Bearing holding tool, bearing structure, bearing lubrication method, and rolling device

Abstract

Provided is a bearing holding tool with which service life can be extended by improving the lubrication performance of a bearing, rather than by using a bearing having a special structure.　The bearing holding tool is provided with a bearing holder that holds a bearing, and a pin that passes through the axial center of the bearing and fixes the bearing and the bearing holder. The bearing holder has: a bearing holding region that supports the bearing; a pin insertion hole through which the pin is inserted; and a first oil hole that is formed so as to penetrate from a bearing holder end part to a pin insertion hole wall surface. The inside of the pin has a second oil hole for supplying lubricating oil to the bearing. An oil supply port of the second oil hole opens at a position that communicates with the first oil hole when fitted to the bearing holder. A discharge port of the second oil hole opens on the inner ring surface side of the bearing.

Description

Bearing holder, bearing structure, bearing lubrication method, and rolling mill

[0001] The present invention relates to a bearing holder, a bearing structure, a bearing lubrication method, and a rolling mill apparatus.

[0002] Bearings, which support rotating parts (rotating shafts) at precise positions and reduce friction with the rotating shaft to prevent energy loss, are used in a wide variety of machines with rotating shafts in a variety of environments, including high-temperature and high-speed rotation environments. These bearings have traditionally become unusable earlier than expected due to factors such as seizure, wear, and flaking caused by compressive stress, and studies have been conducted to extend their lifespan. For example, Patent Document 1 discloses a ball bearing consisting of a single ceramic inner ring, multiple ceramic balls disposed in the inner ring's raceway groove, and a single ceramic outer ring. Because this ball bearing's inner ring, balls, and outer ring are all made of ceramic, it is believed to have high heat resistance, corrosion resistance, and wear resistance, contributing to a longer lifespan.

[0003] Patent Document 2 discloses a rolling bearing characterized in that at least one of the rolling surfaces of a ceramic raceway and the rolling elements is formed from porous ceramics impregnated with lubricating oil. It also discloses a rolling bearing characterized in that at least one of the rolling surfaces and rolling elements is formed from ceramics compounded with a solid lubricant and fired. According to Patent Document 2, lubricating oil uniformly dispersed in the ceramics forming the rolling surfaces or rolling elements can easily seep out to the rolling contact areas, preventing localized stress concentration at the rolling contact areas and reducing frictional resistance, thereby extending the life of the bearing.

[0004] Publication No. 6-15132 Japanese Patent Publication No. 6-129437

[0005] While the bearings described in Patent Documents 1 and 2 are useful inventions that can contribute to longer bearing life, when a large thrust load is applied to the rotating shaft due to high-speed rotation, such as in a rolling mill roll for metal plates, seizure problems can occur even when lubricating oil is supplied, and there is concern that even the bearings described in the patent documents will have a short life due to insufficient lubrication. Therefore, the object of the present invention is to provide a bearing retainer and a bearing structure that can improve the lubrication performance of bearings and extend their life without using bearings with special structures.

[0006] The present invention has been made in view of the above-mentioned problems. That is, one aspect of the present invention is a bearing retainer including a bearing holder that holds a bearing, and a pin that passes through the axis of the bearing and secures the bearing and the bearing holder, the bearing holder having a generally U-shaped cross section that holds both ends of the pin, the bearing holder having a bearing holding area that supports the bearing, a pin insertion hole through which the pin is inserted, and a first oil hole that is formed so as to penetrate from an end of the bearing holder to a wall surface of the pin insertion hole, the pin having a second oil hole inside for supplying lubricating oil to the bearing, an oil inlet of the second oil hole opening at a position that communicates with the first oil hole when the bearing holder is fitted, and an outlet of the second oil hole opening on the inner ring surface side of the bearing. Preferably, the second oil hole outlet of the pin opens in a concave notch that is reduced in size toward the axis of the pin.

[0013] Another aspect of the present invention is a bearing structure formed by combining the bearing retainer with a bearing having a lubricating oil inlet hole formed on the inner ring surface side of the bearing. Another aspect of the present invention is a method for lubricating a bearing using the bearing structure, in which lubricating oil is supplied to the bearing by introducing lubricating oil through a first oil hole formed in the bearing holder and discharging it from a second oil hole communicating with the first oil hole. Another aspect of the present invention is a rolling mill having at least a pair of work rolls for rolling a metal plate, in which the bearing structures are installed at both ends of the work rolls so that the axial ends of the work rolls abut against the bearings.

[0007] According to the present invention, the lubrication performance of the bearing can be improved and the life of the bearing can be extended without using a bearing with a special structure.

[0008] Fig. 4 is a perspective view showing an example of a bearing structure of the present invention when used; Fig. 5 is an exploded schematic view of the bearing structure; Fig. 6 is a schematic view showing a bearing holder of the present invention; Fig. 7 is a cross-sectional view of the bearing holder of Fig. 3; Fig. 8 is a cross-sectional view showing a modified example of the bearing holder; Fig. 9 is a schematic view showing a pin of the present invention.

[0009] An embodiment of the present invention (hereinafter, also referred to as the present embodiment) will be described using a thrust roller bearing structure for work rolls of a rolling mill. FIG. 1 shows an example of the installation of the bearing structure of this embodiment. The components from the bearing structure 1 to the thrust block 6 are provided on both sides of the work roll, but FIG. 1 omits one side. As shown in FIG. 1 , the bearing retainer 2 of the present invention is composed of a bearing holder 3 and a pin 4 and is used in combination with a bearing 5 to form the bearing structure 1 (the bearing retainer on the side showing only the bearing 5 is not shown). In this embodiment, the bearing holder 3 is connected to the thrust block 6, and the bearing 5 contacts the work roll 7 of the rolling mill and bears the axial load generated in the work roll when the work roll rotates at high speed to process a metal plate. To prevent seizure between the work roll and the bearing, a lubricant such as grease or lubricating oil is supplied to the bearing to maintain the lubricating performance of the bearing. However, in a high-load environment such as the work roll of a cold rolling mill in this embodiment, lubrication by grease is unsuitable. Even if lubricating oil is supplied from the outer surface of the bearing, there is a risk of seizure due to insufficient lubrication.

[0010] FIG. 2 is a schematic diagram illustrating the configuration of the bearing retainer of this embodiment. One of the features of the present invention is that the pins that make up the bearing retainer have oil holes formed therein so that lubricating oil can be supplied from the inner ring side of the bearing. A characteristic bearing holder of this invention will now be described. FIG. 3 is a schematic diagram illustrating the configuration of the bearing holder, and FIG. 4 is a schematic cross-sectional view passing through the oil holes of the bearing holder. As shown in FIGS. 3 and 4 , the bearing holder 3 has a substantially U-shaped (approximately a backwards C) cross section, and has a bearing retaining area 10 that holds the bearing, and pin insertion holes 11a and 11b for inserting the pins 4. The bearing holder 3 of this embodiment also has a first oil hole 12 formed so as to penetrate from the bearing holder end 18 to the wall surface of the pin insertion hole. As shown in Figures 3 and 4, this first oil hole 12 has an oil inlet 13 formed in the bearing holder end 18 on the thrust block side and an outlet 14 formed in the wall surface of the pin insertion hole 11b. Lubricating oil supplied from the first oil hole oil inlet 13 passes through the first oil hole and is discharged from the first oil hole outlets 14 (14a, 14b) to be supplied to the bearing. Note that in Figure 4 of this embodiment, the outlet 14 of the first oil hole is formed only in the wall surface of the pin insertion hole 11b, but as shown in Figure 5, it may also be formed on the pin insertion hole 11a side. In this case, the shape of the first oil hole may be appropriately adjusted, for example, to the shape shown in Figure 5, so that lubricating oil can also be supplied to the outlet provided on the pin insertion hole 11a side.

[0011] Next, the pin of this embodiment will be described. The pin of this embodiment is shown in FIG. 6 . The pin of this embodiment has a second oil hole (not shown) for supplying lubricating oil to the bearing. This second oil hole is formed with an oil inlet 15 for the second oil hole so that it communicates with the outlet 14 of the first oil hole formed in the bearing holder 3 when the pin is fitted to the bearing holder 3. For example, in the combination of the bearing holder shown in FIG. 4 and the pin shown in FIG. 6 , when the pin is fitted to the bearing holder, the first oil hole outlet 14 of the bearing holder and the second oil inlet 15 for the second oil hole formed in the pin are aligned in position. This state is called "communication." The pin of this embodiment is formed with an outlet 16 for the second oil hole so that the lubricating oil supplied through this communication can be supplied to the inner ring surface of the bearing. While the outlet 16 for the second oil hole is formed in the axial center of the pin in FIG. 6 , it may be formed at the axial end or other location as long as sufficient lubricating oil can be supplied to the inner ring side of the bearing. The diameter of the oil hole is not particularly limited, and can be adjusted appropriately in accordance with the amount of lubricating oil supplied so as to obtain the effects of the present invention.

[0012] In this embodiment, the second oil hole outlet formed in the pin is preferably formed by providing a concave cutout 17 formed by reducing the size of the pin toward the axial center, and by forming it so as to open into this concave cutout 17. The space formed within this concave cutout allows a sufficient amount of lubricating oil to be present between the inner ring surface of the bearing and the pin, which is expected to further improve the lubrication performance of the bearing and contribute to a longer lifespan.

[0013] The bearing holder and pins of this embodiment may be made of conventional carbon steel or alloy steel. In order to ensure a stable and long life for the bearing holder, especially in high-load environments, it is preferable to use cold-work tool steel, such as SKD11, which has excellent corrosion resistance and wear resistance, as the material for the pins.

[0014] By combining the above-described bearing holder and pin as a bearing retainer with a bearing (bearing structure), lubricating oil can be stably supplied to the inner ring side of the bearing. In this case, in order to ensure that the lubricating oil supplied from the bearing retainer is quickly supplied to the bearing body, it is preferable that a lubricating oil introduction hole 19 is formed on the inner ring surface side of the bearing combined with the bearing retainer of the present invention, as shown in Figure 2.

[0015] The rolling mill of the present invention, in which the bearing structure (thrust roller bearing structure) of the present invention is installed at both axial ends of a work roll, can suppress seizure defects by improving lubrication performance and obtain the effect of improving work efficiency, even when applied to work rolls that are subjected to large thrust loads on the rotating shaft due to high-speed rotation.

[0016] REFERENCE SIGNS LIST 1 Bearing structure 2 Bearing retainer 3 Bearing holder 4 Pin 5 Bearing 6 Thrust block 7 Work roll 8 Metal plate 10 Bearing retaining area 11a, 11b Pin insertion hole 12 First oil hole 13 First oil hole oil supply port 14 First oil hole outlet port 15 Second oil hole oil supply port 16 Second oil hole outlet port 17 Concave notch 18 Bearing holder end 19 Lubricating oil introduction hole

Claims

1. A bearing retainer comprising a bearing holder which holds a bearing, and a pin which passes through the axis of the bearing and secures the bearing to the bearing holder, wherein the bearing holder has a generally U-shaped cross section which holds both ends of the pin, the bearing holder has a bearing retaining area which supports the bearing, a pin insertion hole through which the pin is inserted, and a first oil hole which is formed so as to penetrate from the end of the bearing holder to the wall surface of the pin insertion hole, the inside of the pin has a second oil hole for supplying lubricating oil to the bearing, an oil inlet of the second oil hole opens at a position which communicates with the first oil hole when fitted with the bearing holder, and an outlet of the second oil hole opens on the inner ring surface side of the bearing.

2. A bearing retainer as set forth in claim 1, wherein the second oil hole outlet of said pin opens into a concave cutout formed so as to reduce in size on the axial center side of the pin.

3. A bearing structure comprising the bearing retainer according to claim 1 or 2 combined with a bearing having a lubricating oil introduction hole formed on the inner race surface side of the bearing.

4. A method of lubricating a bearing using the bearing structure according to claim 3, comprising the steps of: introducing lubricating oil through a first oil hole formed in the bearing holder; and discharging the lubricating oil through a second oil hole communicating with the first oil hole, thereby supplying the lubricating oil from the inner ring side of the bearing.

5. A rolling apparatus comprising at least a pair of work rolls for rolling metal plates, wherein the bearing structure according to claim 3 is installed on both ends of the work rolls so that the axial ends of the work rolls abut against the bearings.

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