滚动轴承 Rolling Bearings Rolling bearings is a collective name for shaft support bearings that have revolving elements between a moving and a stationary ring. This is in contrast to plain bearings. 工作时,由滚动体在内外圈的滚 道上进行滚动摩擦,并支承轴的部件 ,叫滚动轴承。 滚动轴承由外圈、内圈、滚动体 和保持架四个部分组成。 1 点、线接触 Point and Line contact With a ball bearing, the load is transmitted to the runway through the balls and a very small surface. This is called a point contact. The bearing capacity is therefore less than that of a roller bearing, where the load is transmitted through a line contact to the runways. 球轴承中,在载荷的作用下,滚动 体(球)与滚道的接触面几乎为一个点 ,称为点接触。 而接触面为一条线,称为线接触。 点接触轴承承载能力不如线接触轴 承。 2 滚动轴承的类型 Radial and Axial Bearings Rolling bearings are subdivided into two main groups, namely Radial rolling bearings. Axial rolling bearings - Radial bearings mainly serve for taking up a load radially, i.e. perpendicular to the shaft. Axial bearings mainly serve for a load in the axial direction of the shaft. Certain types of bearing can take a combined load. 向心轴承。主要承受径向载荷。 推力轴承。只能承受轴向载荷。 向心推力轴承。能同时承受径向载荷和轴向载荷的轴承。 3 滚动轴承和滑动轴承的比较 Rolling bearings compared to a plain bearings 4 滚动轴承的优点 Advantages of rolling bearings to plain bearings 1. 起动灵敏。 Small starting moment 2. 摩擦系数小。 Low friction at all speeds 3. 效率高。Low consumption of energy 4. 旋转精度高。High reliability 5. 轴向尺寸小。 Little width 6. 润滑简便。 Long lubrication intervals 7. 润滑剂消耗最小。 Minimum consumption of lubricant 8. 易于更换。Easy to replace 9. 标准件。 Standardised dimensions 5 滚动轴承的结构及名称 Definitions 6 滚动轴承的类型 Bearing types • 深沟球轴承 • 调心球轴承 • Deep groove ball bearing • Self aligning ball bearing 7 滚动轴承的类型 Bearing types • 角接触球轴承 • 双列角接触球轴承 • Angular contact bearing • Two row angular contact bearing 8 滚动轴承的类型 Bearing types • 调心滚子轴承 • 圆柱滚子轴承 • Spherical roller bearing • Cylindrical bearing 9 滚动轴承的类型 Bearing types • 滚针轴承 • 推力球轴承 • Needle bearing • Thrust ball bearing 10 滚动轴承的类型 Bearing types • 推力圆柱滚子轴承 • 推力调心滚子轴承 • Cylindrical thrust bearing • Spherical roller thrust bearing 11 滚动轴承的代号 Rolling bearing coding 12 例子 An example 22320 EK C3 The significance of the above bearing code is as follows: 2 =two-row barrel shape bearing 调心滚子轴承 23=dimension series 尺寸系列代号,2为宽度系列代 号,3为直径系列代号 20=diameter bore 内径代号 x5=20x5=100 mm E=altered internal construction 内部结构改变 K=conical bore 1:12 内孔锥度为1:12 C3= radial clearance larger than normal. 游隙代号 13 轴承装配的预防措施 Precautionary measures with the assembly of bearings Inspect the parts of the bearing set-up and remove all burrs(毛刺). Clean the shaft and check the seats on diameter tolerance and dimensional accuracy. Inspect the seals and replace them if they are damaged. A rubber seal must always be replaced. 14 轴承装配的预防措施 Precautionary measures with the assembly of bearings Unpack new bearings just before the assembly. They must remain protected against dirt as long as possible. The preserving(保留) agent must not be removed, except from the bearing bore and the outer surface of the outer ring. Wash these surfaces with an oilbased solvent and dry them. Use a lint-free cloth. Large bearings are often protected by a relatively thick layer of hot greasy preserving agent, in which the bearing is immersed(陷入). This layer must be removed by washing before assembly. 15 轴承的清洗方法 Cleaning methods of bears There are two methods to clean bearings: cold and hot. With cold cleaning, the bearing is washed with an oilbased solvent. Always use clean liquid and tools, with the first washing stage being done in one tank and the last rinsing(冲洗) stage in another tank. Dry the bearing and smear(涂上) it immediately after drying with grease or oil. Protect it against dirt until assembly. With hot cleaning, use a thin, clean oil with a flash point of at least 250 °C. The oil must be heated to about 120 °C. Hot cleaning is mostly very efficient, and the remaining oil offers a temporary(临 时的) protection against corrosion(侵蚀). 16 轴承的安排 Bearing arrangement 17 滚动轴承装配的方法 assembly and/or disassembly method 1. 机械压入法。Mechanical method 2. 液压法。 Hydraulic method 3. 压油法。Pressure oil method 4. 温差法。 Thermal method The following division is made with regard to bearing size: Small bearings: bore < 80 mm Medium bearings: bore 80 to 200 mm - Large bearings: bore > 200 mm. 18 圆柱孔轴承的装配 Assembly of bearings with cylindrical bore 不能直接敲打轴承的内外圈、保持架和 滚动体。 During assembly, never strike directly against the bearing rings, cage or the rolling elements. 装配的压力应直接加在待配合的套圈端 面上,决不能通过滚动体传递压力。 Never exert force on the one ring to assemble the other. The force will then be transmitted to the rolling elements. 19 圆柱孔轴承的装配 Assembly of bearings with a cylindrical bore 20 机械方法 Mechanical method(cold assembly) 21 用温差法装配 Thermal method(hot assembly) The temperature difference between the bearing and the seat depends on the tightness of the fit and the bearing size. Usually, a bearing temperature of 80 to 90 °C above that of the shaft is sufficient for assembly. The bearing may never be heated above 125 °C, because there is a chance that the material properties will change. During assembly, use clean protective gloves(手套) to handle the bearing. Slide the bearing over the shaft as far as the contact face and keep it pressed against this until the bearing is fixed. 22 用温差法装配 Thermal method(hot assembly) Depending on the type of bearing to be assembled, there are different heating methods applicable, i.e.: Induction heaters 感应加热器 Electrical heating plates 电子加热盘 Heating cabinets 加热箱 Oil baths. 油浴 23 用温差法装配 Thermal method(hot assembly) Bearings must never be heated in an open fire because this will cause stresses in the bearing material. 24 用温差法装配 Thermal method(hot assembly) • 感应加热器 • 电加热盘 • Induction heater • Electrical heating plate 25 用温差法装配 Thermal method(hot assembly) Heating cabinet Here, the bearings are heated in an electrical heating cabinet, in which a blower(送风机) is fitted. The advantages of these cabinets are that a large number of bearings can be heated at the same time and that the bearings can be kept at the same temperature for a long time. Oil bath When heating a bearing with the aid of an oil bath, we use a tray (盘)filled with oil that is placed on a heating element. Because the bearing may never come into contact with the tray, the tray contains a perforated(打孔) plate on which the bearing lies. Of course, it is also possible to hang the bearing on a bracket(支架) in the oil. It is necessary to watch the temperature of the oil bath carefully. 26 圆柱孔轴承的拆卸 Disassembly of bearings on a cylindrical seating With the disassembly of bearings with a cylindrical bore, the cold disassembly method should be subdivided into: - Mechanical method 机械的方法 - Hydraulic method 液压的方法 - Pressure oil method. 压油的方法 27 圆柱孔轴承的拆卸 Disassembly of bearings on a cylindrical seating Mechanical method Small and medium size bearings with a tight fit on the shaft can be disassembled with the aid of a normal puller. Puller on the inner ring Turning of the bearing during disassembly 28 圆柱孔轴承的拆卸 Disassembly of bearings on a cylindrical seating Disassembly via the outer ring 29 圆柱孔轴承的拆卸 Disassembly of bearings on a cylindrical seating Disassembly by means of a hydraulic puller Tight fit on inner and outer rings 30 Disassembly by means of pressure oil method 圆柱孔轴承的拆卸 Disassembly of bearings on a cylindrical seating Thermal method Disassembly by means of heating is a suitable method to remove the inner rings of cylinder bearings. Here, special tools can be applied, such as aluminium rings. Heating by means of aluminium ring Heating by means of induction heater 31 圆柱孔轴承的装配和拆卸 Cylindrical seating 32 圆锥孔轴承的装配 Assembly of bearings with tapered bore With the cold method, however, another distinction(区别) must also be made: - Mechanical method - Hydraulic method - Oil pressure method. Small bearings are usually assembled cold with the aid of a mounting bush and a hammer or a locking nut and a spanner. Larger bearings can be assembled more easily by using a hydraulic nut and/or the pressure oil method. In certain cases, the bearing can be assembled by means of the thermal method. 33 机械的方法 Mechanical method (cold method) Assembly with the aid of the nut and spanner Assembly with the aid of an impact bush The use of a impact spanner 34 用液压螺母装配轴承 Hydraulic method Bearings with a bore of more than 50mm can be assembled easily and reliably(可靠的) with the aid of a hydraulic nut. 35 压油的方法 Pressure oil method This is a method for medium size and large bearings. Here, oil is injected under high pressure between the surfaces of the bearing and the seat, until both are completely separated. This reduces the friction to practically zero. 36 热配法 Hot assembly When, for one reason or another, the pressure oil method or a hydraulic nut cannot be used, the alternative(可选择的方法) is to heat the bearing. This can be done with the aid of an induction heater, heating cabinet(箱) or an oil bath(油浴). 37 Assembly against a collar Slide the cold bearing on the shaft until it makes good contact with its seat. Measure the distance between the inner ring and the collar(套). This must be reduced by the axial driving on; for this, consult(参考) the tables. 38 Assembly on a shaft without collar Follow the procedure(程序) described above, but measure with respect to a reference(参考) plane instead of to a collar. Increase or reduce this dimension by the length of driving up to obtain the “assembly distance”. Measure the distance while the bearing is slid onto the tapered seat. Keep the bearing in place until it clamps. Place the locking nut and check the clearance when the bearing has cooled down. 39 用紧定套安装轴承 Mounting a bearing with a adapter sleeve 40 用紧定套安装轴承 Mounting a bearing with a adapter sleeve Assembly of a self-adjusting ball bearing on a drawing sleeve 41 用紧定套安装轴承 Mounting a bearing with a adapter sleeve Assembly of a two-row barrel shape bearing on a drawing sleeve 42 用紧定套安装轴承 Mounting a bearing with a adapter sleeve 43 用紧定套安装轴承 Mounting a bearing with a adapter sleeve An alternative method is to heat the bearing. 44 用退卸套安装轴承 Mounting a bearing with a adapter sleeve Assembly on a pressing sleeve(退卸套) 45 用退卸套安装轴承 Mounting a bearing with a adapter sleeve Cold assembly 46 用退卸套安装轴承 Mounting a bearing with a adapter sleeve Use of a hydraulic nut or pressure oil method 47 用液压螺母装配轴承 Assembly of bearings with hydraulic nut 48 用液压螺母装配轴承 Assembly of bearings with hydraulic nut 49 用液压螺母装配轴承 Assembly of bearings with hydraulic nut 50 用液压螺母装配轴承 Assembly of bearings with hydraulic nut 51 用液压螺母装配轴承 Assembly of bearings with hydraulic nut 52 圆锥孔轴承的装配和拆卸 Tapered seating 53 紧定套 Adapter sleeve 54 退卸套 Withdrawal sleeve 55 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a tapered axle journal 56 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a drawing or pressing sleeve 57 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a drawing or pressing sleeve 58 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a drawing or pressing sleeve 59 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a drawing or pressing sleeve 60 圆锥孔轴承的拆卸 Disassembly of bearings with tapered bore on a drawing or pressing sleeve 61