形等に起因して、各パワーローラ１１，１１が入力軸１の軸方向に変位する傾向となった場合でも、各構成部材に無理な力が加わらず、この変位が吸収される。 The displacement shafts 23 and 23 provided on the trunnions 15 and 15 are provided at positions 180 degrees opposite to each other with respect to the input shaft 1. Further, the direction in which the tip end portion 23b of each of these displacement axes 23, 23 is eccentric with respect to the base end portion 23a is the same direction as the rotation direction of both disks 2, 2, 3, 3 (up and down in FIG. 6). In the opposite direction). Further, the eccentricity direction is a direction substantially orthogonal to the arrangement direction of the input shaft 1. Therefore, the power rollers 11 and 11 are supported so as to be slightly displaced in the longitudinal direction of the input shaft 1. As a result, even when the power rollers 11 and 11 tend to be displaced in the axial direction of the input shaft 1 due to elastic deformation of each constituent member based on the thrust load generated by the pressing device 12, each configuration This displacement is absorbed without applying excessive force to the member.

また、パワーローラ１１の外側面とトラニオン１５の支持板部１６の内側面との間には、パワーローラ１１の外側面の側から順に、スラスト転がり軸受であるスラスト玉軸受（スラスト軸受）２４と、スラストニードル軸受２５とが設けられている。このうち、スラスト玉軸受２４は、各パワーローラ１１に加わるスラスト方向の荷重を支承しつつ、これら各パワーローラ１１の回転を許容するものである。このようなスラスト玉軸受２４はそれぞれ、複数個ずつの玉（以下、転動体という）２６，２６と、これら各転動体２６，２６を転動自在に保持する円環状の保持器２７と、円環状の外輪２８とから構成されている。また、各スラスト玉軸受２４の内輪軌道は各パワーローラ１１の外側面（大端面）に、外輪軌道は各外輪２８の内側面にそれぞれ形成されている。 Further, between the outer surface of the power roller 11 and the inner surface of the support plate portion 16 of the trunnion 15, a thrust ball bearing (thrust bearing) 24, which is a thrust rolling bearing, is formed in order from the outer surface side of the power roller 11. , Thrust needle bearing 25 is provided. Of these, the thrust ball bearing 24 allows the rotation of each of the power rollers 11 while bearing the load in the thrust direction applied to each of the power rollers 11. Such thrust ball bearings 24 include a plurality of balls (hereinafter referred to as rolling elements) 26, 26, an annular cage 27 for rotatably holding each of the rolling elements 26, 26, and a circle, respectively. It is composed of an annular outer ring 28. Further, the inner ring raceway of each thrust ball bearing 24 is formed on the outer surface (large end surface) of each power roller 11, and the outer ring raceway is formed on the inner side surface of each outer ring 28.

また、スラストニードル軸受２５は、トラニオン１５の支持板部１６の内側面と外輪２８の外側面との間に挟持されている。このようなスラストニードル軸受２５は、パワーローラ１１から各外輪２８に加わるスラスト荷重を支承しつつ、これらパワーローラ１１および外輪２８が各変位軸２３の基端部２３ａを中心として揺動することを許容する。 Further, the thrust needle bearing 25 is sandwiched between the inner surface of the support plate portion 16 of the trunnion 15 and the outer surface of the outer ring 28. Such a thrust needle bearing 25 bears the thrust load applied to each outer ring 28 from the power roller 11, and causes the power roller 11 and the outer ring 28 to swing around the base end portion 23a of each displacement shaft 23. Tolerate.

さらに、各トラニオン１５，１５の一端部(図６の下端部)にはそれぞれ駆動ロッド（トラニオン軸）２９，２９が設けられており、各駆動ロッド２９，２９の中間部外周面に駆動ピストン（油圧ピストン）３３，３３が固設されている。そして、これら各駆動ピストン３３，３３はそれぞれ、上側シリンダボディ６１と下側シリンダボディ６２とによって構成された駆動シリンダ３１内に油密に嵌装されている。これら各駆動ピストン３３，３３と駆動シリンダ３１とで、各トラニオン１５，１５を、これらトラニオン１５，１５の枢軸１４，１４の軸方向に変位させる駆動装置３２を構成している。 Further, drive rods (trunnion shafts) 29 and 29 are provided at one end of each trunnion 15 and 15 (lower end in FIG. 6), respectively, and a drive piston (drive piston (lower end) on the outer peripheral surface of the intermediate portion of each drive rod 29 and 29 is provided. Hydraulic pistons) 33, 33 are fixed. Each of these drive pistons 33, 33 is oil-tightly fitted in the drive cylinder 31 composed of the upper cylinder body 61 and the lower cylinder body 62, respectively. The drive pistons 33 and 33 and the drive cylinder 31 constitute a drive device 32 that displaces the trunnions 15 and 15 in the axial direction of the pivots 14 and 14 of the trunnions 15 and 15.

このように構成されたトロイダル型無段変速機の場合、入力軸１の回転は、押圧装置１２を介して、各入力側ディスク２，２に伝えられる。そして、これら入力側ディスク２，２の回転が、一対のパワーローラ１１，１１を介して各出力側ディスク３，３に伝えられ、更にこれら各出力側ディスク３，３の回転が、出力歯車４より取り出される。 In the case of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 1 is transmitted to the input side disks 2 and 2 via the pressing device 12. Then, the rotation of the input side disks 2 and 2 is transmitted to the output side disks 3 and 3 via the pair of power rollers 11 and 11, and further, the rotation of the output side disks 3 and 3 is transmitted to the output gear 4 through the pair of power rollers 11 and 11. Will be taken out.

入力軸１と出力歯車４との間の回転速度比を変える場合には、一対の駆動ピストン３３，３３を互いに逆方向に変位させる。これら各駆動ピストン３３，３３の変位に伴って、一対のトラニオン１５，１５が互いに逆方向に変位する。例えば、図６の左側のパワーローラ１１が同図の下側に、同図の右側のパワーローラ１１が同図の上側にそれぞれ変位する。 When changing the rotation speed ratio between the input shaft 1 and the output gear 4, the pair of drive pistons 33, 33 are displaced in opposite directions. With the displacement of each of these drive pistons 33, 33, the pair of trunnions 15, 15 are displaced in opposite directions to each other. For example, the power roller 11 on the left side of FIG. 6 is displaced to the lower side of the figure, and the power roller 11 on the right side of the figure is displaced to the upper side of the figure.

その結果、これら各パワーローラ１１，１１の周面１１ａ，１１ａと各入力側ディスク２，２および各出力側ディスク３，３の内側面２ａ，２ａ，３ａ，３ａとの当接部に作用する接線方向の力の向きが変化する。そして、この力の向きの変化に伴って、各トラニオン１５，１５が、ヨーク２３Ａ，２３Ｂに枢支された枢軸１４，１４を中心として、互いに逆方向に揺動（傾転）する。 As a result, it acts on the contact portions between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 and the inner side surfaces 2a, 2a, 3a and 3a of the input side disks 2 and 2 and the output side disks 3 and 3. The direction of the tangential force changes. Then, as the direction of this force changes, the trunnions 15 and 15 swing (tilt) in opposite directions with respect to the pivots 14 and 14 pivotally supported by the yokes 23A and 23B.

その結果、各パワーローラ１１，１１の周面１１ａ，１１ａと各内側面２ａ，３ａとの当接位置が変化し、入力軸１と出力歯車４との間の回転速度比が変化する。また、これら入力軸１と出力歯車４との間で伝達するトルクが変動し、各構成部材の弾性変形量が変化すると、各パワーローラ１１，１１およびこれら各パワーローラ１１，１１に付属の外輪２８，２８が、各変位軸２３，２３の基端部２３ａ、２３ａを中心として僅かに回動（揺動）する。これら各外輪２８，２８の外側面と各トラニオン１５，１５を構成する支持板部１６の内側面との間には、それぞれスラストニードル軸受２５，２５が存在するため、前記回動（揺動）は円滑に行われる。したがって、前述のように各変位軸２３，２３の傾斜角度を変化させるための力が小さくて済む。 As a result, the contact positions between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 and the inner side surfaces 2a and 3a change, and the rotation speed ratio between the input shaft 1 and the output gear 4 changes. Further, when the torque transmitted between the input shaft 1 and the output gear 4 fluctuates and the amount of elastic deformation of each component changes, the outer rings attached to the power rollers 11 and 11 and the power rollers 11 and 11 are attached. 28, 28 slightly rotate (swing) about the base end portions 23a, 23a of the displacement shafts 23, 23. Since the thrust needle bearings 25 and 25 exist between the outer surface of each of the outer rings 28 and 28 and the inner surface of the support plate portion 16 constituting each trunnion 15 and 15, the rotation (swing) is performed. Is done smoothly. Therefore, as described above, the force for changing the inclination angles of the displacement axes 23 and 23 can be small.

ところで、トロイダル形無段変速機のバリエータ―（自動車用変速機）は、トルク発生時の動力を確実に伝達するため、入力側ディスクおよび出力側ディスクと、パワーローラとの接触部（トラクション面）に大きな押し付け荷重が必要となる。そのため、入力側ディスクおよび出力側ディスクを支持する支持軸には繰り返し大きな軸力（引っ張り荷重）が発生することから、その強度、靭性および耐摩耗性を保つため浸炭焼入れが施されている。 By the way, the variator of the toroidal continuously variable transmission (transmission for automobiles) is a contact portion (traction surface) between the input side disk and the output side disk and the power roller in order to reliably transmit the power when torque is generated. A large pressing load is required. Therefore, since a large axial force (tensile load) is repeatedly generated on the support shaft supporting the input side disk and the output side disk, carburizing and quenching is performed to maintain the strength, toughness, and wear resistance.

また、支持軸の端部にはその軸力を受けるローディングナット締め付け用の雄ねじ部が形成されており、ローディングナットは、無負荷時においてもトラクション面に予圧を与えるため入力側ディスク背面に設定されたさらばねの固定も兼ねている。
雄ねじ部に浸炭焼入れを施すと、雄ねじ部が脆くなって、所定の靭性を確保できなくなるため、雄ねじ部となる部位の外側に予め浸炭を抑制する、例えばマンガンを含む銅合金等の浸炭抑制材料からなる余肉（防炭処理部）が焼入れ前に設けられ、雄ねじ部の仕上げ加工（焼入れ前に施した余肉の除去も含め）は、浸炭焼入れ後に外径部の仕上げ加工（研磨）と同時に実施している。 In addition, a male thread for tightening the loading nut that receives the axial force is formed at the end of the support shaft, and the loading nut is set on the back of the input side disk to give preload to the traction surface even when there is no load. It also fixes the Belleville spring.
When carburizing and quenching is applied to the male threaded portion, the male threaded portion becomes brittle and the predetermined toughness cannot be secured. The surplus meat (carburizing-proof treatment part) is provided before quenching, and the finishing process of the male thread part (including the removal of the surplus meat applied before quenching) is the finishing process (polishing) of the outer diameter part after carburizing and quenching. It is being carried out at the same time.

特開２００３－４１１４号公報Japanese Unexamined Patent Publication No. 2003-4114

しかしながら、ローディングナットが螺合される雄ねじ部は支持軸の先端部に設けられる場合が多く、焼入れ前に支持軸の端部に設ける余肉（防炭処理部）は外径部に加えて端面部にも設ける必要がある。このように支持軸の端面部にも余肉を設けると、当該端面部の余肉の除去は、外径部の余肉の除去および雄ねじ部の仕上加工と別工程で行う必要がある。
つまり、外径部の余肉を旋盤等の加工機によって除去するとともに、雄ねじ部の仕上加工をする際は、加工機の芯押さえ（センタ）を支持軸の端面中央部に押し込み、支持軸を回転させながら外径部の余肉を外周側から切削バイトによって切削除去するとともに、雄ねじ部の仕上加工を行うが、端面中央部に芯押さえが押し込まれているため、当該芯押さえが切削バイトに干渉する。
このため、前記切削バイトのみによって端面部の余肉を切削除去できないので、当該余肉を切削除去するには、外径部の余肉の切削除去および雄ねじ部の仕上加工の後、芯押さえを端面中央部から外したうえで、別の切削バイトによって端面部の余肉を切削除去する必要がある。このように、従来では、支持軸の端部に設ける雄ねじ部の余肉除去および雄ねじ部の仕上加工を同時に行うことはできなかった。 However, the male screw portion to which the loading nut is screwed is often provided at the tip of the support shaft, and the surplus wall (charcoal-proof treatment portion) provided at the end of the support shaft before quenching is added to the outer diameter portion and the end face. It is also necessary to provide it in the department. When the surplus thickness is also provided on the end face portion of the support shaft in this way, it is necessary to remove the surplus wall portion of the end face portion in a separate process from the removal of the surplus wall portion of the outer diameter portion and the finishing process of the male screw portion.
In other words, while removing the excess wall of the outer diameter part with a processing machine such as a lathe, when finishing the male thread part, the center retainer (center) of the processing machine is pushed into the center of the end face of the support shaft to push the support shaft. While rotating, the excess wall of the outer diameter is removed by cutting from the outer peripheral side with a cutting tool, and the male screw part is finished. have a finger in the pie.
For this reason, the surplus wall portion of the end face cannot be removed by cutting only with the cutting tool. After removing it from the center of the end face, it is necessary to cut off the excess wall of the end face with another cutting tool. As described above, conventionally, it has not been possible to simultaneously remove the excess thickness of the male threaded portion provided at the end of the support shaft and finish the male threaded portion.

本発明は、前記事情に鑑みてなされたもので、支持軸の端部に設けられる雄ねじ部の余肉除去および雄ねじ部の仕上加工を同時に行うことができるトロイダル型無段変速機用の支持軸および支持軸の製造方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and is a support shaft for a toroidal continuously variable transmission capable of simultaneously removing the surplus thickness of the male screw portion provided at the end of the support shaft and finishing the male screw portion. And to provide a method of manufacturing a support shaft.

前記目的を達成するために、本発明のトロイダル型無段変速機用の支持軸は、入力側ディスクおよび出力側ディスクを支持するトロイダル型無段変速機用の支持軸であって、
前記支持軸は浸炭焼入れが施されるとともに、端部に浸炭焼入れが施されていない雄ねじ部を有するとともに、当該雄ねじ部の端面に前記雄ねじ部と同軸の逃げ部を有し、
前記逃げ部は、前記雄ねじ部の谷径より小径で、かつ軸方向の長さが前記逃げ部の端面からの浸炭焼入れ硬化層の深さより長いことを特徴とする。 In order to achieve the above object, the support shaft for the toroidal type continuously variable transmission of the present invention is a support shaft for the toroidal type continuously variable transmission that supports the input side disk and the output side disk.
The support shaft is carburized and quenched, has a male threaded portion not carburized and hardened at the end, and has a relief portion coaxial with the male threaded portion on the end surface of the male threaded portion.
The relief portion is characterized in that the diameter is smaller than the valley diameter of the male screw portion and the length in the axial direction is longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion.

本発明においては、雄ねじ部の端面に逃げ部を有し、この逃げ部は雄ねじ部の谷径より小径で、かつ軸方向の長さが逃げ部の端面からの浸炭焼入れ硬化層の深さより長いので、雄ねじ部を形成する部分は端面側から浸炭焼入れされていない。雄ねじ部より径方向外側（外径側）の部分には、従来と同様、防炭用の余肉（防炭処理部）が設けられるが、この余肉は、端面からの浸炭焼入れ硬化層に影響なく、外径側から除去でき、この余肉除去とともに雄ねじ部の仕上加工を行うことができる。また、逃げ部は雄ねじ部の谷径より小径であるので、逃げ部の端面に形成された浸炭焼入れ硬化層は除去する必要がない。
したがって、支持軸の端部に設けられる雄ねじ部の余肉除去および雄ねじ部の仕上加工を同時に行うことができる。 In the present invention, the relief portion has a relief portion on the end face of the male screw portion, and the relief portion has a diameter smaller than the valley diameter of the male screw portion and the axial length is longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion. Therefore, the portion forming the male screw portion is not carburized and quenched from the end face side. Similar to the conventional method, a charcoal-proof surplus (charcoal-proof treated portion) is provided on the radial outer side (outer diameter side) of the male screw portion, but this surplus is used as a carburized and quenched hardened layer from the end face. It can be removed from the outer diameter side without any influence, and the male thread portion can be finished together with the removal of the excess wall. Further, since the relief portion has a diameter smaller than the valley diameter of the male screw portion, it is not necessary to remove the carburized and quenched hardened layer formed on the end face of the relief portion.
Therefore, it is possible to simultaneously remove the excess thickness of the male threaded portion provided at the end of the support shaft and finish the male threaded portion.

また、本発明の前記構成において、前記逃げ部が、前記トロイダル型無段変速機を構成する構成部材と嵌合する嵌合部となっていてもよい。
ここで、前記構成部材としては、例えば、前記支持軸を支持する軸受ユニットや、ケース（トロイダル無段変速機のケーシング）等が挙げられる。 Further, in the configuration of the present invention, the relief portion may be a fitting portion that fits with a component member constituting the toroidal type continuously variable transmission.
Here, examples of the constituent member include a bearing unit that supports the support shaft, a case (casing of a toroidal continuously variable transmission), and the like.

このような構成によれば、逃げ部がトロイダル型無段変速機を構成する構成部材と嵌合する嵌合部となっているので、支持軸の支持剛性の向上を図ることができる。 According to such a configuration, since the relief portion is a fitting portion that fits with the constituent members constituting the toroidal type continuously variable transmission, it is possible to improve the support rigidity of the support shaft.

本発明のトロイダル型無段変速機用の支持軸の製造方法は、入力側ディスクおよび出力側ディスクを支持するトロイダル型無段変速機用の支持軸を製造する方法であって、
前記支持軸の端部に設けられる雄ねじ部およびこの雄ねじ部の端面に前記雄ねじ部と同軸に設けられかつ前記雄ねじ部の谷径より小径の逃げ部に、防炭用の余肉を設けるととともに、前記逃げ部の軸方向の長さを、前記逃げ部の端面からの浸炭焼入れ硬化層の深さより長く設定し、
次に、前記支持軸に浸炭焼入れを施した後、前記余肉を前記支持軸の外周側から切削することによって、前記余肉を除去するとともに、前記雄ねじ部の仕上加工および前記逃げ部の加工を行うことを特徴とする。 The method for manufacturing a support shaft for a toroidal continuously variable transmission of the present invention is a method for manufacturing a support shaft for a toroidal continuously variable transmission that supports an input side disk and an output side disk.
A carburizing surplus is provided at the male threaded portion provided at the end of the support shaft and the relief portion provided coaxially with the male threaded portion on the end surface of the male threaded portion and having a diameter smaller than the valley diameter of the male threaded portion. The axial length of the relief portion is set longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion.
Next, after carburizing and quenching the support shaft, the surplus is cut from the outer peripheral side of the support shaft to remove the surplus, and the male screw portion is finished and the relief portion is processed. It is characterized by performing.

本発明においては、雄ねじ部の端面に設けられた逃げ部は雄ねじ部の谷径より小径で、かつ軸方向の長さが逃げ部の端面からの浸炭焼入れ硬化層の深さより長いので、支持軸に浸炭焼入れを施しても、雄ねじ部を形成する部分は端面側から浸炭焼入れされていない。雄ねじ部より径方向外側（外径側）の部分には、余肉が設けられるので、支持軸に浸炭焼入れを施した後、浸炭硬化した余肉を支持軸の外周側から切削することによって、余肉を除去するとともに、雄ねじ部の仕上加工および前記逃げ部の加工を行うので、支持軸の端部に設けられる雄ねじ部の余肉除去および雄ねじ部の仕上加工を同時に行うことができる。 In the present invention, the relief portion provided on the end face of the male screw portion has a smaller diameter than the valley diameter of the male screw portion, and the axial length is longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion. Even if carburized and hardened, the portion forming the male screw portion is not carburized and hardened from the end face side. Since a surplus wall is provided on the radial outer side (outer diameter side) of the male threaded portion, after carburizing and quenching the support shaft, the carburized and hardened surplus meat is cut from the outer peripheral side of the support shaft. Since the surplus thickness is removed and the male threaded portion is finished and the relief portion is machined, the surplus wall portion of the male threaded portion provided at the end of the support shaft can be removed and the male threaded portion can be finished at the same time.

本発明によれば、支持軸の端部に設けられる雄ねじ部の余肉除去および雄ねじ部の仕上加工を同時に行うことができる。 According to the present invention, it is possible to simultaneously remove the surplus thickness of the male threaded portion provided at the end of the support shaft and finish the male threaded portion.

本発明の第１の実施形態に係るトロイダル型無段変速機用の支持軸の要部を示す断面図である。It is sectional drawing which shows the main part of the support shaft for the toroidal type continuously variable transmission which concerns on 1st Embodiment of this invention. 本発明の第１の実施形態に係るトロイダル型無段変速機用の支持軸の製造方法の工程を示すもので、軸素材を示す要部の断面図である。It shows the process of the manufacturing method of the support shaft for the toroidal type continuously variable transmission which concerns on 1st Embodiment of this invention, and is sectional drawing of the main part which shows the shaft material. 同、浸炭焼入れがされた支持軸の要部の断面図である。It is the cross-sectional view of the main part of the support shaft which was carburized and hardened. 本発明の第２実施形態に係るトロイダル型無段変速機を示すもので、要部の半平断面図である。It shows the toroidal type continuously variable transmission which concerns on 2nd Embodiment of this invention, and is the semi-planar sectional view of the main part. 従来のトロイダル型無段変速機の一例を示すもので、平断面図である。An example of a conventional toroidal type continuously variable transmission is shown, and is a plan sectional view. 図５におけるＡ－Ａ線に沿う断面図である。It is sectional drawing which follows the AA line in FIG.

以下、図面を参照しながら、本発明の実施形態について説明する。
（第１の実施形態）
図１は、第１の実施形態に係るトロイダル型無段変速機用の支持軸の要部を示す断面図である。
支持軸１００は、本実施形態では入力軸であり、入力側ディスク２および出力側ディスク３（図５参照）を支持するものである。支持軸１００は浸炭焼入れが施されている。すなわち、支持軸１００の端部以外の外周面には浸炭焼入れ硬化層１０１ａが設けられている。浸炭焼入れ硬化層１０１ａの層厚は例えば１．５ｍｍ程度である。
また、支持軸１００は、その端部（図１において右端部）に、ローディングナット９（図５参照）が螺合される雄ねじ部１０２を有している。雄ねじ部１０２およびその軸方向両端部の近傍には、浸炭焼入れ時に後述する防炭処理部（余肉）１０５で覆われているため、浸炭焼入れが施されていない。雄ねじ部１０２の端面１０２ａには、円柱状の逃げ部１０３が雄ねじ部１０２と同軸に設けられている。
逃げ部１０３は雄ねじ部１０２の谷径Ｄより小径に形成され、かつ、軸方向の長さＬは逃げ部１０３の端面からの浸炭焼入れ硬化層１０１ｂの深さｄより長くなっている。浸炭焼入れ硬化層１０１ｂの層厚（深さ）ｄは例えば１．５ｍｍ程度である。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a cross-sectional view showing a main part of a support shaft for a toroidal type continuously variable transmission according to the first embodiment.
The support shaft 100 is an input shaft in the present embodiment, and supports the input side disk 2 and the output side disk 3 (see FIG. 5). The support shaft 100 is carburized and quenched. That is, a carburized and quenched hardened layer 101a is provided on the outer peripheral surface other than the end portion of the support shaft 100. The layer thickness of the carburized and quenched hardened layer 101a is, for example, about 1.5 mm.
Further, the support shaft 100 has a male screw portion 102 to which a loading nut 9 (see FIG. 5) is screwed at its end (right end in FIG. 1). Since the male threaded portion 102 and the vicinity of both ends in the axial direction are covered with a charcoal-proofing treatment portion (residual thickness) 105, which will be described later during carburizing and quenching, carburizing and quenching is not performed. A cylindrical relief portion 103 is provided coaxially with the male screw portion 102 on the end surface 102a of the male screw portion 102.
The relief portion 103 is formed to have a diameter smaller than the valley diameter D of the male screw portion 102, and the axial length L is longer than the depth d of the carburized and quenched hardened layer 101b from the end face of the relief portion 103. The layer thickness (depth) d of the carburized and quenched hardened layer 101b is, for example, about 1.5 mm.

このような支持軸１００は以下のようにして製造される。
すなわちまず、図２に示すように、支持軸１００の軸素材１１０を用意する。軸素材１１０は鋼材によって円柱状に形成され、その内部には軸方向に延在する孔１１０ａが設けられ、この孔１１０ａの端部は軸素材１１０の端面に開口している。 Such a support shaft 100 is manufactured as follows.
That is, first, as shown in FIG. 2, the shaft material 110 of the support shaft 100 is prepared. The shaft material 110 is formed in a columnar shape by a steel material, and a hole 110a extending in the axial direction is provided inside the hole 110a, and the end portion of the hole 110a is opened to the end surface of the shaft material 110.

また、軸素材１１０の外周面は、端部（右端部）を除いて、支持軸１００の外周面形状となるように加工されている。軸素材１１０の端部、つまり支持軸１００の端部に設けられる雄ねじ部１０２およびその軸方向近傍の外周側、および雄ねじ部１０２の端面１０２ａに雄ねじ部１０２と同軸に設けられかつ雄ねじ部１０２の谷径Ｄより小径の逃げ部１０３の外周側に、例えばマンガンを含む銅合金等の浸炭抑制材料からなる防炭処理部（余肉）１０５を設ける。この防炭処理部１０５は、浸炭焼入れ処理によって雄ねじ部１０２およびその近傍が焼入れ硬化するのを防止するためのものであり、外周面が軸素材１１０と同軸の円筒面状に形成されている。また、逃げ部１０３の軸方向の長さＬは、逃げ部１０３の端面からの浸炭焼入れ硬化層１０１ｂの深さｄより長く設定する。 Further, the outer peripheral surface of the shaft material 110 is processed so as to have the outer peripheral surface shape of the support shaft 100 except for the end portion (right end portion). The end of the shaft material 110, that is, the male threaded portion 102 provided at the end of the support shaft 100 and the outer peripheral side in the vicinity of the axial direction thereof, and the end surface 102a of the male threaded portion 102 provided coaxially with the male threaded portion 102 and of the male threaded portion 102. On the outer peripheral side of the relief portion 103 having a diameter smaller than the valley diameter D, a charcoal-proof treatment portion (surplus thickness) 105 made of a carburizing suppressing material such as a copper alloy containing manganese is provided. The charcoal-proof treatment portion 105 is for preventing the male screw portion 102 and its vicinity from being quenched and hardened by the carburizing and quenching treatment, and the outer peripheral surface is formed in a cylindrical surface shape coaxial with the shaft material 110. Further, the axial length L of the relief portion 103 is set to be longer than the depth d of the carburized and quenched hardened layer 101b from the end face of the relief portion 103.

次に、防炭処理部（余肉）１０５が設けられた支持軸１００に浸炭焼入れを施す。この浸炭焼入れは、真空浸炭処理によって行う。
支持軸１００に浸炭焼入れを施すと、図３に示すように、支持軸１００の表面に浸炭焼入れ硬化層１０１ａ，１０１ｂが形成される。つまり、支持軸１００の端部（右端部）以外の外周面に浸炭焼入れ硬化層１０１ａが形成されるとともに、防炭処理部１０５が設けられていない支持軸１００の端部の端面に浸炭焼入れ硬化層１０１ｂが形成される。なお、支持軸１００の孔１１０ａの内周面にも浸炭焼入れ硬化層（図示略）が形成されるが、この浸炭焼入れ硬化層は、雄ねじ部１０２のねじ山に影響しないので問題ない。孔１１０ａの内周面に浸炭焼入れが入るのを防止するには、例えば、孔１１０ａの端部開口に蓋を着脱可能に取り付けて、当該蓋で端部開口を塞げばよい。 Next, the support shaft 100 provided with the charcoal-proof treatment portion (surplus thickness) 105 is carburized and quenched. This carburizing and quenching is performed by vacuum carburizing treatment.
When the support shaft 100 is carburized and quenched, as shown in FIG. 3, the carburized and hardened hardened layers 101a and 101b are formed on the surface of the support shaft 100. That is, the carburizing and quenching hardening layer 101a is formed on the outer peripheral surface other than the end portion (right end portion) of the support shaft 100, and the carburizing and quenching hardening is performed on the end surface of the end portion of the support shaft 100 not provided with the charcoal-proof treatment portion 105. Layer 101b is formed. A carburized and hardened hardened layer (not shown) is also formed on the inner peripheral surface of the hole 110a of the support shaft 100, but this carburized and hardened hardened layer does not affect the thread of the male threaded portion 102, so there is no problem. In order to prevent carburizing and quenching from entering the inner peripheral surface of the hole 110a, for example, a lid may be detachably attached to the end opening of the hole 110a, and the end opening may be closed with the lid.

次に、支持軸１００の端部において、防炭処理部１０５を支持軸１００の外周側から切削することによって、防炭処理部１０５を除去するとともに、雄ねじ部１０２の仕上加工および逃げ部１０３の加工を行う。
すなわち、支持軸１００を旋盤等の加工機にセットして、図示しない左端部をチャッキングしたうえで、加工機の芯押さえ（センタ）１０７を支持軸１００の端面中央部から孔１１０ａに押し込む。
そして、支持軸１００をその軸回りに回転させながら、支持軸１００の外周側から切削バイト１０８または切削バイト１０９を用いて切り込むことによって、防炭処理部１０５を切削除去するとともに、雄ねじ部１０２の仕上加工および逃げ部１０３の加工を行う。
次に、雄ねじ部１０２の仕上加工および逃げ部１０３の加工が行われた支持軸１００を別の仕上加工機にセットし、上述と同様の芯押さえ（センタ）を支持軸１００の端面中央部から孔１１０ａに押し込み、図示しない砥石によって支持軸１００の端部以外の外周面を仕上げ加工する。
また、上述したチェッキングを保持した状態で、切削バイト１０８または切削バイト１０９を図示しない砥石に取り替えたうえで、支持軸１００の端部以外の外周面を仕上げ加工してもよい。
支持軸１００の端部以外の外周面には浸炭焼入れ硬化層１０１ａが形成されているので、この浸炭焼入れ硬化層１０１ａを所定厚さだけ残して、浸炭焼入れ硬化層１０１ａの表面を研磨する。これによって、図１に示す、支持軸１００を得ることができる。 Next, at the end of the support shaft 100, the charcoal-proof treatment portion 105 is cut from the outer peripheral side of the support shaft 100 to remove the charcoal-proof treatment portion 105, and the finish processing and relief portion 103 of the male screw portion 102 are removed. Perform processing.
That is, the support shaft 100 is set in a processing machine such as a lathe, the left end portion (not shown) is chucked, and then the center retainer (center) 107 of the processing machine is pushed into the hole 110a from the center portion of the end surface of the support shaft 100.
Then, while rotating the support shaft 100 around the axis, the charcoal-proof processing portion 105 is cut off by cutting from the outer peripheral side of the support shaft 100 using the cutting tool 108 or the cutting tool 109, and the male screw portion 102 is cut. Finishing and processing of the relief portion 103 are performed.
Next, the support shaft 100 on which the male screw portion 102 is finished and the relief portion 103 is processed is set in another finishing machine, and a center retainer (center) similar to the above is set from the center of the end face of the support shaft 100. It is pushed into the hole 110a, and the outer peripheral surface other than the end portion of the support shaft 100 is finished by a grindstone (not shown).
Further, while holding the above-mentioned checking, the cutting tool 108 or the cutting tool 109 may be replaced with a grindstone (not shown), and then the outer peripheral surface other than the end portion of the support shaft 100 may be finished.
Since the carburized and hardened hardened layer 101a is formed on the outer peripheral surface other than the end of the support shaft 100, the surface of the carburized and hardened hardened layer 101a is polished while leaving the carburized and hardened hardened layer 101a by a predetermined thickness. Thereby, the support shaft 100 shown in FIG. 1 can be obtained.

以上のように、本実施形態によれば、雄ねじ部１０２の端面１０２ａに逃げ部１０３を有し、この逃げ部１０３は雄ねじ部１０２の谷径Ｄより小径で、かつ軸方向の長さＬが逃げ部１０２の端面からの浸炭焼入れ硬化層１０１ｂの深さｄより長いので、雄ねじ部１０２を形成する部分は端面側から浸炭焼入れされていない。雄ねじ部１０２より径方向外側（外径側）の部分には、従来と同様、防炭用の余肉（防炭処理部）１０５が設けられるが、この余肉は、端面からの浸炭焼入れ硬化層（硬化層）１０１ｂに影響なく、外径側から切削除去でき、この余肉除去とともに雄ねじ部１０２の仕上加工を行うことができる。また、逃げ部１０３は雄ねじ部１０２の谷径Ｄより小径であるので、逃げ部１０３の端面に形成された浸炭焼入れ硬化層１０１ｂは除去する必要がない。
したがって、支持軸１００の端部に設けられる雄ねじ部１０２の余肉除去および雄ねじ部１０２の仕上加工を同時に行うことができる。 As described above, according to the present embodiment, the relief portion 103 is provided on the end surface 102a of the male screw portion 102, and the relief portion 103 has a smaller diameter than the valley diameter D of the male screw portion 102 and has a length L in the axial direction. Since the depth d of the hardened layer 101b is longer than the depth d of the carburized and hardened layer 101b from the end face of the relief portion 102, the portion forming the male screw portion 102 is not carburized and hardened from the end face side. Similar to the conventional method, a charcoal-proof surplus wall (charcoal-proof treatment section) 105 is provided on the radially outer side (outer diameter side) of the male screw portion 102, but this surplus wall is carburized and hardened from the end face. It can be removed by cutting from the outer diameter side without affecting the layer (hardened layer) 101b, and the male screw portion 102 can be finished together with the removal of the surplus wall. Further, since the relief portion 103 has a smaller diameter than the valley diameter D of the male screw portion 102, it is not necessary to remove the carburized and quenched hardened layer 101b formed on the end face of the relief portion 103.
Therefore, it is possible to simultaneously remove the surplus thickness of the male threaded portion 102 provided at the end of the support shaft 100 and finish the male threaded portion 102.

（第２の実施形態）
図４は支持軸の第２の実施形態を示す断面図である。
本実施形態が第１の実施形態と異なる点は、逃げ部１０３がトロイダル型無段変速機を構成する構成部材と嵌合する嵌合部となっている点であるので、以下ではこの点について説明し、第１の実施形態と同一構成には同一符号を付してその説明を省略する。 (Second embodiment)
FIG. 4 is a cross-sectional view showing a second embodiment of the support shaft.
The difference between the present embodiment and the first embodiment is that the relief portion 103 is a fitting portion that fits with the constituent members constituting the toroidal type continuously variable transmission. The same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

図４に示すように、本実施形態の支持軸１００Ａは、第１の実施形態の支持軸１００より長くなっている。すなわち、本実施形態の支持軸１００Ａでは、逃げ部１０３Ａが第１の実施形態の支持軸１００の逃げ部１０３を延長して、当該逃げ部１０３より長くなっている。 As shown in FIG. 4, the support shaft 100A of the present embodiment is longer than the support shaft 100 of the first embodiment. That is, in the support shaft 100A of the present embodiment, the relief portion 103A extends the relief portion 103 of the support shaft 100 of the first embodiment and is longer than the relief portion 103.

逃げ部１０３Ａは、軸受ユニット１１５に嵌合する嵌合部１０３Ａとなっている。軸受ユニット１１５は、ケース１１６とこのケース１１６に嵌め込まれた軸受１１７とを備えている。ケース１１６には円孔状の凹所１１６ａが設けられ、この凹所１１６ａに軸受１１７が嵌め込まれている。軸受１１７は、支持軸１００Ａと同軸に配置されており、当該軸受１１７に逃げ部１０３Ａが嵌合部１０３Ａとして嵌め込まれている。これによって支持軸１００Ａの端部は軸受ユニット１１５によって回転可能に支持されている。
このような支持軸１００Ａは第１の実施形態の支持軸１００と同様にして製造される。 The relief portion 103A is a fitting portion 103A that fits into the bearing unit 115. The bearing unit 115 includes a case 116 and a bearing 117 fitted in the case 116. The case 116 is provided with a circular hole-shaped recess 116a, and the bearing 117 is fitted in the recess 116a. The bearing 117 is arranged coaxially with the support shaft 100A, and the relief portion 103A is fitted into the bearing 117 as a fitting portion 103A. As a result, the end of the support shaft 100A is rotatably supported by the bearing unit 115.
Such a support shaft 100A is manufactured in the same manner as the support shaft 100 of the first embodiment.

本実施形態によれば、第１の実施形態と同様の効果を奏するとともに、逃げ部１０３Ａがトロイダル型無段変速機を構成する構成部材たる軸受ユニット１１５と嵌合する嵌合部１０３Ａとなっているので、支持軸１００Ａの支持剛性の向上を図ることができる。 According to the present embodiment, the same effect as that of the first embodiment is obtained, and the relief portion 103A becomes a fitting portion 103A that fits with the bearing unit 115 which is a constituent member constituting the toroidal type continuously variable transmission. Therefore, it is possible to improve the support rigidity of the support shaft 100A.

なお、第１および第２の実施形態では、支持軸１００，１００Ａとして入力軸を例にとって説明したが、トロイダル型無段変速機では、入力側ディスクと出力側ディスクの入出力関係を逆にする場合もある。したがって、本発明は出力軸を支持軸とした場合でも適用できる。 In the first and second embodiments, the input shaft is described as an example of the support shafts 100 and 100A, but in the toroidal continuously variable transmission, the input / output relationship between the input side disk and the output side disk is reversed. In some cases. Therefore, the present invention can be applied even when the output shaft is used as the support shaft.

さらに、本実施形態では本発明を、ダブルキャビティ型のハーフトロイダル型無段変速機用の支持軸に適用する場合を例にとって説明したが、これに限ることなく、本発明はダブルキャビティ型のフルトロイダル型無段変速機用の支持軸にも適用でき、さらに、シングルキャビティ型のハーフトロイダル型無段変速機用の支持軸や、シングルキャビティ型のフルトロイダル型無段変速機用の支持軸にも適用できる。 Further, in the present embodiment, the present invention has been described by taking as an example a case where the present invention is applied to a support shaft for a double cavity type half toroidal type continuously variable transmission, but the present invention is not limited to this, and the present invention is not limited to this. It can also be applied to support shafts for toroidal type continuously variable transmissions, and also for support shafts for single cavity type half toroidal type continuously variable transmissions and support shafts for single cavity type full toroidal type continuously variable transmissions. Can also be applied.

２入力側ディスク
３出力側ディスク
１００，１００Ａ支持軸
１０１ａ，１０１ｂ浸炭焼入れ硬化層
１０２雄ねじ部
１０２ａ雄ねじ部の端面
１０３，１０３Ａ逃げ部（嵌合部）
１０５防炭処理部（余肉） 2 Input side disk
3 Output side disk 100, 100A Support shaft 101a, 101b Carburizing and quenching hardened layer 102 Male threaded part 102a End face of male threaded part 103, 103A Relief part (fitting part)
105 Charcoal-proof treatment section (surplus meat)

Claims

A support shaft for a toroidal continuously variable transmission that supports an input side disk and an output side disk.
The support shaft is carburized and quenched, has a male threaded portion not carburized and hardened at the end, and has a relief portion coaxial with the male threaded portion on the end surface of the male threaded portion.
The relief portion has a diameter smaller than the valley diameter of the male screw portion, and the axial length is longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion for a toroidal continuously variable transmission. Support shaft.

The support shaft for a toroidal continuously variable transmission according to claim 1, wherein the relief portion is a fitting portion that fits with a constituent member constituting the toroidal type continuously variable transmission.

A method of manufacturing a support shaft for a toroidal continuously variable transmission that supports an input side disk and an output side disk.
Carburizing prevention is provided on the outer peripheral side of the male threaded portion provided at the end of the support shaft and on the outer peripheral side of the relief portion provided coaxially with the male threaded portion on the end surface of the male threaded portion and having a diameter smaller than the valley diameter of the male threaded portion. Along with providing a surplus, the axial length of the relief portion is set longer than the depth of the carburized and quenched hardened layer from the end face of the relief portion.
Next, after carburizing and quenching the support shaft, the surplus is cut from the outer peripheral side of the support shaft to remove the surplus, and the male screw portion is finished and the relief portion is processed. A method of manufacturing a support shaft, which comprises performing.