JP3549482B2 - Rolling spline device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to 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 contacting an inner wall of the outer cylinder portion via a rolling element.
[0002]
[Prior art]
FIG. 13 is a diagram showing a conventional rolling spline device. In FIG. 13, 1 is a rolling spline device, 2 is an outer cylinder, 3 is a spline shaft, 4 is an outer cylinder main body, 5 is a flange, 6 is a rolling element, 7 is a rolling element holding section, and 8 is a spline shaft. is there.
The spline shaft 8 has a cylindrical or columnar shape as a whole, and has a concave portion formed in the surface thereof in the axial direction, into which the rolling element 6 is fitted. The rolling element holding portion 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.
[0003]
FIG. 12 is a cross-sectional view of an outer cylindrical portion of a conventional rolling spline device. The reference numerals correspond to those in FIG. 13, 41 is a groove, and 51 is a mounting screw hole. The 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 that is straightly ground 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 cylinder 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 moved relative to each other 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 to be solved by the invention]
(problem)
However, the conventional rolling spline device described above 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 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, but the heat treatment at that time causes the outer cylinder body 4 to harden. In addition, the curved surface of the spline shaft 8 is distorted, and many steps are required to maintain the accuracy of the inner groove grinding.
[0005]
(Explanation of the problem)
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 grinding machine, productivity is poor.
Next, the second problem will be described. After finishing the processing of the outer cylinder main body 4 and the spline shaft 8, the depth of the recess provided on the surface of the spline shaft 8 for measuring the depth of the groove 41 or arranging the rolling element 6 is determined. By measuring, the size of the rolling element 6 to be used is selected. This required a high level of skill and was a labor-intensive task because it was a one-item productive handmade operation. This selection is also referred to as “gap adjustment” because the selection is made while taking into account that the gap between the outer cylinder main body 4 and the spline shaft body 8 has an appropriate size.
[0006]
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 part of the spline shaft 8 where the rolling element 6 comes into contact is a recess 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 diameter size changes, the groove depth changes, and the like), and the finishing accuracy is deteriorated.
An object of the present invention is to solve the above problems.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention has a structure in which an outer cylinder portion and a spline shaft portion are provided, and 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. In the spline device, a plurality of first grooves are provided in an axial direction of an outer surface of the spline shaft portion, and the outer cylinder portion is attached to an outer cylinder body and an inner surface of the outer cylinder body, and the spline shaft portion is attached to the outer cylinder body. A middle cylinder having an axial middle cylinder wall hole formed in a wall position corresponding to each of the first grooves when inserted, and a gap between the spline shaft portion in the middle cylinder wall groove. A rolling element which is mounted while being adjusted with screws and has a second groove provided on a surface facing the spline shaft portion, and a rolling element provided with a rolling element so as to partially protrude from the surface. The retainer is brought into contact with the first groove and the second groove by the rolling element. It was to mediate arranged to.
[0008]
(Operation)
The outer cylinder part and the spline shaft part are in contact via the rolling element of the rolling element retainer interposed between the axial groove on the surface of the spline shaft body and the axial groove on the surface of the rail body. are doing. Therefore, when the spline shaft is relatively moved with respect to the outer cylinder, the spline moves smoothly.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described 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, and 81 is a groove. Here, in order to easily show the structure of the spline shaft portion 3, a state in which 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. The rolling element holder 9 is inserted therein.
The rolling element retainer 9 has a square rod shape, which will also be described with reference to FIG. 4, and the rolling elements 6 are provided at portions of each surface in the axial direction so as to partially protrude from the surface of the square rod. . 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 upper two rolling elements 6, and can move in the same manner.
As will be described later in detail, the mounting screw insertion hole 22E and the screw hole 42 are holes for mounting the internal structure of the outer cylinder portion 2 to the outer cylinder body 4 and the like.
[0010]
FIG. 1 is a diagram showing a cross section of a main part of the device 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, and 51 is a screw hole. Is a mounting screw hole, and 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 is provided with 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 retainers 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. A middle cylinder 20 is attached to the inner surface of the outer cylinder main body 4 (there is a hatched portion with reference numeral 20 on the left and right in FIG. 1, which represents both ends of the middle cylinder 20).
[0011]
The middle cylinder 20 is provided with a middle cylinder wall hole 21 in the axial direction (opened between the above-mentioned ends. The hatched area indicates that this is a space. ing.). 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 cross section in this example) is provided on a surface facing the spline shaft body 8 side. The V-shaped groove 111 is covered on the rolling element retainer 9.
The seal bodies 13 on both sides are for preventing dust and the like from entering inside and for positioning the middle cylinder 20 in the axial direction.
[0012]
In the present invention, the groove on the side of the outer cylinder that comes into contact with the rolling element is provided by processing one plane of the prismatic rail body 11 instead of grinding the inner surface of the cylindrical body. Since this processing can be easily performed with a surface grinder, it is possible to adopt a mass production system and the processing cost is reduced.
In addition, regarding the outer cylinder 2, only the rail body 11 needs to be hardened to prevent abrasion. 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 extremely small compared to the conventional one, which facilitates work such as easy handling, and also allows a large amount of heat-treatment 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.
[0013]
FIG. 4 is a diagram 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 is right below, and is inserted into the groove 81 of the spline shaft 8. 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 holder 9 so as to be covered. Therefore, the rolling elements 6 provided on the upper two surfaces of the rolling element holder 9 come into contact with the groove 111 of the rail body 11.
[0014]
FIG. 6 is a sectional view of the middle cylinder 20. Reference numeral 21 denotes an inner wall surface slot, 22 denotes a mounting screw insertion hole, 23 denotes a screw hole, 25 denotes a sinking keyway, and 26 denotes a screw hole. The middle cylinder wall 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 a hole for inserting the mounting screw 12 from the outside to the side surface portion of the middle cylinder wall hole 21, and 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 a portion where the mounting screw insertion hole 22 of the middle cylinder 20 is extended when the middle cylinder 20 is fitted into the outer cylinder main body 4.
[0015]
The mounting of the rail body 11 is performed 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 a prismatic rail body 11 having a role of directly contacting the rolling elements (in other words, a structure in which each surface is made of a flat surface instead of a cylindrical structure) This is because the body can be disposed in the outer cylinder part 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 thereof, as will be described later with reference to FIG. The sinking key 24 and the sinking key groove 25 are known.
[0016]
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. The opening of the screw hole 23 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). Two middle cylinder wall holes 21 are visible up and down, and a sunken key groove 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.
[0017]
FIG. 8 is a cross-sectional view as viewed at a position A in FIG. The end side surface of the outer cylinder 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 accommodated in a groove formed by the sinking key groove 25 and the sinking key groove 27. The sinking key 24 is fixed to the bottom of the sinking key groove 25 (that is, 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 the rolling element holder 9. A clearance adjusting screw 10 is provided at the back of the rail body 11 so as to contact the back, and the front surface of the rail body 11 is adjusted by the clearance adjusting screw 10 so that the rail body 11 and the spline shaft are adjusted. The gap with the body 8 is easily adjusted.
[0018]
FIG. 10 is a cross-sectional view as viewed at a position B in FIG. The 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 opened so that when the middle cylinder 20 is fitted into the outer cylinder main body 4, the mounting screw insertion hole 22 has a position and a shape as if it were extended outward.
After the clearance of the rail body 11 is adjusted by the clearance adjustment screw 10, the rail body 11 is firmly attached to the middle cylinder 20 by the attachment screw 12.
[0019]
FIG. 11 is a cross-sectional view of a portion where the sink key fixing screw 28 is provided. (Speaking of FIG. 7, the portion D having the screw hole 26 corresponds to the portion of the middle cylinder 20 having the sink key fixing screw 28.) The reference numerals correspond to those in FIGS. , 26 are screw holes. 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 therethrough.
The sunk key groove 27 is a groove provided on the inner wall surface of the outer cylinder main body 4, but 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.
[0020]
The middle cylinder 20 is positioned in the axial direction by the seal bodies 13 on both sides, and is positioned in the circumferential direction by the sinking key 24 engaged with the outer cylinder body 4 and fixed inside the outer cylinder body 4. Is done.
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. An appropriate shape (eg, an R shape, a gothic arc shape, etc.) can be adopted according to the shape of the rolling element to be used.
[0021]
【The invention's effect】
As described above, according to the rolling spline device of the present invention, the following effects can be obtained.
{Circle around (1)} The cost of grinding can be greatly reduced, and mass production becomes possible.
The groove provided inside the outer cylinder portion is not provided in the cylindrical outer cylinder body, but is provided in the prismatic rail body 11, so that it can be provided by a surface grinding machine. Surface grinders are very common grinders, and grooving with them is easier than conventional grooving performed using a special grinding device, making mass production easier and cost effective. Is significantly cheaper.
[0022]
(2) The work 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 to 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.
{Circle around (3)} 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 diagram showing a cross section of a main part of the device of the present invention. FIG. 2 is a diagram showing the entire device of the present invention. FIG. 3 is a cross-sectional view of a spline shaft used in the present invention. FIG. 5 is a view showing an arrangement state of a moving body retainer. 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 used in the present invention. FIG. 8 is a cross-sectional view as viewed at 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. FIG. 11 is a cross-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 is a diagram showing a conventional rolling spline device.
DESCRIPTION OF SYMBOLS 1 ... Rolling spline apparatus, 2 ... Outer cylinder part, 3 ... Spline shaft part, 4 ... Outer cylinder main body, 5 ... Flange, 6 ... Rolling body, 7 ... Rolling body holding part, 8 ... Spline shaft body, 9 ... Rolling body Cage, 10: gap adjusting screw, 11: rail body, 12: mounting screw, 13: seal body, 20: middle cylinder, 21: middle cylinder wall groove, 22: mounting screw insertion hole, 23: screw hole, 24: sinking key, 25: sinking key groove, 26: screw hole, 27: sinking key groove, 28: screw for fixing sinking key, 41: groove, 42: screw hole, 51: mounting screw hole, 81: groove

Claims (1)

A rolling spline device having a structure 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 the inner wall of the outer cylinder portion via a rolling element.
Providing a plurality of first grooves in the axial direction of the outer surface of the spline shaft portion;
The outer cylinder portion,
An outer cylinder body,
A middle cylinder attached to the inner surface of the outer cylinder main body and having an axial middle cylinder wall groove formed at a wall position corresponding to each of the first grooves when the spline shaft is inserted;
A rail body provided with a gap between the spline shaft and the spline shaft in the middle cylinder wall surface while being adjusted with a screw, and a second groove provided on a surface facing the spline shaft;
A rolling element retainer provided with a rolling element such that a part thereof protrudes from the surface is interposed between the first groove and the second groove so as to be in contact with the rolling element. Rolling spline device.

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