JP2003269461A - Rolling element and linear motion rolling guide bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling element improving a vibration/sound property without improving the machining precision of the rolling element, and also to provide a linear motion guide bearing using the element. <P>SOLUTION: A guiding rail 1 and a slider 2 are arranged so as to relatively move, and a plurality of balls B is filled in a rolling element rolling passage formed between both the rail 1 and the slider 2. Each ball B makes an overall value of even number crest components of undulation on a rolling surface smaller than an overall value of an odd number crest components, and makes the maximum value of the even number crest components smaller than the maximum value of the odd number components. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

The present invention relates to a linear motion rolling guide bearing such as a ball screw device, a linear guide device, a ball spline device, and a linear ball bushing device used in a high precision machine such as a machine tool.

[0001]

2. Description of the Related Art Recently, linear motion rolling guide bearings have been widely used as a high-speed feed / positioning mechanism for NC machine tools and industrial robots. The speed of these machines is increasing year by year, and there is a demand for higher accuracy and lower noise. For this reason, the linear motion rolling guide bearings used in these machines are those that minimize the machining error of the sphericity of the rolling elements, the surface of the rolling elements and the groove raceways such as the screw shaft. .

Further, in order to reduce the collision noise between rolling elements that occurs during rotation, a separator is interposed between the rolling elements,
It is also practiced to prevent rolling elements from directly colliding with each other.

[0003]

However, in the above-described conventional linear motion rolling guide bearing, noise is generated due to collision between rolling elements, and the rolling elements have minute irregularities that cannot be avoided in processing. It exists on the surface, and for this reason, the diameter of the rolling element slightly changes during one rotation, which causes vibration (noise). In some conventional linear motion rolling guide bearings, a separator is interposed between rolling elements to reduce the collision noise between rolling elements, which can significantly reduce noise. When it is attempted to reduce the number of irregularities, the rolling element surface has irregular asperities, and it is necessary to reduce the shake due to the irregularities.

For this reason, it is necessary to further improve the sphericity of the rolling element, but this has a problem that the manufacturing cost increases. On the other hand, focusing on the peak number component of the rolling element, it is already known that the even-numbered peak component of the rolling element is harmful to the vibration and acoustic characteristics of the linear motion rolling guide bearing, so the accuracy of this component is particularly improved. As a result, it is possible to meet the demand for the linear motion rolling guide bearing.

Therefore, according to the present invention, even if the sphericity of the rolling element is at the current level, the precision of the even-numbered peak component of the rolling element can be improved to effectively reduce vibration and acoustic characteristics. Another object of the present invention is to provide a linear motion rolling guide bearing using the same.

[0006]

In order to achieve the above object, a rolling element according to a first aspect of the present invention comprises an inner member having a guide groove, and a rolling element rolling member facing the guide groove of the inner member. Linear rolling having a guide groove forming a passage and a rolling element return passage communicating with both ends of the rolling element rolling passage, and an outer member movably arranged relative to the inner member In rolling elements loaded in rolling element rolling passages and rolling element returning passages used in guide bearings, the overall value of even-numbered peak components of the number of peaks of surface waviness was made smaller than the overall value of odd-numbered peak components. It is characterized by that.

According to a second aspect of the present invention, there is provided an inner member having a guide groove, a guide groove for forming a rolling member rolling passage facing the guide groove of the inner member, and the rolling member rolling. A rolling element rolling passage and a rolling element rolling passage used in a linear motion rolling guide bearing having a rolling element return passage communicating with both ends of the passage and an outer member movably arranged relative to the inner member. The rolling element loaded in the moving body return passage is characterized in that the maximum value component in the even-numbered mountain component is smaller than the maximum value component in the odd-numbered mountain component among the mountainous components of the surface waviness.

Further, the rolling element according to a third aspect of the present invention includes an inner member having a guide groove, a guide groove that forms a rolling element rolling passage facing the guide groove of the inner member, and the rolling element rolling. A rolling element rolling passage and a rolling element return of a linear motion rolling guide bearing having a rolling element returning passage communicating with both ends of the passage and an outer member movably arranged relative to the inner member. In the rolling element loaded in the passage, the overall value of the even peak component of the number of peaks of the surface waviness is made smaller than the overall value of the odd peak component, and the maximum value component of the even peak components is the odd peak component. It is characterized in that it is smaller than the maximum value component among the components.

Furthermore, a linear motion rolling guide bearing according to a fourth aspect of the present invention includes an inner member having a guide groove, a guide groove that faces the guide groove of the inner member and forms a rolling element rolling passage, and An outer member having rolling element return passages communicating with both ends of the rolling element rolling passage and disposed so as to be relatively movable with respect to the inner member, and the rolling element rolling passage and the rolling element return passage. In a linear motion rolling guide device provided with a large number of rolling elements loaded in a freely rolling manner, the rolling element has an overall value of even-numbered mountain components, and an overall value of odd-numbered mountain components, among the mountain number components of surface undulations. It is characterized by being smaller than.

Furthermore, a linear motion rolling guide bearing according to a fifth aspect of the present invention includes an inner member having a guide groove, a guide groove which faces the guide groove of the inner member and forms a rolling element rolling passage, and An outer member having rolling element return passages communicating with both ends of the rolling element rolling passage and disposed so as to be relatively movable with respect to the inner member, and the rolling element rolling passage and the rolling element return passage. In a linear motion rolling guide device provided with a large number of rolling elements loaded rotatably, the rolling element has a maximum value component among even number mountain components among the number components of surface waviness and an odd number mountain component. It is characterized in that it is smaller than the maximum value component of.

According to a sixth aspect of the present invention, there is provided a linear motion rolling guide bearing, wherein an inner member having a guide groove, a guide groove facing the guide groove of the inner member and forming a rolling element rolling passage, and the rolling member. An outer member having rolling element return passages communicating with both ends of the rolling element rolling passage and disposed so as to be movable relative to the inner member, and rolling into the rolling element rolling passage and the rolling element return passage. In a linear motion rolling guide device including a large number of rolling elements that are movably loaded, the rolling element is configured such that the overall value of the even-numbered mountain component is higher than the overall value of the odd-numbered mountain component, among the mountain number components of the surface waviness. Is also small, and the maximum value component in the even-numbered mountain component is smaller than the maximum value component in the odd-numbered mountain component.

Further, the linear motion rolling guide bearing according to claim 7 is characterized in that, in the invention according to any one of claims 4 to 6, a separator is interposed between each rolling element.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing an embodiment in which the present invention is applied to a linear guide device as a linear motion rolling guide bearing. This linear guide device includes a guide rail 1 as an inner member extending in the axial direction.
And a slider 2 as an outer member laid on the guide rail 1 so as to be relatively movable in the axial direction.

Guide rails 3 are provided on both side surfaces of the guide rail 1 so as to extend in the axial direction. The slider body 2a of the slider 2 faces the inner side surfaces of both sleeve portions 4 of the slider body 2a and faces the guide grooves 3, respectively. So that the rolling element rolling passage 6 is formed by the guide groove 31.
Is provided. Then, a large number of balls B as rolling elements are rotatably loaded in the rolling element rolling passage 6, and the slider 2 can relatively move in the axial direction on the guide rail 1 through the rolling of the balls B. Is configured.

As the slider 2 moves, the ball B interposed between the guide rail 1 and the slider 2 rolls and moves to the end of the slider 2, but the slider 2 is continuously moved in the axial direction. In order to do so, it is necessary to circulate the ball B infinitely. Therefore, the sleeve portion 4 of the slider body 2A
Further, a linear rolling element passage 8 penetrating in the axial direction is further formed therein, and end caps 5 as rolling element rolling element circulating parts are fixed to the front and rear ends of the slider body 2A, respectively. A rolling element communication path 7 that connects the rolling element passage 6 and the rolling element passage 8 and is curved in a semicircular shape.
The rolling element communication passage 7 and the rolling element passage 8 form a rolling element return passage 9, and the rolling element return passage 9 is also loaded with balls B.

The ball B has a minute waviness (unevenness) on the rolling surface, and the waviness causes the guide rail 1 to move.
Also, the distance between the slider 2 and the slider 2 slightly changes during one rotation of the ball B, causing a shake. In the present embodiment, the ball B in which the overall value of the even-numbered mountain component is smaller than the overall value of the odd-numbered mountain component among the number-of-waves mountainous components of the ball surface is applied.

As described above, by making the overall value of the even-numbered mountain component smaller than the overall value of the odd-numbered mountain component, it is possible to reduce the shake and improve the vibration / acoustic characteristics. The reason for this is that vibration due to a minute waviness existing on the rolling surface of the ball B is caused by a change in the diameter of the ball due to this waviness, so that it is sufficient to reduce the deviation in the diameter of the ball.

FIG. 2 shows the case where the number of undulations is an even number, of which FIG. 2A shows the case of two peaks and FIG. 2B shows the case of four peaks. As is clear from FIGS. 2A and 2B, when the number of undulations is an even number, both ends of the diameter of the ball B are located at the top or bottom of the undulation at the same time. Then, the difference between the diameter a when the ridges are connected to each other and the diameter b when the ridges are connected to each other, that is, the diameter deviation is considerably large. As a result, the even peak component of the swell greatly affects the vibration and acoustic characteristics.

On the other hand, FIG. 3 shows the case where the number of peaks of swell is odd, of which FIG. 3A shows the case of 3 peaks and FIG. 3B shows the case of 5 peaks. ing. As is clear from FIGS. 3 (A) and 3 (B), when the number of peaks of the undulation is odd, one end of the diameter ends of the rolling element is located at the top of the undulation and the other end is located at the bottom. Therefore, there is almost no difference between the diameter including one apex and the diameter including another apex, that is, the diameter deviation. For example, R ₁ = R ₂ = R ₃ in FIG. 3A, and R ₁ = R ₂ = in FIG. 3B.
R ₃ = R ₄ = R ₅ . As a result, the influence of the odd peak component of the swell on the vibration / acoustic characteristics becomes small.

As described above, if the overall value of the even peak component of the swell is reduced, the vibration / acoustic characteristics can be improved without reducing the overall value of the odd peak component.

[0021]

EXAMPLES Next, experiments conducted to confirm the effects of the present invention will be described. In the experiment, a ball having a roundness shape of the rolling surface outside the scope of the present invention shown in FIG. 4 and a ball having a roundness shape of the rolling surface belonging to the scope of the present invention shown in FIG. 5 were used. . In these FIG. 4 and FIG.
The broken line shows the reference perfect circle, and the solid line shows the roundness shape of the ball.

The number of crests of the ball having the roundness shape shown in FIGS. 4 and 5 and its one-sided amplitude (half value of the displacement amplitude of the sinusoidally changing shape) were obtained by harmonic analysis, and the results are shown in the following table. 1 and Table 2. In each table, the numerical value in the vertical column at the left end represents the basic numerical value N representing the number of peaks, and the lateral column at the upper end represents the value added to the basic numerical value N. In addition, the unit of one-sided amplitude in each table is μm, Δ represents an odd mountain component, and no mark represents an even mountain component. Furthermore, the part marked with a horizontal line is
This is the part where there is almost no undulation of the number of mountains.

For example, in the second row from the top of Table 1 (N = 5), the value 0.001 written in the central column (N + 2) is 0.001.
Indicates that the one-sided amplitude value is 0.001 μm when the number of crests of the roundness-shaped ball shown in FIG. 4 is 7.

[0024]

[Table 1]

[0025]

[Table 2]

As is clear from Table 1 and Table 2,
Even in the case of a particular ball, there are multiple mountain number components. For example, the number of peaks of a ball having a roundness shape shown in FIG. 4 has components such as 2 to 10 as apparent from Table 1, and 11 and 12 are almost nonexistent. Therefore, the overall value of the even-numbered mountain component (sum total value, that is, the sum of squares of the one-sided amplitude values of the mountain component of each waviness) and the maximum value and the overall number of the odd mountain component in the roundness-shaped ball shown in Table 1 to When the value (sum value) and the maximum value are calculated, it becomes as follows. Even mountain component sum value = 0.010 ² +0.009 ² +0.001 ² +0.004 ² +0.002 ² +0.001 ² +
0.002 ² +0.001 ² +0.001 ² +0.001 ² +0.001 ² +0.001 ² = 0.0002
13 Maximum value = 0.010 Sum of odd peak components = 0.002 ² +0.002 ² +0.001 ² +0.002 ² +0.002 ² +0.001 ² +
0.002 + 0.001 ² = 0.000023 Maximum value = 0.002 As is clear from these, the ball having the roundness shape shown in FIG. , And the maximum value of the even peak component is larger than the maximum value of the odd peak component.

Next, the overall value (sum total value) of the even-numbered mountain component in the roundness-shaped ball shown in Table 2 to FIG.
And the maximum value, and the overall value (sum value) of the odd-numbered mountain component and the maximum value are calculated as follows. Even mountain component sum value = 0.013 ² +0.006 ² +0.004 ² +0.003 ² +0.003 ² +0.003 ² +
0.003 ² +0.001 ² +0.01 ² +0.003 ² +0.002 ² +0.001 ² = 0.0002
73 Maximum value = 0.013 Odd peak component sum value = 0.025 ² +0.005 ² +0.002 ² +0.002 ² +0.002 ² +0.002 ² +
0.001 ² +0.003 ² +0.002 ² +0.002 ² +0.002 ² +0.003 ² +0.002 ² +
0.001 ² +0.001 ² = 0.000703 Maximum value = 0.025 As is clear from the above, the roundness-shaped ball shown in FIG. And the maximum value in the even mountain component is smaller than the maximum value in the odd mountain component.

Therefore, FIG. 6 shows the results of noise measurement by incorporating balls outside the scope of the invention shown in FIG. 4 and balls belonging to the scope of the invention shown in FIG. 5 into the linear motion rolling guide bearings. In FIG. 6, the solid line shows the acoustic characteristics of the linear motion rolling guide bearing in which the balls outside the scope of the invention shown in FIG. 4 are incorporated, and the dotted line shows the linear motion in which the balls belonging to the scope of the invention shown in FIG. 5 are incorporated. The acoustic characteristics of the rolling guide bearing are shown. As is clear from FIG. 7, the frequency spectrum of the noise of the linear motion rolling guide bearing incorporating the ball having the roundness shape shown in FIG. 5 which belongs to the scope of the present invention is shown in FIG. 4 which is out of the scope of the present invention. It can be seen that the peak level is drastically reduced and the vibration and acoustic characteristics are improved compared to the frequency spectrum of the noise of the linear motion rolling bearing incorporating the ball having the roundness shape.

Further, as shown in FIG. 7, between the balls B adjacent to each other in the rolling element rolling passage 6 and the rolling element return passage 9, as shown in FIG. 7, the collision noise between the balls B during driving is eliminated to reduce noise. By interposing the separator S for the purpose of achieving the above, the vibration and acoustic characteristics can be further improved. Here, the separator S is formed by injection-molding an elastomer resin (trade name: Perprene, Hytrel, etc. manufactured by Toyobo Co., Ltd.) or the like into a disk shape having a thickness smaller than the radius, and both ends in the axial direction thereof. A pair of concave rolling element contact surfaces 11L and 11R that contact the ball B are formed on the surfaces.

In the above embodiment, the case where the present invention is applied to the linear guide device has been described.
It is needless to say that the present invention can be applied to other linear motion rolling guide bearings such as a ball screw device, a ball spline device, and a linear ball bushing device.

[0031]

As described above, according to the rolling element of the present invention, the overall value of the even-numbered peak component and / or the maximum value of the peak-number components of the waviness on the surface of the rolling element is the overall value of the odd-numbered peak component. And / or smaller than
Even if the processing accuracy of the rolling elements is not particularly improved, the vibration / acoustic characteristics can be improved and the manufacturing cost can be reduced.

Further, by incorporating the rolling element into the linear motion rolling guide bearing, it is possible to improve the vibration and acoustic characteristics of the linear motion rolling guide bearing, and further, to improve the NC machine tool using the linear motion rolling guide bearing. The effect that the vibration and acoustic characteristics of a precision machine such as an industrial robot can be improved is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment when the present invention is applied to a linear guide device.

FIG. 2 is a diagram for explaining a diameter deviation when the number of waviness peaks is an even number.

FIG. 3 is a diagram for explaining a diameter deviation when the number of waviness peaks is an odd number.

FIG. 4 is a diagram showing a roundness shape of a ball belonging to the technical scope of the present invention.

FIG. 5 is a diagram showing a roundness shape of a ball which is out of the technical scope of the present invention.

FIG. 6 is a characteristic diagram showing a noise level with respect to frequency in the balls of FIGS. 4 and 5;

FIG. 7 is a diagram showing an embodiment in which a separator is arranged between balls.

[Explanation of symbols]

1 Guide rail 2 slider 3,31 guide groove 6 Rolling element passage B ball S separator

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3C048 CC04 DD01 EE10                 3J062 AA21 AB22 AC07 BA25 BA26                       CD04 CD08 CD54 CD62                 3J101 AA03 AA33 AA44 AA64 AA71                       AA85 BA02 FA01 FA44 GA31                 3J104 AA03 AA19 AA23 AA36 AA65                       AA69 AA74 BA01 DA02 DA17                       EA01

Claims (7)

[Claims] 1. An inner member having a guide groove, a guide groove facing the guide groove of the inner member to form a rolling element rolling passage, and a rolling element return communicating with both ends of the rolling element rolling passage. A rolling element loaded in a rolling element rolling passage and a rolling element returning passage of a linear motion rolling guide bearing having an outer member having a passage and arranged to be movable relative to the inner member. A rolling element characterized by making the overall value of the even-numbered mountain component smaller than the overall value of the odd-numbered mountain component out of the number of mountainous components of the surface swell. 2. An inner member having a guide groove, a guide groove facing the guide groove of the inner member to form a rolling element rolling passage, and a rolling element return communicating with both ends of the rolling element rolling passage. A rolling element loaded in a rolling element rolling passage and a rolling element returning passage of a linear motion rolling guide bearing having an outer member having a passage and arranged to be movable relative to the inner member. A rolling element characterized by making the maximum value component in the even-numbered mountain component smaller than the maximum value component in the odd-numbered mountain component among the mountain number components of the surface swell. 3. An inner member having a guide groove, a guide groove that forms a rolling element rolling passage facing the guide groove of the inner member, and a rolling element return communicating with both ends of the rolling element rolling passage. A rolling element loaded in a rolling element rolling passage and a rolling element returning passage of a linear motion rolling guide bearing having an outer member having a passage and arranged to be movable relative to the inner member. Among the number of peaks of surface swell, the overall value of the even-numbered mountain component is made smaller than the overall value of the odd-numbered mountain component, and the maximum value component of the even-numbered mountain component is made smaller than the maximum-value component of the odd-numbered mountain component. A rolling element characterized by being made smaller. 4. An inner member having a guide groove, a guide groove facing the guide groove of the inner member to form a rolling element rolling passage, and a rolling element return communicating with both ends of the rolling element rolling passage. An outer member having a passage and disposed so as to be relatively movable with respect to the inner member; and a large number of rolling elements rotatably loaded in the rolling element rolling passage and the rolling element return passage. In a linear motion rolling guide device provided with the rolling element, the rolling element is characterized in that the overall value of the even-numbered mountain component is smaller than the overall value of the odd-numbered mountain component among the number components of the surface waviness. apparatus. 5. An inner member having a guide groove, a guide groove that forms a rolling element rolling passage facing the guide groove of the inner member, and a rolling element return communicating with both ends of the rolling element rolling passage. An outer member having a passage and disposed so as to be relatively movable with respect to the inner member; and a large number of rolling elements rotatably loaded in the rolling element rolling passage and the rolling element return passage. In the linear motion rolling guide device provided with the rolling element, the maximum value component in the even-numbered mountain component is smaller than the maximum value component in the odd-numbered mountain component among the mountain number components of the surface waviness. Linear motion rolling guide device. 6. An inner member having a guide groove, a guide groove facing the guide groove of the inner member to form a rolling element rolling passage, and a rolling element return communicating with both ends of the rolling element rolling passage. An outer member having a passage and disposed so as to be relatively movable with respect to the inner member; and a large number of rolling elements rotatably loaded in the rolling element rolling passage and the rolling element return passage. In the linear motion rolling guide device provided with the rolling element, the overall value of the even-numbered mountain component is smaller than the overall value of the odd-numbered mountain component among the number of mountain components of the surface undulation, and the maximum of the even-numbered mountain component. A linear motion rolling guide device characterized in that the value component is smaller than the maximum value component of the odd mountain components. 7. The linear motion rolling guide device according to claim 4, wherein a separator is provided between each rolling element.