Bearing with seal and bearing structure

Abstract

To provide a bearing with a seal and a bearing structure which can form a grease applying hole without requiring a specific processing step, and can secure excellent lubrication property for a long term without causing an increase in manufacturing costs and reduction in manufacturing efficiency.SOLUTION: A bearing 110 with a seal includes an outer ring 112, an inner ring 114, rolling bodies 116a, 116b rolling between the inner ring 114 and the outer ring 112, and a seal 120 for sealing an interval between the outer ring 112 and the inner ring 114. The seal 120 is divided into two or more seal pieces (right seal piece 122, left seal piece 124) in a circumferential direction, and a grease applying gap 130 is formed in a boundary between the seal pieces.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a sealed bearing and a bearing structure including the same.

Background Art

[0002] Conventionally, bearings have been used as devices for supporting the rotating shafts of machines such as machine tools. Lubricants such as grease and lubricating oil are supplied to the bearings to maintain the lubricity between the outer ring, inner ring, and rolling elements during bearing rotation. Among bearings, in particular, bearings in which the space between the outer ring and the inner ring is sealed by a seal to keep the lubricating oil in a sealed state are called sealed bearings or sealed type bearings.

[0003] In a sealed bearing, fretting tends to occur in a usage environment where the bearing is subjected to vibration or continuous rocking such as micro-vibration while the bearing is not rotating. Therefore, in order to suppress fretting, there is a demand to appropriately supply a lubricant to the bearing at a desired timing to obtain stable lubrication performance.

[0004] For example, Patent Document 1 discloses "a rolling bearing including an annular seal member that is fitted into a seal groove of an outer ring and forms a seal with a seal surface of an inner ring." The rolling bearing of Patent Document 1 is characterized in that "the outer ring and the inner ring do not have oil holes for containing grease, and the seal member is a bearing seal."

[0005] The bearing seal of Patent Document 1 is formed by "fixing a rubber material to a metal core having an outer ring portion fitted to an end portion of the outer ring and an inner ring portion formed in a flange shape inward from the outer ring portion." And "a grease inlet is provided in the inner ring portion, and a mechanism that can be opened and closed is provided at the opening of the grease inlet according to whether the bearing is replenished with grease or not when the bearing is replenished with grease."

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the rolling bearing of Patent Document 1, by providing a grease inlet on the core metal of the shaft seal, it is stated that grease can be replenished even in a standard bearing without an oil hole in the outer ring or inner ring. However, with the configuration of Patent Document 1, after manufacturing the shaft seal by fixing a rubber material to the core metal, a grease inlet is provided. For this reason, the number of processing steps increases, leading to an increase in manufacturing cost and a decrease in manufacturing efficiency.

[0008] In view of such problems, the present invention aims to provide a sealed bearing and a bearing structure that can form a grease supply hole without requiring a special processing step, ensure good lubrication performance in the long term without increasing manufacturing cost or decreasing manufacturing efficiency.

Means for Solving the Problems

[0009] In order to solve the above problems, a typical configuration of the sealed bearing according to the present invention is a sealed bearing including an outer ring, an inner ring, rolling elements that roll between the outer ring and the inner ring, and a seal that seals between the outer ring and the inner ring, wherein the seal is divided into two or more seal pieces in the circumferential direction, and a grease supply gap is formed at the boundary of the seal pieces.

[0010] In order to solve the above problems, a typical configuration of the bearing structure according to the present invention includes the above sealed bearing and a grease supply pipe that supplies lubricating oil to the sealed bearing, the sealed bearing is attached to a shaft extending in the vertical direction in a horizontal posture, and the grease supply pipe is connected to a grease supply gap of a seal disposed above the sealed bearing.

Effects of the Invention

[0011] According to the present invention, it is possible to form a grease supply hole without requiring a special processing step, and to ensure good lubricating performance in the long term without causing an increase in manufacturing cost or a decrease in manufacturing efficiency, and to provide a sealed bearing and a bearing structure.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values shown in such embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit redundant description, and elements not directly related to the present invention are not shown.

[0014] FIG. 1 is a view showing a bearing structure 100 according to the present embodiment. As shown in FIG. 1, the bearing mechanism of the present embodiment includes a sealed bearing 110 and a grease supply pipe 140. The sealed bearing 110 is a device that receives a shaft 104 of a machine 102 such as a machine tool, and is attached to the shaft 104 extending in the vertical direction in a horizontal posture. Lubricating oil is supplied to the sealed bearing 110 from the grease supply pipe 140.

[0015] Figure 2 is an enlarged view of the sealed bearing 110 of FIG. 1. As shown in FIG. 2, the sealed bearing 110 of the present embodiment includes an outer ring 112, an inner ring 114, two rows of rolling elements 116a, 116b, cages 118a, 118b, and seals 120, 121. In the present embodiment, a double-row ball bearing is exemplified as the sealed bearing 110, but the present invention is not limited thereto, and the present invention can also be applied to a single-row bearing, and rollers may be used instead of balls as the rolling elements.

[0016] The sealed bearing 110 exemplified in the present embodiment is a double-row ball bearing, and two rows of rolling elements 116a, 116b are arranged between the outer ring 112 and the inner ring 114. The two rows of rolling elements 116a, 116b are respectively held by the cages 118a, 118b and roll between the outer ring 112 and the inner ring 114.

[0017] As shown in FIG. 2, the space between the outer ring 112 and the inner ring 114 is sealed by the seals 120, 121 respectively. In the present embodiment, since the sealed bearing 110 is attached to the shaft 104 in a horizontal posture, the upper seal is referred to as the seal 120 and the lower seal is referred to as the seal 121.

[0018] FIG. 3 is a view showing the upper seal 120 shown in FIG. 2. FIG. 3(a) is a plan view of the seal 120 in a state of being attached to the sealed bearing 110. FIG. 3(b) is a plan view of the seal 120 in a state of being removed from the sealed bearing 110 and divided. A gap 130 to be described later is provided in the upper seal 120, but the gap 130 is not provided in the lower seal 121. The lower seal 121 is a conventional annular seal that is not divided.

[0019] As shown in FIG. 3(a), the seal 120 is divided into two seal pieces (hereinafter, for convenience of explanation, referred to as a right seal piece 122 and a left seal piece 124) in the circumferential direction. In the sealed bearing 110 of the present embodiment, a gap 130 for grease supply is formed at the boundary between the right seal piece 122 and the left seal piece 124.

[0020] Specifically, as shown in FIG. 3(b), one end side 122a and 124a of each of the right seal pieces 122 and 124 is notched by an angle θ. In other words, the right seal piece 122 and the left seal piece 124 are in a shape obtained by dividing an annular ring into two parts, and one end side 122a and 124a of each is inclined inward by an angle θ. As a result, when the other end sides 122b and 124b of the right seal piece 122 and the left seal piece 124 are joined as shown in FIG. 3(a), a gap 130 with an angle of 2θ is formed.

[0021] By connecting a grease supply pipe 140 (see FIGS. 1 and 2) to the gap 130 of the seal 120 described above, a lubricant can be supplied into the bearing 110 with a seal through the gap 130. Therefore, according to the bearing 110 with a seal of the present embodiment, a gap 130 for grease supply can be formed without requiring a special processing step. As a result, the step of forming a hole in the conventional seal can be eliminated, and good lubrication performance can be ensured in the long term without increasing the manufacturing cost or reducing the manufacturing efficiency.

[0022] Further, in the bearing structure 100 of the present embodiment, as described above, the bearing 110 with a seal is attached to the shaft 104 extending in the vertical direction in a horizontal posture. For this reason, when the grease supply pipe 140 is connected to the gap 130 of the seal 120 disposed above the bearing 110 with a seal, the lubricant supplied from the grease supply pipe 140 flows downward from above in the bearing 110 with a seal. As a result, it becomes possible to suitably supply lubricating oil to both of the upper and lower rows of rolling elements 116a and 116b.

[0023] FIG. 4 is a diagram for explaining a first modification example of the seal of the present embodiment. FIG. 4(a) is a plan view of a state in which a seal 220 is attached to the bearing 110 with a seal instead of the seal 120. FIG. 4(b) is a plan view of the seal 220 in a state of being removed from and divided from the bearing 110 with a seal.

[0024] The seal 220 illustrated in Fig. 4(a) is also divided into a right seal piece 222 and a left seal piece 224 in the circumferential direction, similar to the seal 120. In the seal 220, grease supply gaps 230a and 230b are respectively formed at the boundaries on both sides of the right seal piece 222 and the left seal piece 224.

[0025] As shown in Fig. 4(b), in the right seal piece 222, the end edges 222a and 222b on both sides are notched by an angle θ, and similarly in the left seal piece 224, the end edges 224a and 224b on both sides are notched by an angle θ. That is, in both the right seal piece 222 and the left seal piece 224, the end edges on both sides are inclined inward by an angle θ. By providing the gaps 230a and 230b at the boundaries on both sides of the right seal piece 222 and the left seal piece 224 in this way, the same effect as the seal 120 in Fig. 3 can be obtained.

[0026] Fig. 5 is a diagram for explaining a second modification example of the seal of the present embodiment. Fig. 5(a) is a plan view of a state where a seal 320 is attached to the sealed bearing 110 instead of the seal 120. Fig. 5(b) is a plan view of the seal 320 in a state of being removed from the sealed bearing 110 and divided.

[0027] The seal 320 illustrated in Fig. 5(a) is also divided into a right seal piece 322 and a left seal piece 324 in the circumferential direction, similar to the seal 120. In the seal 320, gaps 330a and 330b are respectively formed at the boundaries on both sides of the right seal piece 322 and the left seal piece 324.

[0028] As shown in Fig. 5(b), in the right seal piece 322, recesses 322c are formed in the end edges 322a and 322b on both sides, and similarly in the left seal piece 324, recesses 324c are formed in the end edges 324a and 324b on both sides. Thereby, when the end edges of the right seal piece 322 and the left seal piece 324 are joined as shown in Fig. 5(a), hole-shaped gaps 330a and 330b formed by the recesses 322c and 324c are formed. By the configuration of forming the recesses 322c and 324c in this way, the same effect as the seals 120 and 220 can be obtained.

[0029] In the above embodiment, the seals 120, 220, and 320 are illustrated as being divided into two seal pieces in two circumferential directions, but the present invention is not limited thereto, and the seals may be divided into three or more seal pieces in the circumferential direction. When the seal pieces are divided into three or more, if gaps are formed at one or more boundaries, the above-described effects can be obtained.

[0030] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

Industrial Applicability

[0031] The present invention can be used as a sealed bearing and a bearing structure including the same.

Explanation of Signs

[0032] 100... Bearing structure, 102... Machine, 104... Shaft, 110... Sealed bearing, 112... Outer ring, 114... Inner ring, 116a... Rolling element, 116b... Rolling element, 118a, 118b... Cage, 120... Seal, 121... Seal, 122... Right seal piece, 122a... End side, 122b... End side, 124... Left seal piece, 124a... End side, 124b... End side, 130... Gap, 140... Grease supply pipe, 220... Seal, 222... Right seal piece, 222a... End side, 222b... End side, 224... Left seal piece, 224a... End side, 224b... End side, 230a... Gap, 230b... Gap, 320... Seal, 322... Right seal piece, 322a... End side, 322b... End side, 322c... Recess, 324... Left seal piece, 324a... End side, 324b... End side, 324c... Recess, 330a... Gap, 330b... Gap

Claims

1. A sealed bearing including an outer ring, an inner ring, rolling elements that roll between the outer ring and the inner ring, and a seal that seals between the outer ring and the inner ring, The seal is divided into two or more seal pieces in the circumferential direction, A sealed bearing, characterized in that a gap for lubrication is formed at the boundary of the seal piece.

2. A sealed bearing according to claim 1; a grease supply pipe for supplying lubricating oil to the sealed bearing; Equipped with The sealed bearing is attached in a horizontal position to a shaft extending in a vertical direction, A bearing structure characterized in that the grease pipe is connected to the grease gap of a seal arranged above the sealed bearing.

Images