JPH076519U - Ball bearing for linear motion - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a linear motion ball bearing that does not require a special ball retainer, can be made entirely of plastic, and is suitable for light load applications. The bearing body 12 of the linear motion ball bearing assembly 10 has a width of the opening 22 smaller than the diameter of the ball 17 and an outer peripheral length corresponding to the diameter of the ball 17 when viewed in the longitudinal direction. It has a load ball groove 21 having a shape for storing the ball 17 over half,
Has a groove 41 for receiving a ball exposed from the loaded ball groove 21. At both ends of the bearing body 12, fitting pieces 27, 27 having a ball deflection groove 26 in the center are provided.
The corresponding end cap 13 is provided with a ball deflection groove 26 and fitting recesses 37, 37.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a linear motion ball bearing used for rolling guide of a linear motion part, particularly for a light load.

[0002]

[Prior art]

 Ball bearings for linear motion preferably have a ball retainer so that the balls do not fall out when the bearing assembly is pulled out from the way, but conventionally, in order to do so, some kind of ball retainer must be installed along the load ball groove of the bearing body. It was necessary to install a ball cage separately. In addition, conventional ball bearings for linear motion are made of iron regardless of the weight of the linear moving member attached to the ball bearing and the load applied to the bearing.

[0003]

[Problems to be solved by the device]

 Therefore, there has been a problem that an excessive quality ball bearing for linear motion, which has an unnecessarily large capacity, must be used even for an ultra light load application.

[0004]

[Means for Solving the Problems]

 According to the present invention, the bearing body has a shape in which the width of the opening is smaller than the diameter of the ball, and the shape of the ball is such that the diameter of the bearing exceeds half of the outer circumference corresponding to the diameter of the ball when viewed in the longitudinal direction. The bearing base is a linear motion ball bearing having a groove for receiving a ball exposed from the loaded ball groove, and the bearing main body has an unloaded ball return hole penetrating in a longitudinal direction, A pair of semi-circular fitting pieces projecting in the direction, and a ball deflection groove having an approximately semi-circular cross section formed in the middle of the fitting pieces so as to connect the load ball groove and the return hole. And an end cap having a pair of fitting recesses for receiving the fitting pieces described above, and a ball deflection groove forming a ball direction conversion path in a manner complementary to the ball deflection groove on the bearing body side. Straightforward to have By the motion for ball bearings, it has solved the above problems.

[0005]

[Action]

 The loaded ball groove of the bearing body of the present invention not only receives the load between the bearing body and the ball bearing, but also has a ball holding function that prevents the ball from falling off when the bearing body is pulled out from the bearing base. . Further, if not only the end cap but also the bearing body is made of plastic, it is possible to easily obtain the shape by extrusion or injection molding even for an ultra small size or a complicated shape that is difficult to machine. The specific gravity of the material itself is about 1/5 to 1/8 that of iron. Therefore, the linear motion guide mechanism is significantly reduced in weight.

[0006]

【Example】

 As shown in the exploded perspective view of FIG. 1 and the assembly view of FIG. 2, a bearing assembly 10 for a linear motion ball bearing embodying the present invention includes a bearing body 12 and a pair of end caps 13 attached to both ends thereof. , 13, and a pair of seal plates 15 and 15 on the outer side, and each member is fixed with bolts 16, and the assembled parts move linearly along the way 14 as shown in FIG. .

In the present invention, not only the end cap 13 but also the bearing body 12 can be molded by plastic. Examples of the material include polyacetal resin Delrin (trade name: DuPont), polyphenylene sulfide, and polysulfone, which are known as engineering plastics. Each of the exemplified polymeric materials has a density in the range of 1.06 to 1.05 and has properties peculiar to polymeric materials having a low specific gravity with respect to iron. It also has mechanical strength such as wear resistance and fatigue resistance, which are essential for bearings.

As shown in FIG. 3, the bearing body 12 has a load ball groove 21 and an unloaded ball return hole 24 in a leg portion 25, and the load ball groove 21 is a groove on one side of the way 14 on one side. An unloaded ball return hole 24 having a circular cross section is provided at a position facing 41, and penetrates the leg portion 25 in the longitudinal direction. Further, the bearing body 12 is formed with a pair of semi-disc shaped fitting pieces 27 protruding from both ends. In the middle of the pair of fitting pieces 27, there is formed a ball deflection groove 26 connecting the groove 21 and the hole 24 and having a substantially semicircular cross section.

As shown in FIGS. 4 and 5 (and FIG. 1), the end caps 13 attached to both ends of the bearing body 12 have a pair of fitting recesses 37 and 37 for receiving the fitting pieces 27. The end cap 13 is positioned by this fitting. In the middle of the pair of fitting recesses 37, 37, a ball diverting groove 36 that complements the ball diverting groove 26 and forms a direction changing path of the ball 17 from the loaded ball 21 to the unloaded ball return hole 24. Is provided. In addition, a ball scooping guide piece 38 for smoothing the circulation of the ball 17 is provided at the inner end of the ball diverting groove 36.

The bearing body 12 and the pair of end caps 13 and 13 form an endless circulation orbit of balls, and the balls 17 are filled in the orbit, and seal plates 15 and 15 are attached to the outside thereof. Secure with bolts 16. It is desirable that the seal plate 15 is also made of plastic in terms of weight reduction.

As shown in FIG. 3, the groove 41 of the way 14 is a Gothic arch-shaped relatively shallow groove, and the load ball 21 is provided on the leg portion 25 of the bearing body 12 facing the groove 41. This is as described above. This load ball groove 21 is also in the shape of a Gothic arch, which allows it to receive loads with vertical and horizontal directions and moments.

As shown in FIG. 3, the load ball groove 21 has an opening 22 in the longitudinal direction on the groove 41 side of the raceway 14, and the space between the tip portions 23, 23, that is, the opening 22. The width is smaller than the diameter of the ball 17. The loaded ball groove 21 is formed in a shape that accommodates the ball 17 over a half of the length of the outer circumference (that is, the maximum outer circumference) corresponding to the diameter of the ball 17 when viewed in the longitudinal direction. Therefore, the ball 17 is accommodated in the load ball groove 21 of the bearing body 12 in a portion exceeding half the volume thereof, and only half or less of the volume is exposed to the outside. Therefore, the tip portions 23, 23 have a ball holding function of preventing the balls 17 from falling out of the loaded ball groove 21. As a result, the ball 17 rolling in the loaded ball groove 21 is less exposed from the opening 22 and the groove 41 of the way 14 becomes shallower than before, but as long as it is used for light load applications. There is no hindrance.

The portions 39, 39 (see FIG. 4) of the ball diverting groove 36 of the ball cap that are close to the raceway 14 also serve as a guide piece that wraps the ball 17 and guides the ball 17 in and out of the load zone. Therefore, the circulation function of the ball becomes smoother than before. The ball bearing for linear movement of the present invention is not limited to the symmetrical shape, and the main body side and the raceway side can be modularized and fixed to other members. At this time, the elasticity of the plastic material can be used for snap mounting.

[0014]

[Effect of device]

 As described above, the loaded ball groove of the bearing body according to the present invention has a ball holding function by itself, and the ball does not drop out when it is pulled out from the rail even without providing a separate ball holder. In addition, the ball deflection groove of the end cap also serves as a guide action for the ball entering and exiting the load zone, so the ball circulation function becomes smoother. The plastic material can significantly reduce the weight of the linear motion ball bearing. This is especially useful for ultra-compact and ultra-lightweight products, and is 80% lighter than conventional iron products, so it can be moved with a smaller force.

Further, a small-sized one having poor workability and a complicated shape difficult to machine can be easily manufactured by extrusion or injection molding which is a characteristic of plastic. To process a small and complicated iron bearing body, each process is complicated, including polishing, but the shape shown in the embodiments of the present invention is also easy if it is made of plastic. Can be molded into. In addition to the ease of processing, which is a unique effect of molded products, the number of parts and the number of assembly steps can be reduced, and productivity is improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a ball bearing for linear motion excluding a way.

FIG. 2 is a perspective view of a bearing assembly assembled to a rail.

FIG. 3 is a front view of a ball bearing for linear motion without an end cap (a raceway is a sectional view).

FIG. 4 is a front view of an end cap.

5 is a sectional view taken along line 5-5 of FIG.

[Explanation of symbols]

 10 Ball Bearing Assembly 12 Bearing Body 13 End Cap 14 Raceway 17 Ball 21 Loaded Ball Groove 22 Opening 24 Unloaded Ball Return Hole 26 Ball Deflection Groove 27 Fitting Piece 36 Ball Deflection Groove 37 Fitting Recess 41 Raceway Groove

Claims (2)

[Scope of utility model registration request] 1. The bearing main body has a shape in which the width of the opening is smaller than the diameter of the ball and the shape of the ball is larger than half of the outer circumference corresponding to the diameter of the ball when viewed in the longitudinal direction. A ball bearing having a ball groove, wherein the rail is a linear motion ball bearing having a groove for receiving a ball exposed from the loaded ball groove, wherein the bearing body has an unloaded ball return hole penetrating in a longitudinal direction, A pair of semi-disc-shaped fitting pieces projecting in the direction, and a ball-shaped cross section formed in the middle of the fitting pieces so as to connect the loaded ball groove and the unloaded ball return hole with a substantially semi-circular shape. And a pair of fitting recesses for receiving the fitting pieces, and a ball turning groove that forms a ball direction changing path in a manner complementary to the ball turning groove on the bearing body side. With end cap Consisting of Te, linear motion ball bearings. 2. The ball bearing for linear movement according to claim 1, wherein the bearing body and the end cap are made of plastic.