A ball screw spline is a combination of two components — a ball screw and a rotary ball spline. By combining a driving element (the ball screw) and a guiding element (the rotary ball spline), a ball screw spline can provide both linear and rotary motion, as well as spiral motion, in a highly rigid, compact design.
Components of a ball screw spline
Ball screw
A ball screw uses recirculating steel balls in a precisely machined nut to drive a load to an exact position. In most designs, the screw is fixed at one or both ends, and the nut is prevented from rotating via a keyed housing or other anti-rotation setup. A motor drives, or rotates, the screw. But because the screw is constrained from moving linearly, the motion is transferred to the ball nut, which travels along the length of the screw shaft.
Another ball screw design incorporates radialangular contact bearings在螺母的外径上，允许螺母被驱动 - 通常通过带和滑轮组件连接到电动机 - 而螺杆保持完全静止。当电机转动时，它旋转螺母，使其遍历螺钉的长度。此设置通常被称为“驱动坚果“ 设计。
“驱动螺母”设计使用皮带和皮带轮连接到球螺母的外径上的径向轴承组件。
图像信用：SKF组
球花键
A球花键is a type of linear guide system similar to the round shaft and recirculating ball bearing, but with spline grooves precisely machined along the length of the shaft. These grooves prevent the bearing — referred to as a spline nut — from rotating, while also allowing the ball spline to transfer torque.
标准球花键的一个变型是旋转球花键，其增加了旋转元件齿轮，交叉滚子或角接触球轴承 - 花键螺母的外径。这允许旋转球花键提供线性和旋转运动。
A rotary ball spline uses angular contact bearings (shown), crossed rollers, or gears on the outer diameter of the spline nut to produce rotary motion.
Image credit: NB Corporation of America
滚珠丝杠花键如何工作
当从动螺母型滚珠丝杠组件与旋转球花键组合时，所得到的构造通常被称为滚珠丝杠花键。滚珠丝杠花键的轴具有沿其长度的螺纹和花键槽，螺纹和凹槽彼此交叉“。
滚珠丝杠花粉具有滚珠螺母和花键螺母，每个花键螺母，径向轴承在其外径上。
Image credit: Nippon Bearing
三个动作：线性，螺旋和旋转
滚珠丝杠花键组件约束滚珠丝杠螺母和球花键螺母从线性移动。通过将滚珠螺母和样花螺母一起驾驶或分开，可以生产三种不同类型的运动：线性，螺旋和旋转。
为了产生线性运动，驱动球螺母，花键螺母保持静止。由于球螺母不能线性地横穿，因此轴穿过球螺母。然而，静止的样条螺母将轴旋转，使得轴的运动纯粹是线性的，没有旋转。
另外,当spline nut is driven and the ball nut is held stationary, the ball spline causes rotational motion, while the screw threads traveling through the stationary ball nut cause the shaft to travel linearly as it rotates, resulting in a spiral motion.
When both nuts are driven, the rotation of the ball nut essentially counteracts the linear motion caused by the ball spline, so the shaft rotates without any linear travel.
在滚珠丝杠花键组件中，滚珠丝杠螺母和花键螺母可以单独驱动或一起产生线性，螺旋或旋转运动。
Image credit: THK
Filed Under:线性运动Tips
