JPH0228008B2 - MUGENSHUDOBEARINGUYUNITSUTO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a raceway groove in the form of a circular arc groove is formed in the bearing block, which is provided inwardly on both sides of the movable table, and a load ball traveling in the raceway groove is formed in the bearing block. The present invention relates to an endless sliding bearing unit in which a receiving raceway groove is formed on one side of the way, and the way is provided in a bed facing the bearing block.

Conventionally, as shown in FIG. 1, a finite linear bearing unit has a track base on the left and right sides of a bed 5, a track base on the inside of a movable table 6, and bolts 7, 8.
Then, the ball guide 9 is set between both tracks.

In addition, the second infinite linear bearing unit
As shown in the figure, tracks 11 and 12 are installed on the left and right sides of the bed 10, and ball guide bearings 14, 14 are fixed on both sides of the table 13 with bolts and nuts 15.
It is known as a thin and compact bearing that is capable of infinite linear motion because it is mounted in a fixed position.

However, in the above-mentioned finite and infinite linear motion bearing units, the raceway grooves that contact the balls have a gossic arch groove shape with four points of contact, so when a preload is applied or when a load is applied to a bearing with no clearance, the balls deform elastically. When a load is applied from above to a bearing with a gap, the ball deforms elastically and the four-point contact becomes uneven, causing a spin phenomenon.
This has the disadvantage that a large frictional resistance similar to sliding resistance occurs, and the life is significantly shortened due to abnormal wear.

In addition, since the balls contact the raceway grooves at four points, irregularities in the mounting surface or precision errors in the track base cannot be absorbed, and smooth movement cannot be obtained.

Therefore, since high-precision machining is an essential condition, the mounting surface must be machined with high precision on a highly rigid bed, etc., and a high-precision track base must also be installed, which is inconvenient.

The technical problem of the present invention is that machining errors and installation errors between the movable table and the bearing blocks installed opposite to each other on both sides are absorbed, and furthermore, by applying a preload to the bearing blocks, the load ball raceway groove and the load In addition, the raceway grooves for both load balls are formed at 45 degrees with respect to the horizontal plane, and these grooves are formed in circular arc grooves to prevent differential sliding of the load balls. In addition, the bearing blocks are formed in the same shape on both sides, thereby providing a low-cost infinite sliding bearing unit that requires fewer machining steps.

The structure of the present invention, that is, the technical means for solving the above technical problem is as follows.

(A) Bearing blocks are mounted on opposite sides of the movable table, and a bearing is formed on one side of the bearing block, and a raceway groove for a load ball corresponding to the bearing is formed on one side of the way. The two ball rows arranged between the block and the track are placed in a cage,
In an endless sliding bearing unit that is held by a side cover and circulated through a no-load ball guide hole formed in a bearing block, (B) the bearing has a circular arc that guides two rows of balls; A raceway groove for a loaded ball having a shape, and guide holes for a non-load ball are formed at arbitrary intervals in succession to the raceway groove and the U-groove for direction conversion.

(C) Slits are formed parallel to each other on the inner V-shaped inclined sides of the W-shaped retainer that is placed over the load ball raceway grooves of the bearing.

(D) The side cover attached to the end face of the bearing block has a direction changing U that guides the ball from the loaded ball raceway groove to the non-load ball guide hole.
Grooves are formed.

(E) A protruding portion having a substantially triangular cross section is formed on the side of the track corresponding to the raceway groove for the load balls of the bearing, and the raceway groove for guiding two rows of balls above and below the protruding portion is formed in the axial direction. be formed at the top and bottom.

(F) The track base is disposed at a required location on the bed parallel to the axis of the bearing.

That's all (A). (B). (C)． (D). An object of the present invention is to provide an infinite sliding bearing unit characterized by having (E) and (F) as constituent elements.

The above technical means works as follows.

Each raceway groove of the bearing block and raceway mounted opposite to each other on both sides of the movable table has a circular arc groove, so the load ball running between both raceway grooves makes two-point contact in the contact angle direction. Therefore, the load ball is elastically deformed, a wide contact width is obtained, and even if there is some deviation in the mounting surface, it is absorbed inside the bearing, resulting in natural and smooth movement.

In addition, one retainer is formed to have a roughly W-shaped cross section, and slits smaller than the diameter of the balls are formed parallel to the inwardly inclined sides, so in addition to holding the loaded balls, the loaded balls can also be held by force. It also has the function of guiding the ball smoothly without any problems, and since the guide hole for the no-load ball is formed in the bearing block, the overall structure is simple and can be simplified without reducing the strength of each member. Therefore, it has the effect of reducing manufacturing costs.

Next, an embodiment of the technical means of the present invention will be described based on FIGS. 3 to 9.

Reference numeral 101 denotes a movable table that can move forward or backward with respect to the bed 401;
is the movable table 101 as shown in phantom lines.
Bearing blocks 201 and 2 are installed inwardly on both sides of the
02 mounting step portions 102 and 103 are respectively formed in the axial direction.

The stepped portions 102 and 103 form a back surface 107 corresponding to the front surface 106 of the movable table 101.

The bearing blocks 201 and 202 are made by forming a shaft into a desired shape by drawing a steel material and cutting it into a desired size.
Bearings 203, 204 in which load ball raceway grooves 208, 209 are formed on one side of the bearings 01, 202, that is, on the track base side, and a through hole 245 for mounting the bearing blocks 201, 202 on the movable table side are integrally formed. Furthermore, the bearings 203 and 204 are formed with load ball raceway grooves 208 and 209 for guiding two balls 207.

The load ball raceway grooves 208, 209 are aligned with the horizontal plane passing through the axes of the bearings 203, 204.
The raceway grooves 208 and 209 are formed vertically in parallel with the 45 degree angle, and the raceway grooves 208 and 209 are in two-point contact with the circular arc groove, and the radius of curvature of the raceway grooves 208 and 209 is approximately 52 to 53 times the diameter of the ball. % is most preferable.

In addition, the bearings 203 and 204 are arranged at right angles to the horizontal plane passing through their axes and at an arbitrary interval.
Guide holes 210 and 211 for unloaded balls, which are slightly larger than the ball diameter, are formed vertically in parallel.

The balls 207 running in the loaded ball raceway grooves 208 and 209 are connected to the non-load ball guide hole 21.
Direction changing U grooves 212 and 213 for changing the direction to 0 and 211 are formed on the end faces, respectively. (Refer to Fig. 8) Reference numeral 215 denotes a retainer having a substantially W-shaped cross section and integrally formed by punching from a steel plate, and the retainer 215 corresponds to the load ball raceway grooves 208 and 209 of the bearings 203 and 204. Inward slope side 216,2
Slits 218 and 219, which are slightly smaller in diameter than the ball 207, are formed vertically in parallel to the axial direction in the slit 17, and tongue pieces 23 for scooping up the ball 207 are provided at both ends of the slits 218 and 219.
4,235 (see FIG. 10) are formed.

The outer inclined sides 224 and 225 of the retainer 215 are the left and right inclined surfaces 228 of the bearings 203 and 204,
229 via screw 220.

Reference numerals 241 and 242 are through holes formed as necessary in the outwardly inclined sides 224 and 225 of the retainer 215, through which the screws 220 are inserted.

Reference numerals 230 and 231 indicate side covers integrally molded from plastic or die-cast alloy, and the side covers have substantially W-shaped inner and outer inclined sides 239 and 240 and mounting holes 2.
43, 244 are formed, and the running balls are further transferred from the loaded ball raceway grooves 208, 209 to the unloaded ball guide holes 210, 211 or from the unloaded ball guide holes 210, 211 to the loaded ball raceway grooves 208, 209. Direction changing U grooves 232 and 233 are formed to change the direction to
The side covers 230, 230, 231, 231 are attached with bolts 236 before and after the bearing blocks 201, 202.
Fixed via. (See FIGS. 6 and 7) Reference numerals 243 and 244 designate a plurality of mounting holes formed in the side cover 230 through which bolts 236 are inserted.

Reference numeral 245 indicates a through hole formed in the mounting portions 205, 206 of the bearing blocks 201, 202, and mounting bolts 246, 2 inserted through the through hole 245.
46...(one part not shown)
01 female threads 108, 108... (one part not shown)
Fixed.

Reference numeral 248 denotes a bolt screwed into a female thread 110 formed on the side wall 109 of the movable table 101. By tightening the bolt 248, the bearing block 202 is pressed toward the track base 302, and a preload is applied to the two ball rows. Can be applied. (One part is omitted) Reference numerals 301 and 302 are track bases, and the track base 3 has through holes 305, 305... formed at required intervals.
01 and 302 are fixed to the required locations of the bed 401 via mounting bolts 308, and are attached to the track base 3.
01, 302 are formed with protrusions having a substantially triangular cross section, and load ball raceway grooves 303, 304 that guide two rows of balls above and below the protrusions serve as load ball raceways of the bearings 203, 204. Groove 2
Formed parallel to the location corresponding to 08, 209,
Similar to the raceway grooves of the bearings 203 and 204, the circular arc grooves are formed in two-point contact.

In addition, the inner side walls 30 of the tracks 301 and 302
6, 307 are formed to match the vertical walls 404, 405 of the positioning projections 402, 403 formed on the bed 401.

Reference numeral 111 denotes a ball screw, and a nut (not shown) that moves forward or backward as the ball screw 111 rotates is attached to the back surface of the movable table 101 side.

Regarding the action, the rotation of the ball screw 111 moves the movable table 1
01 moves forward or backward, the bearing blocks 201 on both sides of the movable table 101,
The two load balls 207, 207 between the track base 202 and the track base 301, 302 smoothly roll through the direction changing U grooves 232, 233 of the side covers 230, 231 and into the guide holes 210, 211 for non-load balls. circulates. (See Figures 4 and 5) Furthermore, the two rows of load balls are in angular two-point contact due to the circular arc-shaped raceway grooves, and a preload is applied to the rows of load balls by tightening the bolts 248 on the movable table side. Since each ball is in two-point contact with the raceway groove, there is no differential sliding, and the ball has a special effect of being able to perform good rolling motion.

Furthermore, the material of the bearing block is made from square lumber, and the bearings are formed symmetrically to each other, making it suitable for mass production, extremely useful for cost reduction, and compatible. Since it can be attached to a movable table with a holder, it is not affected by the size of the movable table.

Furthermore, since the retainer is W-shaped and left-right symmetrical, it is easy to manufacture and has the advantage of further increasing rigidity.

Furthermore, since the bearing is formed on one side of the bearing block, a space is formed in the center by arranging the bearing block on both sides of the movable table.

One of the drive mechanisms, such as a ball screw, can be incorporated using the space.

[Brief explanation of drawings]

FIGS. 1 and 2 are sectional views of a known bearing unit, FIG. 3 is a partially omitted sectional view of the infinite sliding bearing unit of the present invention, and FIG. 4 is a cage and a slit running in the cage. FIG. 5 is a sectional view showing how the retainer and side cover are attached. FIG. 6 is a plan view of the infinite sliding bearing unit of the present invention. FIG. 7 is a plan view of the infinite sliding bearing unit of the present invention. FIG. 8 is a side view of the infinite sliding bearing unit, FIG. 8 is a perspective view of the bearing block, FIG. 9 is a perspective view of the side cover attached to the bearing body, and FIG. 10 is a perspective view of the retainer attached to the bearing body. 101: Movable table, 201, 202: Bearing block, 203, 204: Bearing body, 208, 209: Raceway groove for load ball, 21
0,211: Guide hole for no-load ball, 230,2
31: Side cover, 301, 302: Track base.

Claims (1)

[Scope of Claims] 1 (A) Bearing blocks 201 and 202 are mounted on opposite sides of the movable table 101, and the bearing blocks 20
Bearings 203, 204 on one side of 1,202
are formed and the bearings 203, 20
Load ball raceway grooves 303, 30 corresponding to 4
4 is formed on one side of the tracks 301 and 302,
The blocks 201, 202 and the tracks 301, 3
The two rows of balls arranged between the cage 21
5. In the endless sliding bearing unit held by the side cover 231 and further circulated through the no-load ball guide holes 210, 211 formed in the bearing blocks 201, 202, (B) the bearings 203, 204; shows circular arc-shaped load ball raceway grooves 208 and 209 that guide two rows of balls, and the raceway groove 20.
8, 209 and the guide holes 210, 211 for unloaded balls are connected to the U grooves 212, 213 for direction conversion.
are formed at arbitrary intervals. (C) Inner V-shaped inclined sides 216, 217 of the W-shaped retainer 215 that are placed over the load ball raceway grooves 208, 209 of the bearings 203, 204.
Slits 218 and 219 are formed parallel to each other. (D) The side covers 230, 231 attached to the end faces of the bearing blocks 201, 202 move the balls 20 from the loaded ball raceway grooves 208, 209 to the non-load ball guide holes 210, 211.
Direction changing U groove 23 that guides 7, 207...
2,233 is formed. (E) A track base 30 corresponding to the load ball raceway grooves 212, 213 of the bearings 203, 204.
A protrusion having a substantially triangular cross section is formed on the side of 1 and 302, and load ball raceway grooves 303 and 304 guide two rows of balls above and below the protrusion.
are formed above and below in the axial direction. (F) The tracks 301 and 302 are arranged at required locations on the bed 401 parallel to the axes of the bearings 203 and 204. That's all (A). (B). (C)． (D). An infinite sliding bearing unit characterized by having (E) and (F) as constituent elements.