KR200271941Y1 - Pre pressure apparatus for feed screw - Google Patents

Abstract

The present invention relates to a feed screw shaft preloading device, comprising: a pair of inner screw portions of a housing of the fixed side support unit, the feed screw being fixed by the fixed side supporter unit and the support side supporter unit to convert rotational force into a linear feed force. The ball bearing is coupled to maintain the gap, the collar is fixed between the stepped portion of the screw rod and the inner surface of the inner ring of the transverse inner portion of the pair of ball bearings, and the inner surface of the outer ring of the transverse inner portion is fixed to the stepped portion of the housing, A spacer ring is inserted between both inner rings, and a ring nut is fastened to a screw formed at one end of the screw rod, and a pressing plate is fixed between the outer surface of the outer ring of the housing and the outer outer ring and the ring nut, and a pressing plate is fixed to the inner ring of the outer outer ring. The collar is inserted and fixed between the outer surface and the ring nut, while the gap between the outer ring on both sides The preload spring is inserted into the groove and / or the insertion groove formed in the presser plate and the pressing plate of the housing, so as to apply a preload force to the ball bearing.

The present invention is to use the ball bearing assembly on the fixed side support unit of the feed screw used to convert the rotational force of the drive unit to the linear feed force of the conveying body, and preload springs by assembling various types of preload springs It is effective to remove radial and axial clearance, and stabilizes transmission of driving force of feed screw by using ball bearing which is very inexpensive compared to angular contact ball bearing, and increases rigidity to reduce product cost and supply volume. There is an effect to increase.

Description

Pre-pressure apparatus for feed screw

The present invention relates to a feed screw shaft preloading device. In particular, a low cost ball bearing is used for a fixed side support unit of a feed screw which is fixed by a fixed side support unit and a support side support unit to convert rotational force into a linear feed force. The present invention relates to a feed screw shaft preloading device for reducing the clearance by applying a preload using spring elasticity.

In general, a variety of forms, such as a ball screw, a TEM screw, a roller screw, are used for the power transmission screw, and one end of the screw rod is condensed to the fixed side support unit, and the other end is condensed to the support side support unit to rotate. The transfer nut is coupled to the screw rod, and in various products, the transfer body coupled to the transfer nut is configured and used to be linearly transferred by the rotation of the screw rod.

The angular contact ball bearing with a large contact angle is pre-loaded and assembled on the fixed side support unit.The outer ring of the bearing is fixed to the support unit by a flange and the inner ring is a ring nut on the screw shaft. It is fixed. Further, a deep groove ball bearing fitted to the housing of the support shaft is fixed to the support side support unit by a snap ring.

Such a conveying screw device is widely used in various machines such as an assembly robot, a cutting machine, a sheet metal machine, a packaging machine, an office automation machine, an welding machine, a printing machine, an assembly machine, and the like.

1 shows a schematic longitudinal cross-sectional view of such a conventional feed screw, and FIG. 2 shows a partial longitudinal cross-sectional view of a conventional feed screw.

As shown in the related art, one end of the screw rod 10 is supported on the fixed side support unit 100 fixed to the base 1, and the screw rod 10 is supported on the support side support unit 200. The other end of the support is supported, the intermediate portion of the screw rod 10 is coupled to the transfer nut 20 to move linearly along the straight guide line by the rotational force of the screw rod (10). The transfer object 20 is coupled to the transfer object.

The driving motor 30 is fixed to one side of the base 1 via the bracket 31, and the driving motor 30 is connected to one end of the screw rod 10 via the coupling 40. The screw rod 10 is rotated by the driving force of the driving motor 30 is coupled.

The fixed side support unit 100 has an outer ring 111 of the angular contact ball bearing 110 fixed to the inner diameter of the housing 101, and a screw rod at the inner diameter of the inner ring 112 of the angular contact ball bearing 110. 10 is fixed to the outer diameter of the support unit 200, the outer ring 211 of the ball bearing 210 is fixed to the inner diameter of the housing 201, the screw on the outer diameter of the inner ring 212 of the ball bearing 210 The rod 10 is fixed, and the screw rod 10 is rotated on the fixed side support unit 100 and the support side support unit 200.

More specifically, the snap ring 14 is fastened to the tip of the screw rod 10 inserted into the ball bearing 210 of the support side support unit 200, and the stepped portion formed in the snap ring 14 and the screw rod 10. The ball bearing 210 is supported between 13.

In addition, the fixed side support unit 100 is more specifically a collar 102 between the stepped portion 11 of the screw rod 10 and the transverse inner surface of the inner ring 112 of the pair of angular contact ball bearings 110. Is fixed, and the transverse inner surface of the outer ring 111 is fixed to the stepped portion 103 of the housing 101.

The ring nut 104 is fastened to the threaded portion 12 formed at one end of the screw rod 10, and the set screw 108 is fastened to the ring nut 104. In addition, the pressing plate 105 is fixed between the housing 101 and the transverse outer surface of the outer ring 111 and the ring nut 104, and the collar between the transverse outer surface of the inner ring 112 and the ring nut 104. An insert 106 is formed so that the collar 106 and the pressing plate 105 are tightened and fixed together by the ring nut 104, and the angular contact ball bearing 110 is formed by the ring nut 104 and the pressing plate 105. ) Is configured to apply a preload. In the figure 107 shows a seal.

An angular contact ball bearing 110 is used for the conventional fixed-side support unit 100, and the inner and outer rings 112 and 111 of both angular contact ball bearings 110 are in contact with the ball 113. The load acts in the diagonal direction connecting the, and the load action lines of the pair of angular contact ball bearings 110 and 110 'are formed opposite to each other, so that the corresponding force is applied to the thrust acting in the lateral direction, thereby providing a clearance. Will not occur.

As described above, the angular contact ball bearing 110 is used for the conventional conveying screw, and the angular contact ball bearing 110 is several times higher than the ball bearing 210, thereby increasing the cost of the product to which the conveying screw is applied. There was a problem letting.

The present invention is devised to solve the above-mentioned conventional defects and problems, and it is inexpensive to the fixed side support unit of the feed screw that is fixed by the fixed side support unit and the support side support unit and converts the rotational force into linear feed force. It is to provide a feed screw shaft preloading device that uses a ball bearing and can apply a spring preload using spring elasticity to reduce the clearance.

In order to achieve the above object, it is composed of an assembly structure of a ball bearing that can be easily applied to a feed screw, and should be able to reduce radial and axial clearance by using a ball bearing, and an easy-to-use preload spring and its An assembly structure should be secured.

1 is a schematic longitudinal cross-sectional view of a conventional feed screw.

2 is a partial longitudinal cross-sectional view of a conventional feed screw.

3 to 11 are views of the present invention feed screw shaft preloading device,

Figure 3 is a longitudinal cross-sectional view showing a feed screw shaft preloading apparatus according to an embodiment of the present invention

Degree.

4a, 4b is a portion of the feed screw shaft preloading device according to an embodiment of the present invention

Longitudinal section view.

5 is a part of the feed screw shaft preloading device according to another embodiment of the present invention

Longitudinal section view.

Figure 6 is a partial longitudinal of the feed screw shaft preloading device according to another embodiment of the present invention

Cross-section.

7 is a plan view showing an example using a single compression coil spring for the preload spring.

8 is a plan view showing an example using a plurality of compression coil springs for the preload spring.

9 to 11 show examples of using different leaf springs for the preload springs.

Top view shown.

<Description of the code | symbol about the principal part of drawing>

10 screw rod 11 stepped portion

11: outer ring 12: threaded portion

200: support side support unit 301: housing

302: collar 303: step

303a, 305a: Insertion groove 304: Ring nut

304a: protrusion 305: pressure plate

306: collar 307: spacer ring

309: spacing 310: ball bearing

311: outer ring 312: inner ring

320: preload spring 321,322: compression coil spring

323,324,325: leaf spring 323a: cut out

323b: stone piece 324a: inner stone piece

324b: outer protrusion 325a: one side protrusion

325b: other side projection 330: preload control element

331: adjustment ring 340: preload direction adjustment element

341: tapering

In order to achieve the above object, the present invention is a feed screw that is fixed by the fixed side support unit and the support side support unit to convert the rotational force into a linear feed force, a pair of inner diameter of the housing of the fixed side support unit The ball bearing is coupled to maintain the gap, the collar is fixed between the stepped portion of the screw rod and the inner surface of the inner ring of the transverse inner portion of the pair of ball bearings, and the inner surface of the outer ring of the transverse inner portion is fixed to the stepped portion of the housing, A spacer ring is inserted between both inner rings, and a ring nut is fastened to a screw formed at one end of the screw rod, and a pressing plate is fixed between the outer surface of the outer ring of the housing and the outer outer ring and the ring nut, and a pressing plate is fixed to the inner ring of the outer outer ring. The collar is inserted and fixed between the outer surface and the ring nut, while the gap between the outer ring Provided is a feed screw shaft preloading device configured to apply a preload force to a ball bearing by inserting a preload spring into a gap portion and / or an insertion groove formed in a pressing portion and a pressing plate of the housing.

At least one cylindrical compression coil spring is used for the preload spring, and various types of leaf springs are used.

In addition, between the transverse outer side ball bearing and the ring nut is configured by inserting a preload adjusting element for adjusting the preload and fastening the ring nut.

It is also possible to insert a preload adjusting element or / and a preload direction adjusting element for adjusting the preload and the preload direction between the transverse outer ball bearing and the ring nut and fasten with the ring nut.

An annular adjustment ring is used for the preload adjustment element, and a tapered adjustment ring having one side of the annular ring as an inclined surface is used for the preload direction adjustment element, and an inner side of the ring nut is provided on an inclined surface of the tapered adjustment ring. Compression protrusions are formed.

Hereinafter, with reference to the accompanying drawings, the present invention as described in detail as follows.

3 to 11 are views of the present invention screw feed shaft preloading device, Figure 3 is a longitudinal cross-sectional view showing a feed screw shaft preloading device according to an embodiment of the present invention, Figures 4a, 4b is the present invention Partial longitudinal sectional view of the feed screw shaft preloading device according to another embodiment of the present invention is shown.

As shown in the figure, the fixed side support unit 300 is fixed to the inner ring of the housing 301, the outer ring (311), 311 of the pair of ball bearing 310 is fixed, the inner ring of the pair of ball bearing 310 The outer diameter of the screw rod 10 is fixed to the inner diameter of the 312 and 312, and the outer ring 211 of the ball bearing 310 is fixed to the inner diameter of the housing 201 of the support side support unit 200. The outer diameter of the screw rod 10 is fixed to the inner ring 212 of the ball bearing 210, and the screw rod 10 is rotated on the fixed side support unit 300 and the support side support unit 200 to perform a rotary motion. do.

More specifically, the ball bearing 320 of the support side support unit 200 is fixed between the stepped portion 13 of the screw rod 10 and the snap ring 14 fixed to the other end of the screw rod 10.

The fixed side support unit 300 is coupled to the inner diameter portion of the housing 301 so that the pair of ball bearings 310 are maintained so that the gap portion 309 is maintained, and the pair of stepped portions 11 of the screw rod 10 are paired. The collar 302 is fixed between the inner surfaces of the transverse inner portion inner ring 312 of the ball bearing 310, and the inner surface of the transverse inner portion outer ring 311 is fixed to the stepped portion 303 of the housing 301. have. In addition, a spacer ring 307 is inserted between both inner races 312, and a preload spring 320 is inserted between both outer races 311.

The ring nut 304 is fastened to the threaded portion 12 formed at one end of the screw rod 10, and the set screw 304a is fastened to the ring nut 304. In addition, the pressing plate 305 is fixed between the housing 301 and the outer surface of the outer outer ring 311 and the ring nut 304, and between the outer surface of the inner ring 312 and the ring nut 304. The collar 306 is inserted into the collar 306 so that the collar 306 and the pressing plate 305 are tightened together by the ring nut 304 to be fixed together.

In addition, FIG. 4A is configured to include a preload control element, and FIG. 4B is configured to include a preload direction control element.

In FIG. 4A, the preload control element 330 is inserted between the lateral outer side ball bearing 310 and the pressing plate 305, and the pressing plate 305 is fastened. Circular control ring 331 is used for the preload control element 330, and is configured to adjust the compressive force by assembling while replacing the various control ring 331 of different thickness.

In FIG. 4B, the preload adjusting element 330 or / and the preload direction adjusting element 340 are inserted between the transverse outer ball bearing 310 and the pressing plate 305, and the ring nut 304 is located behind the pressing plate 305. ) Is fastened. A circular adjustment ring 331 is used for the preload adjustment element 330, and a tapered adjustment ring 341 having one side of the circular ring formed as an inclined surface is used for the preload direction adjustment element 340, FIG. 4B. As shown in the enlarged cross-sectional view of the pressing plate 305, a protruding portion 305a is formed on the inner side of the pressing plate 305, and the protruding portion 305a formed at the distal end of the tapered adjustment ring 341 is tightened as the pressing plate 305 is tightened. The inclined surface is pressed and tightened. Therefore, it is configured to adjust the preload and the preload direction by replacing and assembling various adjustment rings 331 or / and tapered adjustment ring 341 of different thickness.

The protrusion 305a of the pressing plate 305 is pressed against the inclined surface of the tapered adjustment ring 341 to tighten the ball bearing 310 in the inclined direction while the tightening force acts also in the inclined direction. Therefore, the radial and axial clearances can be further reduced.

In the figure, 308 shows a sealing material.

7 is a plan view showing an example using a single compression coil spring for the preload spring, Figure 8 is a plan view showing an example using a plurality of compression coil springs in the preload spring, Figures 9 to 11 are different from each other in the preload spring As a plan view showing an example using a leaf spring, first, referring to FIG. 7, a compression coil spring 321 is inserted between the outer ring 311 of the pair of ball bearings 310 as a preload spring 320. It is.

As shown in FIG. 8, a plurality of compression coil springs 322 are inserted between the outer ring 311 of the pair of ball bearings 310 as a preload spring 320, which is compressed coil springs 322. Consists of six inserts, for example, at 60 degree intervals.

And, as shown in Figure 9, the annular leaf spring 323 can be used as the preload spring 320 is inserted between the outer ring 311 of the ball bearing 310, the annular spring 323 is The plurality of cutouts 323a and the protrusion pieces 323b may be formed inside the cutout holes 323a so that one side edge portion is integrally attached, and the protrusion pieces 323b may be curved in one direction in an arc shape.

In addition, as a preload spring 320 inserted between the outer ring 311 of the ball bearing 310, an annular leaf spring 324 as shown in Figure 10 can be used, the leaf spring 324 is The plurality of protrusion pieces 324a and 324b are formed to protrude radially and outward, and the inner protrusion pieces 324a and the outer protrusion pieces 324b are bent so as to be bent in opposite directions to each other.

In addition, as the preload spring 320 is inserted between the outer ring 311 of the ball bearing 310, the annular leaf spring 325 as shown in Figure 11 can be used, the leaf spring 325 is The one side protrusion 325a and the other side protrusion 325b are formed in a concave-convex shape so as to protrude in opposite directions.

4, the spacer ring 307 is inserted between both inner races 312 of the pair of ball bearings 310, and between the outer races 311 between the two outer races 311. A preload spring 320 as shown in 11, i.e., a compression coil spring 321, 322 or a leaf spring 323, 324, 325, etc. is inserted, and the stepped portion of the housing 301 is inserted. When the clamping force of the ring nut 304 is transmitted to the preload spring 320 supported by the 303 through the pressing plate 305, both inner rings 312 of the ball bearing 310 are pressed onto the spacer ring 307. It is fixed and elastically compressed by the fastening force of the stepped portion 303 of the housing 301 and the pressing plate 305 by the preload spring 320 inserted in the middle of the outer ring 311 of the ball bearing 310 and elastic Since the preload force acts on both sides of the ball 313 in opposite inclined directions, the radial and axial clearances Is reduced, the screw rod 10 is rotated to the very stable so that it increases the rigidity of the resulting ball-bearing (310).

The compression coil springs 321, 322, and leaf springs 323, 324, 325 are different in the bending direction and the shot direction as the shape is different, respectively, to the driving characteristics and assembly characteristics of the required product It can be selected and used accordingly.

As shown in Figure 4a, when the pressing plate 305 is fastened while replacing the insertion ring 331 having a different thickness in the transverse outer ball bearing 310 to the thickness of the adjustment ring 331 and the tightening force of the ring nut 304 As a result, the compression force of the preload spring 320 is changed, and accordingly, the preload is adjusted. Therefore, it is possible to easily adjust the preload during assembly and repair.

The embodiment of FIG. 4B is an adjustment ring 331 or / and tapered which is installed as a preload adjustment element 330 or / and a preload direction adjustment element 340 between the transverse outer ball bearing 310 and the pressure plate 305. When the adjustment ring 341 is replaced with a different thickness as necessary, and tightening the ring nut 304, this tightening force is transmitted to the ball bearing 310 through the pressing plate 305 to adjust the preload as well. When the protrusion 305a of the pressing plate 305 is pressed onto the inclined surface of the tapered adjustment ring 341 and tightens in the lateral direction, the tightening force acts also in the inclined direction and preloads the ball bearing 310 in the inclined direction. Acting further reduces radial and axial clearances.

Figure 5 shows a partial longitudinal cross-sectional view of the feed screw shaft preloading device according to another embodiment of the present invention, the preloading on the inner surface of the outer ring outer side 311 of the transverse inner side of the bearing of the fixed side support unit 300 In addition to the structure in which the spring 320 is inserted and the spacer ring 307 is inserted between the inner races 312 of the ball bearing 310, the stepped portion 11 and the pair of ball bearings of the screw rod 10 are provided. The collar 302 is fixed between the inner surface of the transverse inner part inner ring 312 of 310, and the insertion groove 303a is formed in the stepped part 303 of the housing 301, and this insertion groove 303a is formed. ), Another separate preload spring 320 can be inserted and installed.

In addition, a ring nut 304 is fastened to the threaded portion 12 of the screw rod 10, and a pressing plate is disposed between the outer surface of the outer ring 311 of the housing 301 and the transverse outer side and the ring nut 304. 305 is fixed.

The collar 306 is inserted between the outer surface of the transverse outer portion inner ring 312 and the pressing plate 305, and the collar 306 and the pressing plate 305 are tightened together by the ring nut 304. It is configured to be fixed.

Another embodiment of FIG. 5 is also a preload spring 321, the compression coil springs 321, 322 or the leaf springs 323, 324, 325 are used, as shown in Figure 4a the outer outer ball bearing The control ring 331 is inserted between the 310 and the pressing plate 305 as the preload control element 330, and the ring nut 304 is fastened.

Such another embodiment of FIG. 5 is a preload spring 320 as shown in FIGS. 7-11, ie compression coil springs 321, 322 or leaf springs 323, 324, 325. When the pressure is inserted between the stepped portion 303 of the housing 301 and the pressing plate 305 by the fastening force of the ring nut 304, both inner rings 312 of the pair of ball bearings 310 are It is fixed while being pressed to the spacer ring 307, is installed in the insertion groove 303a formed in the stepped portion 303 of the housing 301, the preload spring 320 is installed, and is adjusted between the pressing plate 305 and the bearing Since the ring 331 is inserted, the preload springs 320 contacting both outer sides of the outer ring 311 of the ball bearing 310 are inserted, respectively, so that both outer ring 311 of the pair of ball bearings 310 are inserted. Since both sides of the ball 313 are elastically compressed while being tightened inward by the fastening force between the stepped portion 303 of the housing 301 and the ring nut 304. In this example pressure acting in an oblique direction opposite to the decreased radial and axial clearance is so screw rod 10 is very stably rotate while increasing the rigidity of the ball bearing 310.

In the other embodiment of Figure 5, the compression coil springs 321, 322 and the leaf springs 323, 324, 325, respectively, as the shape is different, the bending direction and the direction of the bullet is required products Depending on the driving characteristics and assembly characteristics of the will be used.

Figure 6 is a partial longitudinal cross-sectional view of the feed screw shaft preloading apparatus according to another embodiment of the present invention, in this embodiment of Figure 6, the fixed side support unit 300 of the screw rod 10 The collar 302 is fixed between the stepped portion 11 and the inner surface of the inner ring 312 in the lateral direction of the pair of ball bearings 310, and the spacer ring 307 is inserted between the inner rings 312 of both sides. A preload spring 320 is inserted between both outer ring 311, an insertion groove 303a is formed in the stepped portion 303 of the housing 301 to insert the preload spring 320, and a transverse inner ring ( The inner side surface of 311 is fixed to the preload spring 320.

In addition, a ring nut 304 is fastened to the threaded portion 12 of the screw rod 10, and a pressing plate 305 is formed between the housing nut 301 and the lateral outer surface of the outer ring 311 and the ring nut 304. ) Is fixed.

In addition, an insertion groove 305a is formed in the pressing plate 305, and a preload spring 320 is inserted into the insertion groove 305a, and the preload spring 320 is outside of the lateral outer ring 311. The collar 306 is inserted between the outer surface of the transverse outer inner ring 312 and the ring nut 304 so that the collar 306 and the pressing plate 305 are connected by the ring nut 304. It is configured to be fastened together and fixed.

The preload spring 320 may use the same preload spring 320 or different preload springs as necessary.

In the embodiment shown in FIG. 6, the compression coil springs 321, 322 or the leaf springs 323, 324, 325 are different from each other in the bending direction and the elasticity direction as the shape is different. It can be used according to the characteristics of the drive unit and the assembly characteristics of the product to be used, and also as shown in Figure 4b, the pre-pressure regulating element 330 and the preload direction adjusting element between the lateral outer side ball bearing 310 and the ring nut 304 As 340, it is comprised so that compression force can be adjusted by assembling, replacing the various adjustment ring 331 and tapered adjustment ring 341 which differ in thickness.

In the embodiment of FIGS. 4, 5, and 6, the case in which the pair of ball bearings 310 are coupled to the fixed side support unit 300 of the transfer screw by using at least one preload spring 320 has been described. Ball bearing 310 can be used by adding or subtracting numbers as needed, even if the number of the ball bearing 310 can be used by assembling at least one transfer screw shaft preloading device of the present invention in place.

The transfer screw shaft preloading device according to the present invention as described above has a preload spring 320 in the insertion groove 303a formed between the outer ring 311 and / or the stepped portion 303 of the housing 301. Insertion and tightening while applying a preload, and the preload spring 320 is inserted using the same preload spring 320 or using a different preload spring 320, if necessary, while the preload spring 320 Compression coil springs 321, 322 or leaf springs 323, 324, 325 are used as the fastening force of the ring nut 304 and the stepped portion 303 of the housing 301. When the pressure plate is fastened while adjusting the pressure between the pressing plates 305, both side outer rings 311 of the ball bearing 310 are fixed while being elastically compressed by the intermediate part and both outer preload springs 320, and both outer ring ( The preload spring 320 is inserted into the middle part and both sides of 311, Both bearings are elastically compressed by the preload spring 320 while the wheel 311 is compressed inward by the fastening force between the stepped portion 303 of the housing 301 and the ring nut 304. Since 313 has a predetermined preload force depending on the type and elasticity of the preload spring 320 used, radial and axial clearances that may be generated by a load applied along the axial direction applied to the feed screw are provided. Will be reduced.

The present invention as described above is used by assembling the ball bearing to the fixed side support unit of the feed screw used to convert the rotational force of the drive unit to the linear feed force of the conveying body, by assembling various types of preload springs to preload The effect of being able to eliminate radial and axial clearance by adding

In addition, the preload force can be easily set by the thickness of the ring and the tightening force of the ring nut by fastening the ring nut while replacing various control rings having different thicknesses as the preload adjusting element, as necessary, on the outside of the lateral outer ball bearing. Can be assembled.

In addition, the ball bearing is inclined by engaging with the ring nut while replacing the various adjustment rings and tapered adjustment rings having different thicknesses as the preload adjusting element and the preload direction adjusting element between the transverse outer ball bearing and the ring nut. Preloading has the effect of further reducing radial and axial clearance.

Therefore, the present invention stabilizes the driving force transmission of the feed screw using an inexpensive ball bearing compared to angular contact ball bearings, and increases the rigidity, thereby reducing the cost of the product and increasing the supply amount, and preloading during assembly and repair. You can get the effect that can be easily adjusted.

Claims (10)

In the feed screw which is fixed by the fixed side support unit 300 and the support side support unit 200 to convert the rotational force into a linear feed force, The pair of ball bearings 310 are coupled to the inner diameter portion of the housing 301 of the fixed side support unit 300 so that the gap 309 is maintained, and the stepped portion 11 and the pair of ball bearings of the screw rod 10 are fixed. The collar 302 is fixed between the inner surfaces of the transverse inner portion inner ring 312 of the 310, and the inner surface of the transverse inner portion outer ring 311 is fixed to the stepped portion 303 of the housing 301. The spacer ring 307 is inserted between both inner ring rings 312, and the ring nut 304 is fastened to the threaded portion 12 formed at one end of the screw rod 10, and crosswise with the housing 301. The pressing plate 305 is fixed between the outer surface of the outer outer ring 311 and the ring nut 304, and the collar 306 is inserted and fixed between the outer surface of the transverse outer inner ring 312 and the ring nut 304. On the other hand, the preload spring 320 is inserted into the gap portion 309 between the outer ring 311 is configured to apply a preload force to the ball bearing 310 Feed screw shaft preload apparatus as ranging. The method of claim 1, wherein the preload spring 320 is inserted between the two outer ring (11). Feed screw shaft preloading device, characterized in that one compression coil spring (321). The pre-screwing device of claim 1, wherein the preload spring (320) is a plurality of compression coil springs (322). According to claim 1, wherein the preload spring 320 is formed inside the cut hole 323a so that a plurality of cut holes (323a) and the stone pieces (323b) are integrally attached to one side, and the stone pieces (323b) are circled. Feed screw shaft preloading device, characterized in that the leaf spring 323 bent in one direction in an arc shape. The method of claim 1, wherein the preload spring 320 is formed so that the plurality of protrusion pieces 324a, 324b protrude outward in the radial direction, the inner protrusion pieces 324a and the outer protrusion pieces 324b are opposite to each other Feed screw shaft preloading device, characterized in that the leaf spring is bent to be curved (324). According to claim 1, wherein the preload spring 320 is a screw feed shaft pre-loading device, characterized in that the plate spring 325 formed in the concave-convex shape so that the one side protrusion 325a and the other side protrusion 325b protrude in opposite directions to each other. . The pre-loading screw shaft preloading device according to claim 1, wherein a preload adjusting element (330) is inserted between the transverse outer ball bearing (310) and the pressing plate (305) to adjust the preload. The pre-loading screw shaft preloading device according to claim 1, wherein a preload direction adjusting element (340) is inserted between the transverse outer ball bearing (310) and the pressing plate (305) to adjust the preload direction and the preload direction. The pre-screwing device of claim 1, wherein the preload control element (330) is an annular control ring (331). 10. The method of claim 8, wherein the preload direction adjustment element 340 is a tapered adjustment ring (341) formed one side of the annular ring as an inclined surface and protruding to the pressing plate 305 and the tapered adjustment ring (341) Feed screw shaft preloading device, characterized in that consisting of a protrusion (304a) is pressed on the inclined surface.