Turning caster structure

Abstract

To provide a turning caster structure that achieves a silent turning caster including a thrust bearing and a radial bearing.SOLUTION: In a turning caster structure, an upper wheel S1 of a thrust bearing S is supported by a caster attachment plate 1, a lower wheel S2 is sandwiched by a flat surface of a support yoke 3, an upper surface of an inner wheel R1 of a radial bearing R is fixed by a spacer part, a lower surface of the inner wheel is fixed by a spacer part 5 of a lower end of a turning shaft, and an upper surface of an outer wheel of the radial bearing is hooked and fixed by a corner portion of the support yoke.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a swivel caster structure having excellent noise reduction effect and used as wheels for transport equipment, various transport vehicles, carts, etc. [Background technology]

[0002] Conventionally, in the caster and bogie of JP 2007-22254 A shown in Patent Document 1, in the second embodiment shown in Figures 6 to 8 of the publication of Patent Document 1, a caster mounting plate, thrust bearing, first washer, radial bearing (with a yoke portion fixed to the outer ring), and second washer are inserted in that order onto the swivel shaft, and are positioned coaxially with the swivel shaft, and the end of the swivel shaft is crimped. This fixes (holds) each member sandwiched between the flange portion and the end portion of the rotating shaft.

[0003] However, in the above configuration, a separate large-diameter first washer is used between the thrust bearing and the radial bearing to abut the upper surface of the inner ring of the radial bearing, and the lower surface of the outer ring of the radial bearing is supported by the recess of the radial bearing yoke, so there is a drawback in that loads are generated separately on the bearings, making it impossible to prevent noise during vibration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2007-22254 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention relates to a swivel caster structure that realizes noise reduction of a swivel caster having a thrust bearing and a radial bearing with a simple configuration. [Means for solving the problem]

[0006] In order to solve the above problems, this invention provides a bearing comprising a mounting shaft having a flange on an upper end, a mounting plate having a mounting hole through which the mounting shaft is inserted without any gap and through which the flange is hooked, a downward horizontal surface formed on the rear surface of the mounting plate, and a support yoke having a hole on the support yoke side through which the mounting shaft is inserted below the mounting plate and having an upward horizontal surface formed parallel to the downward horizontal surface, the upper wheel of a thrust bearing being supported on the downward horizontal surface, and the lower wheel of a thrust bearing being supported on the upward horizontal surface, an upward step portion that rises on a base end side of the upward horizontal surface of the support yoke, extends in the direction of the pivot axis, and has an L-shaped cross section that extends to a hole on the yoke side; The corner of the upward step hooks the upper part of the outer ring of the radial bearing from above, and the lower part of the outer ring is open. a spacer portion that extends downward along the pivot shaft between the mounting hole and the upward step portion, the lower end of which abuts against the upper end of the inner ring of the radial bearing; The lower end of the inner ring of the radial bearing is fixed to the lower end side of the mounting shaft. Effect of the Invention

[0007] This allows each component sandwiched between the flange portion and the lower end of the rotating shaft to be fixed together without any gaps, so that each component does not swing individually and can bear the load efficiently. It also suppresses the generation of vibration and noise, ensuring quiet operation during driving. [Brief description of the drawings]

[0008] [Figure 1] FIG. 3 is a cross-sectional view of the main parts of a swivel caster. [Diagram 2] FIG. 11 is a cross-sectional view of a main portion with a dust cover added to cover the bearing. [Diagram 3] FIG. [Figure 4] FIG. 11 is a cross-sectional view of a main part showing a different embodiment. [Diagram 5] FIG. [Figure 6]FIG. [Figure 7] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Preferred embodiments of the present invention will now be described with reference to the drawings. EXAMPLES

[0010] FIG. 5 shows an example of the swivel caster 20 of the first embodiment as viewed from a vertical section, FIG. 6 shows a plan view, and FIG. 7 shows a front view. The enlarged view of the main part shown in FIG. 1 shows a cross-sectional view taken along the axis of the rotating shaft 10 in the structure around the rotating shaft 10. In FIG. The rotating shaft 10 has a generally cylindrical shape, and a flange portion 11 is formed on one side in the axial direction.

[0011] The swivel shaft 10 has a bearing mechanism built in between the caster mounting plate 1 and the support yoke 3 that supports the wheel W, and is fixed by the flange portion 11 and a crimped portion 12 that has a large diameter at the lower end to prevent it from coming loose.

[0012] That is, the caster mounting plate 1 has a substantially horizontal flat surface 2a, a mounting hole 1b in the approximate center thereof having an inner diameter smaller than the outer diameter of the flange portion 11 of the head of the swivel shaft 10 and through which the shaft portion 10A of the swivel shaft 10 can be inserted, and a recessed portion 1c extending along the outer periphery of the opening end of the mounting hole 1b and connected to the flat surface 1a.

[0013] The recessed portion 1c is recessed at a position substantially equal to the thickness of the flange portion 11 with respect to the horizontal flat surface 2a on the outer periphery. In addition, the peripheral portion of the mounting hole 1b forms a horizontal surface for horizontally hanging the upper surface of the flange portion 11 of the swivel shaft 10, and the upper surface of the flange portion 11 hung in the mounting hole 1b is set to be substantially the same plane as the flat surface 2a (see Figure 5).

[0014] Next, the thrust bearing S is arranged on the upper outer periphery of the radial bearing R, and is interposed between the caster mounting plate 1 and the support yoke 3. In the illustrated example, the upper surface of the lower ring S2 of the thrust bearing and the upper end surfaces of the inner ring R1 and outer ring R2 of the radial bearing are arranged in close contact with each other in the height direction so as to be substantially flush with each other.

[0015] The upper surface of the upper wheel S1 of the thrust bearing S abuts against the downward horizontal surface 1a on the underside of the caster mounting plate 1, and the bottom side of the lower wheel S2 of the thrust bearing S abuts against an upward horizontal surface 3a formed in the middle section of the support yoke 3 described below, and the tip of the upward horizontal surface 3a forms a hanging wall 3a' at an approximately right angle. Further, a hole 30 on the yoke side, which is concentric with and has a larger diameter than the mounting hole 1b, is formed in the upper part of the support yoke 3 at approximately the center position of the upper surface of the support yoke 3.

[0016] In addition, the tip of the upward step portion 3b adjacent to the upward horizontal surface 3a forms the rim of the hole 30 on the yoke side, and the upward step portion 3b of the support yoke 3 and the corner portion 3c on the inner surface side are formed into an upward step portion 3L having an L-shaped cross section, and abuts against the upper end of the outer ring R2 of the radial bearing R. On the other hand, directly below the mounting hole 1b, there is attached a spacer portion 4 having a cylindrical cross section and made of a washer which abuts against the rim of the mounting hole 1b, fits snugly around the rotating shaft 10, and hangs down to the same position as the corner 3c on the inner surface of the upward step 3b, and the lower end of the spacer portion 4 abuts against the upper end of the inner ring R1 of the radial bearing R.

[0017] The lower end of the inner ring R1 of the radial bearing R is fixed by a crimped portion 12 at the lower end of the mounting shaft 10 or by a lower spacer portion 5 consisting of a lower washer hooked onto the crimped portion 12 and fixed. On the other hand, the lower end of the outer ring R2 of the radial bearing R is open in a hollow position. As a result of the above-mentioned configuration, the thrust bearing S has its upper ring S1 and lower ring S2 each having an open outward side, and the lower end of the outer ring R2 of the radial bearing R is open, so that a noise reduction effect can be achieved with a simple configuration. In addition, the upward step 3b of the support yoke 3 on the rearward movement side of the wheel and the corner portion 3c on the inner surface side form an upward step 3L having an L-shaped cross section, and the upward horizontal surface 3a passes through a mid-step portion 3d, and then through a rear horizontal surface portion 3e, and at its tip forms a hanging wall 3e' at an approximately right angle. EXAMPLES

[0018] In the second embodiment shown in FIG. 2, a dust cover 6 made of flexible and elastic synthetic resin or the like is attached below the mounting plate 1 to cover the outer periphery of the thrust bearing S except for the bottom surface. The dust cover 6 is attached to overlap the rear surface of the mounting plate 1, and overlaps with the downward horizontal surface 1a to perform the same function as the mounting plate 1, so a description thereof will be omitted. The other configurations are the same as those in the first embodiment, and therefore the description will be omitted. EXAMPLES

[0019] In the third embodiment shown in FIG. 3, instead of the separate washer-shaped spacer portion 4, a hanging wall portion that is formed integrally with the mounting hole 1b and extends downward in a cylindrical shape with the same inner diameter as the hole edge portion is formed as the spacer portion 4'. The lower end of the spacer portion 4', which constitutes the hanging wall portion, abuts without any gap against the upper end surface of the inner ring R1 of the radial bearing R, distributing the central load applied to the caster mounting plate 1 to the inner ring R1 side of the radial bearing R. The other configurations are the same as those in the first embodiment, and therefore the description thereof will be omitted. EXAMPLES

[0020] In the fourth embodiment shown in FIG. 4, similarly to the third embodiment shown in FIG. 3, instead of the separate washer-shaped spacer portion 4, a hanging wall portion which is formed integrally with the mounting hole 1b and extends downward in a cylindrical shape with the same inner diameter as the hole edge portion is formed as a spacer portion 4'.

[0021] The lower end of the spacer portion 4', which constitutes the hanging wall portion, abuts without any gap against the upper end surface of the inner ring R1 of the radial bearing R, distributing the central load applied to the caster mounting plate 1 to the inner ring R1 side of the radial bearing R. Furthermore, the lower end of the inner ring R1 of the radial bearing R is hooked and fixed to a step 12a formed on the crimped portion 12 at the lower end of the mounting shaft 10 without providing a lower spacer portion 5. The other configurations are the same as those in the previous embodiment, so the description thereof will be omitted. [Explanation of symbols]

[0022] 1 Mounting plate 1a Downward horizontal plane 1b Mounting hole 3 Support yoke 3a Upward horizontal plane 3b Upward step 4, 4' spacer section 5 Lower spacer part 10 Mounting shaft 11 Flange 12 Crimping part 13 Lower end latching part 30 Hole on the support yoke side S Thrust bearing S1 Upper wheel S2 lower wheel R Radial bearing R1 Inner ring R2 Outer ring W wheels

Claims

1. The mounting shaft has a flange at its upper end, a mounting plate having a mounting hole through which the mounting shaft is inserted without any gap and through which the flange is hooked, a downward horizontal surface formed on the rear surface of the mounting plate, and a support yoke having a hole on the support yoke side through which the mounting shaft is inserted below the mounting plate and an upward horizontal surface formed parallel to the downward horizontal surface, the upper wheel of a thrust bearing is supported on the downward horizontal surface, and the lower wheel of a thrust bearing is supported on the upward horizontal surface, an upward step portion that rises on a base end side of the upward horizontal surface of the support yoke, extends in the direction of the pivot axis, and has an L-shaped cross section that extends to a hole on the yoke side; The corner of the upward step hooks the upper part of the outer ring of the radial bearing from above, and the lower part of the outer ring is open. a spacer portion that extends downward along the pivot shaft between the mounting hole and the upward step portion, the lower end of which abuts against the upper end of the inner ring of the radial bearing; A swivel caster structure characterized in that the lower end of the inner ring of the radial bearing is fixed to the lower end side of the mounting shaft.

2. 2. The swivel caster structure according to claim 1, wherein the spacer portion is separate from the mounting plate and has a washer shape fitted onto the mounting shaft.

3. 2. The swivel caster structure according to claim 1, wherein the spacer portion comprises a hanging wall that hangs down along the edge of the mounting hole in the mounting plate and fits onto the mounting shaft.

4. 2. The swivel caster structure according to claim 1, wherein the lower end of the inner ring of the radial bearing is fixed to a step portion of the crimped portion at the lower end of the mounting shaft.

5. 2. The swivel caster structure according to claim 1, characterized in that the lower end of the inner ring of the radial bearing comprises a lower spacer portion fitted onto the lower end of the mounting shaft and fixed by a crimping portion.

6. A swivel caster structure as described in any one of claims 1 to 5, characterized in that the upper surface of the lower ring of the thrust bearing and the upper end surfaces of the inner ring and outer ring of the radial bearing are arranged in close contact with each other in the vertical direction so as to be approximately flush with each other.

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