CONNECTION STRUCTURE OF BOLT AND NUT WITH THREADS OUTLINING SYMMETRICALLY BIDIRECTIONAL TAPERED OLIVE-LIKE SHAPE

Abstract

A connection structure of a bolt and a nut of a thread outlining a symmetrically bidirectional tapered olive-like shape, an internal thread (6) on the inner surface of a columnar body (2) outlining a bidirectional tapered hole (41), an external thread (9) on the outer surface of a cylindrical body (3) outlining a bidirectional truncated cone body (71), and each complete threaded body unit forming a bidirectional tapered body in an olive-like shape (93) having a large middle part and two small ends, the left conical degree (95) and the right conical degree (96) being same and/or approximately same, solving the problems of poor self-positioning and self-locking of existing threads, etc. The performance mainly depends on the tapered face and conical degrees of the threaded body.

Claims

1. A connection structure of a bolt and a nut of a thread outlining a symmetrically bidirectional tapered olive-like shape, comprising an internal thread (6) and an external thread (9) threaded with each other, wherein, the complete unit thread of the symmetrically bidirectional tapered thread (1) in an olive-like shape (93) forms helically, symmetrically bidirectional tapered bodies in an olive-like shape (93) having a large middle part and two small ends, including a bidirectional tapered hole (41) and/or a bidirectional truncated cone body (71), the threaded body of the internal thread (6) outlines a bidirectional tapered hole (41) in a helical shape on the inner surface of a cylindrical body (2) and is present in form of a non-entity space, the threaded body of the external thread (9) outlines a bidirectional truncated cone body (71) in a helical shape on the outer surface of a columnar body (3) and is present in form of a material entity, the left conical surface of the symmetrically bidirectional tapered body forms a left taper (95) corresponding to a first taper angle (1), the right conical surface forms a right taper (96) corresponding to a second taper angle (2), the left taper (95) and the right taper (96) are opposite in direction and same or approximately same in taper, the internal thread (6) and the external thread (9) are connected through the tapered hole accommodating the tapered body till the internal and external conical surfaces are supported mutually, the technical performance mainly depends on the conical surface and the taper of the fitted threaded body, preferably, 0<the first taper angle (1)<53, 0<the second taper angle (2)<53, in some specific fields, preferably, 53the first taper angle (1)<180, 53the second taper angle (2)<180.

2. The connection structure according to claim 1, wherein the bidirectional tapered internal thread (6) in an olive-like shape (93) comprises a first helical conical surface (421) of the tapered hole, a second helical conical surface (422) of the tapered hole and an internal helical line (5), the shape formed by the first helical conical surface (421) of the tapered hole and the second helical conical surface (422) of the tapered hole is the same as the shape of the helical outer surface of a cyclotron body formed by two inclined sides of a right-angle trapezoid union, the right-angle trapezoid union comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically and coincident with the plane passing through the central axis of the cylindrical body (2), the cyclotron body is formed by rotating the right-angle trapezoid union in a circumferential direction at an even speed around its right-angle side and at the same time moving the right-angle trapezoid union axially towards the central axis of the cylindrical body (2) at an even speed; the bidirectional tapered external thread (9) in an olive-like shape (93) comprises a first helical conical surface (721) of the truncated cone body, a second helical conical surface (722) of the truncated cone body and an external helical line (8), the shape formed by the first helical conical surface (721) of the truncated cone body and the second helical conical surface (722) of the truncated cone body is the same as the shape of the helical outer surface of a cyclotron body formed by two inclined sides of a right-angle trapezoid union, the right-angle trapezoid union comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically and coincident with the plane passing through the central axis of the columnar body (3), the cyclotron body is formed by rotating the right-angle trapezoid union in a circumferential direction at an even speed around its right-angle side and at the same time moving the right-angle trapezoid union axially towards the central axis of the columnar body (3) at an even speed.

3. The connection structure according to claim 2, wherein, when the right-angle trapezoid union makes one revolution at a constant speed, the moving distance of the right-angle trapezoid union in the axial direction is at least double of the sum of the lengths of the right-angle sides of two right-angle trapezoids.

4. The connection structure according to claim 2, wherein, when the right-angle trapezoid union makes one revolution at a constant speed, the moving distance of the right-angle trapezoid union in the axial direction is equal to the sum of the lengths of the right-angle sides of two right-angle trapezoids.

5. The connection structure according to claim 1, wherein the first helical conical surface (421) of the tapered hole, the second helical conical surface (422) of the tapered hole and the internal helical line (5) are all continuous helical surfaces or discontinuous helical surfaces; the first helical conical surface (721) of the truncated cone body, the second helical conical surface (722) of the truncated cone body, and the external helical line (8) are all continuous helical surfaces or discontinuous helical surfaces.

6. The connection structure according to claim 1, wherein, the internal thread (6) is consisted of two same tapered holes (4) that are symmetrically engaged with each other at bottom surfaces in contrary directions, and the top surfaces are located at two ends of the bidirectional tapered hole (41), in a symmetrically bidirectional tapered thread (1) in an olive-like shape (93), the top surfaces of adjacent bidirectional tapered holes (41) are respectively engaged with each other in a helical shape to form the symmetrically bidirectional tapered internal thread (6) in an olive-like shape (93); the external thread (9) is consisted of two same truncated cone bodies (7) that are symmetrically engaged with each other at bottom surfaces in contrary directions, and the top surfaces are located at two ends of the bidirectional truncated cone body (71), in a symmetrically bidirectional tapered thread (1) in an olive-like shape (93), the top surfaces of adjacent bidirectional truncated cone bodies (71) are respectively engaged with each other in, a helical shape to form a symmetrically bidirectional tapered external thread (9) in an olive-like shape (93).

7. The connection structure according to claim 1, wherein in a thread pair (10) formed by the internal thread (6) and the external thread (9), the first helical conical surface (421) of the tapered hole, the second helical conical surface (422) of the tapered hole are matched with the first helical conical surface (721) of the truncated cone body and the second helical conical surface (722) of the truncated cone body, and the contact surfaces between them are the supporting surfaces, under the guide of the helical line, the inner and outer diameters of the internal cone and the external cone are centered till the conical surface (42) of the bidirectional tapered hole and the conical surface (72) of the bidirectional truncated cone body are held together to enable the helical conical surface supporting the load in one direction and/or simultaneously in two directions and/or till the sizes are in self-positioning contact and/or till the sizes are in interference contact to realize self-locking.

8. The connection structure according to claim 1, wherein a connection structure of a bolt and double nuts is used and the nuts are respectively located at the left and right side of the fastened workpiece, and/or a connection structure of a bolt and a single nut is used and the single nut (21) is located at the right or left side of the fastened workpiece, and/or a connection structure of a bolt and double nuts is used and the double nuts are both located at one side of the fastened workpiece; when a nut has been effectively combined with a bolt, namely the internal thread (6) and the external thread (9) which consist of the tapered thread connection pair (10) are effectively held together, the other nut can be kept intact and/or removed, the removed nut is used as an installation process nut, the internal thread of the installation process nut includes the bidirectional tapered thread (1), an unidirectional tapered thread, or any other traditional threads that can be screwed with the above bidirectional tapered external thread (9), such as a triangular thread, a trapezoidal thread, a zigzag thread, a rectangular thread and an arc thread, which conforms to the spirit of the present disclosure.

9. The connection structure according to claim 1, wherein, one end and/or both ends of the columnar body (3) can be the screw-in end screwed into the connection holes of the cylindrical body (2), the connection holes are threaded holes provided on the nut (21) and the nut (22), the connection holes are provided in the nut (21) and the nut (22), the nut refers to a cylindrical body (2) with a threaded structure in its inner surface, such as the nut or other objects.

10. A thread connection pair according to claim 1, wherein the internal thread (6) and/or the external thread (9) includes a single threaded section with incomplete tapered body, namely the single threaded section is an incomplete unit thread.

Description

DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 is a schematic diagram, of a connection structure of a bolt and double nuts with threads outlining symmetrically bidirectional tapered olive-like shapes according to the first embodiment of the present invention.

[0044] FIG. 2 is a schematic diagram of a bidirectional tapered external thread in an olive-like shape and its complete unit thread according to the first embodiment of the present invention.

[0045] FIG. 3 is a schematic diagram of a bidirectional tapered internal thread in an olive-like shape and its complete unit thread according to the first embodiment of the present invention.

[0046] FIG. 4 is a schematic diagram of a connection structure of a bolt and single nut with threads outlining symmetrically bidirectional tapered olive-like shapes according to the second embodiment of the present invention.

[0047] FIG. 5 is a schematic diagram of a connection structure of a bolt and double nuts with threads outlining symmetrically bidirectional tapered olive-like shapes according to the third embodiment of the present invention.

[0048] FIG. 6 is a schematic diagram of a connection structure of a bolt and double nuts (a spacer such as a gasket is provided therebetween) with threads outlining symmetrically bidirectional tapered olive-like shapes according to the fourth embodiment of the present invention.

[0049] FIG. 7 is a diagram of the thread in the conventional thread technology is an inclined plane on the surface of a cylinder or cone involved in the background art of the present invention.

[0050] FIG. 8 is a diagram of the inclined plane slider model in the principle of inclined plane which is the conventional thread technology involved in the background art of the present invention.

[0051] FIG. 9 is a diagram of the thread rise angle in the conventional thread technology involved in the background art of the present invention.

[0052] In the figures, tapered thread 1, cylindrical body 2, nut body 21, nut body 22, columnar body 3, screw body 31, tapered hole 4, bidirectional tapered hole 41, conical surface 42 of bidirectional tapered hole, first helical conical surface 421 of tapered hole, first taper angle 1, second helical conical surface 422 of tapered hole, second taper angle 2, internal helical line 5, internal thread 6, truncated cone body 7, bidirectional truncated cone body 71, first helical conical surface 721 of truncated cone body, first taper angle 1, second helical conical surface 722 of truncated cone body, second taper angle 2, external helical line 8, external thread 9, olive-like shape 93, left taper 95, right taper 96, left-direction distribution 97, right-direction distribution 98, thread connection pair and/or thread pair 10, clearance 101, locking support surface 111, locking support surface 112, tapered-thread supporting surface 122, tapered-thread supporting surface 121, workpiece 130, locking direction 131 of nut body, gasket 132, cone axis 01, thread axis 02, slider A on the inclined plane, inclined plane B, gravity G. gravity component G1 along the inclined plane, friction force F, thread rise angle , equivalent friction angle P, major diameter d of traditional internal thread, minor diameter d1 of traditional internal thread, median diameter d2 of traditional internal thread.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0053] The present disclosure will be further described in detail in combination with the attached drawings and the specific embodiments in the following.

The First Embodiment

[0054] As shown in FIG. 1, FIG. 2 and FIG. 3, in the embodiment, a connection structure of a bolt and double nuts is used. The tapered thread connection pair 10 with the connection structure of the bolt and the nut with the bidirectional tapered threads comprises bidirectional truncated cone bodies 71 helically distributed on the outer surface of the columnar body 3 and bidirectional tapered holes 41 helically distributed on the inner surface of the cylindrical body, namely comprises an internal thread 6 and an external thread 9 that are threaded with each other. The internal thread 6 is presented as bidirectional tapered holes 41 distributed helically and as non-entity spaces, the external thread 9 is presented as bidirectional truncated cone bodies 71 distributed helically and as material entities. The internal thread 6 is an accommodating part, and the external thread 9 is an accommodated part. The internal thread 6 and the external thread 9 are screwed together section by section as bidirectional tapered bodies and joined together till interference fit, namely the bidirectional tapered holes 41 accommodate the bidirectional truncated cone bodies 71 one by one. The bidirectional accommodation can restrict the disordered freedom degree between the tapered holes 4 and the truncated cone bodies 7. However, the helical motion allows the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads to obtain the necessary ordered freedom degree, and thus effectively synthesizing the technical characteristics of the cone pair and the thread pair.

[0055] In the use of the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, the conical surface 72 of the bidirectional truncated cone body and the conical surface 42 of the bidirectional tapered hole are mutually matched.

[0056] The tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads can have the self-locking and self-positioning abilities only when the truncated cone body 7 and/or the tapered hole 4 that consist of the tapered thread connection pair 10 have a certain taper, namely the cones that consist the cone pair, have a certain taper angle. The taper includes a left taper 95 and a right taper 96, and the taper angle includes a left taper angle and a right taper angle. The left taper 95 corresponds to the left taper angle, namely a first taper angle 1, preferably, 0<the first taper angle 1<53. And more preferably, the first taper angle 1 ranges from 2 to 40. The right taper 96 corresponds to the right taper angle, namely a second taper angle 2, preferably, 0<the second taper angle 1<53. More preferably, the second taper angle 2 ranges from 2 to 40. In some specific fields, such as the transmission connection application fields with no need for self-locking and/or with low self-positioning requirements, and/or with necessary anti-lock measures, preferably, 53the first taper angle 1<180, 53the second taper angle 2<180.

[0057] The external thread 9 is provided on the outer surface of the columnar body 3. The columnar body 3 includes a screw body 31, the outer surface of the screw body 31 is provided with truncated cone bodies 7 in helical shape. The truncated cone bodies 7 include symmetrically bidirectional truncated cone bodies 71 which are special bidirectional tapered bodies in an olive-like shape 93. The columnar body 3 can be solid or hollow, including cylinders, cones, tubes and other workpieces and objects that need to be provided with external threads on their outer surfaces.

[0058] The symmetrically bidirectional truncated cone body 71 in an olive-like shape 93 is consisted of two same truncated cone bodies that are symmetrically engaged with each other at bottom surfaces in contrary directions, and the top surfaces are located at two ends of the bidirectional truncated cone body 71. In the symmetrically bidirectional tapered thread 1 in an olive-like shape 93, the top surfaces of adjacent bidirectional truncated cone bodies 71 are respectively engaged with each other. The truncated cone body 7 is provided with the conical surface 72 of the symmetrically bidirectional truncated cone body on the outer surface. The external thread 9 comprises a first helical conical surface 721 of the truncated cone body, a second helical conical surface 722 of the truncated cone body and an external helical line 8. In the cross section passing through the thread axis 02, a complete single section of the symmetrically bidirectional tapered external thread 9 is a special bidirectional tapered body in an olive-like shape 93 having a large middle part and two small ends, and the left taper being the same and/or approximately same as the right taper. The angle between two prime lines of the first helical conical surface 721 of the truncated cone body (namely the left conical surface of the symmetrically bidirectional truncated cone body 71) is the first taper angle 1. The first helical conical surface 721 of the truncated cone body forms a left taper 95 corresponding to the first taper angle 1, and is subjected to a left-direction distribution 97. The angle between two prime lines of the second helical conical surface 722 of the truncated cone body (namely the right conical surface of the symmetrically bidirectional truncated cone body 71) is the second taper angle 2. The second helical conical surface 722 of the truncated cone body forms a right taper 96 corresponding to the first taper angle 2, and is subjected to a right-direction distribution 98. The tapered direction corresponding to the first taper angle 1 is opposite to the tapered direction corresponding to the second taper angle 2. The prime line is the intersecting line of the conical surface and the plane passing through the cone axis 01. The shape formed by the first helical conical surface 721 and the second helical conical surface 722 of the bidirectional truncated cone body is the same as the shape of the helical outer surface of a cyclotron body formed by two inclined sides of a right-angle trapezoid union. The right-angle trapezoid union comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically and coincident with the plane passing through the central axis of the columnar body 3. The cyclotron body is formed by rotating the right-angle trapezoid union in a circumferential direction at an even speed around its right-angle side and at the same time moving the right-angle trapezoid union axially towards the central axis of the columnar body 3 at an even speed. The right-angle trapezoid union is a special body which comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically, and the top sides are respectively located at two ends of the right-angle trapezoid union.

[0059] The internal thread 6 is provided on the inner surface of the cylindrical body 2. The cylindrical body 2 includes a nut body 21 and a nut body 22. The inner surfaces of the nut body 21 and the nut body 22 are provided with tapered holes 4 in a helical shape. The tapered holes 4 comprise the symmetrically bidirectional tapered holes 41 that are special bidirectional tapered bodies in an olive-like shape 93. The cylindrical body 2 includes cylindrical bodies and/or non-cylindrical bodies and other workpieces and objects that need to be provided with internal threads on their inner surfaces.

[0060] The symmetrically bidirectional tapered hole 41 in an olive-like shape 93 is consisted of two same truncated cone bodies that are symmetrically engaged with each other at bottom surfaces in contrary directions, and the top surfaces are located at two ends of the bidirectional tapered hole 41. In the symmetrically bidirectional tapered thread 1 in an olive-like shape 93, the top surfaces of adjacent bidirectional conic holes 41 are respectively engaged with each other. The tapered hole 4 is provided with the conical surface 42 of the symmetrically bidirectional tapered hole. The internal thread 6 comprises a first helical conical surface 421 of the tapered hole, a second helical conical surface 422 of the tapered hole and an internal helical line 5. In the cross section passing through the thread axis 02, a complete single section of the symmetrically bidirectional tapered internal thread 6 is a special bidirectional tapered body in an olive-like shape 93 having a large middle part and two small ends, and the left taper being the same and/or approximately same as the right taper. The angle between two prime lines of the first helical conical surface 421 of the tapered hole (namely the left conical surface of the symmetrically bidirectional tapered hole 41) is the first taper angle 1. The first helical conical surface 421 of the tapered hole forms a left taper 95 corresponding to the first taper angle 1, and is subjected to a left-direction distribution 97. The angle between two prime lines of the second helical conical surface 422 of the tapered hole (namely the right conical surface of the symmetrically bidirectional tapered hole 41) is the second taper angle 2. The second helical conical surface 422 of the tapered hole forms a right taper 96 corresponding to the first taper angle 2, and is subjected to a right-direction distribution 98. The tapered direction corresponding to the first taper angle 1 is opposite to the tapered direction corresponding to the second taper angle 2. The prime line is the intersecting line of the conical surface and the plane passing through the cone axis 01. The shape formed by the first helical conical surface 421 and the second helical conical surface 422 of the bidirectional tapered hole is the same as the shape of the helical outer surface of a cyclotron body formed by two inclined sides of a right-angle trapezoid union. The right-angle trapezoid union comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically and coincident with the plane passing through the central axis of the cylindrical body 2. The cyclotron body is formed by rotating the right-angle trapezoid union in a circumferential direction at an even speed around its right-angle side and at the same time moving the right-angle trapezoid union axially towards the central axis of the cylindrical body 2 at an even speed. The right-angle trapezoid union is a special body which comprises two same right-angle trapezoids that are connected to each other at the bottom sides symmetrically, and the top sides are respectively located at two ends of the right-angle trapezoid union.

[0061] In the embodiment, the connection structure of the bolt and double nuts is used. The double nuts include a nut body 21 and a nut body 22. The nut body 21 is located at the left side of the fastened workpiece 130, and the nut body 22 is located at the right side of the fastened workpiece 130. The connection structure of the bolt and the double nuts is rigidly connected with the fastened workpiece 130 when in use. The rigid connection means that the supporting surface of the nut and the supporting surface of the workpiece 130 are mutually supported, including a locking support surface 111 and a locking support surface 112. The workpiece 130 refers to the objects to be connected, including the workpiece 130.

[0062] In the embodiment, the thread-working supporting surfaces are different, including a tapered-thread supporting surface 121 and a tapered-thread supporting surface 122. When the cylindrical body 2 is located at the left side of the fastened workpiece 130, namely the left end surface of the fastened workpiece 130 and the right end surface of the cylindrical body 2 (namely the left nut body 21) are the locking support surfaces 111 between the left nut body 21 and the fastened workpiece 130, the right helical conical surfaces of the bidirectional tapered threads 1 of the left nut body 21 and the columnar body 3 (namely the screw body 31 or the bolt) are the thread-working support surface. That is, the second helical conical surface 422 of the tapered hole and the second helical conical surface 722 of the truncated cone body are the tapered-thread supporting surfaces 122, and the second helical conical surface 422 of the tapered hole and the second helical conical surface 722 of the truncated cone body are mutually supported. When the cylindrical body 2 is located at the right side of the fastened workpiece 130, namely the right end surface of the fastened workpiece 130 and the left end surface of the cylindrical body 2 (namely the right nut body 22) are locking support surfaces 112 between the right nut body 22 and the fastened workpiece 130, the left helical conical surfaces of the bidirectional tapered threads 1 of the right nut body 22 and the columnar body 3 (namely the screw body 31 or the bolt) are the thread-working supporting surfaces. That is, the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are tapered-thread supporting surfaces 121, and the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are mutually supported.

[0063] In the bolt and the nut with the bidirectional tapered threads, when the tapered thread connection pair 10 is in a transmission connection, it can support the load bidirectionally through the screwed connection between the bidirectional tapered hole 41 of the bidirectional tapered internal thread 6 and the bidirectional truncated cone body 71 of the bidirectional tapered external thread 9. When the internal thread 6 and the external thread 9 form a thread pair 10, there must be clearance 101 between the bidirectional truncated cone body 71 and the bidirectional tapered hole 4. If there is oil or other lubrication medium between the internal thread 6 and the external thread 9, it will be easy to form a supporting oil film. The clearance 101 is conducive to the formation of the supporting oil film. The tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads is equivalent to a set of sliding bearing pairs composed of one and/or several pairs of sliding bearings. Each section of the bidirectional tapered internal thread 6 bidirectionally accommodates a corresponding section of the bidirectional tapered external thread 9, which form a pair of sliding bearings. The amount of the formed sliding bearings can be adjusted according to the application conditions. Namely, the amount of the accommodating and accommodated thread sections in effective bidirectional engagement or embracement of the bidirectional tapered internal thread 6 and the bidirectional tapered external thread 9, can be designed according to the application conditions. The truncated cone body 7 of the tapered external thread 9 is accommodated bidirectionally by the tapered hole 4 of the tapered internal thread 6 and positioned in multiple directions such as radial, axial, angular, and circumferential directions, which realizes a special technology of the combination of the cone pair and thread pair, ensuring the accuracy, efficiency and reliability of the transmission connection of the tapered thread technology, especially the tapered thread connection pair 10 with the connection structure of the bolt and the nut with the bidirectional tapered threads.

[0064] In the bolt and the nut with the bidirectional tapered threads, when the tapered thread connection pair 10 is in a fastening or sealing connection, the technical performances, such as connection, locking, anti-loosening, bearing, fatigue and sealing, are achieved through the screw connection between the bidirectional tapered hole 41 and the bidirectional truncated cone body 71, namely through the first helical conical surface 721 of the truncated cone body and the first helical conical surface 421 of the tapered hole sizing till interference fit, and/or the second helical conical surface 722 of the truncated cone body and the second helical conical surface 422 of the tapered hole sizing till interference fit. According to the application conditions, it can support load in one direction and/or simultaneously in two directions. Namely, under the guide of the helical line, the inner and outer diameters of the internal and external cones of the bidirectional truncated cone body 71 and the bidirectional tapered hole 41 are centered till the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are held together to achieve the interference contact, and/or till the second helical conical surface 422 of the tapered hole and the second helical conical surface 722 of the truncated cone body are held together to achieve the interference contact, thus achieving the technical performances of the mechanical structures, such as connection performance, locking performance, anti-loosening performance, bearing performance, and sealing performance.

[0065] Therefore, the technical performances of the bolt and the nut with the bidirectional tapered threads, such as the transmission accuracy, transmission efficiency, load-supporting capacity, locking force of self-locking, anti-loosening capacity, sealing performance, and reusability are related to the first helical conical surface 721 of the truncated cone body and the left taper 95 formed by it (namely the first taper angle 1), the second helical conical surface 722 of the truncated cone body and the right taper 96 formed by it (namely the second taper angle 2), the first helical conical surface 421 of the tapered hole and the left taper 95 formed by it (namely the first taper angle 1), and the second helical conical surface 422 of the tapered hole and the right taper 96 formed by it (namely the second taper angle 2). The friction coefficient, processing quality, and application conditions of the material of the cylindrical body 2 and the columnar body 3 also have a certain effect on the engagement of the cones.

[0066] In the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, when the right-angle trapezoid union makes one revolution at a constant speed, the moving distance of the right-angle trapezoid union in the axial direction is at least double of the sum of the lengths of the right-angle sides of two same right-angle trapezoids. This structure ensures that the first helical conical surface 721 of the truncated cone body, the second helical conical surface 722 of the truncated cone body, the first helical conical surface 421 of the tapered hole and the second helical conical surface 422 of the tapered hole have sufficient lengths, so as to ensure a sufficiently effective contact area, strength, and efficiency required for helical movement when the conical surface 72 of the bidirectional truncated cone body is fitted with the conical surface 42 of the bidirectional tapered hole.

[0067] In the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, when the right-angle trapezoid union makes one revolution at a constant speed, the moving distance of the right-angle trapezoid union in the axial direction is equal to the sum of the lengths of the right-angle sides of two same right-angle trapezoids. This structure ensures that the first helical conical surface 721 of the truncated cone body, the second helical conical surface 722 of the truncated cone body, the first helical conical surface 421 of the tapered hole and the second helical conical surface 422 of the tapered hole have sufficient lengths, so as to ensure a sufficiently effective contact area, strength, and efficiency required for helical movement when the conical surface 72 of the bidirectional truncated cone body is fitted with the conical surface 42 of the bidirectional tapered hole.

[0068] In the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, the first helical conical surface 721 of the truncated cone body and the second helical conical surface 722 of the truncated cone body are both continuous helical surfaces or discontinuous helical surfaces; the first helical conical surface 421 of the tapered hole and the second helical conical surface 422 of the tapered hole are both continuous helical surfaces or discontinuous helical surfaces.

[0069] In the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, one end and/or both ends of the columnar body 3 can be the screw-in end screwed into the connection hole of the cylindrical body 2.

[0070] In the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads, one end of the columnar body 3 is provided with a head having a size larger than the outer diameter of the columnar body 3, and/or one end and/or each end of the columnar body 3 is provided with a head having a size smaller than the minor diameter of the bidirectional tapered external thread 9 of the columnar body 3 (namely the screw body 31). The connection holes are threaded holes provided on the nut body 21 and the nut body 22. That is, part of the columnar body 3 connected to the head forms a bolt, the part without a head and/or the columnar body 3 having heads at both ends smaller than the minor diameter of the external thread 9 and/or the columnar body 3 having no thread in the middle but having the external thread 9 on both ends is a stud. The connection holes are provided in the nut body 21 and the nut body 22.

[0071] Compared with the existing technology, the advantages of the tapered thread connection pair 10 of the bolt and the nut with the bidirectional tapered threads are as follows. It has a reasonable design and a simple structure. The fastening and connection functions can be achieved through sizing the cone pair consisted of the internal and external cones till interference fit. Besides, it is easy to operate, has a large locking force, a large load-supporting value, a good anti-loosening performance, a high transmission efficiency and precision, a good mechanical sealing effect, a good stability, an ability to prevent loosening during connection, and the self-locking and self-positioning functions.

The Second Embodiment

[0072] As shown in FIG. 4, the structure, principle and implementation steps of this embodiment are similar to those of the first embodiment, except that the connection structure of a bolt and a single nut is used in this embodiment. The bolt body has a hexagonal head larger than the screw body 31. When the hexagonal head of the bolt is on the left, the cylindrical body 2 (namely the nut body 21 or the single nut) is located at the right side of the fastened workpiece 130. The connection structure of the bolt and the single nut are rigidly connected with the fastened workpiece 130 when in use. The rigid connection means that the end surface of the nut body 21 and the end surface of the workpiece 130 which are facing to each other are mutually supporting surfaces. The supporting surfaces refer to the supporting surfaces 111. The workpiece 130 refers to the objects to be connected, including the workpiece 130.

[0073] In the embodiment, the thread-working supporting surface is the tapered-thread supporting surface 122, and the cylindrical body 2 (namely the nut body 21 or the single nut) is located at the right side of the fastened workpiece 130. When the bolt and the single nut is working, the right end surface of the workpiece 130 and the left end surface of the nut body 21 are locking support surfaces 111 between the nut body 21 and the fastened workpiece 130. The left helical conical surfaces of the bidirectional tapered threads 1 of the nut body 21 and the columnar body 3 (namely the screw body 31 or the bolt) are the thread-working supporting surface. That is, the first helical conical surface 421 of the tapered hole, and the first helical conical surface 721 of the truncated cone body are tapered-thread supporting surfaces 122, and the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are mutually supported.

[0074] In the embodiment, when the hexagonal head of the bolt is located at the right side, the structure, principle and implementation steps are similar to this embodiment.

The Third Embodiment

[0075] As shown in FIG. 5, the structure, principle, and implementation steps of this embodiment are similar to those of the first embodiment, except that the positional relationship between the double nuts and the fastened workpiece 130 is different. The double nuts include a nut body 21 and a nut body 22, and the bolt body has a hexagonal head larger than the screw body 31. The hexagonal head of the bolt is on the left, the nut body 21 and nut body 22 are both located at the right side of the fastened workpiece 130. When the connection structure of the bolt and the double nuts are working, the nut body 21 and nut body 22 are non-rigidly connected with the fastened workpiece 130. The non-rigid connection means that the end surfaces of the double nuts (namely the nut body 21 and nut body 22) facing to each other are mutually supporting surfaces, including the locking support surface 111 and the locking support surface 112. The non-rigid connection is mainly used in non-rigid materials or non-rigid connection workpieces 130 such as transmission parts or to meet the needs through double nuts installation. The workpiece 130 refers to the connected object, including the workpiece 130.

[0076] In the embodiment, the thread-working supporting surfaces are different, including the tapered-thread supporting surface 121 and the tapered-thread supporting surface 122. The cylindrical body 2 comprises a left nut body 21 and a right nut body 22. The right end surface (namely the locking support surface 111) of the left nut body 21 faces to and contacts directly with the left end surface (namely the locking support surface 112) of the right nut body 22, and they are mutually supported and locked. When the right end surface of the left nut body 21 is the locking support surface 111, the right helical conical surfaces of the bidirectional tapered threads 1 of the left nut body 21 and the columnar body 3 (namely the screw body 31 or the bolt) are the thread-working supporting surfaces. That is, the second helical conical surface 422 of the tapered hole and the second helical conical surface 722 of the truncated cone body are tapered-thread supporting surfaces 122, and the second helical conical surface 422 of the tapered hole and the second helical conical surface 722 of the truncated cone body are mutually supported. When the left end surface of the right nut body 22 is the locking support surface 112, the left helical conical surfaces of the bidirectional tapered threads 1 of the right nut body 22 and the columnar body 3 (namely the screw body 31 or the bolt) are the thread-working supporting surface. That is, the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are tapered-thread supporting surfaces 121, and the first helical conical surface 421 of the tapered hole and the first helical conical surface 721 of the truncated cone body are mutually supported.

[0077] In the embodiment, when the internal cylindrical body 2 (namely the nut body 21 adjacent to the fastened workpiece 130) has been effectively combined with the columnar body 3 (namely the screw body 31 or the bolt), namely the internal thread 6 and the external thread 9 which consist of the tapered thread connection pair 10 are effectively held together, the external cylindrical body 2 (namely the nut body 22 that is not adjacent to the fastened workpiece 130) can be kept intact and/or removed to leave only one nut according to the application conditions (for example, the application field that has requires for the lightweight of the equipment, or the application field that doesn't need double nuts to ensure the connection reliability, or other application fields). The removed nut body 22 is not used as a connection nut but only as an installation process nut. The external thread of the installation process nut can be processed to the bidirectional tapered thread, or an unidirectional tapered thread or any other non-tapered thread that can be screwed with the tapered thread, such as a triangular thread, a trapezoidal thread, a zigzag thread, etc., to ensure the connection reliability. The tapered thread connection pair 10 is a closed-loop fastening technology system. When the internal thread 6 and the external thread 9 of the tapered thread connection pair 10 are effectively combined together, the tapered thread connection pair 10 will become an independent technical system, but not relying on the technical compensation of a third party to ensure the technical effectiveness of the connection technology system. That is, the effectiveness of the tapered thread connection pair 10 will not be affected even if there is no support from other objects, such as when there is a gap between the tapered thread connection pair 10 and the fastened workpiece 130, which will help to greatly reduce the weight of the equipment, remove the invalid load, and improve the technical performance of the equipment such as the effective load capacity, the braking performance, and the energy saving and emission reducing ability. This is a unique technical advantage that is not available in other thread technology, but only available in the tapered thread connection pair 10, namely the connection structure of the bolt and the nut with the bidirectional tapered threads, no matter it is rigidly or non-rigidly connected with the fastened workpiece 130.

[0078] In the embodiment, when the hexangular head of the bolt is located on the right side, the nut body 21 and the nut body 22 are both located at the left side of the fastened workpiece 130, the structure, principle, and implementation steps are similar to this embodiment.

The Fourth Embodiment

[0079] As shown in FIG. 6, the structure, principle and implementation steps of this embodiment are similar to those of the first embodiment and the third embodiment, except that a spacer such as a gasket 132 is provided between the nut body 21 and the nut body 22 in this embodiment. The right end surface of the left nut body 21 faces to and contacts indirectly with the left end surface of the right nut body 22 through the gasket 132, and they are mutually supported and locked.

[0080] The specific embodiments described herein are merely illustrative of the spirit of the disclosure. Various modifications, additions or equivalents can be made to the described specific embodiments by the skilled in the art to which the present disclosure pertains, without departing from the spirit of the present disclosure or going beyond the range of the appended claims.

[0081] Although many terms are used in the disclosure, such as tapered thread 1, cylindrical body 2, nut body 21, nut body 22, columnar body 3, screw body 31, tapered hole 4, bidirectional tapered hole 41, conical surface 42 of bidirectional tapered hole, first helical conical surface 421 of tapered hole, first taper angle 1, second helical conical surface 422 of tapered hole, second taper angle 2, internal helical line 5, internal thread 6, truncated cone body 7, bidirectional truncated cone body 71, first helical conical surface 721 of truncated cone body, first taper angle 1, second helical conical surface 722 of truncated cone body, second taper angle 2, external helical line 8, external thread 9 olive-like shape 93, left, taper 95, right, taper 96, left-direction distribution 97, right-direction distribution 98, thread connection pair and/or thread pair 10, clearance 101, self-locking force, self-locking, self-positioning, pressure, cone axis 01, thread axis 02, mirror-image, sleeve, shaft, single tapered body, double tapered bodies, cone, external cone, tapered hole, internal cone, tapered body, cone pair, helical structure, helical motion, threaded body, complete unit thread, axial force, axial force angle, counter-axial force, counter-axial force angle, centripetal force, counter-centripetal force, collinear but reverse, external stress, bidirectional force, unidirectional force, sliding bearing, sliding bearing pair, locking support surface 111, locking support surface 112, tapered-thread supporting surface 122, tapered-thread supporting surface 121, non-entity space, material entity, workpiece 130, locking direction 131 of nut body, non-rigid connection, non-rigid material, transmission parts, gasket 132, the possibility of using other terms are not excluded. The terms are used only in order to describe and explain the essence of the present disclosure more conveniently, it is contrary to the spirit of the present disclosure to interpret them as any additional limitation.