Railway rolling stock bearings refer to bearings used in locomotives and vehicles. The bearings on the locomotive include axle box bearings, traction motor bearings, transmission system bearings, power equipment bearings and cooling system bearings, etc.; the bearings on the vehicles are mainly axle box bearings; the passenger axle boxes are mostly short cylindrical roller bearings; The axle box is mainly made of tapered roller bearing; the type, layout and function of the vehicle bearing are basically similar to the locomotive axle box bearing.
1. Axle box bearing
The locomotive wheel is connected to the locomotive body through the axle box, the spring and the bogie frame; the axle box bearing directly receives the sprung gravity of the locomotive and the radial and axial impact of the rail on the wheel; in addition, the traction force is transmitted and the resulting Some additional loads; therefore, axlebox bearings must have a large bearing capacity; can withstand shock oscillation; it is necessary to have a higher life, safety and reliability, smaller scale and quality, easy to view and protect, etc. Therefore, locomotive bearings often use non-standard series of bearings and special bearing skills; commonly used rolling bearings have the following three categories.
(1) Cylindrical roller bearing diesel locomotives and electric locomotives Most of the axle boxes are cylindrical roller bearings. The first two are the following.
1) Four row cylindrical roller bearings
China's locomotive axle box bearings were the first to be selected and the most loaded is the four-row cylindrical roller bearing 972832. The bearing has high bearing capacity; long life; its additional dynamic load is 1445kN. Because it can only accept radial load; Accepts axial loads; it is therefore necessary to have additional axial force devices in the axle box.
2) Double row cylindrical roller bearing
China's Oriental Red 2, 3, 5, 21 and Beijing-type locomotive axleboxes use double-row cylindrical roller bearings 982832T; the bearing receives radial force; and the angular contact ball bearing 146132T accepts axial load.
(2) Spherical roller bearings
The advantage of using spherical roller bearings is that there is no offset compensation between the axle box and the bogie frame. The axle box bearing of the ND2 diesel locomotive imported from Romania is the C-type spherical roller produced by SKF Bearing Company. Sub-bearing. Its type is suitable with domestic bearing 3G4053736KT. The roller of this type of bearing is symmetrical; the inner ring has no outer rib; the middle rib is separable; the roller and outer ring are line touch; the roller is useful. Longer length; the use of asymmetrical spherical roller bearings with a similar life dimension is slightly larger.
(3) Tapered roller bearing
These bearings for locomotive axleboxes are double-row tapered roller bearings; the US ND5 diesel locomotives are loaded with AP-type bearings from TIMKEN. These bearings are in inch sizes; commonly used are B, C, D, E. , F, G, etc.; different from the axles used for different grades.
2. Traction motor bearing
(1) Traction motor armature bearing
The traction motor is the primary equipment in the transmission system of electric locomotives and electric drive diesel locomotives; the armature bearing is one of its primary components. The armature bearing load is large; and the size of the traction motor is affected by the wheel diameter and the inner side of the two wheels. Constraints with the lower limit of the locomotive; therefore, it is necessary to have such a small size and a high limit speed for such bearings.
1) Bearings with single side drive
The armature usually adopts double fulcrum support; the output end of the gear is the swimming support; the commutator end is the positioning support. The bearing of the output end is close to the gear; the force is the largest; it is the key bearing in the two bearings of the armature. Load; usually adopts cylindrical roller bearing NU type without inner rim. The commutator end is usually cylindrical roller bearing NUP type with single rib and inner ring with flat ring; foreign also has single rib for inner ring. And cylindrical roller bearings with slanting rings.
2) Bearings with double side drive
When the motor power is large; if the single-side transmission is still used, the bearing load at the gear end is too large; it is difficult to select the bearing with the additional dynamic load and the limit speed to meet the demand; therefore, the two sides can be used under the condition that the motor draws the promise. Transmission method. The advantage of the double-side transmission is that the helical gear can be selected; the helix angle of the two gears is flat; the direction of rotation is reversed; then the smoother transmission quality is obtained; no axial load occurs. The bearing suitable for this purpose is Cylindrical roller bearings without ribs on the inner ring NU type; if unilateral cylindrical gears are used for double-side transmission; bearings with a certain axial force should be selected; cylindrical roller bearings NJ with single ribs on the inner ring are usually selected. type.
(2) Traction motor holding shaft bearing
The axle suspension traction motor is usually supported on the bogie by one side of the lever; the other side is supported on the axle by the axle bearing. The bearing of the axle is simpler than the sliding bearing; but the smoothness and viewing are not convenient; In the 1950s, the use of rolling bearings was changed. Cylindrical roller bearings, spherical roller bearings and tapered roller bearings have been selected so far.
Cylindrical roller bearings are suitable for high-speed locomotives; their grease-reinforcing cycle is long; the device and protection are simpler; especially when using the whole casing, this strength is more obvious. The tapered roller bearing has good rigidity; it is beneficial to ensure the gears. Engagement accuracy; but its assembly and disassembly and axial clearance adjustment is more difficult. Two sets of spherical roller bearing devices; especially the disassembly is more difficult than tapered roller bearings; but can be used to the twist of the shaft. China's electricity The axle bearing of the traction motor of the locomotive has the choice of spherical roller bearing; its type is 3G3053148T.
(3) traction generator bearing
The body of the modern electric drive diesel locomotive traction generator is usually installed on the end face of the engine at the output end of the diesel engine. Whether it is this device method or other methods; the input end of the armature is rarely equipped with bearings; usually the armature is passed through the elastic coupling. Supported on the crankshaft or output shaft of the diesel engine; in order to shorten the longitudinal dimension of the generator.
The outer end of the armature shaft can usually be used with cylindrical roller bearings; sometimes it is convenient to match the diesel engine for the device; spherical roller bearings can also be used.
3. Bearings for diesel engine hydraulic drive system
The diesel engine hydraulic transmission system usually includes three hydraulic transmission boxes, universal joint shafts and axle gear boxes. The shunting locomotive sometimes also contains a working condition gear box; some of them are equipped with appropriate rolling bearings.
(1) Hydraulic transmission bearing
The working method of the hydraulic transmission box is when the train is towed; the power of the diesel engine is converted into the power to drive the locomotive through the hydraulic torque converter, and the dynamic braking is implemented; the hydraulic brake is used to absorb the kinetic energy of the wheel of the locomotive. The hydraulic transmission box There are several shafting systems in the interior; the bearing of each shaft is fully used with rolling bearings.
(2) Center gear box bearing
The primary components of the center gearbox are the input and output shafts each having two gears; the gear on one of the shafts is a shifting gear; the shaft and its gears have a gathering structure; one gear can be coupled to the shaft, The power is transmitted, and the other gear is only idling in this case. The shifting gear and the diffuser are often placed on the input shaft; because the input torque is more than 庋 诩跣 诩跣 牒掀鞯 牒掀鞯 å½ç»¾ å½ç»¾ å½ç»¾ å½ç»¾ å½ç»¾ å½ å½ å½ å½
(3) Axle gearbox bearing
4. Diesel crankshaft bearing
The diesel engine crankshaft bearing uses only the high-speed diesel engine of the rolling bearing; and the sliding bearing is selected. The 饕钡闶 饕钡闶 饕钡闶 鄹窀撸 鄹窀撸 柿 柿 柿 柿 岢 岢 岢 岢 岢 岢 岢 岢 岢 岢 岢Step wash.
About single-cylinder and twin-cylinder small diesel crankshafts; multi-purpose 0-stage rolling bearings, high-speed and high-power diesel crankshafts; because of their large loads; usually only cylindrical roller bearings.
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