631 軸承座的工藝及鉆孔夾具裝置設(shè)計(jì)【CAD圖+工藝工序卡+文獻(xiàn)翻譯+說(shuō)明書(shū)】
631 軸承座的工藝及鉆孔夾具裝置設(shè)計(jì)【CAD圖+工藝工序卡+文獻(xiàn)翻譯+說(shuō)明書(shū)】,CAD圖+工藝工序卡+文獻(xiàn)翻譯+說(shuō)明書(shū),631,軸承座的工藝及鉆孔夾具裝置設(shè)計(jì)【CAD圖+工藝工序卡+文獻(xiàn)翻譯+說(shuō)明書(shū)】,軸承,工藝,鉆孔,夾具,裝置,設(shè)計(jì),cad,工序,文獻(xiàn),翻譯,說(shuō)明書(shū),仿單
附錄二:工藝規(guī)程
工序
目錄
產(chǎn)品型號(hào)
共18頁(yè)
零組件號(hào)
第 頁(yè)
工序號(hào)
工 序 名 稱(chēng)
設(shè) 備
工序卡 片 數(shù)
備注
00
鑄造毛坯
1
05
人工時(shí)效
10
劃線找正,找底面
15
粗銑底面
臥式銑床
1
20
粗銑左右端面
臥式銑床
1
25
粗鏜軸承座孔
臥式鏜床
1
30
鉆擴(kuò)右孔并倒角
立式鉆床
1
35
鉆擴(kuò)左孔并倒角
立式鉆床
1
40
銑凸塊兩側(cè)至尺寸要求
臥式銑床
1
45
鉆鉸凸塊上通孔
立式鉆床
1
50
銑凸塊中間槽
臥式銑床
1
55
銑凸塊外圓至尺寸要求
臥式銑床
1
60
鏜臺(tái)階孔
立式鏜床
1
65
精銑底面
臥式銑床
1
70
精鏜底面孔
臥式鏜床
1
75
精銑臺(tái)階孔底面
立式銑床
1
80
精銑左右端面
臥式銑床
1
85
銑左右端面上槽
臥式銑床
1
90
鉆鉸右孔
立式鉆床
1
95
鉆鉸左孔
立式鉆床
1
100
磨左右孔
內(nèi)圓磨床
1
105
淬火
110
去毛刺,銳邊倒鈍,清洗
115
檢驗(yàn)
120
入庫(kù)
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鑄造毛坯
00
設(shè) 備
定位
夾緊
共18頁(yè)
第1頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鑄造毛坯
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
粗銑底面
15
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第2頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
粗銑毛坯底面
專(zhuān)用銑床夾具
Φ20端面銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
粗銑左右端面
20
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第3頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
粗銑左右端面
專(zhuān)用銑床夾具
Φ20端銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
粗鏜底孔并倒角
25
設(shè) 備
臥式鏜床
定位
夾緊
共18頁(yè)
第4頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆擴(kuò)底孔至Φ71
專(zhuān)用鉆床夾具
Φ35鉆頭
游標(biāo)卡尺
2
孔倒角1×45o
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鉆擴(kuò)右孔并倒角
30
設(shè) 備
立式鉆床
定位
夾緊
共18頁(yè)
第5頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆右孔至Φ17
專(zhuān)用鉆床夾具
Φ17鉆頭
游標(biāo)卡尺
2
擴(kuò)右孔至Φ17.5
Φ17.5擴(kuò)孔鉆
3
孔倒角1×45o
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鉆擴(kuò)左孔并倒角
35
設(shè) 備
立式鉆床
定位
夾緊
共18頁(yè)
第6頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆左孔至Φ17
專(zhuān)用鉆床夾具
Φ17鉆頭
游標(biāo)卡尺
2
擴(kuò)左孔至Φ17.5
Φ17.5擴(kuò)孔鉆
3
孔倒角1×45o
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
銑凸塊 兩側(cè)
40
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第7頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
銑凸塊兩側(cè)至尺寸要求
專(zhuān)用銑床夾具
Φ15面銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
銑凸塊 兩側(cè)
40
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第8頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
銑凸塊外圓至尺寸
專(zhuān)業(yè)銑床夾具
Φ15端銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
銑凸塊中槽
50
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第10頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
銑凸塊中槽至尺寸要求
專(zhuān)用銑床夾具
Φ60端銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鉆鉸凸塊上通孔
45
設(shè) 備
立式鉆床
定位
夾緊
共18頁(yè)
第9頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆通孔至Φ4.5
專(zhuān)用鉆床夾具
Φ4.5鉆頭
2
鉸孔至Φ5+0.015
Φ5塞規(guī)
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鏜臺(tái)階孔
60
設(shè) 備
立式鏜床
定位
夾緊
共18頁(yè)
第11頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鏜Φ84孔至尺寸要求
專(zhuān)用鏜床夾具
Φ30鏜刀
Φ84塞規(guī)
2
鏜Φ85孔至尺寸要求
Φ84塞規(guī)
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
精銑底面
65
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第12頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
精銑底面至尺寸要求
專(zhuān)用銑床夾具
Φ30面銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
精鏜底面孔
70
設(shè) 備
臥式鏜床
定位
夾緊
共18頁(yè)
第13頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
精鏜底面孔至要求尺寸
專(zhuān)業(yè)鏜床夾具
Φ30鏜刀
Φ72塞規(guī)
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
精銑臺(tái)階空底面
75
設(shè) 備
立式銑床
定位
夾緊
共18頁(yè)
第14頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
精銑臺(tái)階孔底面
專(zhuān)用銑床夾具
Φ30面銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
精銑左右端面
80
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第15頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
精銑左右端面至要求尺寸
專(zhuān)業(yè)銑床夾具
Φ20端銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
精銑左右端面上槽
85
設(shè) 備
臥式銑床
定位
夾緊
共18頁(yè)
第16頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
精銑左右端面上槽至要求尺寸
專(zhuān)業(yè)銑床夾具
Φ2面銑刀
游標(biāo)卡尺
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鉆鉸右端面上孔
90
設(shè) 備
立式鉆床
定位
夾緊
共18頁(yè)
第17頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆鉸右端面上孔至要求尺寸
專(zhuān)業(yè)鉆床夾具
Φ18鉆頭
Φ18塞規(guī)
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
磨左右端面上孔
100
設(shè) 備
內(nèi)圓磨床
定位
夾緊
共18頁(yè)
第19頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
磨左右端面上孔至要求
專(zhuān)業(yè)磨床夾具
Φ18砂輪
專(zhuān)業(yè)儀器
工序卡片
零件名稱(chēng)
材料
硬度
工序名稱(chēng)
工序號(hào)
軸承座
ZG35GrMnSi
HBS=217
鉆鉸左端面上孔
95
設(shè) 備
立式鉆床
定位
夾緊
共18頁(yè)
第18頁(yè)
序號(hào)
加工要求說(shuō)明
夾具
刀具
量具
1
鉆鉸左端面上孔至要求尺寸
專(zhuān)業(yè)鉆床夾具
Φ18鉆頭
Φ18塞規(guī)
21
附錄一:外文資料翻譯
外文資料翻譯原文(一)
EXTENDING BEARING LIFE
Abstract:Nature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect in a bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. After a little detective work, action can be taken to avoid a repeat performance.
Keywords: bearings failures life
Bearings fail for a number of reasons,but the most common are misapplication,contamination,improper lubricant,shipping or handling damage,and misalignment. The problem is often not difficult to diagnose because a failed bearing usually leaves telltale signs about what went wrong.
However,while a postmortem yields good information,it is better to avoid the process altogether by specifying the bearing correctly in The first place.To do this,it is useful to review the manufacturers sizing guidelines and operating characteristics for the selected bearing.
Equally critical is a study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a job.
1 Why bearings fail
About 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environment.Fortunately, a bearing failure caused by environment or handling contamination is preventable,and a simple visual examination can easily identify the cause.
Conducting a postmortem il1ustrates what to look for on a failed or failing bearing.Then,understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the source of the problem.
Brinelling is one type of bearing failure easily avoided by proper handing and assembly. It is characterized by indentations in the bearing raceway caused by shock loading-such as when a bearing is dropped-or incorrect assembly. Brinelling usually occurs when loads exceed the material yield point(350,000 psi in SAE 52100 chrome steel).It may also be caused by improper assembly, Which places a load across the races.Raceway dents also produce noise,vibration,and increased torque.
A similar defect is a pattern of elliptical dents caused by balls vibrating between raceways while the bearing is not turning.This problem is called false brinelling. It occurs on equipment in transit or that vibrates when not in operation. In addition, debris created by false brinelling acts like an abrasive, further contaminating the bearing. Unlike brinelling, false binelling is often indicated by a reddish color from fretting corrosion in the lubricant.
False brinelling is prevented by eliminating vibration sources and keeping the bearing well lubricated. Isolation pads on the equipment or a separate foundation may be required to reduce environmental vibration. Also a light preload on the bearing helps keep the balls and raceway in tight contact. Preloading also helps prevent false brinelling during transit.
Seizures can be caused by a lack of internal clearance, improper lubrication, or excessive loading. Before seizing, excessive, friction and heat softens the bearing steel. Overheated bearings often change color,usually to blue-black or straw colored.Friction also causes stress in the retainer,which can break and hasten bearing failure.
Premature material fatigue is caused by a high load or excessive preload.When these conditions are unavoidable,bearing life should be carefully calculated so that a maintenance scheme can be worked out.
Another solution for fighting premature fatigue is changing material.When standard bearing materials,such as 440C or SAE 52100,do not guarantee sufficient life,specialty materials can be recommended. In addition,when the problem is traced back to excessive loading,a higher capacity bearing or different configuration may be used.
Creep is less common than premature fatigue.In bearings.it is caused by excessive clearance between bore and shaft that allows the bore to rotate on the shaft.Creep can be expensive because it causes damage to other components in addition to the bearing.
0ther more likely creep indicators are scratches,scuff marks,or discoloration to shaft and bore.To prevent creep damage,the bearing housing and shaft fittings should be visually checked.
Misalignment is related to creep in that it is mounting related.If races are misaligned or cocked.The balls track in a noncircumferencial path.The problem is incorrect mounting or tolerancing,or insufficient squareness of the bearing mounting site.Misalignment of more than 1/4·can cause an early failure.
Contaminated lubricant is often more difficult to detect than misalignment or creep.Contamination shows as premature wear.Solid contaminants become an abrasive in the lubricant.In addition。insufficient lubrication between ball and retainer wears and weakens the retainer.In this situation,lubrication is critical if the retainer is a fully machined type.Ribbon or crown retainers,in contrast,allow lubricants to more easily reach all surfaces.
Rust is a form of moisture contamination and often indicates the wrong material for the application.If the material checks out for the job,the easiest way to prevent rust is to keep bearings in their packaging,until just before installation.
2 Avoiding failures
The best way to handle bearing failures is to avoid them.This can be done in the selection process by recognizing critical performance characteristics.These include noise,starting and running torque,stiffness,nonrepetitive runout,and radial and axial play.In some applications, these items are so critical that specifying an ABEC level alone is not sufficient.
Torque requirements are determined by the lubricant,retainer,raceway quality(roundness cross curvature and surface finish),and whether seals or shields are used.Lubricant viscosity must be selected carefully because inappropriate lubricant,especially in miniature bearings,causes excessive torque.Also,different lubricants have varying noise characteristics that should be matched to the application. For example,greases produce more noise than oil.
Nonrepetitive runout(NRR)occurs during rotation as a random eccentricity between the inner and outer races,much like a cam action.NRR can be caused by retainer tolerance or eccentricities of the raceways and balls.Unlike repetitive runout, no compensation can be made for NRR.
NRR is reflected in the cost of the bearing.It is common in the industry to provide different bearing types and grades for specific applications.For example,a bearing with an NRR of less than 0.3um is used when minimal runout is needed,such as in disk—drive spindle motors.Similarly,machine—tool spindles tolerate only minimal deflections to maintain precision cuts.Consequently, bearings are manufactured with low NRR just for machine-tool applications.
Contamination is unavoidable in many industrial products,and shields and seals are commonly used to protect bearings from dust and dirt.However,a perfect bearing seal is not possible because of the movement between inner and outer races.Consequently,lubrication migration and contamination are always problems.
Once a bearing is contaminated, its lubricant deteriorates and operation becomes noisier.If it overheats,the bearing can seize.At the very least,contamination causes wear as it works between balls and the raceway,becoming imbedded in the races and acting as an abrasive between metal surfaces.Fending off dirt with seals and shields illustrates some methods for controlling contamination.
Noise is as an indicator of bearing quality.Various noise grades have been developed to classify bearing performance capabilities.
Noise analysis is done with an Anderonmeter, which is used for quality control in bearing production and also when failed bearings are returned for analysis. A transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air spindle. Noise is measured in andirons, which represent ball displacement in μm/rad.
With experience, inspectors can identify the smallest flaw from their sound. Dust, for example, makes an irregular crackling. Ball scratches make a consistent popping and are the most difficult to identify. Inner-race damage is normally a constant high-pitched noise, while a damaged outer race makes an intermittent sound as it rotates.
Bearing defects are further identified by their frequencies. Generally, defects are separated into low, medium, and high wavelengths. Defects are also referenced to the number of irregularities per revolution.
Low-band noise is the effect of long-wavelength irregularities that occur about 1.6 to 10 times per revolution. These are caused by a variety of inconsistencies, such as pockets in the race. Detectable pockets are manufacturing flaws and result when the race is mounted too tightly in multiplejaw chucks.
Medium-hand noise is characterized by irregularities that occur 10 to 60 times per revolution. It is caused by vibration in the grinding operation that produces balls and raceways. High-hand irregularities occur at 60 to 300 times per revolution and indicate closely spaced chatter marks or widely spaced, rough irregularities.
Classifying bearings by their noise characteristics allows users to specify a noise grade in addition to the ABEC standards used by most manufacturers. ABEC defines physical tolerances such as bore, outer diameter, and runout. As the ABEC class number increase (from 3 to 9), tolerances are tightened. ABEC class, however, does not specify other bearing characteristics such as raceway quality, finish, or noise. Hence, a noise classification helps improve on the industry standard.
外文資料翻譯譯文(一)
如何延長(zhǎng)軸承壽命
摘要: 自然界苛刻的工作條件會(huì)導(dǎo)致軸承的失效,但是如果遵循一些簡(jiǎn)單的規(guī)則,軸承正常運(yùn)轉(zhuǎn)的機(jī)會(huì)是能夠被提高的。在軸承的使用過(guò)程當(dāng)中,過(guò)分的忽視會(huì)導(dǎo)致軸承的過(guò)熱現(xiàn)象,也可能使軸承不能夠再被使用,甚至完全的破壞。但是一個(gè)被損壞的軸承,會(huì)留下它為什么被損壞的線索。通過(guò)一些細(xì)致的偵察工作,我們可以采取行動(dòng)來(lái)避免軸承的再次失效。
關(guān)鍵詞: 軸承 失效 壽命
導(dǎo)致軸承失效的原因很多,但常見(jiàn)的是不正確的使用、污染、潤(rùn)滑劑使用不當(dāng)、裝卸或搬運(yùn)時(shí)的損傷及安裝誤差等。診斷失效的原因并不困難,因?yàn)楦鶕?jù)軸承上留下的痕跡可以確定軸承失效的原因。
然而,當(dāng)事后的調(diào)查分析提供出寶貴的信息時(shí),最好首先通過(guò)正確地選定軸承來(lái)完全避免失效的發(fā)生。為了做到這一點(diǎn),再考察一下制造廠商的尺寸定位指南和所選軸承的使用特點(diǎn)是非常重要的。
1 軸承失效的原因
在球軸承的失效中約有40%是由灰塵、臟物、碎屑的污染以及腐蝕造成的。污染通常是由不正確的使用和不良的使用環(huán)境造成的,它還會(huì)引起扭矩和噪聲的問(wèn)題。由環(huán)境和污染所產(chǎn)生的軸承失效是可以預(yù)防的,而且通過(guò)簡(jiǎn)單的肉眼觀察是可以確定產(chǎn)生這類(lèi)失效的原因。
通過(guò)失效后的分析可以得知對(duì)已經(jīng)失效的或?qū)⒁У妮S承應(yīng)該在哪些方面進(jìn)行查看。弄清諸如剝蝕和疲勞破壞一類(lèi)失效的機(jī)理,有助于消除問(wèn)題的根源。
只要使用和安裝合理,軸承的剝蝕是容易避免的。剝蝕的特征是在軸承圈滾道上留有由沖擊載荷或不正確的安裝產(chǎn)生的壓痕。剝蝕通常是在載荷超過(guò)材料屈服極限時(shí)發(fā)生的。如果安裝不正確從而使某一載荷橫穿軸承圈也會(huì)產(chǎn)生剝蝕。軸承圈上的壓坑還會(huì)產(chǎn)生噪聲、振動(dòng)和附加扭矩。
類(lèi)似的一種缺陷是當(dāng)軸承不旋轉(zhuǎn)時(shí)由于滾珠在軸承圈間振動(dòng)而產(chǎn)生的橢圓形壓痕。這種破壞稱(chēng)為低荷振蝕。這種破壞在運(yùn)輸中的設(shè)備和不工作時(shí)仍振動(dòng)的設(shè)備中都會(huì)產(chǎn)生。此外,低荷振蝕產(chǎn)生的碎屑的作用就象磨粒一樣,會(huì)進(jìn)一步損害軸承。與剝蝕不同,低荷振蝕的特征通常是由于微振磨損腐蝕在潤(rùn)滑劑中會(huì)產(chǎn)生淡紅色。
消除振動(dòng)源并保持良好的軸承潤(rùn)滑可以防止低荷振蝕。給設(shè)備加隔離墊或?qū)Φ鬃M(jìn)行隔離可以減輕環(huán)境的振動(dòng)。另外在軸承上加一個(gè)較小的預(yù)載荷不僅有助于滾珠和軸承圈保持緊密的接觸,并且對(duì)防止在設(shè)備運(yùn)輸中產(chǎn)生的低荷振蝕也有幫助。
造成軸承卡住的原因是缺少內(nèi)隙、潤(rùn)滑不當(dāng)和載荷過(guò)大。在卡住之前,過(guò)大的摩擦和熱量使軸承鋼軟化。過(guò)熱的軸承通常會(huì)改變顏色,一般會(huì)變成藍(lán)黑色或淡黃色。摩擦還會(huì)使保持架受力,這會(huì)破壞支承架,并加速軸承的失效。
材料過(guò)早出現(xiàn)疲勞破壞是由重載后過(guò)大的預(yù)載引起的。如果這些條件不可避免,就應(yīng)仔細(xì)計(jì)算軸承壽命,以制定一個(gè)維護(hù)計(jì)劃。
另一個(gè)解決辦法是更換材料。若標(biāo)準(zhǔn)的軸承材料不能保證足夠的軸承壽命,就應(yīng)當(dāng)采用特殊的材料。另外,如果這個(gè)問(wèn)題是由于載荷過(guò)大造成的,就應(yīng)該采用抗載能力更強(qiáng)或其他結(jié)構(gòu)的軸承。
蠕動(dòng)不象過(guò)早疲勞那樣普遍。軸承的蠕動(dòng)是由于軸和內(nèi)圈之間的間隙過(guò)大造成的。蠕動(dòng)的害處很大,它不僅損害軸承,也破壞其他零件。
蠕動(dòng)的明顯特征是劃痕、擦痕或軸與內(nèi)圈的顏色變化。為了防止蠕動(dòng),應(yīng)該先用肉眼檢查一下軸承箱件和軸的配件。
蠕動(dòng)與安裝不正有關(guān)。如果軸承圈不正或翹起,滾珠將沿著一個(gè)非圓周軌道運(yùn)動(dòng)。這個(gè)問(wèn)題是由于安裝不正確或公差不正確或軸承安裝現(xiàn)場(chǎng)的垂直度不夠造成的。如果偏斜超過(guò)0.25°,軸承就會(huì)過(guò)早地失效。
檢查潤(rùn)滑劑的污染比檢查裝配不正或蠕動(dòng)要困難得多。污染的特征是使軸承過(guò)早的出現(xiàn)磨損。潤(rùn)滑劑中的固體雜質(zhì)就象磨粒一樣。如果滾珠和保持架之間潤(rùn)滑不良也會(huì)磨損并削弱保持架。在這種情況下,潤(rùn)滑對(duì)于完全加工形式的保持架來(lái)說(shuō)是至關(guān)重要的。相比之下,帶狀或冠狀保持架能較容易地使?jié)櫥瑒┑竭_(dá)全部表面。
銹是濕氣污染的一種形式,它的出現(xiàn)常常表明材料選擇不當(dāng)。如果某一材料經(jīng)檢驗(yàn)適合工作要求,那么防止生銹的最簡(jiǎn)單的方法是給軸承包裝起來(lái),直到安裝使用時(shí)才打開(kāi)包裝。
2 避免失效的方法
解決軸承失效問(wèn)題的最好辦法就是避免失效發(fā)生。這可以在選用過(guò)程中通過(guò)考慮關(guān)鍵性能特征來(lái)實(shí)現(xiàn)。這些特征包括噪聲、起動(dòng)和運(yùn)轉(zhuǎn)扭矩、剛性、非重復(fù)性振擺以及徑向和軸向間隙。
扭矩要求是由潤(rùn)滑劑、保持架、軸承圈質(zhì)量(彎曲部分的圓度和表面加工質(zhì)量)以及是否使用密封或遮護(hù)裝置來(lái)決定。潤(rùn)滑劑的粘度必須認(rèn)真加以選擇,因?yàn)椴贿m宜的潤(rùn)滑劑會(huì)產(chǎn)生過(guò)大的扭矩,這在小型軸承中尤其如此。另外,不同的潤(rùn)滑劑的噪聲特性也不一樣。舉例來(lái)說(shuō),潤(rùn)滑脂產(chǎn)生的噪聲比潤(rùn)滑油大一些。因此,要根據(jù)不同的用途來(lái)選用潤(rùn)滑劑。
在軸承轉(zhuǎn)動(dòng)過(guò)程中,如果內(nèi)圈和外圈之間存在一個(gè)隨機(jī)的偏心距,就會(huì)產(chǎn)生與凸輪運(yùn)動(dòng)非常相似的非重復(fù)性振擺(NRR)。保持架的尺寸誤差和軸承圈與滾珠的偏心都會(huì)引起NRR。和重復(fù)性振擺不同的是,NRR是沒(méi)有辦法進(jìn)行補(bǔ)償?shù)摹?
在工業(yè)中一般是根據(jù)具體的應(yīng)用來(lái)選擇不同類(lèi)型和精度等級(jí)的軸承。例如,當(dāng)要求振擺最小時(shí),軸承的非重復(fù)性振擺不能超過(guò)0.3微米。同樣,機(jī)床主軸只能容許最小的振擺,以保證切削精度。因此在機(jī)床的應(yīng)用中應(yīng)該使用非重復(fù)性振擺較小的軸承。
在許多工業(yè)產(chǎn)品中,污染是不可避免的,因此常用密封或遮護(hù)裝置來(lái)保護(hù)軸承,使其免受灰塵或臟物的侵蝕。但是,由于軸承內(nèi)外圈的運(yùn)動(dòng),使軸承的密封不可能達(dá)到完美的程度,因此潤(rùn)滑油的泄漏和污染始終是一個(gè)未能解決的問(wèn)題。
一旦軸承受到污染,潤(rùn)滑劑就要變質(zhì),運(yùn)行噪聲也隨之變大。如果軸承過(guò)熱,它將會(huì)卡住。當(dāng)污染物處于滾珠和軸承圈之間時(shí),其作用和金屬表面之間的磨粒一樣,會(huì)使軸承磨損。采用密封和遮護(hù)裝置來(lái)?yè)蹰_(kāi)臟物是控制污染的一種方法。
噪聲是反映軸承質(zhì)量的一個(gè)指標(biāo)。軸承的性能可以用不同的噪聲等級(jí)來(lái)表示。
噪聲的分析是用安德遜計(jì)進(jìn)行的,該儀器在軸承生產(chǎn)中可用來(lái)控制質(zhì)量,也可對(duì)失效的軸承進(jìn)行分析。將一傳感器連接在軸承外圈上,而內(nèi)圈在心軸以1800r/min的轉(zhuǎn)速旋轉(zhuǎn)。測(cè)量噪聲的單位為anderon。即用um/rad表示的軸承位移。
根據(jù)經(jīng)驗(yàn),觀察者可以根據(jù)聲音辨別出微小的缺陷。例如,灰塵產(chǎn)生的是不規(guī)則的劈啪聲;滾珠劃痕產(chǎn)生一種連續(xù)的爆破聲,確定這種劃痕最困難;內(nèi)圈損傷通常產(chǎn)生連續(xù)的高頻噪聲,而外圈損傷則產(chǎn)生一種間歇的聲音。
軸承缺陷可以通過(guò)其頻率特性進(jìn)一步加以鑒定。通常軸承缺陷被分為低、中、高三個(gè)波段。缺陷還可以根據(jù)軸承每轉(zhuǎn)動(dòng)一周出現(xiàn)的不規(guī)則變化的次數(shù)加以鑒定。
低頻噪聲是長(zhǎng)波段不規(guī)則變化的結(jié)果。軸承每轉(zhuǎn)一周這種不規(guī)則變化可出現(xiàn)1.6~10次,它們是由各種干涉(例如 軸承圈滾道上的凹坑)引起的??刹煊X(jué)的凹坑是一種制造缺陷,它是在制造過(guò)程中由于多爪卡盤(pán)夾的太緊而形成的。
中頻噪聲的特征是軸承每旋轉(zhuǎn)一周不規(guī)則變化出現(xiàn)10~60次。這種缺陷是由在軸承圈和滾珠的磨削加工中出現(xiàn)的振動(dòng)引起的。軸承每旋轉(zhuǎn)一周高頻不規(guī)則變化出現(xiàn)60~300次,它表明軸承上存在著密集的振痕或大面積的粗糙不平。
利用軸承的噪聲特性對(duì)軸承進(jìn)行分類(lèi),用戶(hù)除了可以確定大多數(shù)廠商所使用的ABEC標(biāo)準(zhǔn)外,還可確定軸承的噪聲等級(jí)。ABEC標(biāo)準(zhǔn)只定義了諸如孔、外徑、振擺等尺寸公差。隨著ABEC級(jí)別的增加(從3增到9),公差逐漸變小。但ABEC等級(jí)并不能反映其他軸承特性,如軸承圈質(zhì)量、粗糙度、噪聲等。因此,噪聲等級(jí)的劃分有助于工業(yè)標(biāo)準(zhǔn)的改進(jìn)。外文資料翻譯原文(二)
Machine design theory
The machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.
Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.
If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of product
Must regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.
A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.
Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.
In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.
How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.
Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:
(1) designs whether this product truly does need for the people? Whether there is competitive ability
(2) does this product compare with other companies'' existing similar products?
(3) produces this kind of product is whether economical?
(4) product service is whether convenient?
(5) product whether there is sale? Whether may gain?
Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal.
Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method.
Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Theref
收藏