JPS6014617A - Ball bearing unit for finite straight-line movement and it's manufacture - Google Patents

Abstract

PURPOSE:To miniaturize and lighten the device by forming V-shape orbital grooves which have soft wavy curves through plastic working, on a table and a bed made of thin metallic boards, and grinding a part of the orbital grooves to form ball track surfaces. CONSTITUTION:At the center of outside surfaces of both walls of bed 1, whose sectional drawing is U, V orbital grooves 11 are formed longitudinally. At inside surfaces of both walls of table 2, whose sectional drawing is U, V orbital grooves 11 are formed correspondently with said grooves 11 of bed 1. Bed 1 and table 2 are assembled holding several balls 3 in respective orbital grooves. In the first process, section of each orbital groove 11 has soft wavy curve 14 because it is formed by plastic working. After that, the curve 14 is modified to form ball track surfaces 26 by grinding only a limited part of both inclined faces with V grindstone.

Description

[Detailed Description of the Invention] The present invention relates to a ball bearing unit for finite linear motion, and in particular,
The present invention relates to a shell-shaped ball bearing for finite linear motion in which a thin metal plate, such as a high carbon steel plate, stainless steel, or composite steel plate, is used for the table or bed of the ball bearing unit.

As disclosed in Japanese Patent Application Laid-Open No. 7-f04L4' No. 1 and shown in FIGS. 1 to 5 of the accompanying drawings showing examples thereof, a conventional ball bearing unit for finite linear motion is a table! Both ' and bed/' are made of steel and have thick walls, so
The entire unit was heavy and expensive.

However, for fields where the load is light and is used in a small space, ball bearing units for finite linear motion such as those described above are unsuitable, and therefore there is a strong demand for miniaturized ball bearing units for finite linear motion. Ta.

The disadvantages of conventional ball bearing units for limited linear motion are as follows.

(1) Since it is used for heavy loads, rigidity is required, and the dimensions of the bearing parts inevitably become large.Therefore, the bearing unit becomes large in size and thus increases in weight.

(2) Since the manufacturing process is mainly based on cutting,
This increases the number of processing steps and makes it expensive.

(3) Mass production is difficult.

The present application obviates the drawbacks of the prior art described above.

An object of the present invention is to provide a small, lightweight, and inexpensive ball bearing unit for finite linear motion using thin metal plates for tables and beds.

A further object of the present invention is to provide a ball bearing unit for limited linear motion that is compact and has excellent mass productivity.

The present invention will be described in detail below with reference to the accompanying drawings.

FIGS. 3 to 3g show one embodiment of a ball bearing unit for finite linear motion according to the present invention.

As best seen in Figure 3, it has a U-shaped cross section, and a raceway groove with a V-shaped cross section is provided in the center of the outer surface of both side walls in the longitudinal direction (
Corresponding to the bed// formed in the direction perpendicular to the plane of the paper and its raceway groove//, a V-shaped cross-section raceway groove// is formed on the inner surface of both side walls.
A table head having a U-shaped cross section is assembled with a plurality of balls 3 interposed between each raceway groove.

A retainer is provided on the balls 3 to keep the balls apart by a certain distance and prevent the balls from spinning or coming into contact with each other during sliding (see FIG. 7).

Referring to FIG. ing. This stopper 7 has the function of hitting the bed side plate B when the table moves back and forth and preventing it from moving any further, but if necessary, the stroke amount may be regulated using only the side plate without the stopper. You can also do it. (In this case, it is not necessary to install the side plate on the bed side.) When installing this bearing unit to the device, make mounting holes at appropriate locations on the table λ and the bed/ (not shown in the figure). It sticks.

The assembled state of this bearing unit is shown more clearly in FIG. Next, a method of assembling the bearing unit will be explained mainly with reference to FIG. g.

(1) Attach one side plate O to the bed.

(2) Attach one side plate and the stock lever 7 to the table λ.

(3) H on retainer≠? - Install Rule 3.

(4) After assembling the parts (1), (2) and (3) above, attach the side plate at the other end of the bed and table. At this time, the elasticity of the thin metal plate is used to expand the table λ or contract the bed with less force. By doing both, parts (+), (2) and (3) can be easily assembled (see Figure 10).

Note that a predetermined preload can be applied by bending in the opposite direction (the direction in which the ball is pushed).

Next, the raceway groove/diagram according to the present invention will be described.

A raceway groove according to the invention // is shown in FIG. 1/a.

Figure 1/a shows the shape after the outer surface of the side wall has been ground with the raceway groove // formed in the bed. V-shaped raceway groove/
/ is formed by plastic working (such as press working), so it has a gentle wavy curve /4.

This curve /≠ is ground with a V-shaped grindstone to grind only a part of both inclined surfaces (consisting of wavy curve /ll-), and 778
The orbital plane shown in the figure! Form B.

In the conventional method, the entire surface of the raceway groove with a V-shaped cross section was machined, resulting in a large grinding area and the grinding wheel quickly wearing out. As a result, mass productivity was poor due to an increase in the number of times of dressing, and the dimensional accuracy and surface roughness of the raceway surface were poor.

According to the present invention, since only the raceway surface necessary for the raceway bearing is formed, it is possible to improve the life of the grinding wheel and achieve uniform dimensional accuracy and surface roughness. Since the number of pockets is increased (see Fig. 1/a), the lubrication effect is good and the life of the bearing is extended.

In addition, the tip of the grindstone is sharpened in Fig. 1/a, but if you want to secure a large orbital area, use a grindstone/, 2 with a chamfered tip 15 as shown in Fig. 1/b. By doing so, you can make it happen.

Further, as shown in Fig. 1/b, a groove for providing a larger oil pocket may be formed at the bottom of the raceway groove having a V-shaped cross section, if necessary.

Fig. 1/b also shows that if necessary, if the wavy curve is formed into a slightly wider wavy curve /4'' (as shown by the dotted line), the grinding allowance /
3 becomes large, indicating that a large raceway surface can be secured after grinding. In addition, as shown in Figure 1/'c, the raceway surface 2
B can also be made into a curved surface to increase the contact area of the ball and increase the strength.

Next, a method for manufacturing the table and bed will be described. table! and to manufacture the bed/
As shown in Fig. 7.2a, the thin metal plate 2 is cut to a predetermined size, and cutouts are formed at the portion where the metal plate 2 is bent into a U-shaped cross section and at the end of the raceway groove. Next, as shown in FIG.
As shown in FIG. 12c, the metal plate is plastically deformed and bent into a U-shaped cross section at the notch. Alternatively, the plastic deformation of the raceway groove // and the plastic deformation of bending it into a U-shaped cross section can be carried out directly from the state shown in FIG. 1.2a to the state shown in FIG. 72c in seven steps. Next, as shown in FIG. 73b, a heat source 10 is placed at both longitudinal ends of the metal plate to locally harden the metal plate, and then only a portion of the V-shaped raceway groove in the metal plate is ground. A raceway surface as shown in Figures 1/a to 1/c is formed.

The table and bed manufactured as described above are combined with the required number of balls arranged in the raceway grooves to complete a bearing unit.

Note that the effects obtained by forming the above-mentioned notch portions are as follows. That is, when it is bent into a U-shape, the bent flesh protrudes toward both ends, resulting in poor longitudinal accuracy. By providing the notch 7 in that portion before bending, the dimensional accuracy in the longitudinal direction is improved and width processing after bending is not necessary. This also applies to the machining of V-shaped raceway grooves. Furthermore, the effects of local hardening by placing heat sources 10 at both longitudinal ends of the metal plate are as follows. That is, in the method of placing the heat source 10 near the raceway groove as shown in FIG. 13a, there is a high possibility that even the bent portion will be hardened, making management difficult and causing damage during bending.

As shown in FIG. 13b, according to the method of placing the heat source 10 at the longitudinal end of the table or bed, the heat source 10
Since the distance from the bending part to the bending part becomes longer, it becomes easier to manage the hardened part. One example of locally hardening is induction hardening, for example, tool steel (SK-Yu)! , j seconds g7
A heat source is placed at the position shown in Figure 73 at 0°C ± t°C to heat it, cooled with a plastic quench, tempered at 0°C ± 7°C for 7 hours, and then cooled in a furnace. Only a part of the wavy curved part /≠, /≠' of the cross-sectional V-shaped raceway groove // of the metal plate is ground to form the raceway surface 2B (see Figures 1/a to 1/c).
The effects obtained by forming the layer are as described above.

11I- and 1J are diagrams of the ball bearing unit for finite linear motion according to the present invention. This embodiment further includes a preload adjustment plate 20, a preload adjustment screw 22, and a base 2≠. Thus, the preload adjustment screw 22
can be adjusted to push the preload adjustment plate 20 and apply a required preload to the sol 3. The preload adjustment screw 2.2 is screwed into the base 2t.

[Brief explanation of the drawing]

Figures 1 to 5 show the prior art disclosed in Japanese Patent Application Laid-Open No. 7-♂0II-/I-g; Figure 4 shows seven embodiments of a ball bearing unit for finite linear motion according to the present invention. Fig. 7 is a partially enlarged view of Fig. 6 showing the V-shaped raceway groove; Fig. g is a side view of Fig. 4. 7 is a perspective view of seven embodiments showing the assembly of a bearing unit according to the invention; FIG. 1O shows an assembly method of the same; FIG. In the explanatory diagram of the raceway groove according to; 1st/b
The figure is an explanatory diagram of another raceway groove according to the present invention; Figure 1/c shows the case where the raceway surface in the raceway groove according to the present invention is curved; Figures 7.2a to 12c are according to the present invention. Fig. 1j'a shows the position of an unfavorable heat source for local curing; Fig. 13b shows the preferred position of a heat source for local curing; Fig. 1≠ The figure is a front view in cross section showing another embodiment of the ball bearing unit for finite linear motion according to the present invention; and FIG. 1j is a side view in partial cross section of FIG. 111-. /...Bed, λ...Table, 3...Ball,
≠...retainer, evening...table side plate, O...bed side plate, 7...stopper, d...increase in oil pockets, ri...notch, 10...heat source, //...・・・
V-shaped raceway groove, /! ...Whetstone, /3...Whetstone processing allowance, /≠...wavy curve, /IA'...wavy curve with wide bottom, /Yu...chamfered end, /Otsu...oil Pocket, 20... Preload adjustment plate, 22... Preload adjustment screw 1.
2≠...Base, 2...Thin metal plate, Nootsu...
orbital surface. Name of agent Kawahara 1) - Ei Figure 1 Figure 2 Figure 4 Figure 5 Figure 11a Figure 11b Figure 11c Figure 120 Figure 12b Figure 12c Figure 5 Figure 13a Figure 13b Figure 14 Figure 0 Figure 15 2

Claims (2)

[Claims] (1) In a ball bearing unit for finite linear motion, the sheet is a combination of a table and a bed. The table is formed with a V-shaped raceway groove on the inner side of both side walls, and the bed is also provided with a corresponding V-shaped raceway groove on the outer side of both side walls. A plurality of balls are inserted into the V-shaped raceway groove through the V-shaped raceway groove, and each of the V-shaped raceway grooves has a gentle wavy curve formed by plastic working, and the V-shaped raceway groove A ball bearing unit for finite linear motion, characterized in that only a portion of the ball is ground to form the raceway surface of the balls. (2) In the method for manufacturing a ball bearing unit for finite linear motion, each of the following steps: a) A step of making the table and bed of the ball bearing unit each from a thin metal plate and cutting it to at least a predetermined size; b) forming a notch at each end of the part where the metal plate is bent into a U-shaped cross section and the raceway groove; C) forming a raceway groove with a V-shaped cross section in the metal plate by plastic deformation; d) a step of plastically deforming the metal plate into a U-shaped cross section at the notch and bending it (steps (c) and (d) above are performed in step 7);
and e) producing a table and bed by a step of grinding only a portion of the V-shaped cross-sectional raceway groove of the metal plate to form a raceway surface; and f) on the bed. A method of manufacturing a ball bearing unit for finite linear motion, comprising the steps of: assembling the tilt ring in the raceway groove via a plurality of balls.