JP2011117527A - Chain type transmission member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chain type transmission member capable of moving more smoothly by preventing interference of a connection chain to a screw shaft external surface. <P>SOLUTION: The chain type transmission member includes a screw shaft 1 having a screw shaft rolling groove 11 on an external surface, a nut 2 having a nut rolling groove 21 corresponding to the screw shaft rolling groove 11, a circling member 3 provided on the nut 2, and a rolling body guide module 4 having a plurality of rolling bodies 43 and the connection chain. The connection chain includes a plurality of spacing parts 42 and connection parts 41, the spacing part 42 separates each rolling body 43 at predetermined distance S, and the connection part 41 connects each spacing part 42. The chain type transmission member is composed such that a distance from a contact point of the rolling body 43 and the screw shaft rolling groove 11 to the screw shaft external surface 12 is smaller than a distance from a contact point of the rolling body 43 and the nut rolling groove 21 to a nut internal surface 22. By this, the connection part 41 moves in a direction toward the nut internal surface 22, and a certain distance T is formed with the screw shaft external surface 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a transmission member, and more particularly to a chain transmission member that converts a rotational motion into a linear motion and attaches a chain between rolling bodies.

Recently, a transmission member that satisfies high speed, low noise, and long life has been strongly demanded. For this reason, the transmission member is equipped with a connecting chain that separates the rolling elements at a predetermined interval. Thus, in the transmission member, when the adjacent rolling bodies are rolling, they are prevented from colliding with each other, and even when passing through the circulation path, the rolling bodies do not cause a phase shift, Circulation is performed smoothly, so that high speed and long life are realized.

As the known technique, for example, US Pat. Nos. 6089117 (Patent Document 1) and 6286383 (Patent Document 2) disclose a transmission member provided with a connecting chain. In Patent Document 1 (see FIGS. 2, 8 and 17 in the same specification), both ends of the guiding member 8 are provided with guiding stages 15 for guiding the connecting chain. A configuration is disclosed. However, there is no description of the state of movement of the connecting chain when the rolling element passes through the load region (referring to the region between the nut and the screw shaft). Japanese Patent Application Laid-Open No. H10-228561 discloses a structure that guides the movement of the connecting chain in the load region by attaching one spiral member fitted to the inner surface of the nut inside the nut. However, Patent Document 2 does not describe any movement state of the connecting chain in the load region, as in Patent Document 1.

On the other hand, please refer to FIG. 1 and FIG. The connecting chain mainly includes a spacing portion 72 installed on both sides of the rolling body 73 and a connecting portion 71 that connects each spacing portion 72. The connecting portion 71 is positioned between the screw shaft outer surface 52 and the nut inner surface 62 in the load region, and the thickness T thereof needs to be calculated based on the dimensions of the screw shaft 5 and the nut 6. Otherwise, as shown in FIG. 1, the connecting portion 71 sticks to the outer surface 52 of the screw shaft to generate friction, so that a so-called interference phenomenon occurs. Further, a twisting phenomenon as shown in FIG. In this case, the rolling body 73 does not stick to the spacing portion 72, and only one side of the spacing portion 72 receives force. For this reason, wear of the connecting chain is accelerated, the service life is shortened, circulation is not performed smoothly, and the connecting portion may be ruptured. Then, the transmission member cannot be used or its life is shortened.

United States Patent No. 6089117 United States Patent No. 6,286,383

Therefore, in view of the above-mentioned problems of the prior art, the present inventor has been able to produce an invention that can achieve the following objectives after research and improvement.

That is, a main object of the present invention is to provide a chain type transmission member that can reliably prevent a torsion phenomenon without causing an interference phenomenon in the connection chain during circulation of the transmission member.

Claim 1 of the present invention, which has been made to solve the above-mentioned object, includes a screw shaft in which a spiral screw shaft rolling groove is formed on an outer surface, a through hole for drilling the screw shaft, and the penetration A nut rolling groove formed on the inner surface of the hole corresponding to the screw shaft rolling groove, a nut having a load path formed by the screw shaft rolling groove and the nut rolling groove, and provided on the nut A circulating member having a circulating path that communicates with the load path to form an infinite circulation path, and a rolling body guide module that is guided by the infinite circulation path and has a plurality of rolling bodies and a connecting chain. The connecting chain includes a plurality of spacing portions and a connecting portion, and the spacing portions are positioned between the rolling bodies, thereby separating the rolling bodies by a predetermined distance, and the connecting portions are The interval portions are connected to each other on the side surface of the interval portion, and the rolling element is in contact with the screw shaft rolling groove and the nut rolling groove, and from the contact point between the rolling element and the screw shaft rolling groove. A chain type transmission member configured such that a distance to the outer surface of the screw shaft is smaller than a distance from a contact point between the rolling element and the rolling groove for the nut to the inner surface of the nut.

According to a second aspect of the present invention, in the first aspect, the outer diameter of the screw shaft is calculated by the following relational expression.

Where OD is the outer diameter of the screw shaft, BD is the diameter of the rolling body, PCD is the diameter of the pitch circle, S is the distance between the rolling bodies, K is the thickness of the connecting portion, and T is the surface between the connecting portion surface and the outer surface of the screw shaft. It is the distance to. The pitch circle means the diameter of a circle drawn continuously by the center of the rolling body in the load path.

According to a third aspect of the present invention, in the first aspect, the distance from the center of the rolling body to the inner surface of the nut is configured to be smaller than the distance from the center of the rolling body to the outer surface of the screw shaft.

According to a fourth aspect of the present invention, in the first aspect, the screw shaft rolling groove and the nut rolling groove are formed with different tooth shapes.

In the prior art, when the connecting chain is spirally moved along the outer surface of the screw shaft, the connecting portion does not ride on the motion track according to the diameter of the pitch circle, but on the motion track smaller than the diameter of the pitch circle. It has become. For this reason, the connection portion and the outer surface of the screw shaft are likely to interfere with each other, and thus torsional deformation occurs. As a result, the rolling body does not stick to the gap portion, and the connecting chain cannot move smoothly in the load path. In order to solve such a problem of the prior art, in the present invention, the distance from any one contact point between the rolling element and the screw shaft rolling groove to the outer surface of the screw shaft is the rolling body and the nut rolling groove. Is smaller than the distance from any one contact point to the inner surface of the nut (or the distance from the center of the rolling body to the inner surface of the nut is smaller than the distance from the center of the rolling body to the outer surface of the screw shaft). .

In order to achieve the above-described configuration, at least the following two methods can be employed.
<A> The contact points of the screw shaft rolling groove, the nut rolling groove, and the rolling element are controlled by forming the screw shaft rolling groove and the nut rolling groove with different tooth shapes.
<B> The outer diameter of the screw shaft is calculated based on the relational expression described above. Thereby, the outer diameter of the screw shaft is more effectively reduced.

Since the present invention has the above-described configuration, a constant distance can be generated between the connecting chain and the outer surface of the screw shaft by moving in the direction toward the inner surface of the nut. As a result, the connection portion of the connection chain and the outer surface of the shaft do not interfere with each other, and the connection chain can move smoothly in the load path.

It is explanatory drawing which shows the track | orbit operation condition of a well-known chain type transmission member. It is explanatory drawing which shows the track | orbit operation condition of a well-known chain type transmission member. It is a perspective view which shows the chain type transmission member which concerns on this invention. It is a perspective view after removing the nut of the chain type transmission member concerning the present invention. It is explanatory drawing which shows the track | orbit operation condition of the chain type transmission member which concerns on this invention. It is supplementary explanatory drawing of the code | symbol used for the relational expression of the screw shaft and the outer diameter of a nut in this invention. It is explanatory drawing of the contact point of the rolling body in this invention, the rolling groove for screw shafts, and the rolling groove for nuts.

Hereinafter, in order to further understand the features and technical contents of the present invention, refer to the embodiments and drawings according to the present invention. However, the embodiment or the drawings are merely used for explaining or referring to the present invention, and there is no limitation on the present invention.

Please refer to FIG. 3 to FIG. The chain type transmission member of the present invention mainly includes a screw shaft 1, a nut 2, a circulating member 3, and a rolling element guide module 4.

As shown in FIGS. 3 and 4, the screw shaft 1 has a long columnar shape, and a screw shaft rolling groove 11 is formed on the outer surface. The nut 2 includes a through hole 23 for drilling the screw shaft 1, a nut rolling groove 21 formed on the inner surface of the through hole 23 corresponding to the screw shaft rolling groove 11, and the screw shaft rolling. It includes a load path formed by the groove 11 and the nut rolling groove 21.

The circulation member 3 is provided in the nut 2 and has one circulation path (not shown) that communicates with the load path and forms an infinite circulation path.

The rolling element guide module 4 is provided in the endless circulation path, and has a plurality of rolling elements 43 and one connecting chain. The connecting chain includes a plurality of spacing portions 42 and two connecting portions 41, and the spacing portions 42 are positioned between the rolling bodies 43, whereby the rolling bodies 43 are separated by a distance S between the rolling bodies. Separate. The connecting portion 41 connects the interval portions 42 on the side surface of the interval portion 42.

The rolling body 43 contacts the screw shaft rolling groove 11 and the nut rolling groove 21, and the screw shaft outer surface 12 from any one contact point 62 between the rolling body 43 and the screw shaft rolling groove 11. The distance C2 is configured to be smaller than the distance C1 from any one contact point 61 between the rolling body 43 and the nut rolling groove 21 to the nut inner surface 22. In other words, the distance from the center 431 of the rolling element to the nut inner surface 22 may be configured to be smaller than the distance from the center 431 of the rolling element to the outer surface 12 of the screw shaft.

In the present invention, the distance C2 from any one contact point 62 between the rolling body 43 and the screw shaft rolling groove 11 to the screw shaft outer surface 12 is equal to any one contact between the rolling body 43 and the nut rolling groove 21. Since the distance C1 is smaller than the distance C1 from the point 61 to the nut inner surface 22, by moving the connecting portion 41 in the direction toward the nut inner surface 22, there is one between the connecting portion 41 and the screw shaft outer surface 12. A distance T can be generated. As a result, the connection portion 41 and the screw shaft outer surface 12 do not interfere with each other, and the connection chain can move more smoothly in the load path.

Otherwise, when the connecting chain is spirally moving along the outer surface of the screw shaft, the connecting portion 41 does not ride on the motion trajectory according to the pitch circle diameter PCD but on the motion trajectory smaller than the pitch circle diameter PCD. It becomes like this. For this reason, the connecting portion 41 is liable to cause interference with the outer surface 12 of the screw shaft, and thus torsional deformation occurs. As a result, the rolling body 43 does not stick to the gap portion 42, resulting in a problem that wear occurs only on one side. As a result, the connecting chain cannot move smoothly in the load path. The pitch circle means a diameter of a circle formed by continuously moving the center 431 of the rolling body when the rolling body 43 is rolling along the load path.

By the way, the distance C2 from any one contact point 62 between the rolling member 43 of the transmission member and the screw shaft rolling groove 11 to the screw shaft outer surface 12 is set to any one of the rolling member 43 and the nut rolling groove 21. The following two methods can be employed in order to make the distance smaller than the distance C1 from the contact point 61 to the nut inner surface 22.

<A> When machining the rolling groove 11 for the screw shaft and the rolling groove 21 for the nut, the rolling shaft 11 for the screw shaft and the rolling groove 21 for the nut are formed by machining to make the tooth shape or the cross-sectional shape of both of them different. And the contact point with the rolling body 43 is controlled.

<B> The above-described configuration can be realized by reducing the outer diameter of the screw shaft 1. That is, the outer diameter of the screw shaft 1 can be calculated and determined by the following formula (see FIG. 6).
Where OD is the outer diameter of the screw shaft, BD is the diameter of the rolling body, PCD is the diameter of the pitch circle, S is the distance between the rolling bodies, K is the thickness of the connecting portion, T is the outer surface of the screw shaft from the connecting portion surface It is the distance between.

In summary, the present invention can significantly improve the effectiveness and service life of the transmission member because the connecting portion of the connecting chain does not cause interference with the outer surface of the screw shaft.

In addition, the above content is preferable embodiment of this invention, Comprising: The scope of implementation of this invention is not limited. Accordingly, any modifications or changes that can be made by those skilled in the art, which are made within the spirit of the present invention and have an equivalent effect on the present invention, are included in the scope of the claims of the present invention. Shall.

Part 1 Screw shaft 11 Rolling groove for screw shaft 12 Screw shaft outer surface 2 Nut 21 Rolling groove for nut 22 Nut inner surface 23 Through hole 3 Rolling member 4 Rolling body guide module 41 Connecting portion 42 Spacing portion 43 Rolling body 431 Rolling Center of body 61 Contact point 62 Contact point C1 Distance C2 from contact point 61 of rolling body 43 and nut rolling groove 21 to inner surface 22 of nut C2 From contact point 62 of rolling body 43 and rolling groove 11 for screw shaft to screw shaft Distance OD to outer surface 12 OD of screw shaft BD Diameter of rolling body PCD Diameter of pitch circle S Distance between rolling bodies K Thickness of connecting portion T Distance between connecting portion surface and outer surface of screw shaft Portion 5 Screw shaft 51 Rolling groove 52 Screw shaft outer surface 6 Nut 61 Rolling groove 62 Nut inner surface 71 Connecting portion 72 Spacing portion 73 Rolling body T Thickness

Claims (4)

A screw shaft having a spiral screw shaft rolling groove formed on the outer surface;
A through hole for drilling the screw shaft; a nut rolling groove formed on the inner surface of the through hole in correspondence with the screw shaft rolling groove; the screw shaft rolling groove and the nut rolling groove; A nut having a load path formed by
A circulation member provided on the nut and having a circulation path communicating with the load path to form an infinite circulation path;
A rolling body guide module having a plurality of rolling bodies and a connecting chain, and being guided by the endless circulation path;
The connecting chain comprises a plurality of spacing portions and connecting portions,
The spacing portion is located between the rolling bodies, thereby separating the rolling bodies by a predetermined distance,
The connecting portion connects the interval portions on the side surface of the interval portion,
The rolling body is in contact with the rolling groove for the screw shaft and the rolling groove for the nut, and the distance from the contact point between the rolling body and the rolling groove for the screw shaft to the outer surface of the screw shaft is such that the rolling body and the rolling body A chain transmission member configured to be smaller than the distance from the contact point with the nut rolling groove to the inner surface of the nut. The chain type transmission member according to claim 1, wherein the outer diameter of the screw shaft is calculated by the following relational expression.
Where OD is the outer diameter of the screw shaft, BD is the diameter of the rolling body, PCD is the diameter of the pitch circle, S is the distance between the rolling bodies, K is the thickness of the connecting portion, and T is the surface between the connecting portion surface and the outer surface of the screw shaft. It is the distance to. The chain transmission member according to claim 1, wherein a distance from the center of the rolling body to the inner surface of the nut is smaller than a distance from the center of the rolling body to the outer surface of the screw shaft. The chain-type transmission member according to claim 1, wherein the screw shaft rolling groove and the nut rolling groove are formed with different tooth shapes.