JPH0453721B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an improvement in a caster in which a wheel portion including wheels rotates in the circumferential direction by sliding of a row of steel balls interposed between the wheel portion and the mounting portion.

[Conventional technology]

A row of steel balls is interposed between the mounting part attached to the mounted member and the wheel part to provide a bearing,
A configuration that allows the wheel portion to freely rotate in the circumferential direction is known. For example, caster 10 shown in Utility Model No. 57-58003
In the invention, as shown in FIG. 2, the rotating support plate 11 is rotatably connected to the mounting base plate 12 by interposing steel balls B arranged in a ring shape in a row as a radial ball bearing. It is shown.

[Problems to be solved by the invention]

In the above conventional configuration, the opposing wall surfaces 14 and 15 of the rotating support plate 11 and the mounting base plate 12 that form the steel ball storage portion 13 are set extremely short in the vertical direction, and the respective bottom plates 16 and 17 are set extremely short in the vertical direction. Lubricating oil reservoir 18 filled with steel balls spaced apart in parallel
is formed. Therefore, with the above configuration, it is extremely difficult to arrange the steel balls B in multiple vertical stages. Therefore, the above problem can be solved by extending the opposing wall surfaces 14 and 15 in the vertical direction, but even in that case, in the above structure, the bottom plates 16 and 17 of the rotating support plate 11 and the mounting base plate 12, respectively, prevent the reservoir from forming. 18, an extra vertical space is required for the reservoir portion 18, which has the disadvantage of inevitably increasing the size. In this type of ball bearing structure, the load of the mounted member (and the mounting part) is applied to the wheel part via the steel ball B, so when a heavy load is applied to the steel ball B, the load of the mounted member is is applied as an unbalanced load to the steel ball B, and there is a problem that smooth sliding is not possible. Therefore, for example, JP-A-49-124738 and JP-A-Sho.
As seen in No. 58-126203, if radial ball bearings are provided in two stages, upper and lower, stress can be dispersed and sliding can be performed smoothly. However, when assembling the bearing by inserting steel balls from the hollow side of the mounting board 12 into the steel ball storage section 13 as shown in the second figure, the bottom surface of the mounting board 12 is connected to the bottom plate 16.
Since the steel ball B can only be inserted from above because the steel ball B is blocked by the The disadvantage is that it makes filling work difficult. This invention was made as a result of intensive research in view of the above circumstances.
This is a newly invented device, and its main purpose is to fill the upper and lower radial ball bearings between the mounting part and the wheel part with steel balls. To provide a caster which can withstand heavy loads and whose assembly is simplified by inserting a steel ball through an opening above an inner cylindrical part provided in the holder and inserting the steel ball into a lower locking groove from the opening below.

[Means to solve the problem]

In order to achieve the above-mentioned objects, the present invention provides (a) a mounting portion 2 having a flange portion 21 above and an inner cylinder portion 22 that opens in the vertical direction; (b) A cylindrical outer cylinder part 31 is provided with a hollow part into which the inner cylinder part 22 is fitted. (c) A wheel portion 3 is provided which is integrally connected to the outer cylindrical portion 31 and pivotally supports a wheel 33; (d) The inner circumferential wall surface of the outer cylindrical portion 31 and the inner cylindrical portion 22 are provided.
(e) A pair of upper and lower ball row storage portions 5 and 6 are provided in which a pair of locking receiving grooves are annularly provided at opposing positions when attached to the outer peripheral wall surface of the ball row storage portion and are arranged vertically in parallel. Balls B are provided in each of the parts 5 and 6 in a row to slidably rotate the outer cylindrical part 31 in the circumferential direction. A pair of upper and lower insertion openings 41 and 51 are provided in communication with the pair of ball row storage parts 5 and 6, respectively, into which the balls B can be inserted. (g) A contact surface between the outer cylinder part 31 and the inner cylinder part 22 A technical measure is taken in which oil seal means 7 and 8 are provided on the upper and lower sides.

[Effect]

In the inner wall of the inner cylinder part 22, insertion holes 41 and 51, which communicate with the upper and lower ball row storage parts 5 and 6, extend horizontally and are opened at two positions in the upper and lower positions, respectively. Then, the ball B is inserted into the upper insertion opening 41 from the upper opening of the inner cylinder part 22, and the ball B is inserted into the lower insertion opening 51.
Since the balls B can be inserted into the inner cylindrical portion 22 from the lower opening thereof, it is possible to easily assemble two stages of upper and lower bearings.

【Example】

Hereinafter, a preferred embodiment of the caster of the present invention will be described based on the drawings. This caster 1 is composed of a mounting part 2 and a wheel part 3. That is, the attachment part 2 consists of a hollow cylindrical inner cylinder part 22 having a flange part 21 on the upper side. On the outer circumferential wall surface 23 of the inner cylindrical portion 22, one locking receiving groove having a substantially semicircular cross section and arranged in a horizontal annular shape is provided in the vertical direction, and includes an upper locking receiving groove 4A and a lower locking receiving groove 5A. It has a two-row configuration. The inner cylinder portion 22 also has an upper insertion hole 41 extending horizontally from the inner wall and communicating with the upper locking groove 4A.
A lower insertion hole 51 that similarly extends horizontally and communicates with the lower locking groove 5A is transparently provided. On the other hand, the wheel part 3 includes a hollow cylindrical outer cylinder part 31,
It is comprised of a pair of support legs 32, 32 that are integrally hung on both sides of the lower part of the outer cylindrical part 31, and a wheel 33 that is rotatably mounted on the pair of support legs 32, 32. The outer cylindrical portion 31 is provided with an annular ring having a substantially semicircular cross section on the inner peripheral wall surface 34 of the outer cylindrical portion 31 .
The other locking groove corresponding to one locking groove formed in 2 is formed in the vertical direction, and consists of two rows of upper locking groove 4B and lower locking groove 5B. . The inner cylinder part 22 of the mounting part 2 is fitted into the hollow outer cylinder part 31 of the wheel part 3 configured in this way. Then, by aligning the upper locking grooves 4A and 4B formed in the inner cylinder part 22 and the outer cylinder part 31 and the lower locking grooves 5A and 5B, the upper steel ball row storage part 5 and the lower steel ball row storage part 5 are aligned. A row storage section 6 is formed. A large number of steel balls B are sequentially inserted into the upper steel ball row storage part 5 and the lower steel ball row storage part 6 from the hollow side of the inner cylinder part 22 through the upper insertion hole 41 and the lower insertion hole 51. Steel ball rows are formed in the steel ball row storage section 5 and the lower steel ball row storage section 6, respectively. As a result, a radial ball bearing is formed in two stages by the annular steel ball rows formed in two stages, upper and lower, and the mounting part 2 and the wheel part 3 can slide in the circumferential direction. An upper steel ball row storage section 5 and a lower steel ball row storage section 6 are located at the upper and lower ends of the abutting surfaces of the mounting section 2 and the wheel section 3 mounted in this manner.
An oil seal means is provided for sealing lubricating oil such as grease filled into the row of steel balls held in the steel ball row. In this embodiment, this oil seal means is provided with an O-ring 7 on the lower end side and an oil seal member 8 on the upper end side. That is, the outer peripheral wall surface 2 of the inner cylinder part 22 of the mounting part 2
An O-ring retaining groove 7A is formed in an annular shape on the lower end side of the wheel part 3, and the inner peripheral wall surface 34 of the outer peripheral part 31 of the wheel part 3
An O-ring retaining groove 7B is formed in an annular shape at a position corresponding to the O-ring retaining groove 7A. Therefore, the sides of the O-ring 7 are latched by the O-ring latching grooves 7A and 7B, and the gap formed between the abutment surfaces of the inner cylindrical portion 22 and the outer cylindrical portion 31 is liquid-tight below. This prevents lubricating oil, such as grease, filled in the steel ball rows from leaking downward. Further, on the upper end side, an oil seal member 8 whose lower end is attached to the upper end side of the outer peripheral wall surface of the outer cylinder part 31
are provided, and the inner cylinder part 22 and the outer cylinder part 31
The gap created between the abutting surfaces is closed in a liquid-tight manner above, preventing the lubricating oil filled in the steel ball rows from leaking upward. In addition, in this invention, the oil seal means is not particularly limited, and the oil seal means is not particularly limited.
Any oil sealing means may be used as long as the inner cylinder part 22 and the outer cylinder part 31 provided in the inner cylinder part 22 and the outer cylinder part 31 are respectively rotatable by sliding of the steel ball rows. In the figure, reference numerals 9 and 9 are closing bodies, which contain the steel balls B in the upper steel ball row storage section 5 and the lower steel ball row storage section 6, and then close the upper insertion hole 41 and the lower insertion hole 51. death,
The steel balls B are prevented from falling out of the steel ball rows formed in the upper steel ball row storage section 5 and the lower steel ball row storage section 6. In the illustrated example, this closure body 9 includes an upper insertion hole 41,
and the lower insertion hole 51, respectively, but a screw portion may be provided and screwed into the hole. It is preferable that the end face of the closure body 9 be formed into a hemispherical shape, since this will allow the steel ball row to slide smoothly. In addition, the upper insertion hole 41 and the lower insertion hole 51
are formed horizontally and communicate with the upper steel ball row storage section 5 and the lower steel ball row storage section 6, respectively.

【Effect of the invention】

In this way, in the present invention, the steel balls are laterally received between the mounting part and the wheel part and are interposed in two stages, upper and lower, so that even if a heavy load is applied to the caster, the stress is distributed and the steel balls The rows can slide smoothly. And since the insertion port is formed horizontally, 2
Even if it is a step, space in the height direction can be saved and the size of the mounting portion can be prevented. When assembling the bearing, the steel balls can be inserted into the upper and lower insertion slots that are close to each other from the upper and lower openings of the inner cylinder, so there is no hassle in filling the steel balls, and the horizontally arranged insertion slots can be arranged in two stages. It can be easily assembled.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view showing a preferred embodiment of a caster according to the present invention, and FIG. 2 is a cutaway side view showing a conventional caster. 1... Caster, 2... Mounting part, 3... Wheel part, 5... Upper steel ball row storage part, 6...
Lower steel ball row storage section, 7...O-ring,
8...Oil seal member, 22...Inner cylinder part, 31
...Outer cylinder part, B...Steel ball.

Claims (1)

[Scope of Claims] 1. A mounting part 2 having an inner cylinder part 22 having a flange part 21 above and opening in the vertical direction, and a cylindrical outer part provided with a hollow part into which the inner cylinder part 22 is fitted. When attaching the cylindrical part 31, the wheel part 3 integrally connected to the outer cylindrical part 31 and pivotally supporting the wheel 33, and the inner circumferential wall surface of the outer cylindrical part 31 and the outer circumferential wall surface of the inner cylindrical part 22. A pair of upper and lower ball row storage sections 5 and 6 each having a pair of annular locking grooves arranged at opposing positions and arranged vertically in parallel; and a ball B that is opened in the inner wall of the inner cylinder part 22 and extends horizontally to communicate with a pair of upper and lower ball row storage parts 5 and 6, respectively. A pair of upper and lower insertion openings 41, 51 into which B can be inserted, and oil seal means 7, 8 that seat above and below the contact surfaces of the outer cylinder part 31 and the inner cylinder part 22.
Casta is equipped with the following.