JP2952137B2 - Rolling guide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling guide device, and more particularly to a rolling guide device excellent in adjustability such as dynamic rigidity and damping property in an axial direction.

[0002]

2. Description of the Related Art Conventional rotary rolling bearings are intended to reduce the rolling friction of the rolling surface of the ball, particularly to prevent heat generation during high-speed rotation. The radius of curvature of the groove cross section is set to 0.
It is about 52 to 0.54. That is, when the radius of curvature of the ball rolling groove approaches 0.5 of the diameter of the ball, the contact width of the ball with the ball rolling groove increases, so that the differential sliding between the center and the end of the contact width is performed. Is increased, the rolling friction increases, and the calorific value also increases. Therefore, it is usually set to about 0.52 or more.

[0003] In the case of a thrust ball bearing, the cross-sectional radius of curvature of the ball raceway of the inner race and the outer race of the ball raceway is set to 0.5 of the ball diameter.
It is set to about 4.

[0004] In the rolling guide device, the radius of curvature of the cross section of the ball rolling groove is set to 0.52 to 0.54 of the ball diameter in the same way as above to minimize the increase in the rolling resistance. .

[0005]

By the way, with the recent refinement of machine tools and the like, it has become necessary to control the axial friction of the machine table in accordance with the required accuracy of the machine.

[0006] As described above, the rolling guide device reduces the friction in the axial direction, and cannot expect the dynamic rigidity and damping property. Although measures have been taken to increase the friction of the ball screw to be fed and to control the friction by applying a brake, it was not sufficient.

[0007] The present invention has been made to solve the above-mentioned problems of the prior art.
It is an object of the present invention to provide a rolling guide device capable of adjusting the axial friction by paying attention to the fact that the rolling speed of the rolling guide device is much lower than that of a rotary rolling bearing, and the problem of heat generation is not so problematic.

[0008]

According to the present invention, a track member, a moving member slidably provided along the track member, and the track member and the moving member are provided. A plurality of balls rotatably interposed between ball rolling grooves provided so as to face each other, and the ball rolling of at least one of the track member and the moving member. The cross-sectional shape of the groove is a single arc, and the radius of curvature of the groove of the ball rolling groove is
The diameter of the ball is set to 0.52 times or less, the rolling contact surface of the ball with respect to the ball rolling groove is an arc surface, and it is possible to adjust the axial friction by utilizing the differential slip generated on the rolling contact surface. It is characterized by having done.

The radius of curvature of the cross section of the ball rolling groove is:
0.52 to 0.505 times the diameter of the ball
Can be specified.

[0010] Further, by applying a preload,
The initial contact area of the tool and the differential slip can be adjusted.
it can.

Further, the gap between the ball rolling grooves is
Ball can be preloaded as oversized ball
You.

In the present invention, the equation S = ｛π (d1-d
2) / πd1｝ × 100 (where S is the differential slip
The ratio d1 is the distance between the centers of the contact surfaces. D2 is the distance between the long axis ends.
Is calculated by calculating the differential slip ratio calculated by the ball rolling groove.
Of radius of curvature (R) to ball diameter (Da)
(R / Da), the differential slip
Differential slip ratio (S) of the ball rolling groove with the radius of curvature of
The ratio (R / Da) to the ball diameter is 0.52-0.
505 is set to a range corresponding to the range.
You. Further, in the present invention, the track member, along the track member
A movable member slidably provided, and movable with the track member
Between ball rolling grooves provided on the member so as to face each other
And a number of balls that are rotatably interposed in the
In the bobbin guide device, the shape of the ball rolling groove is
Arc-shaped, and the ball saw against the ball rolling groove
Axial friction is adjusted using differential sliding at the rolling contact surface.
Means for making the adjustment possible, said means having the formula S = ｛π (d
1−d2) / πd1｝ × 100 (where S is differential
Slip rate · d1 is the distance between the centers of the contact surfaces · d2 is the long axis end
The differential slip ratio calculated by the ball
The radius of curvature (R) of the rolling groove with respect to the ball diameter (Da)
When expressed in relation to the ratio (R / Da),
The slip ratio (S) is determined by measuring the straightness of the ball having the radius of curvature of the ball rolling groove.
The ratio (R / Da) to the diameter is 0.52 to 0.505.
It is characterized in that it is set to a range corresponding to the range .

[0013]

The present invention focuses on the fact that the rolling speed is much lower in the case of a rolling guide device than in the case of a rotary rolling bearing, and the problem of heat generation is not much of a problem. The axial friction force is adjusted by utilizing the differential slip generated in the above.

In particular, when the radius of curvature of the ball rolling groove is set to a range smaller than 0.52 of the ball diameter, the differential slip increases, which is effective.

The amount of differential slip and the initial contact area can be adjusted by the amount of preload.

Further, when a load is applied, for example, during heavy cutting, the contact area and the differential slip increase, the dynamic rigidity and the damping property are improved, and vibration, chatter and the like are prevented.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 (a) schematically shows a rolling guide device according to an embodiment of the present invention. That is, reference numeral 1 denotes a rolling guide device as a whole, which includes a track member 2, a moving member 3 slidably provided along the track member 2, and a track member 2 and a moving member 3 which are opposed to each other. And a number of balls 6 rotatably interposed between the provided ball rolling grooves 4 and 5.

The cross-sectional shape of each of the ball rolling grooves 4, 5 cut along a plane perpendicular to the axial direction is a single arc shape, that is, a so-called circular arc groove shape, as shown in FIG. And the ball rolling grooves 4, 5 of the ball 6
The rolling contact surface 7 is an elliptical arc surface having a major axis a in a direction perpendicular to the axial direction.

At each contact position along the long axis a of the rolling contact surface 7, the distance from the rotation center axis O of the ball 6 is different, so that a differential slip occurs on the rolling contact surface 7. That is, when the ball 6 performs a rolling motion, the rolling contact surface 7 makes a rolling contact without slip at a certain position on the long axis of the rolling contact surface 7, and at another position, a rolling contact with slipping.

Conventionally, friction was reduced by reducing the differential slip as much as possible, but the present invention is required to control the axial friction by utilizing the differential slip. Dynamic rigidity and damping properties are obtained.

In order to utilize differential slip positively,
The radius of curvature R of the ball rolling grooves 4 and 5 is determined by the diameter Da of the ball 6
Is preferably set to a range smaller than approximately 0.52. However, if the radius of curvature R is too small, the friction becomes too large, impairing the light-weight movement which is the original characteristic of the rolling guide device.
It is preferable to set in the range of 0.505.

FIG. 2 shows the relationship between the ratio (R / Da) of the radius of curvature R of the ball rolling grooves 4 and 5 to the ball diameter Da and the differential slip ratio S for three types of 30 kg, 50 kg and 80 kg. FIG. 3 shows the relationship between the ratio (R / Da) of the radius of curvature R of the ball rolling grooves 4 and 5 and the differential slip ratio S when the applied load is 50 kg, and the ratio of the radius of curvature of the ball rolling groove ( 5 is a graph showing the ratio as a differential slip ratio (S / S0) based on the differential slip ratio S0 when R / Da) is 0.52. Here, the differential slip ratio S refers to the distance between the centers 7a, 7a of the rolling contact surfaces 7, 7 of the balls sandwiched between the pair of ball rolling grooves with the ball rolling grooves 4, 5, d1, Assuming that the distance at the end of the major axes a and a is d2, S =
It is calculated by {π (d1−d2) / πd1} × 100 (%).

As is apparent from FIGS. 2 and 3, the differential slip ratio S does not change so much up to 0.52, but increases sharply when it becomes 0.52 or less.

Such a shape of the ball rolling groove may be applied to at least one of the ball rolling groove of the track member 2 and the moving member 3.

In the rolling guide device having the above configuration,
In the case of the rolling guide device, attention is paid to the fact that the rolling speed is much lower than that of the rotary type rolling bearing, and the problem of heat generation is not so much a problem, and the rolling contact surface 7 of the ball 6 with respect to the ball rolling grooves 4 and 5 is generated. The differential friction control is used to control the axial friction force. That is, as shown in FIG. 1C, in a state where the moving member 3 is placed on the track member 2, the longitudinal direction of the track member 2 is defined as the Z axis, and the vertical direction orthogonal to the Z axis is defined as the Y axis. When the horizontal direction is the X axis, the frictional force in the Z direction is basically controlled by the differential slip, and the dynamic rigidity and the damping property are improved according to the required characteristics. However, if the dynamic stiffness and damping property in the Z-axis direction are improved, the dynamic stiffness in the other X-axis and Y-axis directions, and further in the moments MX, MY and MZ directions around the X-axis, Y-axis and Z-axis. , The damping property is improved.

In order to improve the positioning accuracy in the axial direction, it is preferable that the friction in the axial direction is as small as possible. However, when the inertial force is large, it is preferable that the friction is large. Further, when axial vibration such as cutting acts, it is preferable that the axial friction is large. The axial dynamic stiffness and damping property depend on the axial friction, and it is extremely effective to control the axial friction.

The factors controlling the axial friction are basically the amount of preload and the load. As the preload amount, control of the initial contact area of the ball and the differential slip amount, that is, a reference axial friction force is set. The application of the preload is performed, for example, by using the ball 6 as an oversized ball from the gap between the ball rolling grooves 4 and 5. Of course, a mechanism for adjusting the preload may be incorporated.

The load acting from the outside acts, for example, as a reaction force on the machine tool. During heavy cutting, the contact area and the differential slip increase, the axial friction increases, and the dynamic rigidity and damping increase. As a result, vibration, chatter, etc. are prevented. In other words, the circular arc groove has a characteristic that it moves lightly when light load is applied, and when processing that requires dynamic rigidity and damping properties, the contact area and differential slip increase due to the processing reaction force, and the axial friction increases. I do.

The present invention is not limited to the rolling guide device of the type shown in FIG. 1; in other words, various rolling guide devices in which the moving member is guided with respect to the track member via a large number of balls. Can be widely applied to. For example, the present invention can be applied to both the infinite sliding type and the finite sliding type, and it is needless to say that a ball spline and the like are included. Further, the present invention is not limited to the linear guide, and can be widely applied to a rolling guide device that is guided in a curved manner along a curved track member.

[0031]

The present invention has the above-described structure and operation. By adjusting the frictional force in the axial direction by utilizing the differential slip generated on the rolling contact surface, the dynamics required at the place of use can be improved. Can be widely used for rigidity and damping rate.

In particular, when a load is applied, for example, during heavy cutting, the contact area and differential slip increase, and the dynamic rigidity and damping properties are improved, so that vibration, chatter, and the like can be prevented.

[Brief description of the drawings]

FIG. 1A is a sectional view showing a basic configuration example of a rolling guide device according to an embodiment of the present invention, and FIG. 1B is an enlarged view showing a space between a ball and a ball rolling groove; FIG. 3C is a conceptual diagram of the force acting on the rolling guide device.

FIG. 2 is a graph showing a relationship between a ratio of a radius of curvature of a ball rolling groove to a ball and a differential slip ratio.

FIG. 3 is a graph showing the relationship between the ratio of the radius of curvature of the ball rolling groove to the ball and the differential slip ratio when the applied load is 50 kg.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling guide device 2 Track member 3 Moving member 4, 5 Ball rolling groove 6 Ball 7 Rolling contact surface

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16C 29/04-29/06

Claims (6)

(57) [Claims] 1. A track member, a moving member slidably provided along the track member, and a ball rolling groove provided to face the track member and the moving member so as to roll freely between the ball rolling grooves. in rolling guide device comprising: a plurality of balls being interposed, and the cross-sectional shape of at least one of the ball rolling grooves of said raceway member and the moving member is a single arc shape, the ball
The radius of curvature of the groove cross section of the rolling groove is 0.5 times the diameter of the ball.
The rolling contact surface of the ball with respect to the ball rolling groove is set to be an arc surface, and the axial friction can be adjusted by utilizing a differential slip generated on the rolling contact surface. Rolling guide device. 2. The curvature radius of a cross section of the ball rolling groove is set to
Set to about 0.52 to 0.505 times the diameter of the ball
The rolling guide device according to claim 1, wherein
Place. 3. The method according to claim 3 , wherein the ball is provided with a preload.
It is characterized by adjusting the initial contact area and differential slip amount of
The rolling guide device according to claim 1 or 2, wherein: 4. The method of manufacturing a ball according to claim 1, further comprising:
Pre-loaded as oversized balls
The rolling guide device according to claim 3. 5. The formula S = {π (d1-d2) / πd1} × 1
00 (where S is the differential slip ratio and d1 is the contact surface
The distance between the center and d2 indicates the distance of the long axis end).
Differential slip ratio of the ball rolling groove with the radius of curvature (R)
Relationship with ratio (R / Da) to ball diameter (Da)
When expressed by the following equation, the differential slip ratio of the differential slip (S)
Is the ratio of the radius of curvature of the ball rolling groove to the ball diameter.
(R / Da) corresponds to the range of 0.52 to 0.505.
5. The method according to claim 1, wherein the predetermined range is set.
A rolling guide device according to any one of the above . 6. A track member, and slidable along the track member.
A moving member provided on the track member and the track member and the moving member.
Between the ball rolling grooves provided so as to face each other
Rolling guide with many balls interposed
In the apparatus, the shape of the ball rolling groove is a single arc, and the rolling contact surface of the ball with respect to the ball rolling groove is provided.
Axial friction can be adjusted using differential slip
Means having the formula S = {π (d1-d2) / πd1} × 1
00 (where S is the differential slip ratio and d1 is the contact surface
The distance between the center and d2 indicates the distance of the long axis end).
Differential slip ratio of the ball rolling groove with the radius of curvature (R)
Relationship with ratio (R / Da) to ball diameter (Da)
When the differential slip ratio (S) is expressed as
Ratio of radius of curvature of rolling groove to ball diameter (R / D
a) is set in the range corresponding to the range of 0.52 to 0.505.
Rolling guide device characterized by the fixed.