Curved groove ball bearing mechanism

Abstract

The invention relates to mechanical engineering, and more particularly to a curved groove ball bearing mechanism, in which a pair of curved groove ball bearings without a retainer are symmetrically arranged to enable the conversion between the rotary motion and the reciprocating linear motion. The bearing mechanism includes an inner ring, a first outer ring, a second outer ring, a plurality of first steel balls and a plurality of second steel balls. The invention is capable of achieving the conversion between the rotary motion of the inner ring into the reciprocating linear motion of the first and second outer rings.

Claims

1. A curved groove ball bearing mechanism, comprising: an inner ring, a first outer ring, a plurality of first steel balls, a connector, a second outer ring, a plurality of second steel balls, a rotation drive, and a slider; wherein: the inner ring is provided with a first curved groove and a second curved groove; the plurality of first steel balls are arranged on the first curved groove, and the plurality of second steel balls are arranged on the second curved groove; outer diameters of each of ends of the inner ring are the same, and an outer diameter of each of ends of the inner ring is equal to or smaller than a distance between centers of two first steel balls or second steel balls which are arranged symmetrically with respect to an axis of the inner ring; an outer diameter of a middle of the inner ring is equal to or smaller than a distance between outermost tangent points of two first steel balls or second steel balls which are arranged symmetrically with respect to the axis of the inner ring; the first outer ring is provided with a third curved groove; the second outer ring is provided with a forth curved groove; the first curved groove, the second curved groove, the third curved groove and the forth curved groove are the same in period, phase and amplitude so that a distance between a center line formed by centers of the first and second steel balls is constant; wherein the first outer ring is divided into a first portion and a second portion by the third curved groove, and the second outer ring is divided into a third portion and a forth portion by the forth curved groove; inner diameters of the first portion of the first outer ring and the third portion of the second outer ring are the same, and inner diameters of the second portion of the first outer ring and the forth portion of the second outer ring are the same; an inner diameter of each of the first portion of the first outer ring and the third portion of the second outer ring is equal to or larger than the outer diameter of each of ends of the inner ring; and an inner diameter of each of the second portion of the first outer ring and the forth portion of the second outer ring is equal to or larger than the outer diameter of a middle of the inner ring; and the first outer ring and the second outer ring are fixedly connected through the connector to form a integral structure.

2. The curved groove ball bearing mechanism of claim 1, wherein the first steel balls are the same as the second steel balls in number; and the length of the center line of each of the first, second, third and forth curved grooves is a positive integral multiple of the diameter of each of the first steel balls.

3. The curved groove ball bearing mechanism of claim 1, wherein the first outer ring and the second outer ring are integrally connected with phases thereof staggered by half a period.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a curved groove ball bearing mechanism according to Example 1 of the invention when an outer ring moves to the left.

(2) FIG. 2 schematically shows the curved groove ball bearing mechanism (a rack is not shown) according to Example 1 of the invention when the outer ring moves to the right.

(3) FIG. 3 schematically shows an inner ring according to Example 1 of the invention.

(4) FIG. 4 is a schematic diagram showing a first outer ring and the arrangement of steel balls according to Embodiment 1 of the invention.

(5) FIG. 5 is a schematic diagram showing a second outer ring and the arrangement of the steel balls according to Example 1 of the invention.

(6) FIG. 6 schematically shows a curved groove ball bearing mechanism with a single row of steel balls according to Example 2 of the invention when an outer ring moves to the left.

(7) FIG. 7A is a schematic view, expanded along a Y-Y line of FIG. 6, of the curved groove ball bearing mechanism with a single row of steel balls according to Example 2 of the invention when the outer ring moves to the left; FIG. 7B is a sectional view taken along an A-A line of FIG. 7A; and FIG. 7C is a sectional view taken along a B-B line of FIG. 7B.

(8) FIG. 8 is a schematic view of the curved groove ball bearing mechanism with a single row of steel balls (the rack is not shown) according to Example 2 of the invention when the outer ring moves to the right.

(9) FIG. 9 is a schematic view, expanded along a Y-Y line of FIG. 6, of the curved groove ball bearing mechanism with a single row of steel balls according to Example 2 of the invention when the outer ring moves to the right.

DETAILED DESCRIPTION OF EMBODIMENTS

(10) The invention will be described further with reference to the drawings.

Example 1

(11) Referring to the drawings, FIG. 1 schematically shows a curved groove ball bearing mechanism of the invention when an outer ring moves to the left, and FIG. 2 schematically shows the curved groove ball bearing mechanism when the outer ring moves to the right, where a first outer ring 5 and a second outer ring 2 are integrally connected via a connector 4.

(12) FIG. 3 schematically shows an inner ring 1 of the curved groove ball bearing mechanism, where the inner ring is provided with a first curved groove and a second curved groove; the plurality of first steel balls are arranged on the first curved groove, and the plurality of second steel balls are arranged on the second curved groove.

(13) Outer diameters d.sub.1 of each of ends of the inner ring are the same, and a nominal diameter of an outer diameter d.sub.1 (negative tolerance) of each of ends of the inner ring 1 is equal to or smaller than a distance d.sub.4 between centers of two first steel balls 6 or second steel balls 3 which are arranged symmetrically with respect to an axis of the inner ring 1.

(14) A nominal diameter of an outer diameter d.sub.2 (negative tolerance) of a middle of the inner ring 1 is equal to or smaller than a distance d.sub.5 between outermost tangent points of two first steel balls or second steel balls which are arranged symmetrically with respect to the axis of the inner ring.

(15) FIGS. 4 and 5 respectively show a first outer ring and a second outer ring and the arrangement of steel balls. The first outer ring 5 is provided with a third curved groove, and the second outer ring 2 is provided with a forth curved groove. The first curved groove, the second curved groove, the third curved groove and the forth curved groove are the same in period, phase and amplitude so that a distance between a center line formed by centers of the first and second steel balls is constant. The first outer ring 5 is divided into a first portion and a second portion by the third curved groove, and the second outer ring 2 is divided into a third portion and a forth portion by the forth curved groove.

(16) Inner diameters of the first portion of the first outer ring and the third portion of the second outer ring are the same, and inner diameters of the second portion of the first outer ring and the forth portion of the second outer ring are the same. A nominal diameter of an inner diameter d.sub.3 (positive tolerance) of each of the first portion of the first outer ring 5 and the third portion of the second outer ring 2 is equal to or larger than the nominal diameter of the outer diameter d.sub.1 of each of ends of the inner ring 1; and a nominal diameter of an inner diameter d.sub.6 (positive tolerance) of each of the second portion of the first outer ring 5 and the forth portion of the second outer ring 2 is equal to or larger than the nominal diameter of the outer diameter d.sub.2 of a middle of the inner ring.

(17) The first steel balls 6 have a same number of 38 with that of the second steel balls 3; and the length of the center line of each of the first, second, third and forth curved grooves is 38 times of the diameter of each of the first steel balls 6 or the second steel balls 3.

Example 2

(18) As shown in FIGS. 6, 7A-C and 8-9, the invention provides another curved groove ball bearing mechanism with a single row of steel balls, where the middle of the inner ring 1 having an outer diameter d.sub.2 has a length H of 0.

(19) Based on the content disclosed herein, various changes and modification with respect to diameter, period and amplitude can be made to obtain other embodiments, which should fall within the scope of the invention