WO2014030727A1

WO2014030727A1 - Taper-land bearing

Info

Publication number: WO2014030727A1
Application number: PCT/JP2013/072503
Authority: WO
Inventors: 拓宏山下; 周神谷
Original assignee: 大豊工業株式会社
Priority date: 2012-08-23
Filing date: 2013-08-23
Publication date: 2014-02-27
Also published as: JP2014040899A

Abstract

Provided is a taper-land bearing for reducing friction in a bearing surface of a sliding component by using a configuration that increases the load capacity of the bearing surface. This taper-land bearing is characterized in comprising a taper land including a tapered surface that rises in the circumferential direction of a bearing surface supporting a rotating shaft, the depth of the tapered surface being 50 µm or less, and the taper ratio, which is the length of the tapered surface in the circumferential direction divided by the length of the taper land in the circumferential direction, being 0.5 to 0.9.

Description

Tapered land bearing

The present invention relates to a taper land bearing, and more particularly to a taper land bearing in which taper lands are formed at a plurality of locations in the circumferential direction of a bearing surface serving as a sliding surface.

In recent years, reduction of wear of sliding parts has been demanded from the viewpoint of global warming and energy saving. For this reason, various studies have been conducted on friction reduction of sliding parts.

On the other hand, conventional tapered land bearings are disclosed in Patent Documents 1 to 3 below. Patent Documents 1 to 3 propose a structure in which tapered lands are provided at a plurality of locations in the circumferential direction of the bearing surface to increase the oil film pressure of the lubricating oil on the bearing surface.

The tapered land bearing of Patent Document 1 discloses a configuration in which a tapered surface is inclined in the radial direction in addition to the circumferential direction, and an oil hole is formed on the inner peripheral side of each tapered surface. The tapered land thrust bearing of Patent Document 2 discloses a configuration in which edges at each corner portion of the tapered land thrust bearing are removed. The tapered land type thrust bearing of Patent Document 3 is provided with a foreign matter discharge groove on the inner peripheral edge of the bearing surface, and discloses a configuration in which foreign matter in the lubricating oil is discharged to the outside of the bearing surface through the foreign matter discharge groove. Yes.

However, in Patent Documents 1 to 3 described above, the setting for increasing the load capacity of the bearing surface in the sliding part is insufficient, and measures for reducing the friction of the impulsive part are insufficient.

JP 58-17214 A Japanese Unexamined Patent Publication No. 60-18614 Japanese Utility Model Publication No. 5-73315

This invention is made in view of the said subject, and it aims at providing the taper land bearing which reduces the friction of a bearing surface.

The present inventors have found a combination in which the optimum taper land shape, for example, the depth of the taper portion, the ratio of the length of the entire taper land and the length of the taper portion, maximizes the load capacity.

A taper land bearing according to an embodiment of the present invention includes a taper land including a taper surface that increases in a circumferential direction of a bearing surface that supports a rotating shaft, and the depth of the taper surface is 50 μm or less, The taper ratio obtained by dividing the length of the taper surface in the circumferential direction by the length of the taper land in the circumferential direction is 0.5 or more and 0.9 or less.

According to the present invention, it is possible to provide a taper land bearing that reduces the friction of the bearing surface by setting so as to increase the load capacity of the bearing surface in the sliding component.

It is a top view which shows the taper land bearing which concerns on one Example of this invention. It is a side view which shows the principal part of the taper land bearing seen from the arrow II direction of FIG. (A) is a figure which shows the relationship between taper ratio and load capacity, (b) is a figure which shows the relationship between taper depth and load capacity, (c) is the number of taper lands, and load capacity. It is a figure which shows the relationship. It is a figure which shows the taper land shape of the taper land bearing used as the test object. It is a schematic sectional drawing which shows the testing machine which measured the friction torque about each taper land bearing shown in FIG. It is a figure which shows the test pattern by the testing machine of FIG. It is a figure which shows transition of the friction torque regarding the 1st taper land bearing in FIG. 5, and a 5th plane bearing. FIG. 5 is a diagram showing the number of bearing characteristics when a torque peak occurs for the taper land bearing of each test sample in FIG. 4.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, although a taper land bearing is demonstrated in a present Example, the taper land bearing which concerns on this invention is not limited to this.

FIG. 1 is a plan view showing a taper land bearing 1 according to an embodiment of the present invention. FIG. 2 is a side view showing the main part of the taper land bearing 1 as seen from the direction of arrow II in FIG.

As shown in FIG. 1 and FIG. 2, the taper land bearing 1 is composed of an annular metal plate member. The taper land bearing 1 includes a bearing surface 1A of the taper land bearing 1 that supports the end surface 2A of the rotating shaft 2 that is the counterpart shaft and slides with the end surface 2A of the rotating shaft 2. As shown in FIGS. 1 and 2, the taper land 1B has six taper lands 1B formed at an equal pitch on the bearing surface 1A in the circumferential direction. As long as the load capacity of 1A can be set so as to reduce the friction of the bearing surface, the pitch may not be equal at a plurality of locations in the circumferential direction and may not be limited to six locations.

Here, as shown in FIG. 1 and FIG. 2, the rotating shaft 2 which is the counterpart shaft of the taper land bearing 1 is rotated in the direction of the arrow. Each tapered land 1B of the tapered land bearing 1 is formed with a tapered surface 1C on the rotational direction side of the rotary shaft 2, and a flat flat surface 1D is formed adjacent to the tapered surface 1C.

In the present embodiment, the taper surface 1C of each taper land 1B is a taper surface where the rotation direction side of the rotary shaft 2 is deepest in the circumferential direction, and the depth h (maximum depth) of the taper surface 1C is 50 μm or less. Is set. If the depth h of the taper surface 1C exceeds 50 μm, the load capacity of the taper land bearing 1 becomes small, and the taper land bearing 1 comes into contact with the mating shaft and seizure occurs, which is not preferable. When the length of the taper land 1B in the circumferential direction is L1, and the length of the taper surface 1C in the circumferential direction is L2, the taper ratio (L2 / L1) obtained by dividing L2 by L1 is It is set to 0.5 or more and 0.9 or less. If the taper ratio is out of the range of 0.5 or more and 0.9 or less, the load capacity of the taper land bearing 1 is reduced, and the taper land bearing 1 comes into contact with the mating shaft and seizure occurs. It is not preferable.

In the embodiment of the present invention, as the optimum tapered land 1B shape, the depth h of the tapered surface 1C is set to 50 μm or less, and the taper ratio is set to 0.5 or more and 0.9 or less. If the friction capacity of the bearing surface can be reduced by setting the load capacity of the bearing surface 1A of the taper land bearing 1 in the sliding component to be increased, the shape of the taper land 1B can be changed.

When the taper land bearing 1 according to the embodiment of the present invention is mounted at a required location of the rotating device, the end surface 2A of the rotating shaft 2 that is the counterpart shaft is supported by the bearing surface 1A, and in a supported state. The rotating shaft 2 is rotated in the direction of the arrow. Thus, when the rotating shaft 2 is rotated in the direction of the arrow and the end surface 2A of the rotating shaft 2 and the bearing surface 1A of the taper land bearing 1 slide, the bearing surface 1A from the inner peripheral portion of the taper land bearing 1 is obtained. Is supplied with lubricating oil. Therefore, an oil film of lubricating oil is formed on the bearing surface 1A, and the end surface 2A of the rotating shaft 2 is supported by the bearing surface 1A via this oil film. Therefore, the distance between the flat surface 1D of the bearing surface 1A and the end surface 2A of the rotating shaft 2 is the thickness t of the lubricating oil film.

And since each taper land 1B in the taper land bearing 1 of a present Example is the dimension setting mentioned above, the load capacity of the bearing surface 1A can be maximized, and it also becomes clear also from the test result mentioned later. The friction of the bearing surface 1A when sliding with the end surface 2A of the rotating shaft 2 can be reduced as compared with the bearings of other configurations.

As described above, in the taper land bearing 1 according to the present embodiment, the six taper lands 1B are formed on the bearing surface 1A at equal pitches in the circumferential direction, and the depth h of the taper surface 1C is 50 μm or less. Further, the taper ratio (L2 / L1) is set to 0.5 or more and 0.9 or less. The dimension of the taper land bearing 1 is set by paying attention to the depth h of the taper surface 1C of the taper land 1B and the taper ratio r, and the load having the depth h of the taper surface 1C of the taper land 1B and the load of the taper ratio r. A value that maximizes the capacity Y was calculated. In addition, a taper land bearing 1 is manufactured in which the load capacity Y is set to a maximum value in these two calculated elements, and the taper land bearing 1 is subjected to friction together with a plurality of bearings having other configurations. A test was conducted on the difference in torque.

In the test results, the taper land bearing 1 having the above-described dimension setting has the maximum load capacity Y. Therefore, in this embodiment, the taper land bearing 1 has the above-described dimension setting.

Hereinafter, the calculation method of the taper surface 1C of the taper land 1B and the taper ratio r, the calculated number x of the taper lands 1B, the depth h of the taper surface 1C of the taper land 1B, and the taper. The taper land bearing 1 having a load capacity Y of the ratio r set to a maximum value is manufactured, and the taper land bearing 1 is tested together with a plurality of taper land bearings of other configurations, and details of tests regarding the difference in friction torque and The test results will be described.

The taper land bearing dimensions and calculation conditions for calculating the maximum load capacity Y with respect to the depth h of the taper surface 1C of the taper land 1B and the taper ratio r are set as follows.

The inner diameter of the taper land bearing is 61.1 mm, the outer diameter of the taper land bearing is 82.6 mm, the rotational speed is 500 rpm, the viscosity of the lubricating oil is 3.74 cP, the density of the lubricating oil is 850 kg / m ³ , and the oil film thickness t is It was 1 μm. In addition, although the internal diameter of the taper land bearing was set to 61.1 mm and the outer diameter of the taper land bearing was set to 82.6 mm, the present invention is not limited to this. For example, the inner diameter and outer diameter of the taper land bearing are not limited as long as the taper ratio r of the taper land 1B and the load capacity Y of the depth h of the taper surface 1C are maximized. The outer diameter of the tapered land bearing may be 40 mm to 110 mm.

First, the oil film pressure per taper land when the oil film thickness t is 1 μm is calculated by fluid lubrication analysis using the taper land bearing 1 based on the Reynolds equation in consideration of centrifugal force. The product of the oil film pressure and the number of taper lands 1B is defined as the load capacity Y of the entire taper land bearing. In this way, the load capacity by the fluid lubrication analysis was set to Y, the taper ratio was set to r, the depth of the taper surface was set to h, and the number of taper lands was set to x, and it approximated by multiple regression analysis. Then, from this approximate expression, the taper ratio that maximizes the load capacity Y, r, the depth of the taper surface, h, and the number x of taper lands were obtained.

3A is a calculation result regarding the taper ratio r and the load capacity Y, FIG. 3B is a calculation result regarding the taper depth h and the load capacity Y, and FIG. 3C is the number x of the taper lands. It is the calculation result regarding the load capacity Y. As shown in FIG. 3A, the calculated load capacity Y is maximized because the taper ratio r is 0.5 or more and 0.9 or less. As shown in FIG. The depth h was 50 μm or less. The number x of taper lands shown in FIG.

Based on the above calculation results, the taper land bearing 1 is manufactured with the taper ratio r, the depth h of the taper surface 1C of the taper land 1B and the number x of the taper lands 1B with the maximum load capacity Y, and Tests on friction torque were performed on tapered land bearings manufactured with other dimensions.

FIG. 4 is a diagram showing the taper land shape of the five taper land bearings that were tested. In FIG. 4, the first test sample is a taper land bearing of the present embodiment, and the fifth test sample is a bearing in which the entire bearing surface is a flat surface.

Next, FIG. 5 is a schematic cross-sectional view showing a testing machine that measures the friction torque for each tapered land bearing shown in FIG. A taper land bearing, which is the sample S to be tested, is mounted on the pedestal 11 of the testing machine, and ATF heated to 120 ° C. is supplied from the axis of the pedestal 11 at 1 liter per minute. A torsion bar 12 is connected to the pedestal 11 holding the test sample S, and a strain gauge 13 is built in the torsion bar 12. The friction torque detected by the torsion bar 12 was continuously recorded.

Here, FIG. 6 is a diagram showing a test pattern by a testing machine. In the test pattern of the testing machine shown in FIG. 6, the rotation speed of the rotating counterpart shaft 14 is kept constant at 5000 rpm, and the load is increased to 6000 N at 500 N / 15 min. When the load reaches 6000 N, the rotation speed is decreased at 50 rpm / 5 min while the load is kept constant. In this test pattern, the number of bearing characteristics is reduced stepwise. Here, the number of bearing characteristics means a numerical value obtained as a calculation result of rotational speed × lubricating oil viscosity / bearing surface pressure. In this test, when contact between the mating shaft 14 and the bearing surface of the taper land bearing occurs, that is, when lubricating oil runs out, a friction torque peak occurs. The smaller the number of bearing characteristics when this friction peak occurs, the higher the load capacity, and the taper land bearing of each test sample S was compared and evaluated using this value.

FIG. 7 is a diagram showing the transition of the friction torque regarding the first taper land bearing (taper land bearing of this embodiment) and the fifth flat bearing in FIG. As shown in FIG. 7, it can be seen that the first tapered land bearing is suppressed from generating torque peaks, and the friction torque is lower by 30% or more than the other flat bearing.

FIG. 8 is a diagram showing the number of bearing characteristics when a torque peak occurs in the taper land bearing of each test sample of FIG. As shown in FIG. 8, the first taper land bearing has the lowest number of bearing characteristics. In other words, the load capacity of the first taper land bearing is the highest. On the other hand, it is clear that the second taper land bearing to the fourth taper land bearing have a lower load capacity than the first taper land bearing. The fifth flat bearing has the highest number of bearing characteristics, in other words, the load capacity of the bearing is the lowest.

As shown in FIGS. 3A to 3C, the contribution ratio of each design parameter obtained from the calculation result increases in the order of the depth h of the tapered surface and the taper ratio. In accordance with the height, it was confirmed that the number of bearing characteristics at which a friction torque peak occurs greatly decreases. The contribution rate of each design parameter obtained from the calculation result of this time to the load capacity has a correlation with the test result, and it has been found that the influence of the taper surface depth h on the load capacity is the largest.

As described above, as is apparent from the test results described above, the taper land bearing 1 according to the present embodiment can maximize the load capacity of the bearing surface 1A, as compared with bearings of other configurations. The friction of the bearing surface 1A when sliding with the end surface 2A of the rotating shaft 2 can be reduced. Therefore, it is possible to provide the taper land bearing 1 that can reduce friction and contribute to lower fuel consumption of the rotating device.

DESCRIPTION OF SYMBOLS 1 ... Tapered land bearing, 1A ... Bearing surface, 1B ... Tapered land, 1C ... Tapered surface, 2 ... Rotating shaft, 2A ... End surface.

Claims

A taper land including a taper surface that increases in the circumferential direction of the bearing surface that supports the rotating shaft, and
The taper surface has a depth of 50 μm or less;
A taper land bearing, wherein a taper ratio obtained by dividing a circumferential length of the tapered surface by a circumferential length of the taper land is 0.5 or more and 0.9 or less.