| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| T-bolt | T型螺栓 |
A threaded bolt having a square or rectangular end which fits into the T slot of a machine table for clamping workpieces. 一种带有方形或矩形端头的螺栓，可嵌入机床工作台的T形槽中，用于夹紧工件。 |
| T-slot | T型槽 |
A recessed or undercut slot made with a special T shaped cutter in the tables of machine tools to receive the square head of a T bolt for clamping workpiece. 在机床工作台上用一种特殊的T形刀具制成的凹槽或底切槽，用于容纳T形螺栓的方头，用于夹紧工件。 |
| Tab washer (lock washer) | 止动垫圈（锁紧垫圈） |
A washer with one or more protruding tabs which can be bent in such a way that a nut or bolt head is prevented from becoming loose. 一种垫圈，具有一个或多个突出凸耳，可弯曲以防止螺母或螺栓头松动。 |
| Tangent modulus | 切线模量 |
The slope of the stress-strain curve at any specified stress or strain. See also modulus of elasticity. 在任何规定的应力或应变下，应力-应变曲线的斜率。另见弹性模量。 |
| Tangent screw | 微动螺旋 |
A worm screw used to adjust measuring instruments such as sextants and vernier callipers. 用于调整六分仪和游标卡尺等测量仪器的蜗杆。 |
| Tangential load (Unit N) | 切向荷载（单位：N） |
The component of load applied to an object, such as a gear, that tends to cause or resist rotation. 旋转力施加在物体上的载荷分量，如齿轮，倾向于引起或阻止旋转。 |
| Tap | 旋塞 |
1. A threaded hard metal plug for cutting screw threads in holes. It has longitudinal grooves for the clearance of chips while cutting. Progressive cutting is achieved by using three taps in succession: taper, second, and plug. First and second taps have tapers to help start the thread along the axis of the hole; the plug tap has no taper and is used on the final cut in a blind hole. 2. A valve in, or at the end of, a pipeline. 1.一种用于在孔中切割螺纹的螺纹硬金属塞。它具有纵向凹槽，用于在切割时清除切屑。渐进式切割通过连续使用三个丝锥实现：锥度、二次和塞。第一和第二丝锥具有锥度，以帮助沿孔的轴线开始螺纹；塞式丝锥没有锥度，用于盲孔的最终切割。2.管道中或管道末端的阀门。 |
| Tap wrench | 螺丝攻扳手 |
A lever with an adjustable square hole at its centre into which is fitted the shank of a tap so that torque can be applied to cut a thread. 一种杠杆，其中心有一个可调节的方孔，丝锥柄安装在该孔中，以便施加扭矩以切断螺纹。 |
| Taper | 变尖 |
A gradual, often linear, reduction in cross section or shape. A shaft or hole that gets gradually smaller toward one end. 横截面或形状的逐渐减小，通常是线性的。一端逐渐变小的轴或孔。 |
| Taper key | 楔键 |
A key with parallel sides but tapering cross section along its length. 边平行但横截面沿其长度逐渐变细的键。 |
| Taper pins | 圆锥销 |
A pin or peg of circular cross section that tapers along its length. Steel pins used for locating and holding the machine parts in position on a shaft. 沿其长度逐渐变细的圆形横截面的销钉或销钉。用于在轴上定位和固定机器零件的钢销。 |
| Tare weight (Unit N) | 皮重（单位N） |
The weight of an empty container. 空容器的重量。 |
| Tear strength (Unit N/m) | 撕裂强度（单位：N/m） |
The tensile force divided by the sheet thickness required to tear a pre-split sheet material at a specified rate. Particularly used for plastics, rubber, fabrics, and elastomers. Since the units are not those of stress but equivalent to J/m², the units of toughness, the term ‘strength’ is strictly incorrect. 按规定速率撕裂预裂片材所需的张力除以片材厚度。特别用于塑料、橡胶、织物和弹性体。由于单位不是应力单位，而是相当于J/m²，韧性单位，“强度”一词是完全错误的。 |
| Teeth | 齿 |
The projecting elements on gears, cutting tools, etc. 齿轮、刀具等上的突出元件。 |
| Temper | 回火 |
(1) In heat treatment, reheating hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing hardness and increasing toughness. The process also is sometimes applied to normalized steel. (2) In tool steels, temper is sometimes used, but inadvisedly, to denote the carbon content. (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working. （1）在热处理中，将硬化钢或硬化铸铁重新加热到共析温度以下的温度，以降低硬度和增加韧性。该工艺有时也适用于正火钢。（2）在工具钢中，有时使用回火来表示碳含量，但这是不恰当的。（3）在非铁合金和一些铁合金（不能通过热处理硬化的钢）中，通过机械或热处理或两者产生的硬度和强度，其特征是在冷加工过程中具有一定的结构、机械性能或面积减小。 |
| Temper color | 回火颜色 |
A thin, tightly adhering oxide skin that forms when steel is tempered at a low temperature, or for a short time, in air or a mildly oxidizing atmosphere. The color, which ranges from straw to blue depending on the thickness of the oxide skin, varies with both tempering time and temperature. 一种薄的、紧密粘附的氧化皮，当钢在低温或短时间内在空气或轻度氧化气氛中回火时形成。颜色范围从稻草色到蓝色，取决于氧化皮的厚度，随回火时间和温度而变化。 |
| Temper embrittlement | 回火脆化 |
Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is manifested as an upward shift in ductile-to-brittle transition temperature but only rarely produces a low value of reduction in area in a smooth-bar tension test of the embrittled material. The anomalous reduction in toughness of martensitic stainless steels when tempered in the range 370–600°C. Embrittlement of alloy steels caused by holding within or cooling slowly through a temperature range just below the transformation range. Embrittlement is the result of the segregation at grain boundaries of impurities such as arsenic, antimony, phosphorus, and tin; it is usually manifested as an upward shift in ductile-to-brittle transition temperature. Temper embrittlement can be reversed by retempering above the critical temperature range, then cooling rapidly. 当某些钢保持在低于转变范围的某一温度范围内或缓慢冷却时产生的脆性。脆性表现为延性到脆性转变温度的向上移动，但在脆性材料的平滑棒材拉伸试验中，很少产生较小的面积减小值。马氏体不锈钢在370–600°C范围内回火时的韧性异常降低。合金钢的脆化是由于在低于转变范围的温度范围内保持或缓慢冷却而引起的。脆化是杂质（如砷、锑、磷和锡）在晶界处偏析的结果；它通常表现为韧脆转变温度的上升。回火脆化可以通过在临界温度范围以上重新回火，然后快速冷却来逆转。 |
| Temperature (Unit K or °C) | 温度（单位K或°C） |
A quantitative measure of the molecular kinetic energy of a substance and so how hot or cold it is. 物质分子动能的定量量度，以及它的冷热程度。 |
| Temperature factor | 温度系数 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. Accounts for the effects of thermal expansion and the temperature-induced change in the velocity of sound. 用于螺栓应力或应变超声波测量的校准常数。说明了热膨胀和温度引起的声速变化的影响。 |
| Tempered martensite embrittlement | 回火马氏体脆化 |
Embrittlement of ultrahigh-strength steels caused by tempering in the temperature range of 205 to 400 °C (400 to 750 °F); also called 350 °C or 500 °F embrittlement. Tempered martensite embrittlement is thought to result from the combined effects of cementite precipitation on prioraustenite grain boundaries or interlath boundaries and the segregation of impurities at prioraustenite grain boundaries. 超高强度钢在205至400°C（400至750°F）温度范围内回火引起的脆化；也称为350°C或500°F脆化。回火马氏体脆化被认为是由于渗碳体沉淀在原奥氏体晶界或层间晶界上以及杂质在原奥氏体晶粒边界处偏析的综合影响。 |
| Temporal decomposition | 时间分解 |
The splitting of a control problem into parts with relatively short and long time constant so that different controllers may be used for the different parts. 将控制问题分解为具有相对较短和较长时间常数的部分，以便不同的部分可以使用不同的控制器。 |
| Tensile strength (Unit Pa) | 抗拉强度（单位Pa） |
In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body. (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。 |
| Tensile stress (Unit Pa) | 拉应力（单位Pa） |
A stress that causes two parts of an elastic body, on either side of a typical stress plane, to pull apart. A stress that tends to stretch a component, or local region of a component, when under load. In simple tension it results from the applied axial load, but tensile stresses occur in bending, torsion and other forms of loading. 一种应力，使弹性体的两个部分在典型应力平面的任一侧分离。在负载下，倾向于拉伸部件或部件局部区域的应力。在简单拉伸中，它由施加的轴向载荷产生，但拉伸应力发生在弯曲、扭转和其他形式的载荷中。 |
| Tensile test (tension test) | 拉伸试验（拉力试验） |
A test in which a precisely-machined tensile specimen (tensile testpiece), typically circular or rectangular in cross section with large end sections that are gripped in the testing machine, is subjected to an increasing tensile load, usually to the point of fracture, to produce a stress–strain curve from which such material properties as modulus of elasticity, limit of proportionality, proof stress, yield point, and ultimate tensile stress can be determined. The relevant standard is ISO 6892-1. 一种试验，在这种试验中，精密加工的拉伸试样（拉伸试件）的横截面通常为圆形或矩形，具有在试验机中夹紧的大端部，受到越来越大的拉伸载荷，通常达到断裂点，以产生应力-应变曲线，从中可以看出弹性模量、比例极限等材料特性，可以确定验证应力、屈服点和极限拉伸应力。相关标准为ISO 6892-1。 |
| Tensiometer | 张力计 |
An instrument used to measure surface tension. 用来测量表面张力的仪器。 |
| Tension | 拉伸 |
The force or load that produces elongation. 1. The condition in a bar, belt, cable, spring, string, wire, etc. that is being pulled from either end. 2. (tensile force) (unit N) The force associated with tension as in (1). It is measured by a tension meter. 伸长力产生伸长的力或载荷。1.从两端拉出的杆、带、电缆、弹簧、线、线等的状态。2.（张力）（单位N）与张力相关的力。 |
| Tension joint | 张力接头 |
A joint which is primarily subjected to loads acting more or less parallel to the axes of the bolts. 主要承受或多或少平行于螺栓轴线的载荷的接头。 |
| Tension testing | 张力测试 |
A method of determining the behavior of materials subjected to uniaxial loading, which tends to stretch the metal. A longitudinal specimen of known length and diameter is gripped at both ends and stretched at a slow, controlled rate until rupture occurs. Also known as tensile testing. 一种确定材料在单轴载荷下的行为的方法，这种载荷倾向于拉伸金属。将已知长度和直径的纵向试样夹持在两端，并以缓慢、受控的速率拉伸，直到发生断裂。也称为拉伸测试。 |
| Tension, bolt | 螺栓张力 |
Tension (tensile stress) created in the bolt by assembly preloads and=or such things as thermal expansion, service loads, etc. 由组件预载和=或热膨胀、工作载荷等因素在螺栓中产生的张力（拉伸应力）。 |
| Tensioner | 张紧器 |
A hydraulic tool used to tighten a fastener by stretching it rather than by applying a substantial torque to the nut. After the tension has stretched the bolt or stud, the nut is run down against the joint with a modest torque, and the tensioner is disengaged from the fastener. The nut holds the stretch produced by the tensioner. 一种液压工具，用于通过拉伸紧固件而不是对螺母施加较大扭矩来拧紧紧固件。张力拉伸螺栓或螺柱后，以适当的扭矩将螺母向下压靠接头，张紧器与紧固件分离。螺母保持张紧器产生的拉伸。 |
| Tensometer | 拉力计 |
A bench-top device, used to perform tension and compression tests. 用于进行拉伸和压缩试验的台式装置。 |
| Tera (T) | 特拉（T） |
An SI unit prefix indicating a multiplier of 1012; thus terawatt (TW) is a unit of power equal to one trillion watts. 指示乘数1012的SI单位前缀；因此，太瓦（TW）是等于1万亿瓦的功率单位。 |
| Terminal temperature difference (Unit K) | 终端温差（单位K） |
The temperature difference between the two fluid streams at either inlet or outlet of a heat exchanger. 热交换器入口或出口处两种流体流之间的温差。 |
| Terminal velocity (Unit m/s) | 终端速度（单位：m/s） |
The velocity reached by an object in free fall through a fluid when the upward drag and buoyancy forces just balance the object’s weight. For an object with a density lower than that of the fluid, the terminal velocity is vertically upwards. 当向上的阻力和浮力正好平衡物体的重量时，物体自由下落通过流体达到的速度。对于密度低于流体密度的物体，终端速度垂直向上。 |
| Testing machine | 试验机 |
A machine used to apply either a steady or oscillatory or impact load to a testpiece. The load may be tensile, compressive, shear, bending, or torsional. 用于向试件施加稳定或振荡或冲击载荷的机器。载荷可以是拉伸的、压缩的、剪切的、弯曲的或扭转的。 |
| Testing machine (load-measuring type) | 试验机（负载测量型） |
A mechanical device for applying a load (force) to a specimen. 向试样施加载荷（力）的机械装置。 |
| Thermal analysis | 热分析 |
A method for determining transformations in a metal by noting the temperatures at which thermal arrests occur. These arrests are manifested by changes in slope of the plotted or mechanically traced heating and cooling curves. When such data are secured under nearly equilibrium conditions of heating and cooling, the method is commonly used for determining certain critical temperatures required for the construction of equilibrium diagrams. 一种通过记录发生热阻的温度来确定金属转变的方法。这些阻力表现为绘制或机械追踪的加热和冷却曲线斜率的变化。当这些数据在加热和冷却的近似平衡条件下得到保证时，该方法通常用于确定构建平衡图所需的某些临界温度。 |
| Thermal compressor | 热压缩机 |
1. (thermocompressor) A jet compressor used to boost the pressure of low-pressure waste or exhaust steam. 2. A device consisting of an absorber, a generator, a pump, and a throttling device, used instead of a mechanical vapour compressor in an absorption-cooling refrigeration system. 1.（热压缩机）用于提升低压废蒸汽或排气压力的喷射压缩机。2.一种由吸收器、发电机、泵和节流装置组成的装置，用于替代吸收冷却制冷系统中的机械蒸汽压缩机。 |
| Thermal efficiency | 热效率 |
The ratio, for a heat engine or thermodynamic cycle, of the net work output to the net heat input into the system. 对于热机或热力循环，净功输出与系统净热输入的比率。 |
| Thermal electromotive force | 热电动势 |
The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from that of the other. 当一个结处于不同于另一个结的温度时，在含有两种不同金属的电路中产生的电动势。 |
| Thermal energy (heat energy) (Unit J) | 热能（单位：J） |
The sensible and latent forms of internal energy. 内能的感知和潜在形式。 |
| Thermal fatigue | 热疲劳 |
Fatigue resulting from the presence of temperature gradients that vary with time in such a manner as to produce cyclic stresses in a structure. 由于温度梯度的存在而产生的疲劳，温度梯度随时间变化，从而在结构中产生循环应力。 |
| Thermal insulation (insulation) | 隔热（绝缘） |
A material that may be a low-conductivity solid, or a porous solid or fabric in which there are voids containing air or another gas, resulting in overall low thermal conductivity. When applied to the surface of a hot or cold object, surface heat transfer is generally reduced. 一种材料，可以是低导电性固体，或多孔固体或织物，其中存在含有空气或其他气体的空隙，从而导致整体低导热性。当应用于热或冷物体的表面时，表面传热通常减少。 |
| Thermal reactor | 热反应器 |
An enlarged exhaust manifold bolted directly to the cylinder head of a piston engine, in which the oxidation of carbon monoxide and unburned hydrocarbons in the exhaust gas is enhanced. 一种扩大的排气歧管，直接用螺栓固定在活塞式发动机的气缸盖上，其中一氧化碳和未燃烧碳氢化合物的氧化作用增强。 |
| Thermal shock | 热冲击 |
The development of a steep temperature gradient and accompanying high stresses within a structure. 在结构内形成陡峭的温度梯度和伴随的高应力。 |
| Thermal stresses | 热应力 |
Stresses in metal resulting from nonuniform temperature distribution. 由不均匀温度分布引起的金属应力。 |
| Thermochemical treatment | 热化学处理 |
Heat treatment carried out in a medium suitably chosen to produce a change in the chemical composition of the object by exchange with the medium. 在适当选择的介质中进行热处理，以通过与介质交换产生物体化学成分的变化。 |
| Thermocouple | 热电偶 |
A device for measuring temperature, consisting of lengths of two dissimilar metals or alloys that are electrically joined at one end and connected to a voltage-measuring instrument at the other end. When one junction is hotter than the other, a thermal electromotive force is produced that is roughly proportional to the difference in temperature between the hot and cold junctions. 一种测量温度的装置，由两种不同的金属或合金组成，一端电连接，另一端与电压测量仪相连。当一个结比另一个结更热时，产生的热电动势大致与热结和冷结之间的温差成比例。 |
| Thermodynamic pressure (Unit Pa) | 热力学压力（单位Pa） |
The pressure within a fluid given by an equation of state such as p(ρ,T) where ρ is the fluid density and T is the absolute temperature of the fluid. 流体中的压力由状态方程给出，如p（ρ，T），其中ρ是流体密度，T是流体的绝对温度。 |
| Thermodynamic process | 热力学过程 |
A change in equilibrium state undergone by a quantity of matter or a system. 一定量的物质或系统所经历的平衡状态的变化。 |
| Thermodynamic properties | 热力学性质 |
Temperature, pressure, and the intensive properties that define the state of a working fluid: specific internal energy, specific enthalpy and specific entropy. 温度、压力和定义工作流体状态的密集属性：比内能、比焓和比熵。 |
| Thermodynamic state | 热力学状态 |
The condition of a system or working fluid according to its properties. 系统或工作流体根据其性质的状态。 |
| Thermodynamics laws | 热力学定律 |
The zeroth, first, second, and third laws of thermodynamics. 热力学第零、第一、第二和第三定律。 |
| Thermoelastic effect | 热弹性效应 |
The change in temperature of material under adiabatic elastic deformation, e.g. when loading is so rapid that the material is not in thermal equilibrium with its surroundings. For most materials, elastic tension lowers the temperature and compression raises it. The reverse occurs in elastomers such as rubber that exhibit entropic elasticity because stretching reduces the number of possible molecular configurations and so reduces the entropy. The thermoelastic effect gives rise to a stress–strain hysteresis loop in cyclic elastic loading and is one mechanism by which vibrational energy is dissipated internally in materials. 材料在绝热弹性变形下的温度变化，例如当加载速度如此之快，以至于材料与其周围环境不处于热平衡时。对于大多数材料，弹性张力降低温度，压缩提高温度。相反的情况发生在弹性体中，如橡胶，其表现出熵弹性，因为拉伸减少了可能的分子构型的数量，从而降低了熵。热弹性效应在循环弹性载荷中产生应力-应变迟滞回线，是振动能量在材料内部耗散的一种机制。 |
| Thermoelectric converter | 热电转换器 |
(thermoelectric generator) A device consisting of series-connected alternate n- and p-type semiconductor elements sandwiched between two ceramic plates. Due to the Seebeck effect, electrical power is generated when a temperature difference is maintained across the plates. Due to the Peltier effect, a thermoelectric converter can act as either a thermoelectric heater or a thermoelectric cooler (thermoelectric refrigerator) by passing an electrical current through it. The thermoelectric figure of merit (Z), with unit 1/K, is a dimensional parameter on which the efficiency of a thermoelectric device is primarily dependent, defined by Z = σα2/k where α is the Seebeck coefficient, σ is the electrical conductivity, and k is the thermal conductivity. The product of Z and a temperature is non-dimensional. （热电发生器）由串联连接的交替的n型和p型半导体元件夹在两块陶瓷板之间组成的装置。由于塞贝克效应，当板之间保持温差时，就会产生电能。由于珀尔帖效应，热电转换器可以通过使电流通过而充当热电加热器或热电冷却器（热电制冷机）。热电优值（Z）和第一单元/K是一个尺寸参数，热电装置的效率主要取决于此，由Z=σα2/K定义，其中α是塞贝克系数，σ是电导率，K是热导率。Z和温度的乘积是无量纲的。 |
| Thermoelectric junction | 热电结 |
A welded, soldered, or twisted connection between the ends of two wires of dissimilar metals, as in a thermocouple. 两根不同金属线的末端之间的焊接、锡焊或绞合连接，如热电偶。 |
| Thermoelectric material | 热电材料 |
A material in which any of the thermoelectric phenomena, such as the Peltier, Seebeck, and Thomson effects, are especially strong. 一种热电现象特别强烈的材料，如珀尔帖效应、塞贝克效应和汤姆森效应。 |
| Thermomechanical working | 热机械加工 |
A general term covering a variety of processes combining controlled thermal and deformation treatments to obtain specific properties. Same as thermal-mechanical treatment. 一个通用术语，涵盖结合受控热处理和变形处理以获得特定性能的各种工艺。与热机械处理相同。 |
| Thread form | 螺纹形式 |
The cross-sectional shape of the threads, defining thread angle, root, and crest profiles, etc. Thread length Length of that portion of the fastener which contains threads cut or rolled to full depth. 螺纹的横截面形状，定义螺纹角度、齿根和齿冠轮廓等。螺纹长度：紧固件中包含全深度切割或轧制螺纹的部分的长度。 |
| Thread grinding | 螺纹磨削 |
A method for producing or finishing very precise screw threads using a profiled grinding wheel. 一种使用异形砂轮生产或精加工非常精密螺纹的方法。 |
| Thread insert | 螺纹嵌件 |
(threaded bushing) Either a thin cylinder with an internal thread (and sometimes also an external thread) or a helical coil of wire, pressed or screwed into a hole to accept a bolt or screw. Used in material too soft or a component too thin to be threaded, to change one form of thread to another or to repair a damaged thread. （螺纹衬套）一种带有内螺纹（有时也有外螺纹）的薄圆柱体或螺旋形线圈，压入或拧入孔中以接受螺栓或螺钉。用于材料太软或部件太薄而无法螺纹连接，用于将一种形式的螺纹更换为另一种形式或修复损坏的螺纹。 |
| Thread milling | 螺纹铣削 |
Thread milling is a method of cutting screw threads with a milling cutter in a thread mill. Thread milling cutters are either single form or multiple form and are used in either conventional or planetary thread mills. 螺纹铣削是在螺纹铣刀中用铣刀切削螺纹的一种方法。螺纹铣刀为单形或多形，用于传统或行星式螺纹铣刀。 |
| Thread rolling | 滚丝 |
Thread rolling (also known as roll threading) is a cold forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Polygonal blanks are also thread rolled for the purpose of fabricating thread-forming and self-locking screws. The preferred polygonal shape is trilobular and is produced in flat die machines. 螺纹滚压（也称为滚压螺纹）是一种冷成型工艺，通过将硬化钢模具的压痕滚压到圆柱形或锥形坯料的表面来生产螺纹或其他螺旋或环形形状。多边形坯料也进行螺纹轧制，以制造螺纹成型和自锁螺钉。优选的多边形形状为三棱形，并在平模机中生产。 |
| Thread run-out | 螺纹耗尽 |
That portion of the threads which are not cut or rolled full depth, but which provide the transition between full-depth threads and the body or head. Officially called thread washout or vanish, although the term run-out is more popular. (Run-out is officially reserved for rotational eccentricity, as defined by total indicator readings or the like.) 未全深度切割或轧制的螺纹部分，但提供全深度螺纹与主体或头部之间的过渡。官方称之为螺纹冲蚀或消失，但术语“耗尽”更为流行。（跳动是官方为旋转偏心度保留的，由总指示器读数等定义。） |
| Threaded fastener | 螺纹紧固件 |
Studs, bolts, and screws of all sorts, with associated nuts. One of the most interesting, complex, useful—and frustrating—components yet devised. 各种螺柱、螺栓和螺钉，以及相关的螺母。 |
| Threading machine | 螺纹机 |
A machine used to cut an external thread on a rod, tube, bolt blank, etc. or an internal thread in a hole, tube, nut blank, etc. 用于切割杆、管、螺栓毛坯等上的外螺纹或孔、管、螺母毛坯等中的内螺纹的机器。 |
| Three-quarters hard | 四分之三硬度 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about midway between those of half hard and full hard tempers. 一种非铁合金和一些铁合金的回火，其特征是抗拉强度和硬度介于半硬回火和全硬回火之间。 |
| Threshold stress for stress-corrosion cracking (σth) | 应力腐蚀开裂阈值应力（σth） |
An experimentally determined critical gross-section stress below which stress-corrosion cracking will not occur under specified test conditions. 实验确定的临界总截面应力，低于该应力，在规定的试验条件下不会发生应力腐蚀开裂。 |
| Thumb screw | 蝶形螺钉 |
A type of screw having a winged or knurled head for turning by hand when a quick and light clamping effect is desired. 一种螺钉，具有翼形或滚花头，当需要快速、轻夹紧效果时，可手动转动。 |
| Tightness | 紧密度 |
A measure of the mass leak rate from a gasketed joint. 垫圈接头质量泄漏率的测量值。 |
| Tightness parameter | 密封参数 |
A dimensionless parameter which defines the mass leakage of a gasket as a functionof contained pressure and a contained fluid constant. 一种无量纲参数，将垫圈的质量泄漏定义为所含压力和所含流体常数的函数。 |
| Tightness, acceptable | 密封性，可接受的 |
Wholly leak-free joints are impossible, at least if the contained fluid is a gas, so it has been proposed that the design of a gasketed joint should start with the selection of an ‘‘acceptable’’ leak rate. The designer would dimension bolts and joint members so that the actual leak rate would never exceed this. Three standard levels of tightness have been proposed as well. 至少在所含流体为气体的情况下，完全无泄漏的接头是不可能的，因此有人建议，垫圈接头的设计应从选择“可接受”的泄漏率开始。设计师将确定螺栓和接头构件的尺寸，以便实际泄漏率永远不会超过此值。还提出了三种标准的密封性等级。 |
| Time quenching | 时间淬火 |
A term used to describe a quench in which the cooling rate of the part being quenched must be changed abruptly at some time during the cooling cycle. 用于描述淬火的术语，其中被淬火零件的冷却速率必须在冷却循环的某个时间突然改变。 |
| Toggle (toggle clamp) | 拨动（拨动夹） |
A device consisting of two pinned levers that are almost in line between two end points in the same plane. Bringing the levers into line generates large forces between the ends. Used to obtain a large mechanical advantage or as a locking mechanism. 由两个销杆组成的装置，在同一平面的两个端点之间几乎成一条直线。将杠杆对齐会在端部之间产生较大的力。用于获得较大的机械优势或用作锁定机构。 |
| Tolerance limits | 公差极限 |
The extreme values (upper and lower) that define the range of permissible variation in size or other quality characteristic of a part. 定义零件尺寸或其他质量特性允许偏差范围的极值（上限和下限）。 |
| Tolerances | 公差 |
A fractional allowance for variation from the specifications. In mass production, using automatic machines, parts are intended to be completely or partially interchangeable, and in batch production parts should ideally fit without the need for selection. In practice it is impossible for mass-produced parts to have exactly the same size, owing to tool wear, variations in raw materials, thermal effects, etc. In consequence, variations from exactness, termed tolerances, are assigned to what is permissible on the basic size. 与规范不同的部分公差。在大规模生产中，使用自动机器时，零件应完全或部分可互换，在批量生产中，零件应理想匹配，无需选择。在实践中，由于刀具磨损、原材料变化、热效应等原因，批量生产的零件不可能具有完全相同的尺寸。因此，将精度偏差（称为公差）指定给基本尺寸上允许的尺寸。 |
| Tooth lock washers | 带齿锁紧垫圈 |
These washers serve to lock fasteners, such as bolts and nuts, to the component parts of an assembly, or increase the friction between the fasteners and the assembly. They are designated in a manner similar to helical spring lock washers, and are available in carbon steel. 这些垫圈用于将紧固件（如螺栓和螺母）锁定到组件的零部件上，或增加紧固件与组件之间的摩擦力。它们的设计方式类似于螺旋弹簧锁紧垫圈，可采用碳钢。 |
| Toothed belt | 齿带 |
A flat belt, typically of a reinforced-rubber material, with transverse teeth that engage with teeth on a wheel or pulley. 一种扁平皮带，通常由增强橡胶材料制成，带有横向齿，与车轮或皮带轮上的齿啮合。 |
| Toothed gearing | 齿轮传动 |
In principle, friction between circular discs in tangential contact could be used to transmit rotation and power between shafts, but the power level would be very limited and the velocity ratio affected by slip. To make the drive positive, gear wheels are used instead in which teeth extend above and below the diameters (the pitch-circle diameters) of discs in ideal rolling contact. The diagram shows the nomenclature for spur gears, the simplest type of gearing between parallel shafts, which are cylindrical in shape with straight teeth parallel to the axis of rotation. 原则上，切向接触的圆盘之间的摩擦可用于在轴之间传递旋转和动力，但动力水平非常有限，速比受滑动的影响。为了使驱动积极，使用齿轮代替，齿轮中的齿延伸到理想滚动接触的圆盘直径（节圆直径）的上方和下方。该图显示了直齿轮的名称，这是平行轴之间最简单的齿轮传动类型，其形状为圆柱形，直齿平行于旋转轴。 |
| Torque (T) (Unit N.m) | 扭矩（T）（单位：N.m） |
The twisting moment, product of force and wrench length, applied to a nut or bolt (for example). The twisting moment of a force or couple about an axis which results in torsion. 施加在螺母或螺栓（例如）上的扭矩，是力和扳手长度的乘积。力或力偶绕轴产生扭转的力矩。 |
| Torque arm | 扭力臂 |
A bar fixed at one end used to resist torque applied at the other, for example by an electric drill. 固定在一端的杆，用于抵抗施加在另一端的扭矩，如电钻。 |
| Torque coefficient | 扭矩系数 |
1. (KT) For a propeller of diameter D, a non-dimensional parameter defined by KT = T/ρΩ2D5 where Ω is the rotational speed (in rad/s) and ρ is the fluid density. 2. (CT) An alternative to (1) for a wind turbine, defined by CT = 2T/ρV2AR where V is the wind speed, A is the swept area of the blades, and R is the blade radius. 3. (K) An empirical coefficient used to calculate the torque T required to achieve an axial load F in a bolt according to T = KFd where d is the nominal bolt diameter. 1.（KT）对于直径为D的螺旋桨，由KT=T/ρΩ2D5定义的无量纲参数，其中Ω是转速（单位为rad/s），ρ是流体密度。2.（CT）对于风力涡轮机（1）的替代方案，由CT=2T/ρV2AR定义，其中V是风速，a是叶片的扫掠面积，R是叶片半径。3.（K）经验系数，用于根据T=KFd计算螺栓中实现轴向载荷F所需的扭矩T，其中d是螺栓标称直径。 |
| Torque control | 扭矩控制 |
A system of optimizing rotor speed for a variable-speed wind turbine by controlling the torque demands of the generator. 通过控制发电机的扭矩需求来优化变速风力涡轮机的转子速度的系统。 |
| Torque converter | 变矩器 |
A turbomachine used for torque amplification consisting of an impeller, a turbine, and a reaction member. Applications include motor-vehicle transmissions. 用于扭矩放大的涡轮机，由叶轮、涡轮机和反作用构件组成。应用包括机动车变速器。 |
| Torque meter | 扭矩计 |
An instrument for measuring torque using spring-loaded, piezoelectric, or strain-gauged devices. 使用弹簧加载、压电或应变测量装置测量扭矩的仪器。 |
| Torque monitor | 扭矩监测器 |
A torque tool control system which monitors the amount of torque being developed by the tool during use, but does not control the tool or the torque produced. 一种扭矩工具控制系统，监控工具在使用过程中产生的扭矩量，但不控制工具或产生的扭矩。 |
| Torque motor | 力矩电机 |
A type of induction motor that can apply a steady torque even when prevented from rotating. 一种感应电动机，即使被阻止旋转也能施加稳定的转矩。 |
| Torque multiplier | 扭矩放大器 |
A gearbox used to multiply the torque produced by a small hand wrench (usually a Torque wrench). The output of the multiplier drives the nut or bolt with a torque that is higher, and a speed that is lower, than input torque and speed. There is no torque gage or readout on the multiplier. 一种齿轮箱，用于增加小手动扳手（通常是扭矩扳手）产生的扭矩。倍增器的输出以比输入扭矩和速度更高的扭矩和更低的速度驱动螺母或螺栓。倍增器上没有扭矩计或读数。 |
| Torque pack | 扭矩包 |
A geared wrench which multiplies input torque and provides a read-out of output torque. In effect, a combination of a Torque wrench and a Torque multiplier. 一种齿轮扳手，可增加输入扭矩并提供输出扭矩读数。实际上，它是扭矩扳手和扭矩倍增器的组合。 |
| Torque reaction (Unit N.m) | 扭矩反作用力（单位：N.m） |
The torque needed to counteract an applied torque. For example, in a helicopter with a single main rotor, the tendency of the fuselage to rotate in the opposite direction to the rotor. 抵消施加扭矩所需的扭矩。例如，在具有单个主旋翼的直升机中，机身沿与旋翼相反的方向旋转的趋势。 |
| Torque wrench | 扭矩扳手 |
A manual wrench which incorporates a gage or measuring apparatus of some sort to measure and display the amount of torque being delivered to the nut or bolt. All wrenches produce torque. Only a torque wrench tells how much torque. A socket wrench or ring spanner that can be set to allow a specific torque to be applied to a nut or bolt head. 一种手动扳手，包括某种量规或测量装置，用于测量和显示传递至螺母或螺栓的扭矩量。所有扳手都产生扭矩。只有扭矩扳手才能显示扭矩大小。一种套筒扳手或梅花扳手，可设置为允许对螺母或螺栓头施加特定扭矩。 |
| Torr | 托尔 |
A non-SI unit of pressure commonly used in vacuum systems; defined by 760 torr = 1 atm so that 1 torr = 133.322 368 4 Pa, and approximately equivalent to the pressure corresponding to 1 mm of mercury. 真空系统中常用的非SI压力单位；由760托=1大气压定义，因此1托=133.3223684帕，近似等于对应于1毫米汞柱的压力。 |
| Torricellean barometer | 托里塞莱气压计 |
A vertical glass tube with its upper end sealed and the lower end submerged in a pool of mercury. The space above the mercury is under vacuum. The height to which the mercury rises up the tube is a measure of the barometric pressure. 一种垂直的玻璃管，上端密封，下端浸入汞池中。水银上方的空间处于真空状态。水银在管道中上升的高度是大气压力的量度。 |
| Torsion | 扭矩 |
A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices. The twisting of an object about an axis due to an applied couple (torque). 一种固体绕轴的扭转变形，在该变形中，最初平行于轴的线变成螺旋线。由于施加的力偶（扭矩），物体绕轴扭曲。 |
| Torsion bar | 扭杆 |
A metal bar designed to act as an elastic spring when torque is applied. 当施加扭矩时用作弹性弹簧的金属棒。 |
| Torsion spring | 扭簧 |
1. A spring in the form of a torsion bar. 2. A helical spring to which torque can be applied at the ends. 1.一种扭杆形式的弹簧。2.一种螺旋弹簧，其端部可施加扭矩。 |
| Torsion test | 扭力测试 |
A test designed to provide data for the calculation of the shear modulus, modulus of rupture in torsion, and yield strength in shear. 为计算剪切模量、扭转断裂模量和剪切屈服强度而设计的试验。 |
| Torsion-bar suspension | 扭杆悬架 |
A type of motor-vehicle suspension in which one end of a torsion bar is rigidly fixed to the chassis while the other carries a lever to which are attached the components that carry a wheel. In a torsion-beam suspension, a beam connects the wheels on either side of the vehicle. 一种汽车悬架，其中扭力杆的一端刚性固定在底盘上，而另一端带有一个杠杆，杠杆上连接着承载车轮的部件。在扭转梁悬架中，梁连接车辆两侧的车轮。 |
| Torsional angle (ϕ) | 扭转角（ψ） |
(Unit ° or rad) The angular deflexion between two locations on a straight bar subjected to a torque. （单位为°或rad）受扭矩作用的直杆上两个位置之间的角偏转。 |
| Torsional shaft vibration | 扭轴振动 |
The rapid back-and-forth angular twisting along a rotating unbalanced shaft which reaches maxima at critical rotation speeds. Shaft eccentricity, unbalanced mass distribution, oscillatory torque, misalignment, etc. all influence torsional vibration. 沿旋转不平衡轴的快速来回角扭转，在临界转速下达到最大值。轴偏心、质量分布不平衡、振荡扭矩、未对准等都会影响扭转振动。 |
| Torsional stress | 扭转应力 |
The shear stress on a transverse cross section resulting from a twisting action. 扭转作用在横截面上产生的剪切应力。 |
| Total carbon | 总碳 |
The sum of the free and combined carbon (including carbon in solution) in a ferrous alloy. 铁合金中游离碳和结合碳（包括溶液中的碳）的总和。 |
| Total combustion air (Unit kg/s) | 总燃烧空气（单位：kg/s） |
1. The combination of the stoichiometric flow of air required for combustion together with any excess air. 2. The flow of fresh air into a boiler plus any flue gas recirculated. 1.燃烧所需的化学计量空气流与任何过量空气的组合。2.进入锅炉的新鲜空气流加上再循环的任何烟气。 |
| Total elongation | 总伸长率 |
A total amount of permanent extension of a test piece broken in a tensile test. 拉伸试验中断裂试样的永久延伸总量。 |
| Total energy (Unit J) | 总能量（单位J） |
The sum of all forms of energy associated with a system, including kinetic, potential, internal, magnetic, chemical, and electrical energy. 与系统相关的所有形式能量的总和，包括动能、势能、内能、磁能、化学能和电能。 |
| Total head (hT) (Unit m) | 总水头（hT）（单位：m） |
Total pressure pT expressed in terms of the vertical height of a column of liquid, typically water or mercury, i.e. hT = pT/ρg where g is the acceleration due to gravity and ρ is the liquid density. 总压力pT以液体柱（通常为水或汞）的垂直高度表示，即hT=pT/ρg，其中g为重力加速度，ρ为液体密度。 |
| Total heat (Unit kJ) | 总热量（单位kJ） |
An alternative term for enthalpy. It is inappropriate as it suggests that it includes kinetic energy in the same way as total enthalpy, but it does not. Also, heat and enthalpy are quite different quantities, as their definitions show. 焓的另一个术语。这是不恰当的，因为它表明，它包括动能的方式与总焓相同，但它实际上并不是的。此外，热和焓是完全不同的量，正如它们的定义所示。 |
| Total-loss lubrication | 全损耗润滑 |
A system in which the lubricating oil for an internal-combustion engine is burned together with the fuel. 内燃机润滑油与燃料一起燃烧的系统。 |
| Toughening mechanisms | 增韧机理 |
Various methods of increasing the resistance to crack initiation and propagation in materials. They include transformation toughening, in which the microstructure around the crack tip alters so as to slow down or arrest cracks; deflexion of cracks; various ways of de-sharpening crack tips; fibre bridging of cracks; and fibre pull-out. 增加材料中裂纹萌生和扩展阻力的各种方法。它们包括相变增韧，其中裂纹尖端周围的微观结构发生变化，以减缓或阻止裂纹；裂纹偏转；消除裂纹尖端锐化的各种方法；纤维桥接裂纹；和纤维拉出。 |
| Toughness (Unit J/m²) | 韧性（单位：J/m²） |
The ability of a metal to absorb energy and deform plastically before fracturing. 1. The ability of a material to resist crack initiation and propagation. 2. The ability of a material to absorb strain energy without fracturing. 金属在破裂前吸收能量和塑性变形的能力。1.材料抵抗裂纹萌生和扩展的能力。2.材料在不发生断裂的情况下吸收应变能的能力。 |
| Tow | 拖拉 |
1. To cause a vehicle to move by pulling with a rope, chain, bar, etc. 2. A bundle of fibres employed in reinforcement. 1.用绳子、链条、钢筋等拉动车辆移动。2.用于加固的纤维束。 |
| Track rod | 横拉杆 |
A bar connecting the ends of the steering arms in an automotive vehicle. 连接汽车转向臂端部的杆。 |
| Tracking problem | 跟踪问题 |
A control problem where the set point changes with time and thus the plant output must follow the changing set point. The opposite of a regulator problem. 一种控制问题，其中设定值随时间变化，因此设备输出必须遵循变化的设定值。与调节器问题相反。 |
| Transducer | 传感器 |
A device which converts one form of energy into another. An ultrasonic transducer, for example, converts electrical energy into acoustic energy (at ultrasonic frequencies) and vice versa. 将一种形式的能量转换为另一种形式能量的装置。例如，超声换能器将电能转换为声能（在超声频率下），反之亦然。 |
| Transfer machines | 转印机 |
These specialized machine tools are used to perform various machining operations on parts or parts in fixtures as the parts are moved along on an automatic conveyor which is part of the machine tool set-up. In a set-up, the parts can move in a straight line from their entry point to their exit point, or the setup may be constructed in a U-shape so that the parts are expelled near where they start. 当零件在自动输送机上移动时，这些专用机床用于对零件或夹具中的零件执行各种加工操作，自动输送机是机床设置的一部分。在设置中，零件可以从其入口点直线移动到其出口点，或者设置可以构造为U形，以便零件在其起点附近排出。 |
| Transfer moulding | 转移模塑 |
(resin-transfer moulding, RTM) A method of compression moulding polymers in which the dies are closed before the operation starts. （树脂传递模塑，RTM）一种对聚合物进行压缩模塑的方法，其中模具在操作开始前关闭。 |
| Transfer ratio | 传输比 |
(transfer constant) A complex variable representing the ratio between the output of a transducer and the input causing that output. （传递常数）一个复变量，表示传感器输出与产生该输出的输入之间的比率。 |
| Transformation temperature | 相变温度 |
The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels. 发生相位变化的温度。该术语有时用于表示转变范围的极限温度。以下符号用于钢铁。 |
| Transformation toughening | 相变增韧 |
The improvement of fracture toughness of a material by stress-induced transformation of the microstructure. 通过微结构的应力诱导转变来提高材料的断裂韧性。 |
| Transgranular | 穿晶 |
Through or across crystals or grains. Also known as intracrystalline or transcrystalline. 穿过或横穿晶体或颗粒。也称为晶内或晶间。 |
| Transgranular fracture | 穿晶断裂 |
Fracture in crystalline materials where the path of cracking is predominantly across grains. 晶体材料中的断裂，其中裂纹路径主要跨越晶粒。 |
| Transition metals | 过渡金属 |
Metallic elements from groups (columns) 3 to 12 of the periodic table. They include important metals such as titanium, vanadium, chromium, manganese, iron, cobalt, zirconium, niobium, molybdenum, tantalum, tungsten, and the noble metals. They have either body-centred cubic, face-centred cubic, or hexagonal close-packed crystal structure at room temperature and have a wide range of mechanical and physical properties. 元素周期表第3组至第12组（列）中的金属元素。它们包括重要的金属，如钛、钒、铬、锰、铁、钴、锆、铌、钼、钽、钨和贵金属。它们在室温下具有体心立方、面心立方或六方密排晶体结构，并具有广泛的机械和物理性能。 |
| Transition temperature (Unit K) | 转变温度（单位K） |
(1) An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear)to primarily crystalline (cleavage) fracture. (2) Sometimes used to denote an arbitrarily defined temperature within a range in which the ductility changes rapidly with temperature. (transition point) 1. The temperature at which the mechanism of fracture in metal alloys having a face-centred cubic crystal structure changes from ductile void growth to brittle cleavage. 2. The temperature at which a material changes from one crystal state to another. （1） 任意定义的温度，位于金属断裂特性（通常通过缺口试样的试验确定）快速变化的温度范围内，如从主要纤维（剪切）断裂到主要结晶（解理）断裂。（2） 有时用于表示延性随温度快速变化的范围内的任意定义的温度。（转变点）1.具有面心立方晶体结构的金属合金的断裂机制从韧性孔洞生长转变为脆性解理的温度。2.材料从一种晶体状态转变为另一种晶体的温度。 |
| Translational joint | 平移铰 |
A robot joint where the controlled variable is straight line movement. 控制变量为直线运动的机器人关节。 |
| Transmissibility | 传递率 |
The ratio of the transmitted force to the disturbing force for a system subjected to a vibratory disturbance. The ratio may also be defined in terms of displacements, velocities, or accelerations. 受到振动干扰的系统的传递力与干扰力之比。该比率也可以用位移、速度或加速度来定义。 |
| Transmission | 传输 |
The system that transmits power and torque from a power source; for example a shaft, belts and pulleys, or a gear train. In the case of a motor vehicle, it includes the gearbox, clutch, propeller shaft, differential and final drive shafts. 从动力源传输功率和扭矩的系统；例如轴、皮带和滑轮或齿轮系。对于机动车辆，包括变速箱、离合器、传动轴、差速器和终传动轴。 |
| Transmission dynamometer | 传动测功机 |
A dynamometer in which the power transmitted by a shaft is obtained from the product of its rotation speed and the torque determined from measured shear strains along the shaft. 一种测功机，其中轴传递的功率由其转速和扭矩的乘积获得，扭矩由沿轴测得的剪切应变确定。 |
| Transverse direction | 横向 |
Literally, the “across” direction, usually signifying a direction or plane perpendicular to the direction of working. In rolled plate or sheet, the direction across the width is often called long transverse, and the direction through the thickness, short transverse. 从字面上看，“横穿”方向，通常表示与工作方向垂直的方向或平面。在轧制钢板或薄板中，横跨宽度的方向通常称为长横向，穿过厚度的方向称为短横向。 |
| Transverse strain | 横向应变 |
Linear strain in a plane perpendicular to the loading axis of a specimen. 垂直于试样加载轴的平面内的线性应变。 |
| Trepanning | 开孔 |
Trepanning is a machining process for producing a circular hole or groove in solid stock, or for producing a disk, cylinder, or tube from solid stock, by the action of a tool containing one or more cutters (usually single-point) revolving around a center. 开孔是一种机械加工工艺，通过包含一个或多个围绕中心旋转的刀具（通常为单点）的作用，在实心坯料中制造圆孔或凹槽，或从实心坯料生产圆盘、圆柱体或管。 |
| Tribology | 摩擦学 |
The science and technology concerned with interacting surfaces in relative motion. 与相对运动中相互作用的表面有关的科学和技术。 |
| True strain | 真应变 |
(1) The ratio of the change in dimension, resulting from a given load increment, to the magnitude of the dimension immediately prior to applying the load increment. (2) In a body subjected to axial force, the natural logarithm of the ratio of the gage length at the moment of observation to the original gage length. Also known as natural strain. Compare with engineering strain. （1）给定载荷增量导致的尺寸变化与施加载荷增量之前尺寸大小的比率。（2）在承受轴向力的物体中，观察时刻标距与原始标距之比的自然对数。也称为自然应变。与工程应变相比。 |
| True stress (σ) (Unit Pa) | 真应力（σ）（单位Pa） |
The value obtained by dividing the load applied to a member at a given instant by the cross-sectional area over which it acts. Compare with engineering stress. The applied load on a test specimen divided by the current cross-section area over which it acts. σ = s expε where s is the engineering stress given by the applied load divided by the original cross-section area over which it acts, and ε is the true strain. 通过将给定时刻施加在构件上的荷载除以其作用的横截面积而获得的值。与工程应力相比。施加在试样上的荷载除以其作用的当前横截面积。σ=s expε，其中s是由施加荷载除以其作用的原始横截面面积得出的工程应力，ε是真实应变。 |
| Turbine | 涡轮 |
A turbomachine in which a rotor (turbine wheel) or impeller is caused to rotate and convert flow energy into shaft power or thrust. 转子（涡轮）或叶轮旋转并将流动能量转换为轴功率或推力的涡轮机。 |
| Turbine blades (turbine buckets) | 涡轮叶片 |
1. The aerofoil-shaped vanes that form the rotor and stator of a gas, steam or hydraulic turbine. 2. The cup-shaped vanes of a Pelton wheel. 1.形成燃气、蒸汽或水力涡轮机的转子和定子的翼型叶片。2.冲击轮的杯形叶片。 |
| Turbine flow meter | 涡轮流量计 |
(axial flow meter, propeller meter) An in-line flow meter in which the rotation speed N of a propeller or rotor is a measure of the mass flowrate ṁ. Calibration is always necessary but with appropriate design ṁ is closely proportional to N over a wide range. （轴向流量计、螺旋桨流量计）一种串联流量计，其中螺旋桨或转子的转速N是质量流量的测量值ṁ. 校准总是必要的，但需要适当的设计ṁ在很宽的范围内与N成正比。 |
| Turbine pump (turbopump) | 涡轮泵 |
An axial or centrifugal pump driven by a turbine. Typically used to supply fuel to the combustion chamber of a rocket engine such as on the space shuttle. 由涡轮驱动的轴向或离心泵。通常用于向火箭发动机（如航天飞机）的燃烧室供应燃料。 |
| Turbo generator | 涡轮发电机 |
(turboset) The combination of a steam or gas turbine and an electrical generator with a single shaft or connected coaxial shafts. （汽轮发电机组）蒸汽或燃气轮机与发电机的组合，具有单轴或连接的同轴。 |
| Turboblower | 涡轮鼓风机 |
A centrifugal or axial compressor or fan. 离心式或轴流式压缩机或风扇。 |
| Turbocharging | 涡轮增压 |
A method of supercharging in which the hot exhaust gas from a piston engine is used to drive a turbine which powers the supercharging compressor. A turbocharger is the turbine/compressor combination. The compressor is usually of radial outflow design while radial, axial, and mixed-flow turbines are all in use. The wastegate is a valve that reduces the flow of exhaust gas into the turbine to limit the boost produced or overspeeding. Not shown in the diagram are bearings, oil passages, etc. 一种增压方法，其中活塞发动机的热废气用于驱动涡轮，涡轮为增压压缩机提供动力。涡轮增压器是涡轮/压缩机组合。压缩机通常为径向流出设计，而径向、轴向和混流式涡轮机都在使用。废气旁通阀是一种减少进入涡轮的废气流量以限制产生的增压或超速的阀。 |
| Turbomachine | 涡轮机械 |
(rotodynamic machine) A machine in which there is a transfer of energy between a continuous stream of fluid and a component, called a rotor, rotating about a fixed axis. Fans and turbines (gas, hydraulic, steam, or wind) are turbomachines in which energy is transferred to the rotor, causing it to rotate. Pumps and compressors are turbomachines in which energy is transferred from the externally driven rotor to the fluid. （旋转动力机器）在连续的流体流和绕固定轴旋转的部件（称为转子）之间进行能量传递的机器。风扇和涡轮机（燃气、液压、蒸汽或风力）是涡轮机械，其中能量传递到转子，使其旋转。泵和压缩机是涡轮机械，其中能量从外部驱动的转子传递到流体。 |
| Turbomolecular pump | 涡轮分子泵 |
A high-vacuum (pressure down to about 10−8 Pa) pump in which momentum is transferred to the gas molecules by a rapidly rotating bladed disc. 高真空（压力降至约10−8Pa）泵，其中动量通过快速旋转的叶片盘传递给气体分子。 |
| Turbulent flow (turbulence) | 湍流 |
Fluid motion characterized by disorderly, rotational (i.e. vortical) three-dimensional velocity fluctuations covering a wide range of frequency and length scales. The pressure, temperature, and other fluid properties also fluctuate and the diffusion of heat, mass, and momentum is greatly enhanced. As are laminar and transitional flow, turbulent flow of a Newtonian fluid is governed by the Navier–Stokes equations which can in principle be solved by direct numerical simulation (DNS) in which all time and length scales of the fluctuating motion are resolved. 流体运动的特点是无序、旋转（即旋涡）三维速度波动，覆盖广泛的频率和长度尺度。压力、温度和其他流体特性也会波动，热、质量和动量的扩散会大大增强。与层流和过渡流一样，牛顿流体的湍流由Navier-Stokes方程控制，该方程原则上可以通过直接数值模拟（DNS）求解，在直接数值模拟中，波动运动的所有时间和长度尺度都可以求解。 |
| Turn-of-nut | 转动螺母 |
Sometimes used to describe the general rotation of the nut (or bolt head) as the fastener is tightened. More often used to define a particular tightening procedure in which a fastener is first tightened with a preselected torque, and is then tightened further by giving the nut an additional, measured, turn such as ‘‘three flats’’ (180°). 有时用于描述紧固件拧紧时螺母（或螺栓头）的总体旋转。更常用于定义一种特定的紧固程序，在该程序中，首先以预选扭矩拧紧紧固件，然后通过使螺母额外转动，如“三平面”（180°）进一步拧紧。 |
| Turn-of-nut method | 螺母转动法 |
It applies preload by turning a nut through an angle that corresponds to a given elongation. 它通过将螺母旋转一个与给定伸长率相对应的角度来施加预载荷。 |
| Turning | 车削 |
Turning is a machining process for generating external surfaces of revolution by the action of a cutting tool on a rotating workpiece, usually in a lathe. The rotation of a workpiece held against a cutting tool in a lathe to produce components with a circular cross section. 车削是一种机械加工过程，通常在车床上，通过刀具对旋转工件的作用产生旋转外表面。在车床中，工件靠着刀具旋转，以生产具有圆形横截面的部件。 |
| Turning angle (θ) | 转向角（θ） |
The change in direction experienced by a gas flow passing through an oblique shock wave or Prandtl–Meyer expansion fan. 气流通过斜激波或Prandtl–Meyer膨胀风机时所经历的方向变化。 |
| Turret lathe | 六角车床 |
A capstan lathe in which the capstan is driven mechanically or hydraulically to provide assigned tool paths to perform a specified sequence of operations in the repetitive production of parts. 一种绞盘车床，其中绞盘由机械或液压驱动，以提供指定的刀具路径，在零件的重复生产中执行指定的操作顺序。 |
| Twist | 扭转 |
The helix produced in a cylindrical component, such as a shaft, wire, tensioned cable, or rope, when one end is rotated relative to the other. Measured either as the number of turns per unit length, or by the helix angle (twist angle). 当一端相对于另一端旋转时，在圆柱形部件（如轴、钢丝、张紧电缆或绳索）中产生的螺旋。以每单位长度的圈数或螺旋角（扭曲角）测量。 |
| Twist drill | 麻花钻 |
A hardened-steel drill bit having one or more helical flutes running from a conical tip to the smooth part of the shank. 一种淬火钢钻头，具有一个或多个螺旋槽，从锥形尖端延伸到柄部的光滑部分。 |
| Two-dimensional flow | 二维流 |
A fluid flow in which the velocity at any time depends upon two spatial coordinates, such as the radial and axial locations in developing pipe flow. 一种流体流动，其中任何时候的速度取决于两个空间坐标，如发展中的管道流中的径向和轴向位置。 |
| Two-phase flow | 两相流 |
A flow in which two phases are present, for example gas bubbles in a liquid, liquid bubbles in another liquid with which it is immiscible, solid particles in a liquid or gas. 两相流动，例如液体中的气泡、与之不混溶的另一种液体中的液体气泡、液体或气体中的固体颗粒。 |
| Two-stage compressor | 两级压缩机 |
A machine in which gas is compressed from low pressure toan intermediate pressure in a low-pressure cylinder, and then to final pressure in a highpressure cylinder. Efficiency is improved if the two cylinders are separated by an intercooler. 一种机器，其中气体在低压气缸中从低压压缩到中压，然后在高压气缸中压缩到最终压力。如果两个气缸由中冷器分离，则效率提高。 |
| Two-stroke engine | 二冲程发动机 |
(two-cycle engine) A petrol or diesel engine in which an air/fuel charge is introduced through an induction port, compressed and burned, expanded and then exhausted through an exhaust port. The two ports in the cylinder wall are opened and closed by the piston. There are two strokes in each revolution of the crankshaft. In total-loss lubrication petrol engines, the lubricating oil is mixed with the fuel. （双循环发动机）一种汽油或柴油发动机，其中空气/燃料通过进气口引入，压缩和燃烧，膨胀，然后通过排气口排出。气缸壁上的两个口由活塞打开和关闭。曲轴每转一圈有两个冲程。在全失润滑汽油发动机中，润滑油与燃油混合。 |
| Typical basis | 典型基础 |
The typical property value is an average value. No statistical assurance is associated with this basis. 典型的属性值是平均值。没有与此基础相关的统计保证。 |
| Tyre | 轮胎 |
A flexible ring-shaped cover mounted on a wheel rim that supports the weight of a vehicle, such as a motor vehicle, aircraft, or bicycle, and transmits power and torque to a road surface. Some pneumatic tyres are inflated directly, others have a separate inner tube that is inflated. For certain applications, solid tyres are used. 车轮罩安装在轮辋上的柔性环形罩，用于支撑车辆（如机动车、飞机或自行车）的重量，并将动力和扭矩传递到路面。有些充气轮胎是直接充气的，有些轮胎有单独的内胎充气。对于某些应用，使用实心轮胎。 |