精度 TOLERANCE
軸承的精度包括尺寸精度和旋轉(zhuǎn)精度,尺寸精度是將軸承安裝于軸或軸承箱時(shí)所要求的項(xiàng)目,它包括內(nèi)徑、外徑、寬度、倒角尺寸公差或允許值。幾何精度包括內(nèi)徑偏差、平均內(nèi)徑差、外徑偏差、平均外徑差、套圈端面平行差的允許值。旋轉(zhuǎn)精度是規(guī)定旋轉(zhuǎn)時(shí)振擺的，包括內(nèi)圈及外圈徑向擺動(dòng)和軸向擺動(dòng)，內(nèi)圈側(cè)擺及外徑面垂直度公差范圍。
軸承的精度等級(jí)從普通級(jí)0級(jí)到6級(jí)、5級(jí)、4級(jí)及2級(jí)，依次增高，下表1是中國(guó)GB307規(guī)定的精度等級(jí)與其他標(biāo)準(zhǔn)的比較。
Bearing tolerance includes dimensional tolerance and revolving tolerance, Dimensional tolerance is a request when bearings are mounted on shafts or in housings. It includes bore/outerside diameter deviation from basic, inner ring/outer ring width deviation in single radial plane. Revolving tolerance includes radial and axial runout of assembled bearing inner ring and outer ring, inner ring reference fcace runout with bore and outside cylindrical surface runout with outer reference face.
Tolerance class ranges from common class 0 to 6,5,4 and 2, from low to high, Table 1 below is the tolerance class stipulated in China GB307 and its comparison with some other standards.

部分國(guó)家軸承精度等級(jí)對(duì)照表 COMPARISON OF TOLERANCE CLASS

游隙 CLEARANCE
軸承的游隙是指軸承在未安裝于軸或軸承箱之前的狀態(tài)下，固定內(nèi)圈或外圈的一方，使未固定的套圈做徑向或軸向移動(dòng)時(shí)套圈的移動(dòng)量。根據(jù)移動(dòng)方向，可分為徑向游隙和軸向游隙。
Bearing clearance means the value of displacement of the unfixed ring when it moves against the fixed ring in radial or axial direction before the bearing is mouted on a shaft or in a housing. According to the movement direction, it falls into radial clearance and axial clearance.

單列深溝球軸承的徑向游隙 RADIAL CLEARANCE

振動(dòng) VIBRATION
軸承振動(dòng)是指軸承零件隨時(shí)間而變化的彈性變形及除軸承功能所必需的運(yùn)動(dòng)以外的其它一切偏離理論位置的運(yùn)動(dòng),它分為振動(dòng)速度(dB)和振動(dòng)速度(μm/S)。振動(dòng)動(dòng)加速度分Ｚ、Ｚ１、Ｚ２和Ｚ３三級(jí)考核，其中Ｚ級(jí)為基本級(jí)，Ｚ１、Ｚ２和Ｚ３依次表示軸承振動(dòng)水平有低到高，具體要求見(jiàn)表３。具體要求見(jiàn)表４。由于振動(dòng)速度測(cè)量更能顯現(xiàn)軸承的加工水平和體現(xiàn)軸承的內(nèi)在質(zhì)量，因而最為通用。
我們公司在對(duì)軸承振動(dòng)速度值控制的同時(shí)，按電機(jī)軸承的要求，對(duì)軸承運(yùn)轉(zhuǎn)異聲也實(shí)施嚴(yán)格的監(jiān)控。
Bearing vibration means bearing components’ elastic deformation that varies with time and all other movement that deviates from a theoretic position except that necessary to bearing functions. It has two modes-acceleration(dB)and velocity(μm/S), Vibration acceleration is examined according to Z, Z4, Z2, and Z3 values. Grade Z is fundamental, Z1, Z2&Z3 successively indicate the vibration level ranges fron low to high. For detailed requirements, see Table3. Simlary, viaration velocity is examined as per V, V1, V2&V3. Grade V is fundamental, V1, V2&V3 successively indicate the vibration level ranges from low to high. For details, see Table4. Generally, velocity examination is better than acceleration examination in that it can more reflect bearings’ manufacturing level and bearings’ inherent quality.
While our company keeps control of vibration velocity values, we also carry out vigorous control on abnormal noise from running bearings in test according to requirements of electric motor quality bearings.

單個(gè)軸承振動(dòng)加速度極限值　VIBRATION(ACCELERATION) LIMITES FOR SINGLE BEARING dB

單個(gè)軸承振動(dòng)速度極限值 VIBRATION (VELOCITY)LIMTES FOR SINGLE BEARING μm/s