Screw is a commonly used transmission component in engineering machinery and precision machinery. The main structure of a screw is composed of a screw and a nut, and its main function is to convert rotational motion into linear motion or torque into axial repeated force. The principle is that when the lead screw is used as the driving body, the nut converts into linear motion according to the corresponding specifications of the lead with the rotation angle of the lead screw. The passive workpiece can be connected through a nut seat and nut to achieve corresponding linear motion. Roller screw has the characteristics of high transmission efficiency and precision, and has basically replaced traditional trapezoidal screw in most scenarios. The commonly used thread screws can be divided into triangular thread screws, trapezoidal thread screws, ball screws, and planetary roller screws.

（1） 三角螺紋絲杠：三角牙絲杠其牙型類似于三角形頂部為尖狀，是各類簡易螺 絲常用的牙型，其加工便當、制作簡略，市場上有較多標準件出售。 （2） 梯形螺紋絲杠：梯形螺紋絲杠的牙型為等腰梯形，上窄下寬。加工相對簡略， 可以依據牙的深淺來調理螺母和絲桿的松緊度。表里螺紋以錐面貼緊不易松 動，工藝較好，牙根強度高，對中性好。梯形絲桿的傳動效率大約為26-46%。

(1) Triangle thread screw: Triangle thread screw has a tooth shape similar to the pointed top of a triangle, which is commonly used for various simple screws. Its processing is convenient and its production is simple, and there are many standard parts available for sale in the market. (2) Trapezoidal thread screw: The tooth shape of the trapezoidal thread screw is an isosceles trapezoid, with a narrow top and a wide bottom. The processing is relatively simple, and the tightness of the nut and screw can be adjusted based on the depth of the teeth. The thread inside the watch is tightly attached with a conical surface, which is not easy to loosen. The process is good, the root strength is high, and it is good for neutrality. The transmission efficiency of the trapezoidal screw is approximately 26-46%.

（3） 滾珠螺紋絲杠：其絲桿和螺母之間選用滾珠翻滾的方式來進行傳動，可通過 替換滾珠的方式來絲杠和螺母之間的空地。故傳動功率高，精度高，靜 音作用好。

(3) Ball screw: The ball rolling method is used for transmission between the screw and nut, and the vacant space between the screw and nut can be eliminated by replacing the ball. Therefore, the transmission power is high, the accuracy is high, and the mute effect is good.

現已廣泛的應用于各種自動化設備，機床等。一般環境下已大部 分替代了梯形絲杠，其傳動效率約為90-96%。

It has been widely used in various automation equipment, machine tools, etc. In general, trapezoidal screws have been mostly replaced, with a transmission efficiency of approximately 90-96%.

（4） 行星滾柱絲杠：標準行星滾柱絲杠主要由絲杠、滾柱、螺母、直齒、內齒圈、 滾柱保持架和彈簧擋圈等組成，其綜合了行星齒輪傳動、諧波齒輪傳動、滾 珠絲桿、滾針軸承等機構的優點。通過在主絲杠周圍布置若干行星螺紋滾柱, 大幅增加絲杠傳動過程的接觸面和受力面,從而具備了“高承載、率、高 精度、高可靠性”等優點。在絲杠轉速、接觸角與螺旋升角較為理想的狀態 下，行星滾柱絲杠傳動效率可達到90%以上。

(4) Planetary roller screw: The standard planetary roller screw is mainly composed of screw, roller, nut, straight tooth, inner gear ring, roller cage, and spring retainer, which combines the advantages of planetary gear transmission, harmonic gear transmission, ball screw, needle roller bearing and other mechanisms. By arranging several planetary thread rollers around the main lead screw, the contact surface and stress surface of the lead screw transmission process are greatly increased, thus possessing the advantages of "high load-bearing, high efficiency, high precision, and high reliability". Under ideal conditions of screw speed, contact angle, and helix angle, the planetary roller screw transmission efficiency can reach over 90%.

其中三角螺紋絲杠與梯形絲杠生產技術相對較為簡單，已基本實現完全國產化。滾 珠絲杠發展起步相對較早，低端滾珠絲杠國產化率已達到相對較高水平。但目前國 內在中滾珠絲杠及行星滾柱絲杠的國產化率相對較低，未來發展空間較大。

The production technology of triangular thread screw and trapezoidal screw is relatively simple and has basically achieved complete localization. The development of ball screws started relatively early, and the localization rate of low-end ball screws has reached a relatively high level. However, at present, the localization rate of high-end ball screws and planetary roller screws in China is relatively low, and there is greater room for future development.

直線導軌結構簡單穩定，大量運用于機械加工過程中。直線導軌在機械加工中比較 常用，其由鋼珠在滑塊跟導軌之間無限滾動循環， 從而使負載平臺沿著導軌輕易的 高精度線性運動。依按摩擦性質而定，直線運動導軌可以分為滑動摩擦導軌、滾動 摩擦導軌、彈性摩擦導軌、流體摩擦導軌等種類。直線導軌下游應用廣泛，主要包括 數控機床、醫療器械、自動化生產線等領域。

The linear guide rail structure is simple and stable, and is widely used in mechanical processing. Linear guide rails are commonly used in mechanical processing, where steel balls infinitely roll and circulate between the slider and the guide rail, allowing the load platform to easily move in high-precision linear motion along the guide rail. According to the friction properties, linear motion guides can be divided into sliding friction guides, rolling friction guides, elastic friction guides, fluid friction guides, and other types. Linear guide rails are widely used downstream, mainly in fields such as CNC machine tools, medical devices, and automated production lines.