故障原因

1 . 平模初次使用模孔光洁度差�? . 物料含水率过高或过低�? . 压辊与平模间隙过大；4 . 压辊或平模磨扣严重；5 . 三角带打滑或老化�?/p>

排除方法

1 . 用含油料研磨润滑，工作一段时间产量即提高; 2 . 调节物料含水率；3 . 调整压紧螺栓�? . 张紧或更换三角带

二�?nbsp; 颗粒中含粉过�?br />  故障原因

1 . 含水率低�? . 平模过度磨损、厚度过小�?/p>

排除方法

1 . 提高含水率；2 . 更换亲平模�?/p>

三�?nbsp; 颗粒表现粗糙

故障原因  

排除方法 

1 . 含水率高�? . 平模初次使用�?/p>

排除方法

1 . 降低含水率；2 . 用含油料反复研磨�?/p>

四、响声异�?/p>

故障原因

1 . 落入硬质杂物�? . 轴承损坏�? . 零部件松动�?/p>

排除方法 

1 . 停机清除异物�? . 更换轴承�? . 紧固零部件�?/p>

五、突然停�?/p>

故障原因  

1 . 负荷过大（甚至保险丝熔断）；2 . 有异物进入腔内�?/p>

1 . 适当加大压辊与平模间隙更换保险丝�? . 停机清除异物�?/p> 查看原文 ]]> 查看原文 ]]> Liyang Yuda Machinery Co., Ltd. is a professional manufacturer of grain feed machinery and grazing machinery. We supply various services, including project design, equipment production, fixing & debugging, work & maintaining training and technological consultation. 

Technology and quality are the life of our enterprise. We adhere to the concept of "creditable with honesty and win with quality", and strictly control quality according to ISO9001:2000 Quality Management System. Relying on abundant technological research strength and sticking to the principle of "creditable & practical, exploitative & innovative", we manufacture high-quality products and our products are deeply recognized by all clients. 

We welcome domestic and foreign clients and friends from all over the world to visit us for consultation.查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> 查看原文 ]]> Analysis to principal axis bearing of ring mode pellet machine

Preface

According to the difference in the working condition of bearing outer ring, antifriction bearings can be divided into the following categories: outer ring is stationary, comparing with load direction and outer ring spins, comparing with load direction. For the latter, inner ring of the bearing is stationary, comparing to the load direction, and rotating load acts on outer ring. Bearing of the ring mode pellet machine’s rotor is revolving form. Picture 1 is the sketch map of rotor unit of the ring mode pellet machine. 1. rotor/ 2. principal axis/ 3. bearing. The principal axis is stationary and the rotor is revolving under the driving force. Rotating load acts on the outer ring of the bearing. This transmission form of bearing usually applies interference fit with hull.

If the rotor bearing has the symptom of high temperature, noises, bearing attrition, short working life and so one, the cooperation between rotating bearing’s inner and outer ring and radial clearance work have a great influence on it. The following is the analysis to the  cooperation between rotating bearing’s inner and outer ring and radial clearance work.

1. Cooperation

1.1The cooperation between inner and outer ring of the bearing

The cooperation between inner ring and hull holes interference fit. But if you choose small magnitude of interference, when outer ring revolves, the rolling element rubs against the rollaway nest and the bearing and the hull expand after they are heated. Because of the difference in heating, when the hull expand larger than the outer ring of the bearing, magnitude of interference will become smaller. There will be harmful slipping between the bearing outer ring and hull bores, which is called creep. Once there is creep, there will be obscure attrition and damages on bearing outer ring and hull. Therefore, the cooperation between bearing outer ring and hull bores should meet the minimum of the magnitude of interference.

In addition, magnitude of interference cannot be too large for the reason that under the action of the working load, radial clearance of the bearings will be decreased and the bearing’s temperature will rise. Meanwhile, large magnitude of interference will trouble the process of installation and uninstall. Therefore, workers should choose appropriate magnitude of interference according to the load condition.

1.2 Cooperation between bearing inner ring and axis

The cooperation between bearing inner ring and axis is clearance fit. The magnitude of clearance fit depends on the load borne by the bearing, the cooperation between  bearing outer ring and hull, and the bearing clearance. At the same time, the cooperation between inner ring and axis will also influences the radial clearance work of the bearing.

2 radial clearance work

Clearance is an important parameter of rotating bearing cooperation, which directly influences the loads distribution, quake, noises, attrition, temperature rise, working life, machine operation accuracy and other technical skills.　Basic load rating of bearing is changing with the clearance. The larger the clearance is, the less the rolling element that bears load. Then the carrying capacity of the bearing is lowered. The stress of the rotating contact surface is larger. The bearing operation accuracy decreases. The quake and noises increase. Working life is shortened. If the work clearance is too small, it can lead to temperature rise of the bearing, even make the bearing stuck when it’s revolving.

The factors that influence the radial clearance work of the bearing

6) Bearing outer ring and hull are interference installed. Therefore, there is stress in fitting surface. Outer ring gets out of shape and draws back inside so as to make the radial clearance work larger.

7) Under the action of working load, rotating load acts on bearing outer ring. The radial force make the outer ring contract there by make the radial clearance work smaller.

8) The temperature rise’s effect on radial clearance work. Rise of temperature make the inner ring expand and make the radial clearance work smaller. Outer ring and hull will expand when they are heated, but because of the difference in materials, the degree of expansion varies. The speed of heat dissipation influences the degree of expansion. As the expansion of outer ring gets smaller, the radial clearance work gets smaller. On the contrary, it gets larger.

9) When bearing is operating, lubricating grease will become flexible flowing oil film pressure between rolling element and inner/outer ring, which bears the load. Oil film pressure can make the radial clearance work smaller. Dynamic pressure oil slick’s thickness is related to the viscosity of the lubricating grease.

3. Practical application

A certain king of ring mode pellet machine, principal axis, d, inner diameter of hull, D, Its bearing is SKF spherical roller bearing. The standard clearance of bearing is 95-145μm. Principal axis, d, has a upper variation of tolerance of 0, and has a lower one of -25μm. Hull diameter of bore, D, has a upper variation of tolerance of -14μm and a lower one of -60μm.Bearing outer ring and hull diameter of bore are interference fit. When the equipment is used, bearing’s temperature may rise and its working life may be shortened. Adjust the allowance of rotor principal axis’s diameter to clearance fit. Then the situation can be improved, the temperature can remain normal, and the bearing can revolve normally.

Initial bearing outer ring and hull bore are interference fit, and inner ring and axis are transition fit. Under the action of working load, radial force makes outer ring contract so as to make radial direction clearance work smaller. Under the radial force, inner ring contract and radial direction clearance work becomes larger. Because at first it’s transition fit, the deformation is not obscure, and the radial direction clearance work is very small. At this time, radial direction clearance work is smaller than the minimum clearance when the bearing is working properly. Therefore, the bearing’s temperature is too high. After increasing the fit clearance of bearing inner ring and axis diameter, inner ring contracts because of the radial force and the radial clearance work increases. At this time, radial clearance work meets the minimum need of clearance. When the bearing has been through a span of operation break-in, bearing inner and outer ring will be relatively stable and so will be the clearance work. At last, the bearing can function stably. Thus, choosing right size of fit clearance is very important for the normal operation of ring mode pellet machine.

4. Conclusion

Selection of Antifriction bearing’s inner and outer and the radial clearance work are significant for the normal operation of ring mode pellet machine. All these factors above have mutual influence on each other. Therefore, when designing such similar structure, designers should decide appropriate size of the radial clearance according to the load bearing and  should consider the deformation of bearing inner and outer ring, under the action of interference fit installation and radial force. They should take into account of the influence of the temperature rise caused by the expansion of inner and outer ring and hull. They should choose appropriate fit between bearing outer ring and hull and fit between bearing inner ring and axis.