機(jī)械專業(yè)英語詞匯-中英文對照

1、機(jī)械專業(yè)英語詞匯陶瓷 ceramics合成纖維 synthetic fibre電化學(xué)腐蝕 electrochemical corrosion車架 automotive chassis懸架 suspension轉(zhuǎn)向器 redirector變速器 speed changer 板料沖壓 sheet metal parts 孔加工 spot facing machining 車間 workshop工程技術(shù)人員 engineer氣動(dòng)夾緊pneuma lock數(shù)學(xué)模型mathematical model畫法幾何descriptive geometry機(jī)械制圖Mechanical drawing投影 pro

2、jection視圖 view剖視圖profile chart標(biāo)準(zhǔn)件standard component零件圖part drawing裝配圖assembly drawing尺寸標(biāo)注 size marking技術(shù)要求 technical requirements剛度rigidity內(nèi)力internal force位移displacement截面section疲勞極限 fatigue limit斷裂 fractureterial剛度準(zhǔn)則 ri脆性材料塑性變形stic distttlenessRegistered墊圈 washer墊片 spacer直齒圓柱齒輪 straight toothed spu

3、r gear斜齒圓柱齒輪 helical-spur gear直齒錐齒輪 straight bevel gear運(yùn)動(dòng)簡圖 kinematic sketch齒輪齒條 pinion and rack蝸桿蝸輪 worm and worm gear虛約束 passive constraint曲柄 crank搖桿 racker凸輪 cams共軛曲線 conjugate curve范成法 generation method定義域 definitional domain值域 range導(dǎo)數(shù) 微分 differential coefficient求導(dǎo) derivation定積分 definite integra

4、l 不定積分 indefinite integral 曲率 curvature 偏微分 partial differential 毛坯 rough 游標(biāo)卡尺 slide caliper千分尺 micrometer calipers攻絲 tap二階行列式 second order determinant逆矩陣 inverse matrix線性方程組 linear equations概率 probability隨機(jī)變量 random variable排列組合 permutation and combination氣體狀態(tài)方程 equation of state of gas動(dòng)能 kinetic e

5、nergyc胛軸線 axes余子式 cofactor邏輯電路 logic circuit觸發(fā)器 flip-flop脈沖波形 pulse shape勢能 potential energy動(dòng)量 momentum桁架 truss數(shù)模 digital analogy液壓傳動(dòng)機(jī)構(gòu) fluid drive mechanism機(jī)械零件 mechanical parts淬火冷卻 quench淬火 hardening回火 tempering調(diào)質(zhì) hardening and tempering磨粒 abrasive grain結(jié)合劑 bonding agent砂輪 grinding wheelistered后角

6、clearance angle龍門刨削 planing主軸 spindle主軸箱 headstock卡盤 chuck加工中心 machining center車刀 lathe tool車床 lathe鉆削 鏜削 bore車削 turning磨床 grinder基準(zhǔn) benchmark鉗工 locksmith鍛 forge壓模 stamping焊 weld拉床broaching machine拉孔broaching裝配assembling鑄造found流體動(dòng)力學(xué) fluid dynamics流體力學(xué) fluid mechanics加工 machiningg 機(jī)電一體化 mechanotronic

7、s mechanical-electrical integration 氣壓 air pressure pneumatic pressure介質(zhì) medium液壓驅(qū)動(dòng)泵 fluid clutch 液壓泵 hydraulic pump 閥門 valveinvalidation液壓 hydraulic pressure切線 tangent穩(wěn)定性 stability失效強(qiáng)度 intensity載荷 load應(yīng)力 stress安全系數(shù) safty factor 可靠性 reliability 螺紋 thread 螺旋 helix 鍵 spline 銷 pin滾動(dòng)軸承 rolling bearing滑動(dòng)

8、軸承 sliding bearingistered彈簧 spring制動(dòng)器 arrester brake十字結(jié)聯(lián)軸節(jié) crosshead聯(lián)軸器 coupling鏈 chain 皮帶 strap 精加工 finish machining 粗加工 rough machining 變速箱體 gearbox casing 腐蝕 rust 氧化 oxidation磨損 wear耐用度 durability隨機(jī)信號 random signal 離散信號 discrete signal 超聲傳感器 ultrasonic sensor 集成電路 integrate circuit 擋板 orifice pla

9、te殘余應(yīng)力 residual stress 套筒 sleeve 扭力 torsion冷加工 cold machining電動(dòng)機(jī) electromotoregR優(yōu)化設(shè)計(jì) optimal design工業(yè)造型設(shè)計(jì) industrial moulding design有限元 finite element滾齒 hobbing插齒 gear shaping汽缸 cylinder過盈配合 interference fit熱加工 hotwork攝像頭 CCD camera倒角 rounding chamfer伺服電機(jī) actuating motor銑床 milling machine鉆床 drill ma

10、chine鏜床 boring machine步進(jìn)電機(jī) stepper motor絲杠 screw rod導(dǎo)軌 lead rail組件 subassembly可編程序邏輯控制器 Programmable Logic Controller PLC電火花加工 electric spark machining電火花線切割加工 electrical discharge wire - cuttingistered相圖 phase diagram熱處理 heat treatment固態(tài)相變 solid state phase changes有色金屬 nonferrous metal陶瓷 ceramics合成

11、纖維 synthetic fibre電化學(xué)腐蝕 electrochemical corrosion車架 automotive chassis懸架 suspension轉(zhuǎn)向器 redirector變速器 speed changer板料沖壓 sheet metal parts孔加工 spot facing machining車間 workshop工程技術(shù)人員 engineer氣動(dòng)夾緊pneuma lock數(shù)學(xué)模型mathematical model畫法幾何descriptive geometry機(jī)械制圖Mechanical drawing投影 projection視圖 view剖視圖profile

12、 chartReg技術(shù)要求 technical requirementsrigidityinternal forcedisplacementsecUtiofantiguelimit標(biāo)準(zhǔn)件零件圖裝配圖standard componentpart drawingassembly drawing尺寸標(biāo)注 size marking剛度內(nèi)力位移截面疲勞極限istered斷裂 fracture塑性變形 plastic distortion脆性材料 brittleness material剛度準(zhǔn)則 rigidity criterion墊圈 washer墊片 spacer直齒圓柱齒輪 straight too

13、thed spur gear 斜齒圓柱齒輪 helical-spur gear 直齒錐齒輪 straight bevel gear 運(yùn)動(dòng)簡圖 kinematic sketch 齒輪齒條 pinion and rack蝸桿蝸輪 worm and worm gear虛約束 passive constraint曲柄 crank搖桿 racker凸輪 cams共軛曲線 conjugate curve范成法 generation method定義域 definitional domain 值域 range導(dǎo)數(shù) 微分 differential coefficient求導(dǎo) derivation定積分 def

14、inite integral 不定積分 indefinite integral 曲率 curvature偏微分 partial differential毛坯 rough游標(biāo)卡尺 slide caliper千分尺 micrometer calipers 攻絲 tap二階行列式 second order determinant 逆矩陣 inverse matrix線性方程組 linear equations概率 probability隨機(jī)變量 random variableeg機(jī)械能守恒 conservation of mechanical energy動(dòng)量 momentum桁架 truss軸線

15、axes余子式 cofactor邏輯電路 logic circuit排列組合 permutation and combination氣體狀態(tài)方程 equation of state of gas動(dòng)能 kinetic energy勢能 potential energy觸發(fā)器 flip-flop 脈沖波形 pulse shape 數(shù)模 digital analogy液壓傳動(dòng)機(jī)構(gòu) fluid drive mechanism機(jī)械零件 mechanical parts淬火冷卻 quench淬火 hardening回火 tempering調(diào)質(zhì) hardening and tempering磨粒 abras

16、ive grainistered結(jié)合劑 bonding agent砂輪 grinding wheelAssembly line 組裝線Layout 布置圖Conveyer 流水線物料板Rivet table 拉釘機(jī)Rivet gun 拉釘槍Screw driver 起子Pneumatic screw driver氣動(dòng)起子worktable 工作桌OOBA 開箱檢查fit together 組裝在一起fasten 鎖緊（螺絲 ）fixture 夾具（治具 ）pallet 棧板barcode 條碼barcode scanner 條碼掃描器fuse together 熔合fuse machine 熱

17、熔機(jī)repair 修理operator 作業(yè)員QC 品管Reginner parts inspect 內(nèi)部檢查thumb screw 大頭螺絲lbs. inch 鎊、英寸EMI gasket 導(dǎo)電條前板rear plate 后板supervisor 課長ME 制造工程師MT 制造生技cosmetic inspect 外觀檢查front plateisteredchassis 基座bezel panel 面板power button 電源按鍵reset button 重置鍵Hi-pot test of SPS 高源高壓測試Voltage switch of SPS 電源電壓接拉鍵 sheet m

18、etal parts沖件plastic parts 塑膠件SOP 制造作業(yè)程序material check list物料檢查表work cell 工作間trolley 臺車carton 紙箱sub-line 支線 left fork 叉車personnel resource department人力資源部production department 生產(chǎn)部門planning department 企劃部QC Section 品管科stamping factory 沖壓廠 painting factory 烤漆廠 molding factory 成型廠 common equipment常用設(shè)備un

19、coiler and straightener整平機(jī)punching machine 沖床robot 機(jī)械手hydraulic machine 油壓機(jī)lathe 車床planer |plein| 刨床miller 銑床grinder 磨床linear cutting 線切割 electrical sparkle 電火花welder 電焊機(jī)staker=reviting machine鉚合機(jī)position 職務(wù)president 董事長general manager 總經(jīng)理special assistant manager特助factory directoristeredReg廠長depart

20、ment director副理deputy manager | =vice mger課ice section superisor組長section supedeputy section superviso副課長group leader/suline supervisor 線長assistant manager 助理to move, to carry, to handle搬運(yùn)be put in storage 入庫pack packing 包裝to apply oil 擦油to file burr 銼毛刺final inspection 終檢to connect material接料to rev

21、erse material翻料wet station 沾濕臺Tiana 天那水cleaning cloth 抹布to load material 上料to unload material 卸料to return material/stock to退料scraped |skr?pid| 報(bào)廢scrape .v. 刮; 削deficient purchase 來料不良manufacture procedure 制程deficient manufacturing procedure制程不良o(jì)xidation | ksidei?n|氧化scratch 刮傷dents 壓痕defective upsid

22、ing down抽芽不良defective to staking 鉚合不良embedded lump 鑲塊feeding is not in place送料不到位stamping-missing 漏沖production capacity生產(chǎn)力education and training教育與訓(xùn)練proposal improvement提案改善spare parts=buffer備件forklift 叉車eg壓板administration/general affairs dept總務(wù)部automatic screwdriver 電動(dòng)啟子thickness gauge 厚薄規(guī)gauge(or

23、jig) 治具電源線trailer=long vehiclecompound die 合模die locker 鎖模器拖板車pressure plate=plate pinchbolt 螺栓power wirebuzzle 蜂鳴器defective product label 不良標(biāo)簽identifying sheet list 標(biāo)示單location 地點(diǎn)present members 出席人員 subject 主題 conclusion 結(jié)論 decision items 決議事項(xiàng)responsible department負(fù)責(zé)單位pre-fixed finishing date預(yù)定完成日

24、isteredapproved by / checked by / prepared by核準(zhǔn)/審核 /承辦PCE assembly production schedule sheet PCE組裝廠生產(chǎn)排配表model 機(jī)鍾work order 工令revision 版次remark 備注production control confirmation生產(chǎn)確認(rèn)checked by 初審approved by 核準(zhǔn)department 部門stock age analysis sheet庫存貨齡分析表on-hand inventory現(xiàn)有庫存available material良品可使用obsol

25、ete material良品已呆滯to be inspected or reworked待驗(yàn)或重工total 合計(jì)cause description原因說明part number/ P/N料號type 形態(tài)item/group/class類別quality 品質(zhì)prepared by 制表notes 說明year-end physical inventory difference analysis sheetphysical inventory 盤點(diǎn)數(shù)量physical count quantity帳面數(shù)量difference quantity 差異量cause analysis 原因分析ra

26、w materials 原料materials 物料finished product 成品成品semi-finished product包packing mategood product/s/ accepted parts/good parts不良品defective produd parts處理品Reg年終/epted g良品disposed goodswarehouse/hub倉庫on way location在途倉oversea location海外倉spare parts physical inventory list備品盤點(diǎn)清單spare molds location 模具備品倉sk

27、id/pallet 棧板tox machine 自鉚機(jī)wire EDM 線割EDM 放電機(jī)coil stock 卷料sheet stock 片料tolerance 工差score=groove 壓線cam block 滑塊pilot 導(dǎo)正筒trim 剪外邊pierce 剪內(nèi)邊drag form 壓鍛差pocket for the punch head 掛鉤槽 slug hole 廢料孔feature die 公母模expansion dwg 展開圖radius 半徑shim(wedge)楔子torch-flame cut火焰切割set screw 止付螺絲form block 折刀stop p

28、in 定位銷round pierce punch=die button圓沖子shape punch=die insert 異形子stock locater block 定位塊under cut=scrap chopper清角active plate活動(dòng)板e(cuò)gRair-cushion eject-rod 氣墊頂桿spring-box eject-plate 彈簧箱頂板bushing block 襯套insert 入塊club car 高爾夫球車baffle platecover plate擋塊蓋板male die 公模female die 母模groove punch 壓線沖子capabilit

29、y 能力parameter 參數(shù)factor 系數(shù)phosphate 皮膜化成 viscosity 涂料粘度 alkalidipping 脫脂 main manifold 主集流脈 bezel 斜視規(guī) blanking 穿落模 dejecting 頂固模demagnetization 去磁 ; 消磁isteredhigh-speed transmission 高速傳遞 heat dissipation 熱傳 rack 上料 degrease 脫脂rinse 水洗alkaline etch 齡咬desmut 剝黑膜D.I. rinse 純水次Chromate 鉻酸處理Anodize 陽性處理se

30、al 封孔revision 版次part number/P/N料號good products 良品scraped products報(bào)放心品defective products不良品finished products成品disposed products處理品barcode 條碼flow chart 流程表單assembly 組裝stamping 沖壓molding 成型spare parts=buffer備品egRthermocouple 熱電偶sand blasting 噴沙grit 砂礫derusting machine 除銹機(jī)degate 打澆口coordinate 座標(biāo)dismantl

31、e the dieauxiliary fuctionpoly-line 多義線折模輔助功能heater band 加熱片dryer 烘干機(jī)induction 感應(yīng)induction light 感應(yīng)光response=reaction=interaction 感應(yīng)ram 連桿edge finder 巡邊器concave 凸convex 凹short 射料不足nick 缺口speck 瑕 ?isteredshine 亮班splay 銀紋 gas mark 焦痕 delamination 起鱗 cold slug 冷塊 blush 導(dǎo)色gouge 溝槽; 鑿槽satin texture 段面咬花w

32、itness line 證示線patent 專利grit 沙礫granule=peuet=grain細(xì)粒grit maker 抽粒機(jī)cushion 緩沖magnalium 鎂鋁合金magnesium 鎂金metal plate 鈑金lathe 車 mill 銼plane 刨grind 磨drill 鋁boring 鏜blinster 氣泡egRcrank shaft 曲柄軸augular offset 角度偏差velocity 速度production tempo 生產(chǎn)進(jìn)度現(xiàn)狀torque 扭矩fillet 鑲; 嵌邊through-hole form 通孔形式voller pin forma

33、lity滾針形式cam driver 鍘楔shank 摸柄spline=the multiple keys花鍵quenching 淬火tempering 回火annealing 退火carbonization 碳化tungsten high speed steel鎢高速的moly high speed steel 鉬高速的 organic solvent 有機(jī)溶劑bracket 小磁導(dǎo)liaison 聯(lián)絡(luò)單volatile 揮發(fā)性isteredresistance 電阻 ion 離子 titrator 滴定儀 beacon 警示燈 coolant 冷卻液 crusher 破碎機(jī) 阿基米德蝸桿

34、Archimedes worm安全系數(shù) safety factor; factor of safety安全載荷 safe load凹面、凹度 concavity 扳手 wrench 板簧 flat leaf spring 半圓鍵 woodruff key變形 deformation擺桿 oscillating bar擺動(dòng)從動(dòng)件 oscillating follower擺動(dòng)從動(dòng)件凸輪機(jī)構(gòu) cam with oscillating follower擺動(dòng)導(dǎo)桿機(jī)構(gòu) oscillating guide-bar mechanism擺線齒輪 cycloidal gear擺線齒形 cycloidal toot

35、h profile擺線運(yùn)動(dòng)規(guī)律 cycloidal motion擺線針輪 cycloidal-pin wheel包角 angle of contactegRscalespecific heat capacityclosed kinematic chain閉鏈機(jī)構(gòu) closed chain mechanism保持架 cage背對背安裝 back-to-back arrangement背錐 back conenormal cone背錐角背錐距比例尺比熱容閉式鏈back angleback cone distanceistered臂部 arm變頻器 frequency converters變頻調(diào)速

36、frequency control of motor speed 變速 speed change變速齒輪 change gear change wheel變位齒輪 modified gear變位系數(shù) modification coefficient標(biāo)準(zhǔn)齒輪 standard gear標(biāo)準(zhǔn)直齒輪 standard spur gear表面質(zhì)量系數(shù) superficial mass factor表面?zhèn)鳠嵯禂?shù) surface coefficient of heat transfer表面粗糙度 surface roughness并聯(lián)式組合 combination in parallel并聯(lián)機(jī)構(gòu) para

37、llel mechanism并聯(lián)組合機(jī)構(gòu) parallel combined mechanism并行工程 concurrent engineering 并行設(shè)計(jì) concurred design, CD 不平衡相位 phase angle of unbalance 不平衡 imbalance (or unbalance) 不平衡量 amount of unbalance 不完全齒輪機(jī)構(gòu) intermittent gearing 波發(fā)生器 wave generator 波數(shù) number of waves 補(bǔ)償 compensation 參數(shù)化設(shè)計(jì) parameterization design

38、, PD殘余應(yīng)力 residual stress 操縱及控制裝置 operation control device 槽輪 Geneva wheel槽輪機(jī)構(gòu) Geneva mechanism ； Maltese cross 槽數(shù) Geneva numerate槽凸輪 groove cam 側(cè)隙 backlash差動(dòng)輪系 differential gear train差動(dòng)螺旋機(jī)構(gòu) differential screw mechanism差速器 differential常用機(jī)構(gòu) conventional mechanism; mechanism in common useRemension seri

39、esR齒槽 tooth space齒槽寬 spacewidth齒側(cè)間隙 backlashaddendumistered車床 lathe承載量系數(shù) bearing capacity factor承載能力 bearing capacity成對安裝 paired mounting尺寸系列 dimension serie齒頂高齒頂圓 addendum circle齒根高 dedendum齒根圓 dedendum circle齒厚 tooth thickness齒距 circular pitch 齒寬 face width 齒廓 tooth profile 齒廓曲線 tooth curve齒輪 gear

40、齒輪變速箱 speed-changing gear boxes齒輪齒條機(jī)構(gòu) pinion and rack齒輪插刀 pinion cutter; pinion-shaped shaper cutter 齒輪滾刀 hob ,hobbing cutter齒輪機(jī)構(gòu) gear 齒輪輪坯 blank 齒輪傳動(dòng)系 pinion unit 齒輪聯(lián)軸器 gear coupling 齒條傳動(dòng) rack gear 齒數(shù) tooth number 齒數(shù)比 gear ratio 齒條 rack 齒條插刀 rack cutter; rack-shaped shaper cutter 齒形鏈、無聲鏈 silent cha

41、in 齒形系數(shù) form factor齒式棘輪機(jī)構(gòu) tooth ratchet mechanism 插齒機(jī) gear shaper重合點(diǎn) coincident points重合度 contact ratio沖床 punch傳動(dòng)比 transmission ratio, speed ratio 傳動(dòng)裝置 gearing; transmission gear傳動(dòng)系統(tǒng) driven system傳動(dòng)角 transmission angle傳動(dòng)軸 transmission shaft串聯(lián)式組合機(jī)構(gòu) series combined mechanismgRg串聯(lián)式組合 combination in ser

42、ies串級調(diào)速 cascade speed control創(chuàng)新 innovation creation創(chuàng)新設(shè)計(jì) creation design垂直載荷、法向載荷唇形橡膠密封lip rubber磁流體軸承g(shù)netic fl從動(dòng)帶輪 dripulley從動(dòng)件 drivenistered從動(dòng)件平底寬度width of flat-face從動(dòng)件停歇 follower dwell 從動(dòng)件運(yùn)動(dòng)規(guī)律 follower motion 從動(dòng)輪 driven gear粗線 bold line粗牙螺紋 coarse thread 大齒輪 gear wheel 打包機(jī) packer 打滑 slipping 帶傳動(dòng) b

43、elt driving帶輪 belt pulley帶式制動(dòng)器 band brake單列軸承 single row bearing單向推力軸承 single-direction thrust bearing單萬向聯(lián)軸節(jié) single universal joint單位矢量 unit vector當(dāng)量齒輪 equivalent spur gear; virtual gear當(dāng)量齒數(shù) equivalent teeth number; virtual number of teeth 當(dāng)量摩擦系數(shù) equivalent coefficient of friction當(dāng)量載荷 equivalent loa

44、d刀具 cutter導(dǎo)數(shù) derivative倒角 chamfer導(dǎo)熱性 conduction of heat導(dǎo)程 lead導(dǎo)程角 lead angle等加等減速運(yùn)動(dòng)規(guī)律 parabolic motion; constant acceleration and deceleration motion等速運(yùn)動(dòng)規(guī)律 uniform motion; constant velocity motion等徑凸輪 conjugate yoke radial cam等寬凸輪 constant-breadth cam等效構(gòu)件 equivalent link等效力 equivalent force等效力矩 equi

45、valent moment of force等效量 equivalenteg 等效動(dòng)力學(xué)模型 dynamically equivalent model R 點(diǎn)劃線 chain dotted line（疲勞）點(diǎn)蝕 pitting墊圈 gasket墊片密封 gasket seal碟形彈簧 belleville spring等效質(zhì)量 equivalent mass等效轉(zhuǎn)動(dòng)慣量 equivalent moment of inertia底座 chassis低副 lower pairistered頂隙 bottom clearance定軸輪系 ordinary gear train; gear train

46、 with fixed axes 動(dòng)力學(xué) dynamics動(dòng)密封 kinematical seal動(dòng)能 dynamic energy動(dòng)力粘度 dynamic viscosity動(dòng)力潤滑 dynamic lubrication動(dòng)平衡 dynamic balance動(dòng)平衡機(jī) dynamic balancing machine動(dòng)態(tài)特性 dynamic characteristics動(dòng)態(tài)分析設(shè)計(jì) dynamic analysis design動(dòng)壓力 dynamic reaction動(dòng)載荷 dynamic load 端面 transverse plane端面參數(shù) transverse parameter

47、s端面齒距 transverse circular pitch端面齒廓 transverse tooth profile端面重合度 transverse contact ratio端面模數(shù) transverse module端面壓力角 transverse pressure angle鍛造 forge對稱循環(huán)應(yīng)力 symmetry circulating stress 對心滾子從動(dòng)件 radial (or in-line ) roller follower 對心直動(dòng)從動(dòng)件 radial (or in-line ) translating follower對心移動(dòng)從動(dòng)件 radial recip

48、rocating follower對心曲柄滑塊機(jī)構(gòu) in-line slider-crank (or crank-slider) mechanism多列軸承 multi-row bearing多楔帶 poly V-belt多項(xiàng)式運(yùn)動(dòng)規(guī)律 polynomial motion多質(zhì)量轉(zhuǎn)子 rotor with several masses惰輪 idle gear額定壽命 rating life額定載荷 load ratingII 級桿組 dyad發(fā)生線 generating line發(fā)生面 generating plane法面 normal plane法面參數(shù) normal parameters法面

49、齒距 normal circular pitch法面模數(shù) normal modulepitch法向直廓蝸桿法向齒距 no法向齒廓 no法面壓力角 normal pressangltoothileRegisteredded normal worm法向力 normal force反饋式組合 feedback combining反向運(yùn)動(dòng)學(xué) inverse ( or backward) kinematics 反轉(zhuǎn)法 kinematic inversion反正切 Arctan范成法 generating cutting仿形法 form cutting方案設(shè)計(jì)、概念設(shè)計(jì) concept design, C

50、D 防振裝置 shockproof device 飛輪 flywheel飛輪矩 moment of flywheel非標(biāo)準(zhǔn)齒輪 nonstandard gear非接觸式密封 non-contact seal非周期性速度波動(dòng) aperiodic speed fluctuation非圓齒輪 non-circular gear粉末合金 powder metallurgy分度線 reference line; standard pitch line分度圓 reference circle; standard (cutting) pitch circle 分度圓柱導(dǎo)程角 lead angle at reference cylinder 分度圓柱螺旋角 helix angle at reference cylinder 分母 denominator分子 numerato