JP2008039048A - Stepped recirculation element of ball screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a stepped recirculation element of a ball screw to avoid the drop of a ball or interference with a screw feed opening by use of a technique for assembling and coupling front and rear portions together, so as to eliminate design limitations on the screw feed opening of a conventional screw body, and to provide a stable assembling and fixing method to maintain a low noise characteristic. <P>SOLUTION: Before a ball and a screw element are held in place, a block of inner recirculation is positioned between a screw and a nut to avoid the drop of the ball or interference with the screw feed opening. After the ball and the screw element are held in place, a block of outer recirculation and a block of recirculation bonded to the inside of the nut are fitted in and assembled and the ball screw is fixed onto the nut by the block of outer recirculation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ball screw attachment, and more particularly to a stepped reflux element for a ball screw. Thereby, the restriction of installing the screw feed port in the conventional ball screw is eliminated, and a joint effect that can be stably fixed with lower noise can be achieved.

Ball screws are now being used in many industrial applications. In addition to providing high-precision effects as linear feed transmission, they also have low frictional wear rate, high energy conversion rate, low noise and high rigidity. Needless to say, the ball screw is in fact important for each industrial application machine and the like.

  In the conventional ball screw design, in order to continuously circulate the ball between the screw and the nut and release the stress, both of the nuts are equipped with a reflux element corresponding to the screw thread and the ball at both ends. It will be. The reflux element is mainly used as a key point for causing the ball inside the ball screw to complete the operation between the screw and the nut and reflux again. Therefore, it can be understood how research and development on the reflux device is important for the industry to improve more competitive products.

  Conventionally used or recognized reflux elements are divided into two types according to the mounting method, one of which is an axial mounting method (the conventional method shown in FIG. 1) and the other is: This is a radial mounting method (not shown), which will be described below.

《Axial mounting method》
FIG. 1 is a ball screw of US Pat. No. 4,357,838. Such a conventionally used axially mounted reflux screw ball screw includes a nut (10), a screw (11), a number of balls (12) and an axially mounted reflux device (13). The reflux element (13) is designed to be attached from the end face of the nut (10), and the reflux element (13) is attached to the end of the ball (12) via the reflux element (13). (Not shown) and has a very important part on the reflux element (13), the so-called industry-known claw (14), which mainly straddles the nut (10). Even if the product by the axial mounting method is put into practical use, it is connected to the ball screw groove by the claw (14) integrally manufactured by the reflux element (13). Have a problem.

  First, the reflux element (13) as described above has an advantage that the path is smooth and can be operated at high speed. However, since the claw (14) is fitted in the thread groove (101) of the screw (11), conventionally, in order to attach the claw (14) manufactured integrally with the reflux element (13), One end of the thread groove (101) must adopt an open type (a design of a screw feed port usually called by a contractor). As a result, the shoulder produced by the conventional screw (11) must also adopt the screw feed design. Therefore, the screw feed groove of the screw (11) so far leaves a notch on the contact surface of the shoulder portion of the screw (11), and the integrity of the diameter of the contact surface of the shoulder portion cannot be maintained. Further, both ends of the screw (11) are attached to a bearing sheet (not shown) of the machine base, and when the motor of the machine base is started and the screw (11) is in an operating state, both ends of the screw (11) are An axial load is generated by the rotational inertia. Further, due to the incomplete factor of the diameter of the contacted load in the axial direction, the distribution of the received load of the screw (11) is not uniform, and the end face (not shown) of the bearing attached to the machine base bearing seat is compressed. In addition to being damaged, the screw (11) is bent and deformed in the operating state, which not only directly affects the circulation smoothness of the reflux member, but also reduces the service life of the ball screw. .

  Secondly, in the prior art, first, the screw (11) and the nut (10) are always inserted in order to allow the screw (11) to penetrate the appropriate part of the nut (10) and to smoothly put all the balls (12). It is necessary to put the balls (12) one by one through and to be attached to the reflux element (13) from an appropriate angle by an expert (if the claw (14) is not pushed in at an appropriate angle). Difficult to assemble). Assembling work such as the claw (14), screw (11), and nut (10) is likely to interfere with each other, so that it takes a long time for the assembling process. It is considered possible to damage the reflux element (13).

  Third, when both ends of the screw (11) are attached to the bearing seat of the machine base, the assembling person first inserts the screw (11) into the nut (10) and loads the ball (12). . Assembling of the ball screw can be performed using a manual method, but the assembling process requires a step of blending or adjusting by experience. As a result of this step, when the nut (10) and the screw (11) are assembled separately, the ball (12) rotates unexpectedly and falls off when the stroke is exceeded.

<Diameter mounting method>
In view of the above problems, other radial mounting methods appear in the market, opening from the outside of the nut to the inside (radial direction), and passing through the reflux element when assembled directly using this opening Such a radial mounting method can solve the problem that it is difficult to match the claw of the reflux element and the screw swivel rail, but the following other problems arise.

  First, the radial opening of the nut loses its close contact with the nut, and further, noise generated during the rotation of the ball leaks without reservation, resulting in ball rotation noise that affects competitiveness.

Second, placing the reflux element through the radial opening of the nut is harder to fix than the mounting method from the axial direction, and the vibration is large and loosened, damaging the ball screw structure in severe cases. become.
In order to effectively solve the above-mentioned problems, the inventor of the present application has started from the viewpoint of increasing assembly strength and easy assembly by making use of research and development technology and experience accumulated in the ball screw field for many years. Eventually, a novel ball screw branching reflux element could be created.
U.S. Pat.No. 4,357,838

  An object of the present invention is to provide a ball screw branching reflux element that is not mainly limited by the design of a screw feed port.

  In order to achieve the above-mentioned object, the staged reflux element of the ball screw of the present invention is composed of an inner reflux mass and an outer reflux mass. The staged reflux element of the ball screw is used when a ball is assembled to a nut. The stage characteristics can be used. Before positioning the ball and the screw element, first, in order to avoid the ball falling off or interfering with the screw thread, place a nail part that easily interferes between the screw and nut, and place the ball and screw element. After localization, the outer reflux mass and the inner reflux mass bonded in the nut are fitted and combined, and fixed on the nut with the outer reflux mass.

As a result, the step-by-step reflux element of the ball screw according to the present invention can avoid the drop-out of the ball or the interference with the screw thread by operating the technical configuration assembled in the front and rear, and the conventional screw body It is possible to effectively solve the limitation of installing a screw feed port.

  Next, an object of the present invention is to provide a ball screw branching reflux element having features that are easy to assemble, a fixing method is stable, and low noise can be maintained.

  When assembling and removing the ball screw according to the present invention, it is not necessary to deal with the problem that the claw of the refluxing element easily interferes with the conventional refluxing screw as in the conventional ballscrew. In addition to simplifying the assembly procedure or time by eliminating the interference of the space, the ball screw branching reflux elements of the present invention are inserted and arranged at the same time, and simultaneously tightened to the nut by the fastener In addition, the tightening method is stable, can maintain the sealing performance of the nut, and can effectively maintain the characteristics of low noise.

The present invention enumerates more preferred embodiments of techniques, means and other effects adopted by the object to be achieved, and at the same time, will be described in detail with reference to the drawings. I am confident that this will provide a deeper and more specific understanding of the objects, features and other advantages of the present invention.

  As shown in FIGS. 2 to 8, the embodiment of the present invention includes a nut (20), a screw (30), a reflux element (40), and a plurality of balls.

  The nut (20) includes a reflux hole (21) penetrating the main body and a spiral groove (22) that spirals and surrounds the inside, and the end surface of the nut (20) is a spiral groove (22) and a reflux hole ( 21) a recess-receiving groove (23) is formed in a portion corresponding to

  The screw (30) includes a spiral groove (31) that spirals and surrounds the outside, and the screw (30) is inserted through the nut (20), so that the spiral goulb (31) and the nut (20) A space for accommodating a relatively large number of balls is formed with the spiral groove (22),

  The reflux element (40) includes an inner reflux mass (41) and an outer reflux mass (42), and is further fitted and accommodated in the recess accommodating groove (23) of the nut (20),

The inner reflux mass (41) is integrally manufactured from a body (413) having a claw (411), a projecting insert (412) and an inner guide rail (414), and the claw (411) is formed on the body (413). On the other hand, it projects into the spiral groove (31) of the screw (30) and is fitted and positioned, and the body (413) is fitted and positioned in the spiral groove (22) of the nut (20). (413) is connected to the return hole (21) corresponding to the spiral groove (22) guided in the nut (20) by the inner guide rail (414), and the projecting insert (412) Protrudes outward.

  The outer reflux mass (42) is integrally manufactured from a main body (421) and a fixed convex ear (422), and the main body (421) of the outer reflux mass (42) is an inner guide of the inner reflux mass (41). A rail (414) and a corresponding outer guide rail (425) are provided, and the inner guide rail (414) and the outer guide rail (425) form a complete return channel. The main body (421) is inserted and positioned in the spiral groove (22) of the nut (20), and the main body (421) opens a concave insertion groove (423) in a direction corresponding to the inner reflux mass (41). The fastening groove (423) and the projecting insert (412) of the inner reflux mass (41) are further fitted to each other, so that the fixed convex ear (422) is further tightened with respect to the nut (20). 424) and tightening with the nut (20) in accordance with the tightening groove (424) of the fixed convex ear (422) by a tightening tool (not shown), thereby returning the reflux element (40). Can be stably tightened in the recess receiving groove (23) of the nut (20). The above is the mutual relationship position of each element related to the present invention and its outline.

  Among them, between the inner reflux mass (41) and the outer reflux mass (42) of the reflux element (40), a plurality of projecting inserts (412) and recess fitting grooves (423) can be manufactured, and The relative positions manufactured in the projecting insert and the recessed insert groove will be described together with changing by design.

  In order to explain the implementation features of the present invention more clearly, a progressive or practical system for the stepped reflux element of the ball screw will be described as follows.

  When assembling the ball screw according to the present invention, the user first inserts the screw (30) into the nut (20), so that the spiral groove (31) and the nut (20) of the screw (30) are inserted. The spiral groove (22) forms a space that can accommodate a relatively large number of balls, and the assembly person first divides and easily enters between the screw (30) and the nut (20). The lump (41) is placed in the recess receiving groove (23) of the nut (20), and further shifted slightly in the radial direction so that the claw (411) portion does not interfere with the screw (30). The inner reflux mass (11) is axially pushed to the pre-positioned position of the spiral groove (22) of the nut (20), and the assembler pushes the inner reflux mass (41) in the radial direction again. At this time, the main body (413) of the inner reflux mass (41) is combined with the outer guide rail (425) of the outer reflux mass (42) by the inner guide rail (414). Connected to the reflux hole (21) corresponding to the reflux channel and corresponding to the spiral groove (22) guiding the inside of the nut (20).

  Next, after assembling as many balls as necessary, the assembling person places the outer reflux mass (42) in the recess receiving groove (23) of the nut (20), and places the outer reflux mass (42). The nut is inserted into the helical groove (22) of the nut (20) and is positioned, and the protruding fitting (412) of the inner reflux mass (41) is further utilized by utilizing the recess fitting groove (423) of the outer reflux mass (42). Fit and place.

  Finally, by tightening the nut (20) in accordance with the tightening groove (424) of the fixed convex ear (422) with a tightening tool (not shown), the reflux element (40) is attached to the nut (20). It can be stably tightened in the recess housing groove (23). According to the present invention, the ball is dropped or the interference of the screw can be avoided by applying the technique that is assembled and coupled in the front-rear direction by the above-described assembling method.

  Most importantly, the reflux element (40) of the present invention is divided into the inner reflux mass (41) and the outer reflux mass (42) in this order, and is fitted into the recess receiving groove (23) of the nut (20). Arrange. Therefore, the nail (411) part does not interfere with the screw (30), and the stepped inner reflux mass (41) easily enters between the screw (30) and the screw (20). The inventive screw (30) is not limited to the screw feed design. Conventional screw bodies can surely solve the design restrictions on the screw feed port, and the range of use of the ball screw is further expanded.

  On the other hand, the reflux element (40) of the present invention is arranged in such a manner that the inner reflux mass (41) and the outer reflux mass (42) are stepped in order and fitted into the recess housing groove (23) of the nut (20). Thus, in order to avoid interference with the claws, it is not necessary to install a through hole in the radial direction in particular. Therefore, the present invention can fix the tightening groove (424) of the fixed convex ear (422) and the nut by the tightening tool. The method of tightening the nut and the screw is sufficiently stable, the nut (20) is kept sealed, and low noise characteristics can be maintained. It is a reflux element.

  In general, the staged reflux element of the ball screw according to the present invention is formed by assembling the inner reflux mass and the outer reflux mass. Step characteristics can be used, and before the ball and screw element are localized, the inner reflux mass is first positioned between the screw and nut to avoid ball drop or screw feed port interference and to localize the ball and screw element. Thereafter, the outer reflux mass and the reflux mass pasted into the nut are further fitted and combined and fixed on the nut with the outer reflux mass.

The ball screw branching and recirculating element prevents the ball from falling off or interfering with the screw feed port due to the technology of assembling the front and rear, and surely solves the design limitations of the screw feed port in the conventional screw body. In addition, the mounting and fixing method is stable and can maintain low noise characteristics. Therefore, it goes without saying that the present invention already has “industrial applicability”. In addition, the technical features disclosed in the present embodiment are not disclosed in the publications before the application, The technical features listed in the embodiments of the present invention can be used not only for public purposes, but not only have the fact that the effects as described above are enhanced, but also the additional effects cannot be overlooked. Since it is not disclosed in publications before filing and is not used for public use, and has the fact that the effect is enhanced as described above, the present invention is not limited to “novelty” or “inventive step”. Is also consistent with the patent requirements, and is expected to be filed by law and granted early through examination.

It is drawing of the ball screw in the US Patent 4357838 as a prior art example. 1 is a three-dimensional view of the overall appearance of a ball screw according to an embodiment of the present invention. It is an external appearance three-dimensional view of the stepped reflux element of the ball screw of the present invention. It is a three-dimensional exploded view of the stepped reflux element of the ball screw of the present invention. It is a figure which shows the state which assembles and implements the Example of this invention. It is a sketch which shows the state which puts the internal recirculation | reflux mass of the Example of this invention into an axial direction. It is a sketch which shows the state which puts the inner recirculation | reflux mass of the Example of this invention to radial direction. It is a sketch of the outer reflux mass of the Example of this invention.

Explanation of symbols

<Conventional technology>
10 Nut 101 Thread Groove 11 Screw 12 Ball 13 Reflux Element 14 Claw <Invention>
20 Nuts 21 Recirculation hole 22 Groove 23 Receiving groove 30 Screw 40 Recirculation element 41 Internal recirculation lump 411 Claw 412 Insertion element 413 Main body 414 Inner guide rail 42 Outer recirculation lump 421 Main body 422 Fixed convex ear 423 Retention groove 424 Tightening groove 425 Outer guide rail

Claims (4)

An accommodation groove that is assembled by positioning at the end of the nut, and the accommodation groove is a stepped reflux element of a ball screw corresponding to the spiral groove and the reflux hole,
The reflux element includes an inner reflux mass and an outer reflux mass, and the inner reflux mass includes a main body having a claw and an inner guide rail, and the claw protrudes into the spiral groove of the screw with respect to the main body and is localized. The outer reflux block body includes an outer guide rail corresponding to the inner guide rail of the inner reflux block, and the inner guide rail and the outer guide rail are assembled and positioned in the axial direction of the nut. A complete return channel is formed by combining with the outer guide rail, and this return channel is connected to the return hole corresponding to the spiral groove that guides the inside of the nut, and the inner return block accommodates the nut edge. A stepped reflux element for a ball screw, which is assembled at the bottom of a groove, and the outer reflux mass is positioned so as to cover the outside of the inner reflux mass. Combine nuts, screws and many balls,
The nut includes a return hole, a spiral groove that spirals and surrounds the inside, and a recess groove is formed in a portion of the spiral groove and the return hole corresponding to the end surface of the nut,
The screw includes a spiral groove that spirals and surrounds the outside, and the screw is formed in the nut, and the spiral groove is formed with a space for accommodating a large number of balls with respect to the spiral groove of the nut. ,Also,
The reflux element includes an inner reflux mass and an outer reflux mass, and the inner reflux mass includes a main body having a claw and an inner guide rail, and the claw protrudes into the spiral groove of the screw with respect to the main body and is localized. The outer reflux block body includes an outer guide rail corresponding to the inner guide rail of the inner reflux block, and the inner guide rail and the outer guide rail are assembled and positioned in the axial direction of the nut. A complete return channel is formed by combining with the outer guide rail, and this return channel is connected to the return hole corresponding to the spiral groove that guides the inside of the nut, and the inner return block accommodates the nut edge. 2. The stepped reflux element of a ball screw according to claim 1, wherein the outer reflux mass is assembled at the bottom of the groove and is positioned so as to cover the outside of the inner reflux mass.   The outer reflux mass of the reflux element is further provided with a fixed convex ear, and a fastening groove for fastening the nut to the nut is established on the fixed convex ear. 3. The stepped reflux element for a ball screw according to claim 1 or 2, wherein the step is tightened.   The insert according to the axial direction of the nut is installed on the inner reflux mass, and the insertion groove along the axial direction of the nut is installed on the outer reflux mass. -Stage reflux element for ball screw.

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