JPS591859A - Machine element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention includes a roller bearing interposed between mechanical elements, particularly the male and female parts, in order to reduce friction between them, and a groove for accommodating the rotating body in the male and female parts. Relating to a mechanism, in particular a screw movement mechanism in the form of a screw and nut arrangement with roller bearings, each having a helical groove in the female part of the screw and nut or similar; Regarding what has been established.

Ball bearings are already known, and in these known screw motion mechanisms, the balls of the ball bearing circulate in hardened grooves consisting of concave helical grooves formed in the screw and nut, respectively. All the forces acting between the screw and nut are transmitted by the ball, which simply makes direct contact between the elements. When the screw and nut rotate relative to each other and the Nand is displaced axially along the length of the screw, the ball is gradually displaced from one end of the nut and passes through the tubular return ξ-eve to the other end of the Nand. will be moved. In this way, the Jail continuously cycles through the mechanism.

With such a known mechanism it is possible to reduce the friction between the screw and the nut to a considerable extent, i.e. the sliding friction of the conventional screw mechanism is converted on the one hand into rotational friction between the sX parts and On the other hand, it is converted into rotational friction between the nut and screw. Even so, elements such as screws and nuts have been used only to a limited extent. The reason for this is that they are relatively complex in construction, resulting in high production costs. For this reason, they have been employed only in difficult cases where high costs can or must be tolerated.

The present invention, while having a simpler construction than currently available ball bearing screws and their corresponding elements, reduces the resistance during relative movement of the male and female parts to the considerably more expensive ball bearing screws and their corresponding elements developed to date. The object of the present invention is to provide a mechanism of the above-mentioned type, which can be reduced to a degree that is fully comparable to that of other elements. As a result, the scope of application of the mechanism of the present invention can be greatly expanded. Examples of such areas of applicability include lift jacks, truck hoisting systems, vehicles for the disabled, hydraulic table and hospital equipment, actuators for hydraulic valves, food industry, rodent applications, loading equipment, and motor vehicle applications. Mention may be made, for example, of actuating devices for adjustable speed mechanisms of safety belts, and actuating devices in the paper industry. Such scope of application is merely an example and does not limit the scope of the present invention in any way. In general, the present invention is useful when two members of an element have to perform an axial movement relative to each other, especially when it is necessary to convert a rotational movement, such as a nut, into an axial movement, such as a screw. It can be adopted in certain cases.

In the present invention, a rolling element is arranged between the male and female parts, and the rolling element is
enclosed in at least one blind groove provided in the female part and extending between two fixed end stops, so that when the male and female parts are moved relative to each other, the rolling elements remain in position within the blind groove; It is characterized by a groove that guarantees sliding and rotation against the groove surface.

Particularly, in one embodiment of the present invention, the female part consists of a nut or the like, and the male part consists of a screw or the like, the groove extends spirally on the inner surface of the screw or the NAND, and furthermore, the blind groove is formed on the inner surface of the NAND. Zuro is characterized by extending at least once around the mouth. Basically, the rolling elements occupy the entire length of the blind groove between the two end stops. However, the machine element of the present invention can function even if one or both of the rolling elements are removed, but how does it function when the curved portion of the blind groove is not occupied by the rolling element? This has not been studied.

However, one preferred embodiment of the invention is of course characterized in that at least essentially the entire groove is occupied by rolling elements.

According to one preferred embodiment, the rolling elements consist of balls. However, the rolling elements may have shapes other than strictly spherical. For example, the rolling elements may be more or less cylindrical with a suitably domed end, or they may be oval shaped. With such a configuration, the axial space requirements can be reduced by oriented the grooves in a helical manner. According to another preferred embodiment, two end stops are arranged axially spaced from both end faces of the female part. The part located between the engine stop and the end face of the female part is
As a result of the sliding contact between the inner surface of the female part outside the blind groove and the upper side of the bar thread between adjacent grooves of the male part, it acts as a guide. It is also possible to consider that the groove of the female part extends beyond the end stop, according to which the surface of the bar thread between the adjacent grooves of the female part outside the end stop faces the male part. and serve as an information desk. In this case, the end stops include, for each of them, a screw which projects outwardly into the groove through the wall of the female part through a through hole provided in the female part;
The pins exhibit the shapes of the elements corresponding to them. In this case, the end stop should normally have a cylindrical convexity, but in addition to this it can also have, for example, a planar spherical concave surface or a planar cylindrical concave surface facing the blind groove. On the other hand, the endstop is connected to the adjacent sF −
The shape of the roller or its corresponding rolling element must not be such that it is caught between the end stop and the female part or between the male part of the end stop. Instead, the end stop must be formed such that its contact with the ball occurs at a point on a line defined by the point of contact between the balls, which is usually the centerline of the blind groove.

In a further preferred embodiment, the blind groove together with the groove of the male part forms a circular cross section with the same radius as the ball-shaped rolling element.

However, instead of this, it is also possible to form the blind groove to have a non-circular shape together with the groove of the male part, so that the ball contacts the groove surface along a tangent line extending along the groove. For example, as described above, the shape formed by the cooperation of the blind groove and the groove of the male portion may be a polygon or a combination of a circular arc portion and a polygon. Furthermore, according to selected embodiments, the blind groove and the male groove have the same cross-section;
The opposite case is also possible. According to an alternative preferred embodiment, the blind groove has an arc-shaped cross section that is smaller than a semicircle, and the male groove occupies only a small part of the same circle.

The mechanism of the invention may also include means or members for locking the male and female parts in various positions relative to each other. For example, the female part may include hinged locking jaws. Other means for locking this member include passing from the outside through the female part and abutting one of the rolling elements or, suitably, passing between the two rolling elements and passing through the end ball or corresponding thereto. by means of set screws or clamp screws or pins which separate the rolling elements from each other until they are pressed firmly against the end stop. In the latter case, the prerequisite is to ensure that the total amount of play between the rolling elements is not larger than the diameter of the set screw or stop pin.

The female part and, of course, the male part can be manufactured by conventional methods by conventional processing, but also by powder compaction, stamping and molding,
Manufacturing methods such as forging and drop forging can also be used.

The female part can also be made from two or more parts that are joined together. The mechanism of the invention is not limited to the use of any particular material, but can be made of, for example, a variety of metals and plastics, as well as combinations of two or more materials.

Further features and advantages of the invention will become apparent from the claims and the following description of some preferred embodiments.

In the drawings, the screw movement mechanism of the present invention is generally designated by the reference numeral 12.
It is shown by. The mechanism includes a tubular screw 1 and a nut 2.
and a large number of balls 3 of ball bearings. The screw 1 has a threaded groove formed by a groove 4, which extends spirally around the screw 1, and a bar-shaped thread 5 is formed between adjacent grooves.

The nut 2 is provided with a groove 6 having the same pitch as the thread groove 4 on its inside. As shown in FIG. 2, the thread groove 4 of the screw 1 and the groove 6 of the nut 2 have the same semicircular cross section, and the ball 3 is formed between the screw 1 and the nut 2 and has a spirally twisted tubular shape. It is fitted into the space with tolerances.

According to the embodiment shown in FIGS. 2 and 3, □
The groove 6 in the nut 2 extends approximately one full revolution on the inner face of the nut. As shown in FIG. 3, the groove 6 is terminated transversely by a transverse wall 7 at each end of the groove forming a blind groove, the end balls having a centerline of the ball.
In other words, it comes into contact with the wall 7 at a point on a line passing through the contact points of the balls in the blind groove. In this way,
The end balls are prevented from becoming jammed between the end stop consisting of the wall 7 and the nut 2 or screw 1. As shown in this embodiment, the blind groove 6 closed at both ends in a lever-like manner is H? - fulfilled by Rule 3.

The completely smooth cylindrical parts 8 and 9 of the nut 2, which are arranged on the outside of the end stop 7, act according to this embodiment as guides, i.e. they are arranged between adjacent grooves. The outer peripheral surface of the bar-shaped thread 5 of the screw J slides against the outer peripheral surface]0.

In the embodiment shown in FIG. 4, the groove 6' of the nut 2' extends to the end face of the core nut 2'. In this case, a pair of screws 11 are screwed through the wall of the nut 2', forming an end stop, similar to the end stop 7 of the previous embodiment, with the end screws 11 at the contact point on the center line 12. The trap is configured to abut the end N-le at the end. In this case too, a blind groove 6' is formed which is closed at both ends and which is filled with the ball 3.

When the screw 1 is rotated around its central axis, the ball 3
slides and rolls against the grooves 4 and 6 or 6' without changing its position in the blind groove relative to the nut 2'.

However, as mentioned at the outset, it is also possible for the blind groove not to be completely filled with balls 3. In that case, the ball 3 rolls without sliding and advances to a new position from one end of the blind groove to the other, ie, until the ball at the forward end collides with the stop at the forward end.

In the embodiment described above, the blind groove 6 and the groove 4 of the screw 1 are
have the same cross section. FIG. 5 shows that other shapes are also possible.

The blind groove 6" can also be constructed to have a larger cross section than the semicircular arc. In this case, the groove 4 of the screw 1"
" is relatively shallow and has an arcuate cross-section forming the remainder of a circle with the same radius as the seal 3. This embodiment is suitable even if the nut 7 is completely removed from the screw J". l
? - has the advantage that the rule 3 does not "deviate" from the nut 2.

[Brief explanation of the drawing]

The drawings represent embodiments of the present invention, in which FIG. 1 is an end view of the screw movement mechanism according to the present invention, and FIG.
The line sectional view, FIG. 3, is II of FIG. 2 according to the first embodiment.
I-III line sectional view, FIG. 4 is a modified example of the third
FIG. 5 is a cross-sectional view similar to the one shown in the figure, and FIG. 5 is a cross-sectional view showing still another modification. 1.1//...screw 2.2', 2'ζ...
Nut 6...Ball 4.4"...Groove 5...
・Slope 6・6・6゛°°°° Groove A...Wall 8, 9...Cylindrical part 10...
・Outer periphery 11...Screw 12...Center line

Claims (9)

[Claims] (1) In a machine element having a male and female part and a roller bearing that reduces friction between them, the male and female parts are each provided with a groove for tightly accommodating a rolling element, wherein the rolling element (3) is at least one blind groove (6', 6') formed in the female part (2), arranged between the male and female parts (1, 2) and extending between one fixed end stop (7, 11); The male and female parts (1
, 2) are moved relative to each other, the rolling element (3) remains at a proper position within the blind groove (6, 6', 6'') and touches the surface of the groove of the male and female parts (1, 2). A mechanical element characterized by sliding and rolling against a mechanical element. (2) The mechanical element comprises a screw movement mechanism, the male part comprises a nut, etc., the male part comprises a screw, etc., and the groove of the male and female parts spirals around the inner surface of the screw or nut. Machine element according to claim 1, characterized in that the blind groove extends at least once around the inner surface of the nut. (3) The machine element according to claim 1 or 2, wherein the rolling element essentially occupies the entire straight groove between the end stops. (4) Both end stops of the blind groove are arranged axially apart from both end surfaces of the female part, and
4. The mechanical element according to claim 1, wherein the inner surface of either side of the end stops also serves as a guide for the male part. (5) At least one end, preferably both ends, of the groove in the female part extend outwardly through the wall of the female part through holes drilled in the female part, one for each end stop. Machine element according to any one of claims 1 to 4, characterized in that it extends beyond a mechanical stop consisting of a screw (11), a pin or the like, which extends into a groove provided in the machine element. (6) The machine element according to any one of claims 1 to 5, wherein the end stop has a planar spiral concave shape, a planar cylindrical convex shape, or a planar cylindrical concave shape. . (7) The machine element according to any one of claims 1 to 6, wherein the rolling element is a spiral ball. (8) The machine element according to claim 1, wherein the blind groove has a circular cross section having the same radius as the sail, together with the groove of the male part. (9) The blind groove has a non-circular shape together with the groove of the male part, and the rolling element contacts the surface of the groove along a tangent line extending along the groove. Machine element according to any one of items 1 to 8. , 00) The machine element according to any one of claims 1 to 9, wherein the blind groove and the groove of the male part have the same cross section. 0υ The blind groove (6") and the groove of the male part (1") (
The machine element according to any one of claims 1 to 9, characterized in that the rolling elements (4'') have different cross sections. 12. Machine element according to any one of claims 1 to 11, characterized in that it abuts the end stop at a point on a line defined by like contact points.