机械设计制造及其自动化-外文翻译-外文文献-英文文献-电力驱动桥说明书.doc

Electric drive axle descriptionAbstract: An electric drive axle, which is located between and powers the left and right drive wheels of an automotive vehicle, includes an electric motor and left and right torque couplings. Torque developed by the motor transfers through the torque couplings to axle shafts which are connected to the drive wheels. Each torque coupling includes a magnetic particle clutch and a planetary set organized such that the current flowing through the electromagnet of the clutch controls the torque delivered through the coupler. The magnetic particle clutches also accommodate slippage so that the drive wheels may rotate at different angular velocities.BACKGROUND OF THE INVENTION This invention relates in general to automotive vehicles and, more particularly, to an electically-powered drive axle for an automotive vehicle. The typical automobile derives all the power required to propel it from an internal combustion engine which is coupled to left and right drive wheels through a transmission and differential. Indeed, the differential divides the torque produced by the engine evenly between the drive wheels to which it is coupled. Recently several automotive manufacturers have demonstrated an interest in automobiles that in one way or another utilize electric motors to propel the vehicles. But these vehicles still rely on differentials of conventional construction to divide torque between the left and right drive wheels and to accommodate variations in speed between the drive wheels, such as when the vehicle negotiates a turn. However, an equal division of torque between the drive wheels on each side of a differential is not always desirable. For example, if the traction available to one of the drive wheels is diminished, most of the torque should flow to the other drive wheel. Also in turns, handling improves if most of the torque flows to the drive wheel on the outside of the turn. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a schematic view of an automotive vehicle provided with an electric drive axle constructed in accordance with an embodying the present invention;FIG. 2 is an end view of the vehicle cut away to show the electric drive axle; FIG. 3 is a sectional view of the drive axle; FIG. 4 is an enlarged sectional of one of the torque couplers in the drive axle; FIG. 5 is an end view of a vehicle provided with a modified electric drive axle; FIG. 6 is a sectional view of the modified electric drive axle. DETAIL DESCRIPTION OF THE INVENTION Referring now to the drawings, an automotive vehicle A (FIG. 1) has a left and right drive wheels 2 and 4, respectively, that are powered through an electric drive axle B. To this end, the vehicle A has a source 6 of electrical energy, which could be a generator powered by an internal combustion engine or a bank of batteries or even fuel cells. In any event, the energy source 6 and the drive axle B are mounted on a supporting structure 8, which could be a frame or a unified body, and the supporting structure 8 is in turn supported in part by the wheels 2 and 4. The drive axle B is coupled to the wheels 2 and 4 through left and right axle shafts 10 and 12. It is organized about an axis X and includes (FIG. 2) a housing 20, an electric motor 22, and left and right torque bias couplings 24 and 26, respectively. The motor 18 and couplings 24 and 26 are located within the housing 20. The motor 18, which is of the radial flux construction, includes (FIG. 3) a stator 30 which is mounted in the housing 20 in a fixed position around the axis X. It also includes a rotor 32 which is located within the stator 30 where it revolves about the axis X. The rotor 32 includes a motor shaft 34 which at its ends is supported in the housing 20 on antifriction bearing 36. The housing 20 also encloses the two torque couplings 24 and 26, each of which includes a drive hub 40, a magnetic particle clutch 42, a planetary gear set 44, and a drive flange 46. They too are organized along the axis X. The two drive hubs 40 are connected to the motor shaft 34 of the rotor 32 through splines or other devices which enable them to rotate with the shaft 34 and transfer torque from the rotor 32 to their respective torque couplings 24 and 26. Indeed, the two drive hubs 40 rotate in the bearings 36 and support the shaft 34 and likewise the rotor 32 on the bearings 36. The drive flanges 46 are for the most part located externally of the housing 20 and serve to couple their respective torque couplings 24 and 26 to the axle shafts 10 and 12. The drive hubs 40 function as torque input members, whereas the drive flanges 46 serve as torque output members. The clutch 42 for each torque coupling 24 and 26 includes (FIG. 4) an electromagnet 50 and an armature 52. Both are annular in configuration and are organized about the axis X. The armature 52 resides within the electromagnetic 50, with the two being separated by antifriction bearings to the maintain a uniform annular gap g between them. The gap g contains magnetic particles. In the absence of a magnetic field at the gap g, the magnet 50 and armature 52 can rotate, essentially freely with respect to each other. However, when an electrical current is directed through the magnet 52, torque applied to the magnet 52 will transfer to the armature 54. Some slippage between the two may and in most instances will occur. The magnet 50 around its periphery carries slip rings 56 which are wiped by brushes 58 fitted to the housing 20. The brushes 58 in turn are connected to a source of electrical energy, the potential of which may be varied to vary the current in the electromagnet 52 and the strength of the magnetic field it produces. This controls the torque transferred by the clutch 42. The electromagnet 50 of the clutch 42 is secured firmly to the flange of the drive hub 36 at that end of the motor shaft 34 nearest the coupling 24 or 26 of which the clutch 42 is a component. Thus, the electromagnet 52 rotates with the rotor 32 of the electric motor 32. Should the electromagnet 52 be energized, torque applied to the electromagnet 52 will transfer to the armature 54. The planetary set 44 for each torque coupling 24 and 26 includes (FIG. 4) a sun gear 64, a ring gear 66, and planet gears 68 located between and engaged with the sun and ring gears 64 and 66. In addition, it has a carrier 70 which establishes the axes about which the planet gears 68 rotate. The sun gear 64 lies along the axis X, its axis coinciding with the axis X. It is provided with a stub shaft 72 which projects into the armature 56 of the clutch 42, to which it is coupled through mating splines. The ring gear 66 is attached to the electromagnet 54 of the clutch 42 and to the flange on the drive hub 40 at the end of the motor shaft 34, so that the hub 36, the electromagnet 54, and the ring gear 66 rotate in unison about the axis X and at the same angular velocity. The carrier 70 has pins 74 which project into the planet gears 68, so that the planet gears 68, when they rotate, revolve about the pins 74. The pins 74 thus establish the axes of rotation for the planet gears 68. In addition, the carrier 70 has a spindle 76 which projects through the end of the housing 20 and there is fitted with the drive flange 46. The left axle shaft 10 is connected through a universal joint to the drive flange 46 for the left torque coupling 24, whereas the right axle shaft 12 is connected through another universal joint to the drive flange 46 of the right torque coupling 26. The motor 22 drives the two axle shafts 10 and 12 through their respective torque couplings 24 and 26. The magnetic particle clutches 24 and 26 control the distribution of torque to the two axle shafts 10 and 12. In the operation of the drive axle A, the electrical energy source 6 produces an electrical current which powers the motor 22, causing the rotor 32 and motor shaft 34 of the motor 22 to rotate about the axis X. The motor shaft 34 delivers the torque to the two torque couplings 24 and 26. In each torque coupling 24 and 26, torque from the motor 22 is applied through the hub 40 at that coupling 24 or 26 to the electromagnet 50 of the clutch 42 and to the ring gear 66 of the planetary set 44 simultaneously. Here the torque splits. Some of it passes from the ring gear 66 through the planetary gears 68 to the carrier 70 and thence to the drive flange 46 through the spindle 76. The remainder of the torque, assuming that the electromagnet 50 of the clutch 42 is energized, passes through the gap g to the armature 52 of the clutch 42. The armature 52 rotates and transfers the component of the torque passing through the clutch 42 to the sun gear 64 of the planetary set 44, inasmuch as the armature 52 and sun gear 64 are coupled through the stub shaft 72 of the latter. The sun gear 64 transfers the torque to the planet gears 68 where it combines with the torque transferred from the ring gear 66, so that the carrier 70 and the drive flange 78 see essentially the full torque applied at the hub 40. In other words, the torque flows through each torque coupling 24 and 26 in two paths-a mechanical path, including the ring gear 68, planet gears 68 and carrier 70, and a clutch path, including the electromagnet 50 and armature 52 of the clutch 42, and the sun gear 64, planet gears 68 and carrier 70, of the planetary set 44. Most of the torque transfers through the mechanical path, with the apportionment between the two paths depending on the gear ratio U between ring gear 66 and the sun gear 64. The higher the ratio, the less the amount of torque transferred through the clutch path. The relationship between the torque in the two paths may be expressed with a plot on Cartesian coordinates (FIG. 5). The arrangement is such that a small change in torque transferred through the clutch 42 results in a much greater change in torque transmitted through the coupling 24 or 26 of which the clutch 42 is a component, and the torque transmitted through the clutch 42 is dependent on the magnitude of the current passing through the electromagnet 50 of the clutch 42. The torque varies almost linearly with the current passing through the electromagnet 50. By controlling the current in the clutches 42 of the two torque couplings 24 and 26, the torque can be divided between the two drive wheels 2 and 4 to best accommodate the driving conditions under which the vehicle A operates. For example, if the vehicle A negotiates a left turn, particularly at higher speeds, more torque should be delivered the right drive wheel 2 than to the left drive wheel 4. The clutches 42 in the two torque couplings 24 and 26 are adjusted accordingly. To this end the vehicle A may be provided with accelerometers for determining lateral and longitudinal accelerations and yaw, and hence the severity of turns negotiated, as well as speed sensors for determining the velocities of the two axle shafts 10 and 12, preferably from the antilock braking system for the wheels 2 and 4. More sensors may determine the position of the steering wheel and the temperatures of the clutches 42 and of the wheel service brakes. These sensors produce signals which may be fed to a microprocessor in the vehicle, which microprocessor would determine the best apportionment of torque between the two driving wheels 2 and 4 and control the current in the clutches 42 of the two torque couplings 10 and 12 accordingly. A modified electric drive axle C (FIGS. 6 & 7) likewise distributes torque between the left and right drive wheels 2 and 4, apportioning it best to respond to the conditions under which the vehicle A operates. It includes (FIG. 7) an axial flux motor 84, a housing 86 in which the two torque couplings 24 and 26 are enclosed, and a right angle drive 88 located within the housing 86 between the motor 84 and the hubs 40 of the torque couplings 24 and 26. The motor 84 includes a stator 92 and a rotor 94, as well as a motor shaft 96 in which the rotor 94 is mounted. The shaft 96 rotates about an axis Y oriented at a right angle to the axis X. The right angle drive 88 includes a pinion shaft 100 which rotates in the housing 86 about the axis X on antifriction bearings 102. One end of the shaft 100 is connected to the motor shaft 94, while the other end has a beveled pinion 104 on it. In addition, the right angle drive 88 has a connecting shaft 106 which extends between the two hubs 40 and rotates about the axis X. Its ends are fitted to the two drive hubs 40 with mating splines, and the hubs 40 rotate in the housing 86 on bearings 36. The motor 84, when energized, applies torque to and rotates the pinion shaft 100. The pinion 104 at the end of the shaft 100 rotates the spur gear 108 which in turn rotates the connecting shaft 106 and the hubs 40 at the end of it. The hubs 40 deliver the torque to the torque couplings 24 and 26 which function as they do in the drive axle A. Other so-called "hook ups" are possible for the two torque couplings 24 and 26-one, for example, in which the armature 52 of the clutch 42 may be connected to the drive hub 40. Also the positions of the clutch 42 and 44 in each of the torque couplings 24 and 26 may be reversed, with the clutch 42 being connected to the drive flange 46.TABLE-US-00001 ELECTRIC DRIVE AXLE A automotive vehicle B electric drive axle C electric drive axle X axis 2 drive wheel 4 drive wheel 6 energy source 8 supporting structure 10 left axle shaft 12 right axle shaft 20 housing 22 motor 24 left torque coupling 26 right torque coupling 30 stator 32 rotor 34 shaft 36 bearings 40 drive hub 42 magnetic clutch 44 planetary set 46 drive flange 50 electromagnet 52 armature 54 bearings 56 slip rings 58 brushes 62 64 sun gear 66 ring gear 68 planet gears 70 carrier 72 stub shaft 74 pins 76 spindle 84 motor 86 housing 88 right angle drive 90 92 stator 94 rotor 96 motor shaft 100 pinion shaft 102 bearings 104 pinion 106 connecting shaft 108 spur gear 电力驱动桥说明书摘要：电动驱动桥一般是安装在车辆的左右驱动轮之间，包括一个电机和左右联轴器。扭矩通过联轴器传到与驱动轮相连的半轴。每个联轴器包括一个磁粉离合器和一个行星组，所以通过调节离合器中的电磁体的电流就能控制经过联轴器传递的扭矩大小。磁粉离合器还能允许滑移，因此驱动轮能得到不同的角速度。发明背景这项发明一般和汽车，尤其是电驱动汽车有联系。典型的汽车输出所需要的能量是从内燃机的做功通过差速器分至左右驱动轮。事实上，差速器把发动机的力矩平均分给了驱动轮，这对力矩是共轭的。最近几次有汽车制造商对利用电机推进车辆感兴趣。但是这些车辆的差速的实现仍然靠传统的差速器将转矩分至左右驱动轮，且能适应驱动轮的速度变化范围小，例如，当车辆转弯时。然而，能把扭矩平均分给驱动轮的差速器并不是一直我们所需要的产品。举个例子，如果一个驱动轮的牵引扭矩降低，那么大部分的扭矩应该流向另一个驱动轮。还有在转弯时，如果大部分的扭矩流向外侧的驱动轮，那么应做改善处理。简要介绍几个图纸的意见图1是从一个原理的角度来展示电动汽车电驱动桥的发明；图2是从车辆尾部的一个剖切面来展示电驱动桥；图3表示的是驱动桥的分解图；图4是一个耦合器在驱动桥上的放大截面图；图5是改进的车辆驱动桥的的最终观点；图6是修改后的电驱动桥的局部观点。详细说明现在要提到一些些图纸，一辆汽车A（图1）有左右驱动轮2和4，分别通过电驱动桥B传递动力。为此，车辆A有一个电源装置6，可以使用内燃机或一组蓄电池甚至燃料电池给电机供电。在任何情况下，电源装置6和驱动桥B是被支承在支护结构8上的，支护结构可以是一个框架或一个阀体，支护结构8是轮流支护在轮子2和4之间。驱动桥B通过左、右半轴10和12联接到车轮2和4。他的结构包括一根轴X和一个桥壳20，左右转矩分别被传递至联轴器24和26。电机18和联轴器24和26被安装在桥壳20上。电机18的径向结构包括（图3）一个定子30，它是安装在桥壳20的一个轴向固定位置。它也包括了在定子30里面围绕轴X旋转的转子32。转子32包括一个末端固定在位于桥壳20里滚动轴承36上的电机轴34。桥壳20也拥有两个扭矩联轴器24和26，它们每一个都包括一个驱动鼓40，一个磁粉离合