JP2002155934A - Rolling spline device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent high cost due to bothersome grinding of curved line grooves in an inner wall face of an outer cylinder main body for fitting in rolling elements, to facilitate gap adjustment which is bothersome due to measuring of a gap between a spline shaft body and the outer cylinder main body and selecting of a rolling element with suitable size, and to prevent distortion in curved portions due to heat of hardening by heat treatment of the outer cylinder main body and the spline shaft body contacted by the rolling elements. SOLUTION: A Line groove 81 is axially provided in an axial direction of the spline shaft body 8. An inner cylinder 20 is fit inside the outer cylinder main body 4, and a rail body 11 is attached inside an inner cylinder wall face line hole 21. A line groove 111 is axially provided in a face of the rail body facing the spline shaft body 8. A rolling element cage 9 with rolling elements 6 is arranged between the two line grooves. Since the rail body is prismatic and not cylindrical, groove machining can be inexpensively carried out by a surface grinder. The gap adjustment can be easily carried out by a gap adjusting screw 10 pressing a back part of the rail body. Since the rail body is prismatic, there is almost no distortion even when it is treated with heat for groove surface hardening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling structure having an outer cylinder portion and a spline shaft portion, wherein the spline shaft portion relatively moves in the axial direction while contacting the inner wall of the outer cylinder portion via a rolling element. The present invention relates to a spline device.

[0002]

2. Description of the Related Art FIG. 13 is a view showing a conventional rolling spline device. In FIG. 13, 1 is a rolling spline device, 2 is an outer cylinder portion, 3 is a spline shaft portion, 4 is an outer cylinder body, 5 is a flange, 6 is a rolling element, 7 is a rolling element holding section, 8
Is a spline shaft. The spline shaft 8 has a cylindrical or columnar shape as a whole, and has
A recess is provided in the axial direction, into which the rolling element 6 is fitted. The rolling element holding section 7 is for holding the rolling element 6 so as not to protrude. As the rolling element 6, a roller, a ball, a needle, or the like is used.

FIG. 12 is a sectional view of an outer cylindrical portion of a conventional rolling spline device. The symbols correspond to those in FIG.
41 is a groove, 51 is a mounting screw hole. Mounting screw hole 51
Is a hole through which a mounting screw is inserted when the flange 5 is mounted on another device. The groove 41 is a groove ground straight in the axial direction of the inner wall surface of the outer cylinder body 4. When the spline shaft 8 of FIG. 13 is inserted into the outer cylindrical portion 2, the rolling element 6 on the surface of the spline shaft 8 is inserted so as to fit into the groove 41. Therefore, when the spline shaft 8 and the outer cylinder 2 are to be relatively moved in the axial direction, they are smoothly moved relative to each other while being in contact with each other via the rolling elements 6.

[0004]

(Problems) However, the above-mentioned conventional rolling spline device has the following problems. The first problem is that it is necessary to grind the groove 41 on the inner wall surface of the outer cylinder main body 4, but the processing is troublesome and the cost is high. The second problem is that it is necessary to select the size of the rolling element 6 according to the size of the gap between the inner wall surface of the outer cylindrical portion 4 and the surface of the spline shaft portion 3. The point is that the adjustment work requires a great deal of skill and time. The third problem is that the outer cylinder main body 4 and the spline shaft 8 are hardened by heat treatment in order to reduce the wear of the portion where the rolling elements 6 come into contact. In this case, the curved surface of the spline shaft 8 is distorted, and many steps are required to maintain the accuracy of the inner surface groove grinding.

(Explanation of Problems) First, the first problem will be described. Since the process of providing the groove 41 on the inner wall surface of the outer cylinder body 4 is a process of grinding the inner surface of the cylindrical body, it must be performed using a special grinding device called an inner surface groove grinder, and the processing efficiency is also increased. Is bad and very troublesome.
In addition, since this processing is performed manually by setting the outer cylinder main bodies 4 one by one on a grinder, productivity is poor. Then the second
The problem will be described. After finishing the processing of the outer cylinder main body 4 and the spline shaft body 8, the depth of the recess provided on the surface of the spline shaft body 8 for measuring the depth of the groove 41 or arranging the rolling element 6 is determined. Rolling element 6 to be measured and used
Choose the size of This requires a high degree of skill,
Since it was a one-product production handmade work, it took a lot of time and effort. This selection is also called “gap adjustment” because it is performed while considering that the gap between the outer cylinder main body 4 and the spline shaft body 8 has an appropriate size.

Next, a third problem will be described. The portion of the outer cylinder body 4 where the rolling element 6 comes into contact is the groove 41, and the portion of the spline shaft 8 where the rolling element 6 comes into contact is a concave portion into which the rolling element 6 is fitted. It is sufficient that only those portions are hardened, but it is not possible to harden only that portion. After all, the entire outer cylinder body 4 and the entire spline shaft 8 are hardened by heat treatment. However, the outer cylinder main body 4 has a cylindrical shape, and an important portion has a curved surface. Therefore, when the heat treatment is performed, distortion due to the heat treatment often occurs in the important portion (for example, the size of the diameter is changed, the depth of the groove is changed, and the like), and the accuracy of the finish is deteriorated. An object of the present invention is to solve the above problems.

[0007]

In order to solve the above-mentioned problems, the present invention has an outer cylinder and a spline shaft, and the spline shaft contacts the inner wall of the outer cylinder via a rolling element. In a rolling spline device having a structure of relatively moving in an axial direction, a plurality of first grooves are provided in an axial direction of an outer surface of the spline shaft portion, and the outer cylindrical portion is provided with an outer cylindrical body and an inner surface of the outer cylindrical body. And an inner cylinder having an axially extending inner cylindrical wall groove at a wall position corresponding to each of the first grooves when the spline shaft portion is inserted, and an inner cylindrical wall groove. And a rail body having a second groove provided on a surface facing the spline shaft portion while adjusting a gap with the spline shaft portion with a screw, and partially protruding from the surface. The rolling element holder provided with a rolling element is connected to the first groove. It was to mediate arranged to contact the rolling member and a second groove.

(Operation) The outer cylinder portion and the spline shaft portion are provided with a rolling element retainer interposed between the axial groove on the surface of the spline shaft and the axial groove on the surface of the rail body. Are in contact through the rolling elements. Therefore, when the spline shaft portion is moved relative to the outer cylinder portion, the spline shaft portion moves smoothly.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a diagram showing the entirety of the apparatus of the present invention. Reference numerals correspond to those in FIG. 13, 9 is a rolling element retainer, 22E is a mounting screw insertion hole, 42 is a screw hole, 8
1 is a groove. Here, in order to clearly show the structure of the spline shaft portion 3, a state where the rolling element retainer 9 is out of the outer cylinder main body 4 is illustrated. The groove 81 is a straight groove provided in the axial direction of the spline shaft body 8, and has a V-shaped cross section in this example. And the rolling element holder 9 is put in it. Rolling element retainer 9
As will be described with reference to FIG. 4 as well, it is in the shape of a square bar, and rolling elements 6 are provided on each surface in the axial direction so as to partially protrude from the surface of the square bar. Therefore, the rolling element holder 9 can move smoothly in the axial direction of the groove 81 while being in contact with the rolling elements 6 on the two lower surfaces.
The rolling element holder 9 is also in contact with the inner surface of the outer cylindrical portion 2 via the rolling elements 6 on the upper two surfaces, and can move similarly. The mounting screw insertion hole 22E and the screw hole 42 will be described in detail later.
It is a hole for attaching to etc.

FIG. 1 is a diagram showing a cross section of a main part of the apparatus of the present invention. The reference numerals correspond to those in FIG. 2, 10 is a gap adjusting screw, 11 is a rail body, 12 is a mounting screw, 13 is a seal body, 20 is a middle cylinder, 21 is a middle cylinder wall groove, 42 is a screw hole,
51 is a mounting screw hole, 111 is a groove. First, an outline of the configuration will be described. The spline shaft 8 has a cylindrical shape or a column shape, and has several grooves 81 in its outer peripheral surface in the axial direction. FIG. 3 shows a cross section of the spline shaft 8. As shown in FIG. 1, the rolling element holders 9 are fitted into the respective grooves 81. The main part of the outer cylinder part 2 is composed of the outer cylinder body 4, the middle cylinder 20 and the rail body 11. An inner cylinder 20 is attached to the inner surface of the outer cylinder main body 4 (there is a hatched portion indicated by reference numeral 20 on the left and right in FIG.
Represents both ends. ).

The middle cylinder 20 is provided with an inner cylinder wall groove 21 in the axial direction.
Is opened (between both ends described above.
The absence of diagonal lines indicates that this is a space. ). Then, the rail body 11 is accommodated in the inner cylinder wall surface slot 21 and attached to the inner cylinder 20 with the attachment screw 12. Although the rail body 11 has a prismatic shape, a groove 111 (V-shaped section in this example) is provided on a surface facing the spline shaft body 8 side. This V-shaped groove 111
Is placed on the rolling element holder 9. The seal members 13 on both sides prevent dust and the like from entering inside,
This is for positioning the middle cylinder 20 in the axial direction.

In the present invention, the groove on the outer cylinder portion side that comes into contact with the rolling element is not provided by grinding the inner surface of the cylindrical body but by processing one plane of the prismatic rail body 11. Become. Since this processing can be performed easily with a surface grinder, it is possible to take mass production.
Processing costs are also reduced. In addition, regarding the outer cylinder part 2, the parts that need to be cured to prevent wear are:
Only the rail body 11 is provided. The rail body 11 is a part that can be separated from the outer cylinder part 2 and is extremely smaller than the conventional outer cylinder body 4. Therefore, in the present invention, it is only necessary to heat-treat a component that is much smaller than in the past, which facilitates work such as easy handling, and also allows a large amount of heat treatment to be performed at once. Furthermore, since the rail body 11 has a prismatic shape as a whole and each surface is made of a flat surface, the distortion caused by the heat treatment is smaller than that of the conventional case in which the entire cylindrical outer cylinder body 4 is heat-treated. Much smaller.

FIG. 4 is a view showing the arrangement of the rolling element retainers according to the present invention. The reference numerals correspond to those in FIG.
The rolling element retainer 9 has a prismatic shape, and is inclined obliquely so that one ridge line thereof is directly below.
Put in one. The rolling elements 6 provided on the lower two surfaces of the rolling element holder 9 come into contact with the V-shaped groove 81.
The rail body 11 is disposed on the rolling element retainer 9 so as to cover it. Accordingly, the rolling elements 6 provided on the upper two surfaces of the rolling element retainer 9 are provided with the grooves 11 of the rail body 11.
Touch 1.

FIG. 6 is a sectional view of the middle cylinder 20. Reference numeral 21 denotes a hole in the wall surface of the middle cylinder, 22 denotes a mounting screw insertion hole, 23 denotes a screw hole,
25 is a sink keyway, and 26 is a screw hole. The middle cylinder wall surface hole 21 is a hole that is formed so as to penetrate from the outside to the inside of the middle cylinder 20, and the rail body 11 is accommodated therein. In order to attach the rail body 11 to the middle cylinder 20, an attachment screw 12 is used. The mounting screw insertion hole 22 is
The screw hole 23 is a hole into which the tip of the mounting screw 12 is screwed. In addition, as shown in FIG. 10 later, a mounting screw insertion hole 22E is also formed in the outer cylinder body 4. The position is such that when the middle cylinder 20 is fitted into the outer cylinder body 4, the middle cylinder 20
This is a portion where the mounting screw insertion hole 22 is extended.

The rail 11 is attached as follows. The rail body 11 is fixed by inserting the mounting screw 12 into the mounting screw insertion hole 22, penetrating the rail body 11, and screwing the tip into the screw hole 23. However, before the rail body 11 is finally firmly fixed, its position is finely adjusted by the gap adjusting screw 10 (see FIG. 10). The reason why the middle cylinder 20 is provided in the present invention is that the prismatic rail body 11 having a role of directly contacting the rolling element (in other words,
This is because, instead of a cylindrical structure, a structure in which each surface is made of a flat surface) can be disposed in the outer cylinder portion 2 by an assembling operation. The sunk key groove 25 is a groove for accommodating the sunk key 24 for engaging the middle cylinder 20 with the outer cylinder main body 4 outside the middle cylinder 20, as will be described later with reference to FIG. The sinking key 24 and the sinking key groove 25 are publicly known.

FIG. 5 is a first side view of the middle cylinder 20 (a side view as viewed from above in FIG. 6). Since the opening of the mounting screw insertion hole 22 is viewed obliquely, not from the front, it looks like a deformed ellipse. Screw hole 2
The opening 3 is visible in the opening of the mounting screw insertion hole 22. FIG. 7 is a second side view of the middle cylinder 20 (a side view as viewed from the right side in FIG. 6). The inner cylinder wall slot 21 has two vertical
The book is visible, and the sinking keyway 25 is visible in the center. The sunken key groove 25 is not a through hole penetrating from the outside to the inside but a groove. A screw hole 26 for fixing the sinking key is provided in some places of this groove.

FIG. 8 is a cross-sectional view as viewed from the position A in FIG. The end side surface of the outer cylindrical portion 2 is prevented from entering dust and the like by the seal body 13. FIG. 9 is a cross-sectional view as viewed at a position C in FIG. The sunken key groove 27 is a groove provided on the inner wall surface of the outer cylinder body 4 at a position facing the sunken key groove 25 provided in the middle cylinder 20. The sinking key 24 is placed in a groove formed by the sinking key groove 25 and the sinking key groove 27. The sinking key 24 is located at the bottom of the sinking keyway 25 (ie,
It is fixed to the middle cylinder 20). Since the upper half of the sinking key 24 is fitted in the sinking key groove 27, the rotation of the middle cylinder 20 and the outer cylinder body 4 is performed by the sinking key 24. Therefore, when a rotational force acts on one side, the rotational force is transmitted to the other via the sinking key 24. The spline shaft 8 of the spline shaft 3 and the rail 11 of the outer cylinder 2 are in contact with each other via a rolling element holder 9. A clearance adjusting screw 10 is provided at the back of the rail body 11 so as to abut the back. The gap with the body 8 is easily adjusted.

FIG. 10 is a cross-sectional view as viewed at the position B in FIG. Reference numerals correspond to those in FIGS. 6 and 9, and reference numeral 22E denotes a mounting screw insertion hole formed in the outer cylinder body 4. The mounting screw insertion hole 22E is located at a position as if the mounting screw insertion hole 22 was extended outward when the middle cylinder 20 was fitted into the outer cylinder main body 4.
It is opened to be shaped. After the gap is adjusted by the gap adjusting screw 10, the rail body 11 is
By this, it is firmly attached to the middle cylinder 20.

FIG. 11 is a cross-sectional view of a portion having a sink key fixing screw 28. (Speaking of FIG. 7, the portion D having the screw hole 26 is the screw 2 for fixing the sinking key in the middle cylinder 20.
8 corresponds to the portion where there is. 7 and 9 correspond to those in FIGS. 7 and 9, and 26 is a screw hole. The screw hole 26 is formed at the bottom of the sink key groove 25, and the sink key 24 is fixed by screwing a sink key fixing screw 28 penetrating the sink key 24 there. Sinking keyway 27
Is a groove provided on the inner wall surface of the outer cylinder body 4, but it is not a groove that comes into contact with the rolling element. Therefore, the processing for providing this does not require much labor and does not require accuracy.

The position of the middle cylinder 20 in the axial direction is determined by the seal members 13 on both sides, and the position in the circumferential direction is determined by the sinking key 24 engaged with the outer cylinder body 4. It is fixed inside. In the above-described embodiment, the cross section of the groove in the axial direction is V-shaped. However, the present invention is not limited to this. According to the shape of the rolling element to be used,
It can be formed into an appropriate shape (eg, an R shape, a gothic arc shape, etc.).

[0021]

As described above, the rolling spline device of the present invention has the following effects. The cost of the grinding process can be greatly reduced, and mass production becomes possible. Since the groove provided inside the outer cylinder portion is provided not in the cylindrical outer cylinder body but in the prismatic rail body 11, it can be provided by a surface grinder. Surface grinders are very common grinders, and grooving with them is easier than conventional grooving performed using special grinding equipment, which makes mass production easier and reduces costs. Is significantly cheaper.

The operation of adjusting the gap between the outer cylinder main body 4 and the spline shaft 8 becomes extremely easy. Since the gap between the outer cylinder part 2 and the spline shaft part 3 can be adjusted by the gap adjusting screw 10 pressing the back of the rail body 11, compared with the conventional gap adjustment that is performed by selecting the rolling element diameter. It does not require much skill, it is extremely easy to do, and the cost is greatly reduced. The heat treatment work becomes easier, the distortion due to the heat treatment is reduced, and the accuracy of the apparatus is improved. Since the rolling elements 6 come into contact with the groove 111 of the rail 11 and the groove 81 of the spline shaft 8, those which need to be heat-treated and hardened are the rail 11 and the spline shaft 8. . Since the rail body 11 is extremely small when viewed from the entire outer cylinder part 2, the heat treatment work becomes easy. Further, since the rail body 11 is a small prismatic part (not a large cylindrical part), distortion due to heat treatment is reduced as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is a view showing a cross section of a main part of a device of the present invention.

FIG. 2 is a diagram showing the entire apparatus of the present invention.

FIG. 3 is a sectional view of a spline shaft used in the present invention.

FIG. 4 is a diagram showing an arrangement state of a rolling element retainer according to the present invention.

FIG. 5 is a first side view of a middle cylinder used in the present invention.

FIG. 6 is a sectional view of a middle cylinder used in the present invention.

FIG. 7 is a second side view of the middle cylinder used in the present invention.

FIG. 8 is a cross-sectional view as viewed from a position A in FIG. 1;

FIG. 9 is a cross-sectional view as viewed at a position C in FIG. 1;

FIG. 10 is a cross-sectional view as viewed at a position B in FIG. 1;

FIG. 11 is a sectional view of a portion having a sinking key.

FIG. 12 is a cross-sectional view of an outer cylindrical portion of a conventional rolling spline device.

FIG. 13 shows a conventional rolling spline device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rolling spline apparatus, 2 ... outer cylinder part, 3 ... spline shaft part, 4 ... outer cylinder main body, 5 ... flange, 6 ... rolling element, 7
... rolling element holding part, 8 ... spline shaft body, 9 ... rolling element holder, 10 ... gap adjustment screw, 11 ... rail body, 12 ... mounting screw, 13 ... seal body, 20 ... middle cylinder, 21 ... middle cylinder wall surface Slot hole, 22: mounting screw insertion hole, 23: screw hole, 24: sink key, 25: sink key groove, 26: screw hole, 27: sink key groove, 28: sink key fixing screw, 41: groove , 42
... Screw hole, 51 ... Mounting screw hole, 81 ... Slot

Claims (1)

[Claims] 1. A rolling spline device having an outer cylinder portion and a spline shaft portion, wherein the spline shaft portion relatively moves in the axial direction while being in contact with an inner wall of the outer cylinder portion via a rolling element. A plurality of first grooves are provided in the axial direction of the outer surface of the shaft portion, and the outer cylinder portion is attached to the outer cylinder body and the inner surface of the outer cylinder body, and the first spline shaft portion is inserted when the spline shaft portion is inserted. An inner cylinder having an axially extending inner wall surface wall hole at a wall position corresponding to each of the first grooves, and a gap between the spline shaft portion and the inner cylinder wall surface hole being adjusted by a screw while being adjusted. And a second surface facing the spline shaft portion.
And a rolling element retainer provided with a rolling element such that a part thereof protrudes from the surface is provided in the first groove and the second groove. A rolling spline device, wherein the rolling spline device is provided so as to be in contact with rolling elements.