Has 20 years of history, Since 1987 began

NTN Corporation (hereafter, NTN) will provide specially designed bearings for the Institute of the University to participate in the "World Solar Challenge" international solar car cross bearing  race was held in Australia in October this year. NTN interaction with  the Institute of the University College of Engineering increased by Mechanical Engineering Tribology workshop, and the development of the motor shaft and bearings as a student, "Institute of the University of automatic" support for the activities section, will participate in the first challenge. World Solar Challenge "is one of the largest solar car race in the world, participants race over 3021 km, through the Australian desert between Darwin and Adelaide, using the sun as the only power source. Has 20 years of history, Since 1987 began, the race attracts participants from around the world, including many spherical roller bearing  universities and businesses. Institute's goal is to win in the game the first time on the podium. Solar car electric car, the sun's energy into electrical energy drive motor and steering tires. With minimal power dissipation structure design requires long-distance driving using only electric power obtained from solar cells. Deep groove ball bearings NTN challenges provided by the JIS 5 magnitude, which is higher than the general JIS 0 级 two levels to help improve machining accuracy. Ceramic balls has changed ball rolling contact surface curvature is optimized to reduce the contact area and achieve a lower torque, while stirring resistance with minimal low-viscosity grease has been used. This helps to reduce 50% of the torque compared to conventional products. Gangdun has been changed to non-contact rubber seals to improve driving through the desert to prepare to resist the penetration of foreign substances. In addition to wheel motors, NTN bearings used in the drive wheel shaft rotational torque reduction. This helps to achieve high speed with minimum power consumption, but also contribute to long-distance driving.

Germany FAG Bearing Group Automotive Division: skilled, powerful

Schaeffler Group's three active Division With FAG, LUK and three strong brands INA Schaeffler (Germany FAG bearings) Group, its mainly active in the automotive division, industrial and aerospace division Division.Germany FAG spherical roller bearing Group Automotive Division: skilled, powerfulSchaeffler Group's largest customer is the most important automotive industry, about 60% of the Schaeffler Group's sales from the automotive industry, the Schaeffler Group, as an almost all major automobile manufacturers and suppliers a reliable partner, FAG slewing ring bearing Group Automotive Division for the entire drive train, passenger commercial vehicle engines, chassis, transmissions and other parts units and suppliers to provide the most professional knowledge and innovative ideas and products. Germany FAG Bearing Group Aerospace Division: aerospace equipment and aerospace manufacturing partner of choiceGermany FAG Bearing Group Aerospace Division to support the development and production of special bearings for aerospace applications. Almost all aircraft using modern techniques to accomplish FAG Bearings, FAG is to become the world's leading technology development partners helicopter manufacturers and suppliers.

Cause bearing failure caused

According to the bearing surface grinding metamorphic layer formation mechanism, the impact grinding metamorphic layer of the main factors is the grinding heat and grinding force. The following analysis on the reasons for bearing failure.

1 bearing the grinding heat

The roller bearing grinding, the grinding wheel and the workpiece contact area, consume large amounts of energy, resulting in a large number of grinding heat, causing the local instantaneous grinding zone temperature. Use of linear motion heat transfer theory derivation, calculation or application infrared and thermocouple method measured the instantaneous temperature under experimental conditions can be found in the 0.1 ~ 0.001ms instantaneous temperature within the grinding zone up to 1000 ~ 1500 ℃. Such instantaneous temperature, a certain depth sufficient to work the surface layer of high temperature oxidation, amorphous structure, high-temperature tempering, secondary hardening, cracking and other changes or burns.

(1) the surface oxide layer

The instantaneous high temperature steel surface under the role of oxygen in the air, up into very thin (20 ~ 30nm) thin layer of iron oxide. It should be noted that the oxide layer thickness and the total thickness of the surface layer of grinding deterioration test results showed a corresponding relationship. This shows that the thickness of the oxide layer which is directly related with the grinding process, the grinding quality is an important symbol.

(2) amorphous tissue layer

Instantaneous grinding zone so that the surface temperature reaches a molten state, the molten metal molecular flow has been evenly coated on the work surface, and is the base metal at breakneck speed cooling, forming a thin layer of amorphous tissue layer. It has high hardness and toughness, but it is only about 10nm, it is easy to be removed precision grinding.

(3) high-temperature tempering layer

Instantaneous grinding zone temperature to a certain depth can (10 ~ 100nm) is heated to a temperature above the tempering heating the workpiece. Does not reach the austenitizing temperature in the case, as the heating temperature is increased, the surface layer by layer will be generated corresponding to the temperature of the heating or tempering retempered organizational changes, hardness is decreased. The higher the heating temperature, the hardness decreased also more powerful.

Talking grinder hydrostatic bearing maintenance experience

Rotary hydrostatic bearing its high accuracy, good rigidity, high capacity, no wear, high durability and is widely used M210, M131W, 3160A grinder and 2A710, FYT10 Diamond boring head. With the development of digital technology, hydrostatic bearings are also widely used in machining centers, CNC machine tool spindles. YTO AG first engine plant, there are many static pressure and static pressure diamond grinder boring head, in the maintenance carried out some exploration and attempts to obtain experience points.

Orifice restrictor (a) outside the internal throttle to throttle, and to install the upper and lower chamber pressure gauge real-time display. So easy maintenance, in particular, can easily be cleaned regularly, this is an internal restrictor unmatched. (2) throttling ratio. Throttling than the theoretical value of β is 1.2 to 1.5, and 1.25 based on years of experience with preferred. So that the maintenance, the need for geometric precision spindle, bearing around the geometric accuracy, concentricity, roundness and taper strictly controlled in order to ensure β values. According to the carrying capacity of the machine to determine the value of e (the geometric center of the spindle and bearing eccentricity), the β value best. (3) is not installed in the oil chamber spindle, each column of oil out of the oil port must be consistent (observation), if not, should be taken to change the restrictor aperture methods to alter the flow. With 4 cavities, for example, generally lower, left and right chamber of the oil column at between 20 ~ 25mm, hole diameter of 0.25 ~ 0.4mm.

Thin film feedback Feedback restrictor throttle special bearing stiffness is great, but the machine in operation often appear hold tile, brushed, lost pressure and so on. The most critical is the feedback film film practice that locking bush, brushed the main reasons are: ① thin plastic deformation due; ② feedback slow. External load mutation, the film did not react when the axis and tile has been rubbed; ③ film fatigue. Film using a long time, fatigue deformation, the equivalent of changing the feedback parameters. Increasing film thickness and use some of the fatigue resistance of the material, can receive good results. Generally rigid film, a pre-load, reserve gap approach. Specific approach is: the 1.4mm thick rigid 4mm thick film to film, the inferior vena pad 0.05mm thick aluminum foil, so that the spindle than the ideal position to adjust to the high position of 0.05mm. Purpose is force when the spindle (wheel weights, cutting force) after return exactly to the ideal center.

Hydrostatic bearing oil supply system improvement in the fuel supply system, in addition to the coarse filter, fine filter, the rest of the components have a protective effect on the hydrostatic bearing. On the basis of the original system, fuel system improvements. (A) in the throttle plate after the oil pressure switch and pressure gauge connection port (the original in the accumulator in front), so that the operator can see the chamber pressure and the size of the inlet pressure. When the pressure is greater than a certain value, in order to immediately shut down, in order to avoid bearing locking. Such as: inlet pressure 2MPa, exit chamber pressure 1.2 ~ 1.6MPa, 1.2MPa below will shut down. (2) increasing the number of detection means hydrostatic bearing between the shaft and the bearing gap of 0.04 ~ 0.05mm, during which the oil has a certain resistance value of the resistance variation detection, it can learn the size of the gap . With spindle pole, bush for another pole, measure the resistance change. After processing this signal sent to the photoelectric alarms and control system amplifier, controls the spindle motor start and stop, in order to avoid friction axis and tile.

Bearing installation basics

A, clear of bearing
Bearing the model number indicates the basic dimensions of the bearing, the original clearance, cage type, sealed form, lubrication requirements, so before starting the installation must be clearly bearing model is correct.
B, the positioning of the spherical roller bearing
A shaft for smooth operation, generally at least two pivot for axial and radial support, each with at least one or more pivot bearings. Generally, from a role in positioning the bearing, the other bearing is positioned afford effect. In exceptional circumstances, the role of the two bearings also act as positioning.
Locating bearing provides radial support and axial orientation. Therefore, locating bearing on the shaft and the bearing chamber must also be fixed. Deep groove ball bearings, spherical roller bearings, double row angular contact ball bearings, single row pair angular contact ball bearings can be used as locating bearing. A pair of tapered roller bearings can be used. No flange cylindrical roller bearings and a thrust bearing with radial clearance, they can be used as locating bearing.
Non-locating bearing only provides radial support, which must be able to move in the axial direction. By axial movement of the bearing itself (for example, cylindrical roller bearing), it can be supported with the bearing inner ring or outer ring of the relative movement.
Cross-locating bearing may be formed in at least one direction while the axial load ball bearings or roller bearings components.