JPS638328B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to the improvement of a linear bearing unit, which is capable of reciprocating while supporting a sliding surface such as the table side of an industrial machine or a conveying device. A linear bearing in which a ball hole is formed in a bearing case and a raceway groove is formed directly in the cylindrical inner cavity of the bearing case, and a raceway base having a corresponding raceway groove formed therein is inserted through the balls. Regarding units.

"Conventional technology" Generally used linear bearings are ball bushing types, so they can support vertical loads, but they can only support a fraction of moment loads and upward loads. .

Further, a female member having a substantially V groove formed on the axially outward side of the male member and a corresponding substantially V groove formed on the axially inward side of the male member, and a round bar between the two members. A slide assembly is known in which a ball bushing is fitted in sliding contact with the outer periphery of the slide assembly. (Refer to Japanese Patent Publication No. 45-31202.) However, although the outer casing of the ball bush of the slide assembly is held in the groove of the female member, and the female member is formed so that a preload is applied from the lower side, Since the balls of the ball bushing slide on the curved surface of the round bar, the vertical load is a fraction of that of the ball bushing mentioned above, so it can be used for machines with relatively small loads, but it can be used for machines with relatively small loads, but it can be used for machines with large loads such as machine tools. The field has deficiencies that make it unusable.

Therefore, in order to solve the above-mentioned defects, the inventor of the present invention provided ball rows on the bearing body in opposite left and right directions in the axial direction.
A linear bearing with a retainer has been developed in which a side cover having a U-shaped groove for changing the direction of the balls, which corresponds to the ball row, is fitted and fixed to the end face of the bearing body. (Refer to Japanese Unexamined Patent Publication No. 55-72912) ``Problem to be solved by the invention'' However, when the length of the linear bearing body is changed, the retainer must also be made to have the same dimensions proportionally. In order to reduce the cost of this type of bearing, which is often produced in small quantities in a wide variety of colors, it has become one of the most popular colors.

Furthermore, linear bearings generally have an appropriate clearance selected depending on the application and are given a preload.

However, it is difficult to apply preload to various machines after they have been set.

Therefore, the technical objective of the present invention is to ensure that bearing performance does not deteriorate even if the retainer is omitted, and that an optimal preload can be applied to the load balls in the four groove rows even after they are installed in various machines. Take it as a challenge.

"Means for Solving the Problems" The present invention solves the above-mentioned problems by: (A) Among the four load ball raceway grooves, the upper left and right load ball raceway grooves pass through the center of the bearing case. Approximately 45 degrees above the horizontal line X-X'
Arranged symmetrically with an angle of degrees.

(B) The lower left and right load ball raceway grooves are arranged symmetrically with respect to the horizontal line That's what I'm doing.

(C) A slit is formed in the axial direction from the end surface of the bearing case between the lower relief ball hole and the lower load ball raceway groove.

(D) A pressurizing screw hole opening into the slit is formed at right angles to the direction of the slit from the side wall of the bearing case.

(E) The side cover fixed to the end face of the bearing case has an annular recess that matches the annular convex part and a direction changing U that crosses the annular recess.
A ball guide tongue piece is integrally formed below the U-shaped recess and the direction changing U-shaped recess.

(F) A track base having four R-shaped raceway grooves formed in the axial direction facing the load ball raceway grooves of the bearing case is fitted into the bearing case via the balls.

That's all (A). (B). (C)． (D). The object of the present invention is to provide a linear bearing unit that satisfies the conditions (E) and (F).

``Function'' The present invention provides relief ball holes in the bearing case and deep raceway grooves in the inner circumferential surface of the bearing case, thereby increasing the contact area between the load balls and the raceway grooves, and The angle formed by connecting the left and right raceway grooves to the center is a right angle, and edge loads (also called edge extreme pressure loads) do not act on the raceway grooves. Preload (also called preload) can be applied to the load balls in the groove row.

In addition, raceway grooves are formed on the inner peripheral surface of the outer cylinder that fits into the bearing case, and side covers (also called return plates) fixed to both end surfaces of the bearing case are formed on the outer cylinder end surfaces. An annular recess that matches the annular protrusion, a half-moon-shaped U-shaped recess for changing the direction of the ball that matches the four groove rows of the outer cylinder, and a tongue piece on the track base side are formed, so that the four grooves of the track base are formed. Together with the row of grooves, a circulating track is formed that can guide the ball over the entire surface.

Further, the bearing case has a circular inner cavity formed in a rectangular square piece, and four raceway grooves for load balls are formed in the inner cavity parallel to the longitudinal direction at predetermined angular intervals on the same circumference. Therefore, even if there is an error in the alignment (indexing) of the raceway grooves or in the raceway grooves of the way, the contact area of the raceway grooves becomes wider and the required contact angle can be maintained, while the preload (preload) is reduced. can also be applied easily.

"Embodiments" Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of the linear bearing unit of the present invention, FIG. 2 is a front view of the linear bearing unit of the present invention, and FIG. 3 is a cross-sectional front view taken along line A-A in FIG.
Figure 4 is a cross-sectional front view taken along the line B-B in Figure 3, Figure 5 is a cross-sectional front view of the track, Figure 6 is a partial cross-sectional side view of the linear bearing unit, and Figure 7 is a partial cross-section of the bearing case. A side view, FIG. 8 is a front view of the bearing case, FIG.
FIG. 10A is a sectional view taken along line D-D in FIG. 9A, and FIG. 10B is a bottom view showing the shape of the tongue piece of the side cover.

Reference numeral 1 in Figures 1 to 3 and Figure 8
00 is a bearing case, and the bearing case 100 is a rectangular steel member with raceway grooves 102, 1 for upper and lower loaded balls having R-shaped upper and lower load ball raceway grooves 102 and 1 in a cylindrical cavity 101 having approximately the same radius of curvature as the balls.
03, 104, and 105 are formed.

Raceway grooves 102 to 105 for the upper and lower load balls
is a horizontal line
They are arranged symmetrically at a position approximately 45 degrees upward with respect to
04 and 105 are arranged symmetrically at 15 degrees with respect to the horizontal line X-X' passing through the center of the bearing case 100.

Reference numerals 106 and 107 denote annular convex portions for ball return guides formed on both end surfaces of the bearing case 100, and inner diameter edges 108 of the convex portions 106 and 107
are formed continuously with the raceway grooves 102 to 105. (See FIG. 7) Reference numerals 109, 110, 111, and 112 are upper and lower relief ball holes having slightly larger diameters than the balls in the radial direction of the cylindrical cavity 101 of the bearing case 100. Lower relief ball hole 109-1
12 are arranged through each on a straight line formed by connecting the four raceway grooves 102 to 105 and the center O, and the upper and lower relief ball holes 1
09 to 112 are continuous with the outer diameter edge 113 of the annular convex portion.

114 is a slit formed in the bearing case 100 by electrical discharge machining;
is located between the relief ball hole 111 and the lower load ball raceway groove 104, and the lower relief ball hole 1
It is formed in the axial direction close to the 11 side, and the narrower the width, the more suitable it is, and the most suitable width is around 0.5 mm.

The slit 114 is formed in the bearing case 100.
The upper limit 162 of the slit 114 is formed parallel to the side wall of the upper relief ball hole 10.
9, a lower limit 163 cuts through the bottom wall 164 of the bearing case.

Therefore, as the hexagonal bolt 161 advances, the right side toward the slit is bent, and a preload is applied to the load ball raceway groove.

The portion of the lower ball of the bearing case 100 sandwiched between the left and right relief ball holes 111 and 112 is cut at an angle of about 40 to 45 degrees with respect to the vertical line Y-Y' and the bottom horizontal line Z-Z' of the bearing case 100. However, open end surfaces 115 and 116 are formed in the longitudinal direction.

Further, mounting holes 117, 118, 119, 119 are provided on the upper surface of the bearing case 100, and side lid mounting holes 126 are provided on both side end surfaces 120, 121 for screwing the flat portions 124, 125 of the side lids 122, 123. Female threads are formed with taps in 127, 128 and the side cover mounting hole.

Next, reference numerals 112 and 123 in FIG. 4, FIG. 6, and FIG. Concave portions 12 corresponding to annular convex portions 106 and 107 formed on the front and rear end surfaces of the bearing case 100
9 and U-shaped recesses 130 to 133 for changing the direction of the balls to match the upper and lower loaded ball raceway grooves 102 to 105 and the unloaded upper and lower relief ball holes 109 to 112 of the bearing case 100.
are integrally formed.

Reference numerals 134 to 137 indicate half-moon-shaped ball guide tongues formed on the side covers 122 and 123. These tongues are formed below the U-shaped recesses 130 to 133 for direction change, and are located in the raceway groove 10 of the bearing case 100.
2 to 105, and the track platform 138 as shown in FIG.
This is to guide the loaded balls 143 traveling between the raceway grooves 139 to 142 to the escape ball holes 109 to 112 of the non-loaded balls of the bearing case 100 from the so-called linear direction to the rotational direction. (See FIGS. 10A and 10B) Attachment holes 145 to 147 are formed at required locations in the flat portions 124 and 125.

The track 138 in which the track grooves 139 to 142 are formed is centered from a square piece of timber,
Align it with the center O of the bearing case 100.

After that, upper and lower parallel surfaces 148, 149 and left and right parallel surfaces 150, 151 are formed, and these are used as machining reference planes, and the upper left and right raceway grooves 139, 140 are aligned with the horizontal line X-X' passing through the center O of the track 138. On the line approximately 45 degrees upward, the lower left and right raceway grooves 1
41,142 is also 15 for the horizontal line X-X'
Concave raceway grooves 139 to 142 are formed symmetrically on the line of degree and have substantially the same radius of curvature as the ball from a position intersecting a pitch circle diameter (PCD) a with a required radius r from the center O. Ru.

165 and 166 are inclined surfaces formed between the raceway grooves 139 and 141 and 140 and 142, and 152 is a mounting hole.

153 to 157 are the inner top sides and side sides of the side lids 122, 123.

158 and 159 are screws for fixing the side covers 122 and 123 to both sides of the bearing case 100. (See FIG. 6) Reference numeral 160 denotes a pressurizing screw hole. Hex bolt 161
Screw together. (See FIG. 3) Since each part of the linear bearing unit of the present invention is constructed as described above, the order of assembling it will be explained one by one.

First, one end surface 1 of the bearing case 100
Attach the side cover 122 to 20 via screws 158,
Thereafter, the track 138 of a required length is inserted into the bearing case 100, and in this state, the upper and lower relief ball holes 109 to 100 of the other end surface 121 are inserted.
112 and the raceway groove 102 of the bearing case 100
105 and the raceway grooves 139 to 142 on the track base side are sequentially filled with balls 143, and the side cover 123 is attached with screws 159.

``Effects of the Invention'' When the linear bearing unit of the present invention is incorporated into a machine tool or the like, and the necessary tools are set therein, when the bearing case 100 of the bearing unit moves forward together with the necessary tools, the R-shaped raceway grooves 139 of the way base 138... 142 and bearing case 100
The load balls 143, 143 are sandwiched between the side R-shaped raceway grooves 102 to 105...
travels together with the bearing case 100, and the side cover 1
Ball guide tongue piece 134 formed at 22 to 123
137 and pushed up into the U-shaped recesses 130 to 133 for direction change, and smoothly fed into the escape ball holes 109 to 110 of the bearing case 100.

Inner upper load ball 143, 1 of the above load balls
43... is the contact angle between the contact point of the bearing case 100 and the contact point of the track base 138 in the upward direction with respect to the axis O.
Located on the 45 degree line, the lower load ball is centered at O
These raceway grooves are located on a line at a 15 degree angle downward from the ball, and these raceway grooves can be formed into deep almost semicircular raceway grooves without a retainer, increasing the contact area with the balls. It is possible to increase the load-bearing performance, that is, the upper load and the left and right lateral loads.

Also, since the raceway grooves are deep, a very large reverse load (upward load) can be taken.

In addition, the side lids fixed to the front and rear end surfaces of the bearing case are made by punching and forming a steel plate to form an annular recess, a U-shaped recess for changing the direction of the ball, and a tongue for guiding the ball below the U-shaped recess for changing the direction. Since the pieces are integrally formed, it has the advantage that the whole can be easily molded with a press, and it is easy to assemble, further improving work efficiency, and the loaded ball can be smoothly scooped up by the ball guiding tongue. and are pushed up one after another into the U-shaped recess for changing direction.
It can be sent to the escape ball hole in the bearing case.

Further, in the bearing case of the present invention, a slit is formed in the axial direction from the end surface in parallel to the side wall,
Since the slit is close to the relief ball hole and located between the load ball raceway grooves,
By advancing the bolt, an appropriate preload can be applied to the load ball raceway groove.

As a result, the life of the linear bearing can be extended and the rigidity can be increased, and since adjustment is performed from the side of the bearing case, adjustment after fastening is easy.

[Brief explanation of the drawing]

FIG. 1 is a side view of the linear bearing unit of the present invention, FIG. 2 is a front view of the linear bearing unit of the present invention, and FIG. 3 is a cross-sectional front view taken along line A-A in FIG.
Figure 4 is a cross-sectional front view taken along the line B-B in Figure 3, Figure 5 is a cross-sectional front view of the track, Figure 6 is a partial cross-sectional side view of the linear bearing unit, and Figure 7 is a partial cross-section of the bearing case. A side view, FIG. 8 is a front view of the bearing case, FIG.
FIG. 10A is a sectional view taken along line D-D in FIG. 9A, and FIG. 10 is a bottom view showing the shape of the tongue piece of the side cover. 100: Bearing case, 102-105:
Raceway grooves for upper and lower load balls, 109-112:
Upper and lower relief ball holes, 122, 123: side cover, 152: track base, 139-142: track groove of track base, 114: slit, 143: ball.

Claims (1)

[Claims] 1. Bearing case 10 having an open end at the bottom
R-shaped load ball raceway groove 1 having almost the same radius of curvature as the ball 143 in the cylindrical inner cavity 101 of 0
Four grooves 02 to 105 are formed in the axial direction, and the balls escape radially outward across annular protrusions 106 and 107 that are continuously formed at the edges of the load ball raceway grooves 102 to 105. Hole 109-1
12 is formed through the bearing case in the axial direction, (A) the four load ball raceway grooves 102 to 105;
Among them, upper left and right load ball raceway grooves 102~
103 are arranged symmetrically at an upward angle of approximately 45 degrees with respect to the horizontal line X-X' passing through the center of the bearing case 100. (B) Lower left and right load ball raceway grooves 104, 10
5 are arranged symmetrically with respect to the horizontal line X-X' passing through the center of the bearing case 100 at an angle of about 15 degrees, which is smaller than the above-mentioned upward angle of about 45 degrees. (C) A slit 114 extends from the end surface of the bearing case 100 in the axial direction to form the lower relief ball hole 11.
1 and the lower load ball raceway groove 104. (D) A pressurizing screw hole 160 opening into the slit is formed perpendicularly to the direction of the slit from the side wall side 167 of the bearing case. (E) The side covers 122 and 123 fixed to the end surface of the bearing case 100 are attached to the annular convex portion 1.
06, 107, an annular recess 129, U-shaped recesses 130 to 133 for changing direction that cross the annular recess 129, and U for changing direction.
Ball guiding tongues 134 to 137 are integrally formed below the letter-shaped recesses 130 to 133. (F) A raceway 138, which has four R-shaped raceway grooves 139 to 141 formed in the axial direction to face the load ball raceway grooves 102 to 105 of the bearing case 100, is attached to the bearing case 100 via the balls 143. be inserted into the That's all (A). (B). (C)． (D). Linear bearing unit with conditions (E) and (F).