539 352履帶拖拉機－單級最終傳動裝置設計（有cad原圖+中英文翻譯）
539 352履帶拖拉機－單級最終傳動裝置設計（有cad原圖+中英文翻譯）,539,352履帶拖拉機－單級最終傳動裝置設計（有cad原圖+中英文翻譯）,履帶,拖拉機,最終傳動,裝置,設計,cad,原圖,中英文,翻譯
轉向系統
轉向系統是駕駛員按自己的意愿操縱汽車或者卡車，通過轉動前輪在路面上實現左右轉動。轉向系統有兩種形式，機械式和動力式。
1. 動力轉向系統
動力轉向系統中增加了一對重要的機構齒輪齒條機構和循環(huán)球機構。
2.泵
葉片泵為轉向系統提供液壓動力（見下面的圖表），泵是由汽車的發(fā)動機通過皮帶傳動的動力而運動的。泵的內腔中有一組可旋轉的葉片
當葉片快速旋轉時，他們從低壓口內吸入液壓油同時從高壓口排出。油泵提供的流量與汽車的發(fā)動機轉速有關。在發(fā)動機不轉的時候葉片泵必須提供足夠的油液。結果，當發(fā)動機以快速運轉時泵必須提供更多的液壓油。
泵里有卸壓裝置來實現泵里壓力不是太高，尤其在發(fā)動機高速運轉時油液的進出很多時。
3. 滑閥
駕駛員通過操縱動力轉向系統來實現車輪的轉向（僅僅當開始轉動時）。當 駕駛員沒有施加壓力時，轉向系統是不工作的?；y時駕駛員在操縱中有路感。
旋轉的關鍵是轉向軸。轉向軸是一個金屬桿，當對它施加扭矩時開始運動。當駕駛員旋轉方向盤時，轉向軸傳遞扭矩到車輪，使車輪旋轉。駕駛員為了使車輪旋轉的角度增大就需要有更大的扭矩。
轉向閥關鍵是一根扭力桿。 扭力桿是細金屬桿，在傳遞扭矩是運動。 扭力桿的頂端被連接到方向盤，而且它的底部被連接到齒輪或蝸桿上( 轉輪子) ，因此，它傳遞的力矩跟駕駛員操縱方向盤所施加的扭矩相等。為了是車輪的轉動角度增大就需要增加扭矩。
從輸入軸輸入的扭矩部分進入伺服閥。并且它連接到扭力桿的最底端。扭力桿的底端連接到伺服閥的外部。 在其他的汽車轉向中扭力桿也從轉向傳動裝置輸出, 連接到其他的轉向齒輪或蝸桿上。
當扭力桿旋轉時它是從伺服閥的內部向外部傳遞動力。 由于伺服閥的內部也連接在轉向軸 ( 或直接到方向盤) ，在伺服閥的內部和外部之間的力矩大小以來于駕駛員作用于方向盤多少轉力矩。
在伺服閥中的轉動方向來自于方向盤的轉動。當方向盤沒有被旋轉的時候,兩邊的液體是相通的內部壓力相當。但是當它從一個位置旋轉到另一個位置時，內部兩端的壓力將會改變。
動力轉向系統是高效地傳遞動力。讓我們看一看我們在以后怎樣提高轉動效率就需要我們來看看最近中她的一些發(fā)展前景。
4. 未來的動力轉向系統
由于大多數汽車的動力轉向泵是一直使液體流動，這就浪費了動力。 浪費動力的同時就是浪費燃料。
你所能期待就僅僅是去改善燃料的使用經濟性。一種大家夢想的是電控或電磁控制的轉向系統。 這些系統會完全地除去方向盤和傳動軸之間的機械連結,用一個純電子的控制系統來更換它。 本質上，方向盤會像你能為你的家買計算機玩游戲的那一個一樣工作。它將包含告訴駕駛員如何去操縱轉向輪，而且動力裝置可以提供給駕駛員反饋感覺到轉向器在如何的運動。 這些感應器的輸出會用來控制一個自動化的轉向系統。這將在轉向橋和動力裝置間留下足夠的空間。 它也會減輕汽車的震動。
通用汽車已經介紹一輛概念汽車,Hy-wire是轉向系統的代號。 GM Hy 的最令人興奮的事物之一是汽車的電控系統能使汽車在沒有機械系統的條件下改變方向，它的整套設施流程都是由計算機軟件來控制的。在將來的電控汽車中，你將會很有可能能夠完全地通過按下電控按鈕來控制汽車轉向，就像今天大家能調節(jié)汽車座位的位置一樣簡單。 它也可能按照每個人的愛好來裝配合適的電控裝置來協助駕駛員的操作。
在過去五十年中，汽車轉向系統沒有多大的改變。 但是在未來十年中，我們將看到高效迅捷安全的轉向系統安裝在汽車上。
本田汽車選用的是可變齒厚的齒輪電力轉向裝置，它明顯要好于液壓動力轉向系統。
一個典型的液壓動力轉向系統，即使不需要轉向時發(fā)動機也是在一直運轉的。因為當需要轉向時沒有多余的動力來傳遞動力，在運動時就需要電力來提供額外的動力能源來達到轉向的目的。
電力轉向系統比機械式轉向系統更簡單，操作更可靠。 電力轉向系統也被設計提供好道路感覺和反饋。電控動力轉向系統統部份舍棄本田 S2000 轉向系統。
簡單高效的轉向系統更多的參考底盤的設計。帶竿全部被裝在隔壁上的高度, 而且經由掌舵引導輪子在每個前面上的聯編中止高視闊步。 當改良安全的時候，選擇是為了達到轉向系統安全可靠的性能 選擇電力轉向系統。
系統為了更簡單的操作，更容易反映駕駛員的意圖，而且路感強類，整體的轉向比是16：1，同時3.32的轉向被固定。
EPS 操作系統
其操作系統除了以下的幾點其他都與液壓動力轉向系統相同：
電力傳感器的應用代替了閥體的功能；
電控系統代替了液壓系統；
一每個EPS系統是添加的.
機械式的機構
車架經常安裝在轉向軸的上部，位于發(fā)動機的周圍，而且需要把他安裝在車架的中心位置。在高處裝備的好處是為了減輕零部件之間的干涉。
連接桿是鋁制物，而且他們正好被安裝在連接桿位置下邊的合適位置。
電控機構
EPS控制系統經常安裝在車架的里邊，并且在轉向器的下邊。 它通過車輛的輸入速度傳感器接受反饋信息，并且資訊科技接受來自車輛的輸入速度傳感器，而且速度傳感器通過傳動軸來傳遞信息。
轉力矩傳感器跟S2000系統是一樣的。轉向軸的扭矩經由一根扭力桿傳遞到齒輪。扭矩傳遞跟傳動比是成一定比例的，它對應與轉向盤的輸入扭矩。 在扭力桿上的一個大頭針答應感應器核心的一個對角線的水溝, 移動上邊的按紐, 和旋轉的方向之外 ，它依賴與扭矩的大小。 芯片的核心控制兩者的數量 , 和運動的方向。
使用這數據, EPS控制系統決定轉向系統的扭矩和方向。然后提供信息來驅動發(fā)動機的運動。助力系統不僅有利于車輛的轉向行駛，而且有很好的路感。
轉力矩傳感器
轉力矩感應器是控制轉向盤方向而且是得到路面反饋的一個裝置。轉力矩感應器的測知區(qū)段有兩個磁鐵和一個核心 (滑動器) 。 轉向輸入橋和轉向齒輪經由一根扭力桿連接。 滑動器在一定程度上與轉向一起預訂齒輪它連同齒輪一起轉齒輪但是能垂直地移動。 轉向主銷被安裝在轉向橋和轉向節(jié)之間的部分，通過轉動實現車輪的轉動。
當道路反饋很低的時候,轉向輸入橋，齒輪和滑動器不需要滑動器的垂直運動就一起運動。
當道路反饋很高的時候,扭力桿旋轉而引起在輸入橋和齒輪之間的一種轉向的不同角度齒輪。 換句話說，駕駛員的旋轉角度用主銷控制，而且滑動器不一致, 和轉向主銷的上下移動有關。
轉向系
轉向系必須提供精確的轉向控制，同時也必須是司機輕松操縱方向盤?？ㄜ嚨霓D向系統既有手動操作又有動力協助。使用液壓和氣壓協助機構的動力協助裝置使轉向更容易。
轉向系除了對車輛控制有著重要的作用以外，還與前懸架。車橋和輪胎等裝置有著密切的關系。不適合的轉向調節(jié)會帶來定位和輪胎安裝的問題。前懸架，車橋和輪胎的問題可能會影響到汽車的轉向和操作。
轉向系的主要組成部分有轉向盤，轉向柱管，轉向器，轉向搖臂，轉向直拉桿，轉向節(jié)臂，轉向橫拉桿裝置。
球頭接頭
這種球接由一個鑄鐵的鐵球和與其相聯的螺柱組成。凹殼包住了球。球狀螺柱的旋轉為各種轉向的連接提供了自由運動。當前軸彎曲時，多種轉向的連接滿足了軸向和徑向的相對移動。球狀螺柱安裝在每個轉向節(jié)臂的末端并且聯接了牽引接口和轉向節(jié)臂。
轉向橫拉桿裝置
轉向節(jié)臂或操縱桿控制著駕駛員的轉向節(jié)的運動，同時也有辦法反向改變傳動，就是乘客側的轉向節(jié)。通過使用轉向橫拉桿裝置連接兩個轉向節(jié)，并使他們工作和諧。
THE STEERING SYSTEM
The steering system enables the driver to guide the automobile or wheeled tractor down the road and turn right or left, as desired, by turning wheels， There are two types of steering systems. These are manual and power.
1. Power Steering
There are a couple of key components in power steering in addition to the rack-and-pinion or recalculating-ball mechanism.
2. Pump
The hydraulic power for the steering is provided by a rotary-vane pump (see diagram below). This pump is driven by the car's engine via a belt and pulley. It contains a set of retractable vanes that spin inside an oval chamber.
As the vanes spin, they pull hydraulic fluid from the return line at low pressure and force it into the outlet at high pressure. The amount of flow provided by the pump depends on the car's engine speed. The pump must be designed to provide adequate flow when the engine is idling. As a result, the pump moves much more fluid than necessary when the engine is running at faster speeds.
The pump contains a pressure-relief valve to make sure that the pressure does not get too high, especially at high engine speeds when so much fluid is being pumped.
3. Rotary Valve
A power-steering system should assist the driver only when he is exerting force on the steering wheel (such as when starting a turn). When the driver is not exerting force (such as when driving in a straight line), the system shouldn't provide any assist. The device that senses the force on the steering wheel is called the rotary valve.
The key to the rotary valve is a torsion bar. The torsion bar is a thin rod of metal that twists when torque is applied to it. The top of the bar is connected to the steering wheel, and the bottom of the bar is connected to the pinion or worm gear (which turns the wheels), so the amount of torque in the torsion bar is equal to the amount of torque the driver is using to turn the wheels. The more torque the driver uses to turn the wheels, the more the bar twists.
The input from the steering shaft forms the inner part of a spool-valve assembly. It also connects to the top end of the torsion bar. The bottom of the torsion bar connects to the outer part of the spool valve. The torsion bar also turns the output of the steering gear, connecting to either the pinion gear or the worm gear depending on which type of steering the car has.
As the bar twists, it rotates the inside of the spool valve relative to the outside. Since the inner part of the spool valve is also connected to the steering shaft (and therefore to the steering wheel), the amount of rotation between the inner and outer parts of the spool valve depends on how much torque the driver applies to the steering wheel.
Animation showing what happens inside the rotary valve when you first start to turn the steering wheel
When the steering wheel is not being turned, both hydraulic lines provide the same amount of pressure to the steering gear. But if the spool valve is turned one way or the other, ports open up to provide high-pressure fluid to the appropriate line.
It turns out that this type of power-steering system is pretty inefficient. Let's take a look at some advances we'll see in coming years that will help improve efficiency.
4. The Future of Power Steering
Since the power-steering pump on most cars today runs constantly, pumping fluid all the time, it wastes horsepower. This wasted power translates into wasted fuel.
You can expect to see several innovations that will improve fuel economy. One of the coolest ideas on the drawing board is the "steer-by-wire" or "drive-by-wire" system. These systems would completely eliminate the mechanical connection between the steering wheel and the steering, replacing it with a purely electronic control system. Essentially, the steering wheel would work like the one you can buy for your home computer to play games. It would contain sensors that tell the car what the driver is doing with the wheel, and have some motors in it to provide the driver with feedback on what the car is doing. The output of these sensors would be used to control a motorized steering system. This would free up space in the engine compartment by eliminating the steering shaft. It would also reduce vibration inside the car.
General Motors has introduced a concept car, the Hy-wire, that features this type of driving system. One of the most exciting things about the drive-by-wire system in the GM Hy-wire is that you can fine-tune vehicle handling without changing anything in the car's mechanical components -- all it takes to adjust the steering is some new computer software. In future drive-by-wire vehicles, you will most likely be able to configure the controls exactly to your liking by pressing a few buttons, just like you might adjust the seat position in a car today. It would also be possible in this sort of system to store distinct control preferences for each driver in the family.
In the past fifty years, car steering systems haven't changed much. But in the next decade, we'll see advances in car steering that will result in more efficient cars and a more comfortable ride.
5.
The Honda Insight uses a variable-assist rack and pinion electric power steering (EPS) system rather than a typical hydraulic power steering system.
A typical hydraulic power steering system is continually placing a small load on the engine, even when no steering assist is required. Because the EPS system only needs to draw electric power when steering assist is required, no extra energy is needed when cruising, improving fuel efficiency.
Electric power steering (EPS) is mechanically simpler than a hydraulic system, meaning that it should be more reliable. The EPS system is also designed to provide good road feel and responsiveness. The Insight's EPS system shares parts with the Honda S2000 steering system.
The system's compactness and simplicity offer more design freedom in terms of placement within the chassis. The steering rack, electric drive and forged-aluminum tie rods are all mounted high on the bulkhead, and steer the wheels via steering links on each front suspension strut. This location was chosen in order to achieve a more compact engine compartment, while improving safety.
The system is also smoother operating, more responsive to driver input, and has minimal steering kickback. The overall steering ratio is 16.4 to 1, and 3.32 turns lock-to-lock.
EPS Operation
The operating principle of the EPS is basically the same as hydraulic power steering except for the following:
· A torque sensor is used in place of the valve body unit
· An electric assist motor is used in place of the hydraulic power cylinder
· An EPS control unit is added
Mechanical Construction
The rack is unusual in that it is mounted high on the rear engine bulkhead, and that the tie rods engage the rack in the center. The high mount location is used for crash safety, as it keeps these components out of the Insight's crumple zone.
The tie rods are aluminum, and they connect to an ackerman arm that is mounted to the struts just below the spring seat.
The EPS control unit is mounted inside the car on the right side bulkhead, underneath the dash. It receives input from the vehicle speed sensor and torque sensor mounted on the steering pinion shaft.
The torque sensor is identical in construction to the unit on the S2000. The pinion shaft engages the pinion gear via a torsion bar, which twists slightly when there is a high amount of steering resistance. The amount of twist is in proportion to both the amount of resistance to wheel turning, and to the steering force applied. A pin on the torsion bar engages a diagonal slot in the sensor core, which moves up or down depending on the amount of torsion bar twist, and the direction of rotation. Two coils surrounding the core detect both the amount, and the direction of movement.
Using this information, the EPS control unit determines both the amount of steering assist required, and the direction. It then supplies current to the motor for steering assist. The amount of assist is also modified in proportion to vehicle speed to maintain good steering feel.
Torque Sensor
The torque sensor is a device to detect steering turning direction and read resistance. The sensing section of the torque sensor consists of two coils and a core (slider). The steering input shaft and pinion gear are connected via a torsion bar. The slider is engaged with the pinion gear in a way that it turns together with the pinion gear but can move vertically. A guide pin is provided on the input shaft and the pin is in a slant groove on the slider.
When road resistance is low, the steering input shaft, pinion gear and slider turn together without the slider's vertical movement.
When road resistance is high, the torsion bar twists and causes a difference of steering angle between the input shaft and pinion gear. In other words, the turning angle of the guide pin and slider differ, and the guide pin forces the slider to move upward or downward.
Steering System
The steering system must deliver precise directional control. And it must do so requiring little driver effort at the steering wheel. Truck steering systems are either manual or power assisted, with power assist units using either hydraulic or air assist setups to make steering effort easier.
In addition to its vital role in vehicle control, the steering system is closely related to front suspension , axle, and wheel/tire components. Improper steering adjustment can lead to alignment and tire wear problems. Suspension, axle, and wheel problem can affect steering and handing.
The key components that make up the steering system are the steering wheel, steering column, steering shaft, steering gear, pitman arm, drag link, steering arm, ball joints, and tie-rod assembly.
Ball Joints
This ball-and-socket assembly consists of a forged steel ball with a threaded stud attached to it. A socket shell grips the ball. The ball stud moves around to provide the freedom of movement needed for various steering links to accommodate relative motion between the axle and the frame rail when the front axle springs flex. A ball stud is mounted in the end of each steering arm and provides the link between the drag link and the steering arm.
Tie-Rod aseembly
The steering arm or lever controls the movement of the driver’s side steering knuckle. There must be some method of transferring this steering motion to the opposite, passenger side steering knuckle. This is done through the use of a tie-rod assembly that links the two steering knuckles together and forces them to act in unison. The tie-rod assembly is also ealled a cross tube.
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