JPH06105090B2 - Linear sliding bearing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to, for example, a linear slide that linearly guides a movable body to be slid in a slide part of a machine tool such as an NC machine or an industrial robot. It relates to dynamic bearings.

[Prior Art] For example, when a workpiece is machined by a machine tool or the like, either the machine tool side or the workpiece side is fixed and the other is moved. For this, a linear sliding bearing is usually used.

As a linear sliding bearing used for this purpose, a raceway having a rolling surface on which rolling elements roll along the axial direction, a load rolling surface facing the rolling surface, and this load rolling surface Between the load rolling surface of the sliding table and the rolling surface of the raceway, which circulates in the above-mentioned endless track, and a slide table consisting of an unloaded rolling path connecting both ends of It is generally made up of a large number of rolling elements that bear a load. In this type of linear sliding bearing, loads in four directions orthogonal to the axial direction of the raceway can be applied, and by applying preload to the rolling elements, sliding bearings in the four directions can be obtained. By increasing the rigidity with respect to the way, it is possible to suppress chattering and vibration generated between the tool on the machine tool side and the workpiece during machining as much as possible to improve machining accuracy.

On the other hand, in the axial direction of the way, the load cannot be applied for the original purpose of the linear sliding bearing, which is to reduce the sliding resistance and smoothly guide the movable body in a straight line. Regarding the rigidity of the guideway in the axial direction, it is necessary to rely on the rigidity of the feed drive system that feeds the linear guides, and in order to obtain high rigidity, the size and cost of the device increase as the size of the feed drive system increases. There is a problem that ups and the like occur.

Therefore, as a solution to such a problem, Japanese Unexamined Patent Publication
A linear sliding bearing disclosed in Japanese Patent Laid-Open No. 63-169241 has been proposed. Specifically, as shown in FIG. 16, a recess is formed on the surface of the slide base a facing the track b, and the pressing force is applied to the facing surface of the track b in the recess. By disposing a pressure vessel c for applying the pressure vessel and applying an arbitrary pressure to the pressure vessel c, the friction plate d attached to the pressure vessel c presses the raceway b and the raceway of the slide stand a. The sliding resistance with respect to b is increased. According to this linear sliding bearing, the sliding resistance of the sliding table a is freely adjusted by adjusting the pressure applied to the pressure vessel c, so that the bearing itself has an arbitrary rigidity in the axial direction of the track b. Therefore, it is possible to reduce the load on the feed drive system, which has been a problem of the conventional technology.

[Problems to be Solved by the Invention] By the way, a sliding base of a straight-rigging bare rig used for a sliding portion of a machine tool or the like has a high rigidity because a heavy load of the machine itself or an impact load due to processing acts on the sliding base. However, in the proposed linear sliding bearing, the pressure vessel c having airtightness is housed in the slide base a and the friction plate d contacting the raceway b is separated from the pressure vessel c. In order to provide the slide base a, a relatively large concave portion must be formed in the slide base a. Therefore, the thickness of the slide base a is reduced, and the rigidity of the slide base a itself is reduced. This is one of the factors that hinder the achievement of the original purpose of strengthening rigidity in all directions. Further, if it is attempted to maintain the rigidity of the slide base a, the thickness of the slide base a becomes unnecessarily large, and if the mounting position of the pressure vessel c is above the track base b, the bearing cross-section height becomes high. There is a problem that the moment load acting on the slide base a is increased, and when the disposition position is on the side of the track base b, the bearing disposition area is increased.

The present invention has been made in view of the above problems,
The purpose is not only to have rigidity in four directions orthogonal to the way, but also to give arbitrary rigidity in the way of the way and adjust it, and to make it compact. To provide a simple linear sliding bearing.

[Means for Solving the Problems] In order to achieve the above object, the linear sliding bearing of the present invention has a rolling surface on which rolling elements such as balls or rollers roll along the axial direction of a machine. The raceway is provided with a raceway fixed to a device, a load rolling surface facing the rolling surface, and an unloaded rolling passage that connects both ends of the load rolling surface to each other. A slide table that moves along
In a linear sliding bearing composed of a number of rolling elements that circulate in the endless track and apply a load between the load rolling surface of the sliding table and the rolling surface of the track table, the sliding table Is
A pressure plate is formed in cooperation with one surface of the slide table, and a brake plate is provided which comes into contact with or separates from the track surface according to the fluid pressure acting on the pressure chamber, and the direction in which the brake plate presses the track plate. It is characterized in that a load acting in the opposite direction can be applied.

In such a technical means, the sliding base has an endless track in which rolling elements circulate and can freely slide on the base, and a direction in which the braking plate presses the base. If a load in the opposite direction can be applied, the structure or the like may be appropriately selected. For example, the structure has a horizontal part and a pair of sleeve parts that hang downward from both sides of the horizontal part. A concave portion on the side, each of the sleeve portions is provided so as to have a load rolling surface along the longitudinal direction of the inner surface of the sleeve portion so as to straddle the raceway, and a sleeve portion that hangs from the horizontal portion and one end thereof. And a load rolling surface along the longitudinal direction of the lower surface of the horizontal portion and the inner surface of the sleeve portion along the longitudinal direction. Or a substantially rectangular strip having a load rolling surface along the longitudinal direction of its side surface,
Various structures are conceivable such as those arranged on the side surface of the way.

As for the above-mentioned endless track, the number of threads, the inclination angle of the load rolling surface, etc. may be appropriately changed depending on the intended use of the bearing, the structure of the sliding base, etc., and the formation of the unloaded rolling passage is possible. As the method, it is possible to appropriately select and design, for example, a method of forming an unloaded rolling hole in the sliding base or a method of forming the rolling element holder from the outside by attaching the rolling element holder.

Further, as the rolling element circulating in the endless track, a cylindrical roller, a barrel roller, a ball or the like may be appropriately selected, and when a cylindrical roller is used, the load rolling surface of the sliding table and the raceway are The rolling surface should be flat, and when using barrel rollers and balls, the load rolling surface and rolling surface should be curved surfaces that are slightly larger than the axial curvatures of the rollers and balls. preferable.

Further, if the braking plate has a pressing surface for pressing the surface of the raceway and can form a pressure chamber in cooperation with one surface of the sliding base, its design, shape, etc. may be appropriately changed. The pressure chamber may be formed by forming a recess in the braking plate and sealing the space between the recess and one surface of the slide base, or, conversely, forming a recess on the slide base side. It may be done. Further, from the viewpoint of omitting the retainer of the load rolling element rolling on the load rolling surface and simplifying the device configuration, the braking plate is a rolling element rolling on the load rolling surface of the slide base. Is located in a grooved groove formed with one surface of the braking plate as a side surface, and the opening width of the grooved groove is the length in the rotation axis direction of the rolling element (its diameter in the ball, its diameter in the roller). It is preferable that it is attached to the slide base so as to be smaller than the axial length) and also has a function as a retainer for the load rolling element. Furthermore, the braking plate can be pressed anywhere on the raceway surface, but when a large radial load is applied to the slide table, the raceway is designed to bring the rigidity values of the bearing in the radial and reverse radial directions closer to each other. It is preferable to apply a load in the reverse radial direction to the slide table by pressing the top surface of the table, and when the braking plate presses the side surface of the track table, the slide table is displaced laterally with respect to the track table. In order to prevent this, it is preferable to press both the left and right side surfaces of the track simultaneously.

Further, as a mode in which the brake plate presses the raceway base, both members are engaged so that the brake plate and the slide base can come into contact with and separate from each other, and one surface of the brake plate facing the raceway is the raceway. The pressing force may be applied by contacting the entire surface of the base, or both ends of the braking plate may be fixed to the sliding base and fluid pressure may be applied to the central part to bend the braking plate in the longitudinal direction. Therefore, the pressing force may be applied by contacting only the central region with the track.

[Operation] The braking plate provided on the slide base comes into contact with or separates from the surface of the raceway according to the fluid pressure acting on the pressure chamber, and presses this when it comes into contact with the surface of the raceway. Since the slide base can apply a load in the direction opposite to the direction in which the brake plate presses the raceway base, the brake plate is pressed against the surface of the raceway base, and a frictional force is generated between the brake plate and the raceway base to cause sliding. The sliding resistance when the platform slides on the track is increased. In this case, since the pressure chamber is formed by using one surface of the slide table as the pressure partition wall, a pressing mechanism for pressing the track table is formed only by disposing the braking plate in the gap between the slide table and the track table. Therefore, it is not necessary to provide a special space for disposing the pressing mechanism.

[Examples] Hereinafter, the linear sliding bearing of the present invention will be described in detail with reference to the accompanying drawings.

◎ First Embodiment As shown in FIGS. 4 to 5, the linear sliding bearing in this embodiment has a horizontal portion 1a and left and right sleeve portions 1b hanging from both ends thereof, and has a substantially inverted C-shaped cross section. A slide base 1 formed with a concave portion on the lower surface, and left and right sleeve portions 1b of the slide base 1.
A pair of ball cages 6 attached to the lower ends, and a rail 2 fixed to a mechanical device or the like with a fixing bolt as a fixing means.
And a large number of balls 4 which circulate in a ball endless track formed on the slide table 1 and apply a load between the slide table 1 and the track table 2, the lower surface of the horizontal portion 1a, and the track table. 2 and a braking plate 5 that is located in a gap between the upper surface and moves appropriately up and down according to the pressure of the fluid introduced from the sliding base 1 side to press the surface of the track base 2.

As shown in FIGS. 5 and 6, the sliding base 1 has an upper ball endless track and a lower ball endless track along the axial direction on the lower surface side of the horizontal portion 1a and the inner surface sides of the left and right sleeve portions 1b, respectively. The load rolling surfaces 11, 12 of the track are formed in a curved shape with a radius of curvature larger than the radius of the ball 4. In addition, the left and right sleeves 1b have load rolling surfaces of the upper ball endless track and the lower ball endless track.
Unloaded rolling holes 13 corresponding to 11 and 12 are formed.
The four load rolling surfaces 11 and 12 are inclined at a predetermined angle so as to face the upper rolling surface 21 and the lower rolling surface 22 of the track 2 when the bearing is assembled. or,
Mounting portions 1c are provided at both ends of the sliding base 1 in the width direction, and mounting holes 14 through which mounting bolts pass are formed from the lower surface to the upper surface of the mounting portion 1c. Further, the lower surface of the horizontal portion 1a of the slide base 1 is a mounting portion of the brake plate 5 to the slide base 1, and an oil hole 15 through which oil for applying pressure to the brake plate 5 comes in and out is provided in the central portion thereof. A mounting hole that penetrates vertically from the upper surface to the lower surface and is engaged with a screw 9 that penetrates the braking plate 5.
16 are formed.

A lid 3 made of synthetic resin is provided at each longitudinal end of the slide base 1.
Are fixed with fixing bolts 31. Further, the lid body 3 has a groove ball swivel portion (not shown) which connects and connects the loaded rolling surfaces 11, 12 formed on the slide base 1 and the corresponding unloaded rolling holes 13 with each other. ) Has been formed.

The ball cage 6 is formed into a substantially L-shaped cross section by press molding of a metal plate or injection molding of hard synthetic resin, and the tip thereof has a load rolling surface 12 of the lower ball endless track. Locking claw that prevents the ball 4 rolling over from falling off
61 is provided. The ball cage 6 is screwed to the lower ends of the left and right sleeve portions 1b of the sliding base 1 by screws 62, and the load rolling surfaces 12 formed at the lower ends of the left and right sleeve portions 1b, respectively.
Also, together with the unloaded rolling hole 13 and the ball turning portion formed in the lid 3, a ball endless track is formed to guide each ball 4.

On the other hand, the raceway 2 has a cross-sectional shape in which both side surfaces of the rectangle are cut out in a trapezoidal shape and both left and right shoulders are cut out, and the downward inclined surface of these trapezoidal cutouts is the inner surface of the sliding base sleeve portion 1b. Lower rolling surface 22 corresponding to the lower ball endless track provided on the side
On the other hand, the upward slope of the shoulder notches is the horizontal part of the slide base.
The upper rolling contact surface 21 corresponds to the upper ball endless track provided on the lower surface side of 1a. Further, a fixing bolt mounting hole 23, through which a fixing bolt screwed to the fixing portion penetrates, is formed in the central portion of the way 2 perpendicularly to the upper surface of the way 2 and at appropriate intervals in the longitudinal direction of the way 2. It is set up.

As shown in FIGS. 5 and 6, the braking plate 5 is a substantially rectangular flat plate positioned in the gap between the lower surface of the sliding base horizontal portion 1a and the upper surface of the rail 2 at the time of assembly. It is made of a softer metal material and has a function of pressing the surface of the way 2 as required, and a function of preventing the balls 4 rolling on the upper and lower rolling contact surfaces 21 of the way 2 from falling off and holding them. ing. As shown in FIG. 7, FIG. 8 and FIG. 9, a concave oil pocket is provided on the upper surface of the braking plate 5 for filling the oil coming in and out through the oil hole 14 formed at the center of the sliding base horizontal portion 1a. While 51 is formed, the lower surface of the braking plate 5 is a pressing surface 52 that comes into proper contact with the upper surface of the raceway 2. Further, a through hole 54 through which a screw 9 that is screwed to the lower surface of the slide base horizontal portion 1a penetrates is formed vertically in the center in the width direction from the lower surface to the upper surface.

As shown in FIG. 10, the braking plate 5 thus formed is fitted with an O-ring 7 for preventing oil leakage on the inner peripheral edge of the oil pocket 51, and then a disc spring washer 8 is interposed. The screw 9 is passed through the through hole 54 from the lower surface side, and the screw 9 is inserted into the mounting hole 15 provided on the lower surface of the slide base horizontal portion 1a.
Is attached to the slide base 1 by engaging with. At this time, the screw 9 is elastic enough to be elastically deformed by the pressure of the fluid acting on the brake plate 5 by the disc spring washer 8 interposed between the top of the screw 9 and the lower surface of the brake plate 1.
When the O-ring 7 is tightened to such an extent that it is in close contact with the lower surface of the slide base horizontal portion 1a at all times and no pressure is applied to the brake plate 5, the elastic force of the disc spring washer 8 causes the brake plate 5 to move to the slide base horizontal portion. Make sure that it is pushed up to the bottom side of 1a. By mounting the braking plate 5 on the slide base 1, the load rolling surface 11 of the upper ball endless track has a recess formed so that the opening width is smaller than the diameter of the ball 4 rolling on the load rolling surface 11. The ball 4 is positioned in the groove, and when the slide base 1 is removed from the track base 2, the ball 4 is locked in the opening of the groove and is prevented from falling off.

In the linear sliding bearing of this embodiment configured as described above, the raceway 2 is fixed to a mechanical device or the like with a fixing bolt, and various machines are mounted on the slideway 1 sliding along the raceway 2. While mounting the table on which the equipment is placed with the mounting bolts,
A hydraulic device (not shown) driven in the oil hole 15 of the slide base 1 based on a command signal output from a control device (not shown).
Is used by applying an arbitrary hydraulic pressure to the oil pocket 51 of the brake plate 5 at a required place on the way 2.

At this time, when the oil pressure is not applied to the oil pocket 51, the braking plate 5 is pushed up toward the lower surface of the sliding base horizontal portion 1a by the elastic force of the disc spring washer 8, and Since the pressing surface 52 does not come into contact with the upper surface of the raceway 2, the sliding resistance of the slide table 1 sliding on the raceway 2 is the load ball 4
Therefore, the sliding table 1 can slide on the track 2 with a slight sliding resistance (see FIG. 11). Further, when the hydraulic pressure P is applied to the oil pocket 51, the braking plate 5 is pushed down by the hydraulic pressure, and the pressing surface 52 comes into pressure contact with the upper surface of the raceway 2, so that between the pressing surface 52 and the upper surface of the raceway 2. A frictional force is generated in the frictional force, and this frictional force is added to the sliding resistance, so that a large sliding resistance acts when the sliding base 1 slides on the raceway 2 (see FIG. 12).

As described above, in the linear sliding bearing of the present embodiment, the inner peripheral edge of the oil pocket 51 of the braking plate 5 and the horizontal portion of the sliding base are.
A pressure chamber is formed by sealing an O-ring 7 between the lower surface of 1a and a braking plate 5 that forms a partition of the pressure chamber.
Moves vertically and comes into direct contact with the track rail 2.

Therefore, it is possible to dispose a pressing mechanism capable of adjusting the pressing force on the slide table 1 by merely forming a slightly wider gap between the lower surface of the slide table horizontal portion 1a and the upper surface of the track table 2. It is possible to enhance the rigidity of the linear slide bearing in the two axial directions of the track base while maintaining the rigidity of the base 1 itself.

In the linear sliding bearing of this embodiment, balls are used as the rolling elements, but as shown in FIG. 13, the same effect can be obtained by using cylindrical rollers as the rolling elements. .

Second Example This example shows another example of the manner of mounting the braking plate 5 to the slide base 1.

In the first embodiment described above, the braking plate 5 is screwed to the slide base 1 by the screw 9 with the disc spring washer 8 interposed. In this case, the elastic coefficient of the disc spring washer 8 or the braking plate 5 Although there is a difference depending on the rigidity and the like, it has been found that when the hydraulic pressure is applied, the braking plate 5 is slightly bent and only the central portion of the pressing surface 52 tends to press the upper surface of the track way 2.

In view of this, in the present embodiment, the plate springs 10 are used to slide both ends of the braking plate 5 in the longitudinal direction so that the braking plate 5 brings the entire pressing surface 52 into contact with the track 2 when hydraulic pressure is applied. It is attached to the moving base 1 (see Fig. 13).

As shown in FIG. 14, the braking plate 5 used in this embodiment is basically the same as that used in the first embodiment, but notches for assembling the leaf springs 10 on both sides in the longitudinal direction thereof. A portion 55 is formed, and a step portion 56 for fixing the side end portion 10a of the leaf spring 10 is further provided.

Then, in this braking plate 5, the side end 10a of the leaf spring 10 is fixed to the stepped portion 56 by laser welding, and the other side end 10b of the leaf spring 10 is also laser welded to the slide base 1. By being fixed to the lower surface of the horizontal part 1a of the
Held in.

In addition, in this embodiment, since the essential parts other than the support of the braking plate 5 described above, that is, the sliding base 1, the raceway 2, etc. are common to the first embodiment, the first embodiment is shown in the drawings. The same reference numerals are given and their explanations are omitted.

Also in the linear sliding bearing of the present embodiment configured as described above, the operation is exactly the same as that of the first embodiment, that is,
By applying an arbitrary hydraulic pressure to the pressure chamber formed by the oil pocket 51 of the braking plate 5 and the lower surface of the horizontal portion 1a of the sliding base 1, the braking plate 5 moves up and down to make the upper surface of the track 2 hydraulic. It is pressed with a corresponding pressure.

Incidentally, in the linear sliding bearing in each of the above embodiments,
Although balls are used as the rolling elements, the same effect can be obtained by using cylindrical rollers as the rolling elements as shown in FIG.

[Advantages of the Invention] As described above, according to the linear sliding bearing of the present invention, when the sliding base slides on the track base without providing a special installation space in the sliding base. Since a pressing mechanism that adjusts the sliding resistance can be mounted on the slide base, the rigidity of the slide base can be enhanced without impairing the rigidity of the slide base, and the rigidity in each of the three dimensions can be enhanced. It is possible to obtain a compact linear sliding bearing.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a linear sliding bearing according to the present invention, FIGS. 2 and 3 are side views and a plan view thereof, and FIG. 4 is a linear sliding bearing according to the first embodiment. Fig. 5 is a perspective perspective view showing Fig. 5, Fig. 5 is a sectional view taken along line II of Fig. 3, Fig. 6 is a sectional view taken along line II-II of Fig. 3, and Fig. 7 is a plan view showing a braking plate according to the first embodiment. 8 is a sectional view taken along the line III-III in FIG. 7, FIG. 9 is a sectional view taken along the line IV-IV in FIG. 7, and FIG. 10 is an exploded perspective view showing the assembled state of the brake plate according to the first embodiment. FIG. 11 is a cross-sectional view of an essential part showing a state where hydraulic pressure is not acting on the brake plate, FIG. 12 is a cross-sectional view of an essential part showing a state where hydraulic pressure is acting on the brake plate, and FIG. 13 is a linear slide according to the present invention. FIG. 14 is a perspective perspective view showing a second embodiment of the dynamic bearing, FIG. 14 is a perspective exploded view showing an assembled state of the braking plate according to the second embodiment, and FIG. 15 is a linear sliding according to the first and second embodiments. Motive FIG. 16 is a front sectional view showing a case where a roller is used as a rolling element in the bearing, and FIG. 16 is a front sectional view showing a conventional linear sliding bearing equipped with a pressing mechanism for a rail. [Description of symbols] 1: Sliding base, 2: Rail base 3: Lid, 4: Ball (rolling body) 5: Braking plate, 6: Ball cage 7: O-ring, 8: Disc spring washer 10: Leaf spring , 11, 12: Rolling surface 13: Unloaded rolling hole (rolling passage without load) 21, 22: Rolling surface

Claims (8)

[Claims] 1. A track base fixed to a machine or the like having a rolling surface on which rolling elements such as balls or rollers roll along the axial direction, and a load rolling facing the rolling surface. Surface and an endless track consisting of an unloaded rolling passage that connects and connects both ends of this load rolling surface, and a slide table that moves along the track table and a slide table that circulates in the track. In the linear sliding bearing consisting of a number of rolling elements that apply a load between the loaded rolling surface and the raceway rolling surface, the sliding base works together with one surface of the sliding base. It is equipped with a brake plate that forms a pressure chamber and contacts or separates from the raceway surface according to the fluid pressure acting on this pressure chamber, and loads the load that acts in the direction opposite to the direction in which this brake plate presses the raceway. A linear sliding bearing characterized by being possible. 2. The linear sliding bearing according to claim 1, wherein the braking plate has a recess for forming a pressure chamber in cooperation with one surface of the sliding base. 3. A braking plate is movably attached to a slide base to form a pressure chamber, and is separated from the slide base and presses the surface of the track base according to the fluid pressure acting on the pressure chamber. The linear sliding bearing according to claim 1. 4. The linear sliding bearing according to claim 3, wherein both sides of the braking plate are supported by the slide base via leaf springs. 5. A braking plate is fixed to a slide base near both ends in the lengthwise direction to form a pressure chamber, and the raceway surface is caused by the lengthwise bending caused by the fluid pressure acting on the pressure chamber. The bearing for linear sliding according to claim 1, wherein the bearing is pressed. 6. A slide base has a horizontal portion and a pair of sleeve portions that hang downward from both sides thereof, and is provided with a recessed portion on the lower surface side, and both sleeve portions are provided along the inner surface longitudinal direction thereof. And a pair of left and right upper load areas and a lower load area, and the braking plate is disposed on the lower surface side of the horizontal portion and is in contact with or separated from the facing track upper surface.
The bearing for linear sliding described. 7. A load rolling surface forming an endless track is provided in a groove groove formed with one surface of a braking plate as a side surface, and when the rolling element rolling in the groove groove is a ball, 2. The linear sliding bearing according to claim 1, wherein an opening width of the groove is formed to be smaller than at least a diameter of the ball. 8. A load rolling surface forming an endless track is provided in a groove groove formed with one surface of a braking plate as a side surface, and when the rolling element rolling in the groove groove is a roller, 2. The linear sliding bearing according to claim 1, wherein the groove width of the groove is smaller than at least the axial length of the roller.