Ball screw

Abstract

A ball screw can reduce noise generation through a structure in which a ball circulates inside a nut. Besides, a return path is formed through a sleeve impregnated with a lubricant inserted in an insertion hole of a nut body, so that the lubricant is supplied to the rolling ball in the return path to achieve the aim of being free from lubricating maintenance. A nut 2 which is inserted in a screw shaft 1 with a spiral groove 11 includes a tube-shaped nut body 3 having a spiral groove 12 and a return path 13, an end cap 4, and a sleeve 6, wherein the end cap 4 is provided with an end portion guide unit 6 which is arranged at the end portion 18 of the nut body 3; the sleeve 7 is formed by a porous forming body in the insertion hole 24 of the nut body 3; and the rolling ball 9 is supplied with the lubricant when the rolling ball rolls in the return path 13 of the sleeve 7, so that the aim of of being free from lubricating maintenance can be achieved.

Description

technical field [0001] The present invention relates to a ball screw, which can be incorporated into various equipment such as a precision positioning table and other mechatronic products, detection devices, etc. Greasing unit composed of relatively moving nuts. Background technique [0002] Conventionally, as a linear motion device that stably supplies a lubricant by a self-lubricating method, for example, there is a device disclosed in JP-A-2013-174255. The linear motion device is a ball screw driving device of end cover deflection circulation mode, which includes: a nut with a spiral groove formed on its inner peripheral surface; a screw shaft formed on its outer peripheral surface opposite to the spiral groove of the nut. a helical groove; and a plurality of balls fitted between helical raceway surfaces formed by the helical grooves of the nut and the helical grooves of the screw shaft. In the inside of the nut, a return passage is integrally injected with oil-containi...

AI Technical Summary

Problems solved by technology

Since the oleoresin material is formed by mixing the resin material and lubricating oil in advance, and then injecting the mixed material, when the capacity of the lubricating oil decreases, the lubricating oil cannot be replenished, which easily leads to poor lubricity. In addition, the oil-impregnated resin material needs to be injection-molded integrally with the nut, so there is a problem that it takes time and effort to increase the manufacturing cost.

In addition, the rolling guide assembly achieves lubrication-free maintenance by having an oil supply part in the direction changing path of the end cover of the ball spline and an oil-containing part in the outer cylinder. However, the oil-containing part is assembled in the In the assembly hole, there are problems of complex structure and high cost

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