Patent Description:
This application relates to the field of mechanical structure technologies, and in particular, to a rotating shaft and a terminal device.

With development of society, rotating shafts are more widely used, for example, in laptop computers. An existing rotating shaft is complicated to mount, has a large mounting error, and a short service life. In addition, during use of the terminal device including the foregoing rotating shaft, a torsion force fluctuation will occur, which affects user experience. <CIT> describes a pivoting mechanism for an electronic device includes a pivot shaft, a first connecting member disposed on the pivot shaft for being connected with a support of the electronic device, a second connecting member disposed on the pivot shaft for connected with a main body of the electronic device, and a torque adjusting assembly. The torque adjusting assembly includes four sleeves and an elastic member through which the pivot shaft is disposed. Each of the sleeves includes at least one protrusion. The protrusion of one of the four sleeves is slidable relative to the protrusion of another sleeve for adjusting an amount of deformation of the elastic member. <CIT> describes a hinge device and foldable terminal. <CIT> describes a spring made of plastics.

In view of this, it is necessary to provide a rotating shaft and a terminal device that is easy to mount, has a stable torsion force, and a long service life, so as to resolve the foregoing problem.

According to a first aspect, this application provides a rotating shaft as defined in claim <NUM>. The rotating shaft includes a central shaft, a first bracket, a second bracket, an elastic member, and a concave cam assembly. The first bracket is rotatably mounted on the central shaft, and the second bracket is fixedly connected to the central shaft. The elastic member is disposed on the central shaft, the elastic member is a hollow cylinder of an integrated structure, and a hollowed-out hole is disposed on a cylinder wall of the cylinder. The concave cam assembly is disposed on the central shaft, and the concave cam assembly may enable the elastic member to be deformed. When the first bracket rotates relative to the second bracket, the concave cam assembly generates an extrusion force acting on the elastic member, so that the elastic member in a hollowed-out shape is deformed, and then a specific included angle is formed between the first bracket and the second bracket.

In the foregoing design, the elastic member that is of the integrated structure and that is in the hollowed-out shape is used, and may be assembled to the central shaft at one time, and therefore mounting is simple, thereby improving mounting efficiency. The elastic member replaces a disc spring group including a plurality of disc springs, so as to fundamentally avoid problems of low efficiency and high error rate that are caused by assembling the plurality of disc springs, and no additional automatic assembly device needs to be disposed. In addition, the elastic member of the integrated structure may avoid a torsion force fluctuation in a direction perpendicular to an axial direction when a plurality of disc springs or springs are used in a related technology. A structure of the elastic member in this application is more conducive to ensuring stability after the first body and the second body are opened. In addition, the elastic member is always in an elastic deformation area of the elastic member in a process of being deformed by the extrusion force, and no plastic deformation occurs. Therefore, plastic deformation and elastic attenuation of the disc spring in the related technology do not occur, and a use frequency is improved. In addition, based on the structure of the elastic member in this application, when the extrusion force acting on the elastic member exceeds a critical point, the elastic member features a constant force.

A plurality of hollowed-out holes and a plurality of connecting ribs are disposed on a cylinder wall of the elastic member, and the plurality of hollowed-out holes are interleaved with the plurality of connecting ribs and are disposed at intervals to form the elastic member.

In the foregoing design, when the hollowed-out hole is disposed to enable the elastic member to be subjected to the extrusion force along the axial direction, the elastic member is deformed along the axial direction. An extending direction of the connecting rib may be any direction. The connecting rib may cause the elastic member to be deformed along the axial direction, and cause the elastic member to be deformed in another direction.

In a possible design, a shape of the hollowed-out hole includes at least one of a polygon and an arc shape.

In the foregoing design, when the hollowed-out shape is a regular shape, it is more conducive to designing and processing the elastic member based on the extrusion force that needs to act on the elastic member, and a force acting on the elastic member along the axial direction of the central shaft is uniform.

In a possible design, the polygon includes at least one of a square, a rectangle, a diamond, a pentagon, or a hexagon; and the arc shape includes at least one of a spiral shape, a circular shape, an oval shape, or a semicircular shape.

In the foregoing design, the hollowed-out shape is related to a clamping force that needs to act on a rotating shaft.

In a possible design, a material of the elastic member is selected from one of a metal, a metal alloy, and a plastic.

In the foregoing design, an elastic member of a metal or a metal alloy material has stronger toughness and can be used more frequently. The elastic member of the plastic material may be used to form the elastic member through injection molding, and processing costs are low.

The central shaft includes a fastening part, a blocking part, and a rod part that are fixedly connected, and the blocking part is located between the rod part and the fastening part; and the second bracket is fastened to the fastening part, the rod part sequentially passes through the first bracket, the concave cam assembly, and the elastic member, and the first bracket is held against the blocking part.

In the foregoing design, the fastening part is configured to fasten the second body. The blocking part is configured to cooperate with a fastener, so that a distance between the blocking part and the fastener remains unchanged. When a total width of the concave cam assembly changes, the elastic member is extruded, so that the elastic member is deformed. The rod part is configured to connect the elastic member and the concave cam assembly into a whole.

In a possible design, the first bracket includes a first fastening plate, a first through hole is disposed on the first fastening plate, the rod part passes through the first through hole, and the first fastening plate is held against the blocking part.

In the foregoing design, the blocking part limits the first fastening plate, so that the first bracket is relatively fastened to the central shaft.

In a possible design, the concave cam assembly includes a concave wheel and a cam wheel that are adjacent to each other, where one of the concave wheel and the cam wheel is fixedly connected to the first bracket, and the other of the concave wheel and the cam wheel is fixedly connected to the central shaft.

In the foregoing design, because the first bracket is rotatably connected to the central shaft, the concave wheel is movably connected to the cam wheel, so that a total width of the concave cam assembly along the axial direction can be changed, and then the elastic member is deformed.

In a possible design, a fastening hole is disposed on the first fastening plate, the concave wheel includes a concave wheel part and a clamping part that are connected to each other, the concave wheel part is sleeved onto the rod part, and the clamping part is clamped in the fastening hole.

In the foregoing design, the clamping part cooperates with the fastening hole, so that the concave wheel is fixedly connected to the first fastening plate.

In a possible design, a second through hole is disposed in the concave wheel part, and a minimum diameter of the second through hole is greater than a maximum diameter of the rod part.

In the foregoing design, the rod part and the concave wheel can rotate relative to each other.

In a possible design, a third through hole is disposed in the cam wheel, the third through hole is in a flat shape, the rod part is in a flat shape, and the cam wheel is sleeved onto the rod part.

In the foregoing design, when the central shaft rotates, the cam wheel rotates synchronously with the central shaft, and the rod part in a flat shape and a third through hole in a flat shape are disposed. With simple structural design, the cam wheel may be fixedly connected to the central shaft, and assembly of the rotating shaft is further facilitated.

In a possible design, a surface that is of the concave wheel part and that connects to the cam wheel includes a recessed part and a flat grinding area that are connected, a surface that is of the cam wheel and that connects to the concave wheel includes a protruding part, and the protruding part may be accommodated in the recessed part.

In the foregoing design, the recessed part and the flat grinding area of the concave wheel part match with the protruding part of the cam wheel. When the cam wheel and the concave wheel rotate relative to each other, a change of a total width of the concave cam assembly along the axial direction can be implemented, so that the elastic member is deformed.

In a possible design, the cam wheel and the concave wheel rotate relative to each other, and before the protruding part comes into contact with the flat grinding area, the elastic member reaches a critical point at which the extrusion force is a constant force.

In the foregoing design, even if a surface located in the flat grinding area is not flat, when the protruding part comes into contact with the flat grinding area and rotate relative to each other, and the extrusion force acting on the elastic member is a constant force, the cam wheel and the concave wheel are extruded by a reaction force of a same magnitude, so that the concave wheel and the cam wheel are relatively stable, and then the first body and the second body maintain an opening/closing angle needed by the user.

In a possible design, the rotating shaft further includes a fastener, and the fastener is fastened to a side of the rod part facing away from the blocking part and is held against a surface of the elastic member facing away from the concave cam assembly.

In the foregoing design, the fastener is configured to cooperate with the blocking part, so that a distance between the fastener and the blocking part remains unchanged. When a total width of the concave cam assembly changes, the elastic member is extruded, so that the elastic member is deformed.

In a possible design, the rotating shaft further includes a friction sheet, the friction sheet includes a fourth through hole, the fourth through hole is in a flat shape, and a shape of the fourth through hole matches with a shape of the rod part; and the friction sheet is located between the fastener and the blocking part.

In the foregoing design, a distance between the fastener and the concave cam assembly may be reduced, a width of the elastic member along the axial direction is further reduced, and a reaction force acting on the concave cam assembly by the elastic member is increased; and a friction force of each element in a direction perpendicular to the axial direction is also increased, thereby improving stability when the first body and the second body are opened or closed.

In a possible design, the friction sheet is located between the concave wheel and the first fastening plate.

In the foregoing design, surfaces that are of the friction sheet and that connect to the concave wheel to the first fastening plate have specific roughness. Because the concave wheel is fixedly connected to the first fastening plate, the friction sheet is fixedly connected to the central shaft. The friction sheet is disposed to increase a friction force, and may increase recovery resistance of the first body or the second body along a gravity direction, thereby improving stability when the first body and the second body are opened or closed. The disposition of the friction sheet may also reduce a distance between the fastener and the concave cam assembly, further reduce a width of the elastic member along the axial direction, and increase a reaction force acting on the concave cam assembly by the elastic member; and further increase a friction force of each element on a surface perpendicular to the axial direction, thereby improving stability when the first body and the second body are opened or closed.

According to a second aspect, this application provides a terminal device. The terminal device includes a first body, a second body, and a rotating shaft. The first body is fixedly connected to a first bracket, and the second body is fixedly connected to a second bracket.

To better understand the foregoing objectives, features, and advantages of this application, the following describes this application in detail with reference to the accompanying drawings and specific implementations. It should be noted that the implementations of this application and the features in the implementations may be combined with each other provided that no conflict occurs. Many specific details are described in the following description, so as to fully understand this application. The described implementations are only some of the implementations of this application, not all the implementations.

Unless otherwise defined, all technical terms and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of this application. The terms used in the specification of this application are merely intended to describe specific implementations, but not intended to limit this application. The term "and/or" used in the specification includes all and any combinations of one or more associated listed items.

In embodiments of this application, for ease of description but not limitation of this application, the term "connection" used in the specification and claims of this application is not limited to a physical or mechanical connection, whether direct or indirect. "Top", "bottom", "above", "below", "left", "right", and the like are only used to indicate a relative position relationship. When an absolute position of a described object changes, the relative position relationship also correspondingly changes.

<FIG> shows a terminal device <NUM>. The terminal device <NUM> includes, but is not limited to, a computer, a mobile phone, a door, a Bluetooth headset box, a glasses box, and other products that need to use a rotating shaft <NUM>. In this example, the terminal device <NUM> is a laptop computer.

The terminal device <NUM> includes a first body <NUM>, a second body <NUM>, and the rotating shaft <NUM>. The rotating shaft <NUM> is connected to the first body <NUM> and the second body <NUM>. The rotating shaft <NUM> can be used to change an opening/closing angle between the first body <NUM> and the second body <NUM>, and maintain the opening/closing angle needed by the user.

Specific names of the first body <NUM> and the second body <NUM> are related to a use scenario of the rotating shaft <NUM>. For example, when the terminal device <NUM> is a laptop computer, the first body <NUM> may be a keyboard, and the second body <NUM> may be a display; or when the terminal device <NUM> is a door, the first body <NUM> may be a door frame, and the second body <NUM> may be a door plate. The foregoing is merely an example for description, not a limitation.

<FIG> shows a rotating shaft 100a. The rotating shaft 100a includes a central shaft 10a, a first bracket 20a, a second bracket 30a, a disc spring group 40a, and a concave cam assembly 50a. The first bracket 20a is rotatably disposed on the central shaft 10a, the second bracket 30a is fastened to the central shaft 10a, the disc spring group 40a is disposed on the central shaft 10a, the concave cam assembly 50a is disposed on the central shaft 10a, and the concave cam assembly 50a may enable the disc spring group 40a to be deformed in an extending direction of the central shaft 10a. The first bracket 20a is configured to be fastened to the first body <NUM>, and the second bracket 30a is configured to be fastened to the second body <NUM>. The first bracket 20a is rotatably connected to the second bracket 30a, so that the first body <NUM> and the second body <NUM> can be opened or closed.

Referring to both <FIG> and <FIG>, the disc spring group 40a is formed by assembling a plurality of disc springs 41a, each disc spring 41a is a circular arched sheet, and a thickness of the disc spring 41a may be <NUM>-<NUM>. In this example, the disc spring group 40a is formed by assembling five disc springs 41a. The disc spring 41a has a front side and a back side in the process of assembling to form the disc spring group 40a. In the process of assembling, the front side and the back side need to be assembled manually and alternately, so as to form the elastic disc spring group 40a.

The inventors of this application have found that manual assembly has low efficiency and is prone to errors. In some use scenarios, for example, a size of the disc spring 41a is relatively small, it is difficult to distinguish the positive side and the negative side of the disc spring 41a, or a quantity of the disc springs 41a that need to be used are relatively large, which increases a probability of manual error. By replacing manual assembly with automated assembly, additional automated assembly device is needed, improving production costs. Second, the terminal device <NUM> including the rotating shaft 100a is usually used for a plurality of times. Therefore, the rotating shaft 100a can be used more frequently, and a quantity of times that the foregoing disc spring group 40a can be used generally is limited (for example, <NUM>,<NUM> to <NUM>,<NUM> times), a relatively large elastic force attenuation may occur, thereby causing a sharp decrease in a torque of the rotating shaft 100a, and affecting use of the user. In addition, the disc spring group 40a includes a plurality of disc springs 41a. When a specific included angle is formed between the first body <NUM> and the second body <NUM>, because of gravity of the first body <NUM> or the second body <NUM>, the first body <NUM> or the second body <NUM> has a recovery tendency along the direction of gravity, and the plurality of disc springs 41a have a torsion force fluctuation perpendicular to an axial direction, so that it is difficult to maintain an angle after the first body <NUM> and the second body <NUM> are opened. The inventors of this application have also found that the following problem also exists when the spring is used to replace the foregoing disc spring group 40a: When the spring is used to replace the foregoing disc spring group 40a, the elasticity of the spring is difficult to support the first body <NUM> or the second body <NUM> after the first body <NUM> and the second body <NUM> are opened. In addition, an external force acting on the disc spring group 40a or the spring is positively correlated with a deformation quantity. That is, when a magnitude of the external force changes, the deformation quantity of the disc spring group 40a or the spring changes, and consequently, a force acting on the first body <NUM> or the second body <NUM> is unstable.

Referring to <FIG>, some embodiments of this application provide a rotating shaft <NUM>. The rotating shaft <NUM> includes a central shaft <NUM>, a first bracket <NUM>, a second bracket <NUM>, an elastic member <NUM>, and a concave cam assembly <NUM>. The first bracket <NUM> is relatively and rotatably connected to the central shaft <NUM>, the second bracket <NUM> is fixedly connected to the central shaft <NUM>, the elastic member <NUM> is disposed on the central shaft <NUM>, the elastic member <NUM> is in a hollowed-out shape, the concave cam assembly <NUM> is disposed on the central shaft <NUM>, and the concave cam assembly <NUM> may enable the elastic member <NUM> to be deformed. When the first bracket <NUM> rotates relative to the second bracket <NUM>, the concave cam assembly <NUM> enables the elastic member <NUM> in a hollowed-out shape to be deformed, so that a specific included angle is formed between the first bracket <NUM> and the second bracket <NUM>.

Specifically, referring to <FIG>, the central shaft <NUM> includes a fastening part <NUM>, a blocking part <NUM>, and a rod part <NUM> that are fixedly connected. The blocking part <NUM> is located between the fastening part <NUM> and the rod part <NUM>. The rod part <NUM> extends outward on a side of the blocking part <NUM> facing away from the fastening part <NUM>. For ease of description, a direction in which the rod part <NUM> extends is defined as an X-axis direction (that is, an axial direction of the rod part <NUM>). In a direction perpendicular to the X-axis direction, a diameter of the blocking part <NUM> is greater than a diameter of the rod part <NUM>.

The fastening part <NUM> is in a flat block shape, and a first penetrating hole <NUM> is disposed on the fastening part <NUM>. The first penetrating hole <NUM> may cooperate with a nut, and is configured to fasten the second body <NUM>.

The rod part <NUM> sequentially passes through the first bracket <NUM>, the concave cam assembly <NUM>, and the elastic member <NUM>. The first bracket <NUM> is held against the blocking part <NUM>. The concave cam assembly <NUM> is located between the elastic member <NUM> and the first bracket <NUM>. The rotating shaft <NUM> further includes a fastener <NUM>, and the fastener <NUM> is located at an end of the rod part <NUM>, so that the first bracket <NUM>, the elastic member <NUM>, and the concave cam assembly <NUM> are fastened to the rod part <NUM>, and then the fastener <NUM> and the first bracket <NUM> are fastened at a distance D along the X-axis direction. In this embodiment, the fastener <NUM> is a nut. In another implementation, a fastening manner is not limited to fastening with a nut, or may be bonding, clamping, or the like.

The first bracket <NUM> includes a first fastening plate <NUM> and a second fastening plate <NUM>, and the first fastening plate <NUM> is fixedly connected to the second fastening plate <NUM>. The second fastening plate <NUM> is disposed on a surface of the first fastening plate <NUM> and has a specific included angle with the first fastening plate <NUM>. In this embodiment, the second fastening plate <NUM> and the first fastening plate <NUM> are perpendicular to each other. In other embodiments, an angle between the second fastening plate <NUM> and the first fastening plate <NUM> is not limited, and may be set according to needs.

A second penetrating hole <NUM> is disposed on the second fastening plate <NUM>, and the second penetrating hole <NUM> may cooperate with a nut, and is configured to fasten the first body <NUM>.

A first through hole <NUM> and a fastening hole <NUM> are disposed on the first fastening plate <NUM>. The first through hole <NUM> penetrates two opposite surfaces of the first fastening plate <NUM>, the first through hole <NUM> is configured to pass through the central shaft <NUM>, and the first fastening plate <NUM> is held against a surface of the blocking part <NUM> facing away from the fastening part <NUM>. The fastening hole <NUM> may be a through hole, or may be an accommodation slot. In this embodiment, the fastening hole <NUM> is a through hole, and is configured to limit the concave cam assembly <NUM>.

The concave cam assembly <NUM> is sleeved onto the rod part <NUM>. The concave cam assembly <NUM> includes a concave wheel <NUM> and a cam wheel <NUM> that are adjacent to each other. Surfaces connecting the concave wheel <NUM> and the cam wheel <NUM> cooperate with each other, and the concave wheel <NUM> is movably connected to the cam wheel <NUM>. One of the concave wheel <NUM> and the cam wheel <NUM> is fixedly connected to the first bracket <NUM>, and the other of the concave wheel <NUM> and the cam wheel <NUM> is fixedly connected to the central shaft <NUM>. When the concave wheel <NUM> moves relative to the cam wheel <NUM>, a total width of the concave wheel <NUM> and the cam wheel <NUM> along the X-axis direction changes, so that a relative extrusion force F acts on the elastic member <NUM> and enables the elastic member <NUM> to be deformed.

Specifically, referring to both <FIG> and <FIG>, in this embodiment, the concave wheel <NUM> is fixedly connected to the first fastening plate <NUM>, and the cam wheel <NUM> is fixedly connected to the rod part <NUM>. The concave wheel <NUM> includes a concave wheel part <NUM> and a clamping part <NUM>. The clamping part <NUM> is connected to an edge area of the concave wheel part <NUM>, and extends toward a direction of the first fastening plate <NUM>, and at least a part of the clamping part <NUM> is clamped in the fastening hole <NUM>, so that the concave wheel <NUM> is fixedly connected to the first bracket <NUM>. A second through hole <NUM> is disposed in the concave wheel part <NUM>, and a minimum diameter of the second through hole <NUM> is greater than a maximum diameter of the rod part <NUM>, so that the rod part <NUM> and the concave wheel <NUM> can rotate relative to each other. A third through hole <NUM> is disposed in the cam wheel <NUM>, the third through hole <NUM> is in a flat shape, the rod part <NUM> is in a flat shape, and the third through hole <NUM> matches with the rod part <NUM>. The cam wheel <NUM> is relatively fastened to the rod part <NUM>. When the central shaft <NUM> rotates, the cam wheel <NUM> rotates synchronously with the central shaft <NUM>, and the rod part <NUM> in a flat shape and the third through hole <NUM> in a flat shape are disposed. With simple structural design, the cam wheel <NUM> may be fixedly connected to the central shaft <NUM>, and assembly of the rotating shaft <NUM> is further facilitated. In other embodiments, the cam wheel <NUM> may be fastened the central shaft <NUM> through bonding, clamping, or the like.

A surface that is of the concave wheel part <NUM> and that connects to the cam wheel <NUM> includes a recessed part <NUM> and a flat grinding area <NUM> that are connected, and a surface that is of the cam wheel <NUM> and that connects to the concave wheel <NUM> includes a protruding part <NUM>. When the concave wheel <NUM> and the cam wheel <NUM> do not rotate relative to each other, the protruding part <NUM> corresponds to the recessed part <NUM>, that is, the protruding part <NUM> is accommodated in the recessed part <NUM>. In this embodiment, there are two recessed parts <NUM> and two protruding parts <NUM>, and the two recessed parts <NUM> and the two protruding parts <NUM> are separately correspondingly disposed. There are also two flat grinding areas <NUM>, and the recessed part <NUM> and the flat grinding area <NUM> are disposed at intervals. The quantity of the recessed part <NUM> or the protruding part <NUM> is related to an angle that needs to be maintained after the first body <NUM> and the second body <NUM> are opened. In other embodiments, the quantity of recessed part <NUM> and the quantity of the protruding part <NUM> are not limited.

Referring to <FIG>, when the concave wheel <NUM> and the cam wheel <NUM> do not rotate relative to each other, the concave wheel <NUM> and the cam wheel <NUM> have a total width W1 along an X-axis direction. The concave wheel <NUM> is fastened, and the cam wheel <NUM> is rotated, so that the protruding part <NUM> and the concave wheel <NUM> gradually generate relative rotation along a sidewall of the recessed part <NUM>. As an angle of relative rotation increases, the total width W1 of the cam wheel <NUM> and the concave wheel <NUM> along the X-axis direction gradually increases. Because a distance D between the fastener <NUM> and the first fastening plate <NUM> is constant, a width of the elastic member <NUM> gradually decreases, and an extrusion force F acting on the elastic member <NUM> gradually increases. Referring to <FIG>, when the protruding part <NUM> rotates to a connection point between the recessed part <NUM> and the flat grinding area <NUM>, a total width W2 of the cam wheel <NUM> and the concave wheel <NUM> reaches a maximum, and an extrusion force F acting on the elastic member <NUM> reaches a maximum. The relative rotation between the cam wheel <NUM> and the concave wheel <NUM> continues to be increased, and the total width W2 of the cam wheel <NUM> and the concave wheel <NUM> does not change. In this case, the force acting on the elastic member <NUM> no longer changes. Theoretically, the flat grinding area <NUM> should be a plane. However, an absolute flatness cannot be reached due to a limitation on an actual processing plane. Therefore, in an actual product, when the protruding part <NUM> and the flat grinding area <NUM> come into contact and rotate relative to each other, a small fluctuation may occur because the flat grinding area <NUM> is not flat, and consequently, a deformation quantity of the elastic member <NUM> may also fluctuate.

It may be understood that the concave wheel <NUM> is fixedly connected to the first bracket <NUM>, the first bracket <NUM> is fixedly connected to the first body <NUM>, the cam wheel <NUM> is fixedly connected to the central shaft <NUM>, and the central shaft <NUM> is fixedly connected to the second body <NUM>. Therefore, the concave wheel <NUM> and the cam wheel <NUM> generate relative rotation, to synchronously drive the first body <NUM> and the second body <NUM> to generate relative rotation. An angle of relative rotation between the first body <NUM> and the second body <NUM> may be set according to needs.

The surfaces on which the recessed part <NUM> and the protruding part <NUM> are formed are arc surfaces. When the concave wheel <NUM> and the cam wheel <NUM> generate relative rotation movement, it is conducive to smooth transition of the extrusion force F acting on the elastic member <NUM>, thereby improving user experience.

Referring to <FIG>, the elastic member <NUM> is a hollowed-out cylinder, and the elastic member <NUM> is of an integrated structure. The center of the elastic member <NUM> has a fifth through hole <NUM>, and is configured to be sleeved onto the rod part <NUM>. The elastic member <NUM> that is of an integrated structure may be assembled to the central shaft <NUM> at one time, and therefore mounting is simple, thereby improving mounting efficiency. The elastic member <NUM> replaces the disc spring group 40a including the plurality of disc springs 41a, so as to fundamentally avoid problems of low efficiency and high error rate that are caused by assembling the plurality of disc springs 41a, and no additional automated assembly device needs to be disposed.

A hollowed shape may be a regular shape or an irregular shape. A regular shape includes, but is not limited to, a polygon (refer to <FIG>), an arc shape (refer to <FIG> and <FIG>), or the like. The polygon includes, but is not limited to, a square, a rectangle, a diamond, a pentagon, a hexagon, or the like; and the arc shape includes, but is not limited to, a spiral shape, a circular shape, an oval shape, or a semicircular shape. In a same embodiment, the foregoing shapes may be combined with each other. When the hollowed-out shape is a regular shape, it is more conducive to designing and processing the elastic member <NUM> based on the extrusion force F that needs to act on the elastic member <NUM>, and a force acting on the elastic member <NUM> along the X-axis direction is uniform.

Specifically, referring to <FIG>, a plurality of hollowed-out holes <NUM> and a plurality of connecting ribs <NUM> are disposed on a cylinder wall of the hollowed-out elastic member <NUM> in this embodiment of this application. The hollowed-out hole <NUM> is connected to the fifth through hole <NUM>, and a shape of the hollowed-out hole <NUM> is a hexagon shape. The plurality of hollowed-out holes <NUM> are interleaved with the plurality of connecting ribs <NUM>, and are disposed at intervals to form the hollowed-out elastic member <NUM>, so that the cylinder wall of the elastic member <NUM> forms a hollowed-out cylinder wall in a honeycomb-like shape.

Referring to <FIG>, a plurality of hollowed-out holes 63a and a plurality of connecting ribs 65a are disposed on a cylinder wall of another hollowed-out elastic member 60a in this embodiment of this application. The hollowed-out hole 63a is connected to a fifth through hole (not shown in the figure), and the hollowed-out hole 63a is in a diamond shape. The plurality of hollowed-out holes 63a are interleaved with the plurality of connecting ribs 65a and are disposed at intervals to form the hollowed-out elastic member 60a.

Referring to <FIG>, a plurality of hollowed-out holes 63b and a plurality of connecting ribs 65b that are located between the hollowed-out holes 63b are disposed on a cylinder wall of another hollowed-out elastic member 60b in this embodiment of this application. The hollowed-out hole 63b is connected to the fifth through hole <NUM>, and the hollowed-out hole 63b is in a spiral shape. The plurality of hollowed-out holes 63b are interleaved with the plurality of connecting ribs 65b and are disposed at intervals to form the hollowed-out elastic member 60b. An extending direction of the connecting rib 65b includes extending along an X-axis direction (an axial direction) and extending along an intersection direction with the X-axis direction. The connecting rib 65b extending along an X-axis direction enables the elastic member 60b to be deformed in the intersection direction with the X-axis direction when being subjected to the extrusion force F.

Referring to <FIG>, a plurality of hollowed-out holes 63c and a plurality of connecting ribs 65c are disposed on a cylinder wall of another hollowed-out elastic member 60c in this embodiment of this application. The hollowed-out hole 63c is connected to a fifth through hole (not shown in the figure), and the hollowed-out hole 63c is in a circular shape. The plurality of hollowed-out holes 63c are interleaved with the plurality of connecting ribs 65c and are disposed at intervals to form the hollowed-out elastic member 60c.

Depending on the position of the connecting rib <NUM>, formed hollowed-out shapes are different, and an extending direction of the connecting rib <NUM> may be any direction. The connecting rib <NUM> may cause the elastic member <NUM> to be deformed along the axial direction, or to be deformed along another direction. When a total width of the concave cam assembly <NUM> along the X-axis direction changes, the elastic member <NUM> is subjected to the extrusion force F. Because the elastic member <NUM> is in a hollowed-out shape, referring to <FIG>, an example in which the hollowed-out shape is a hexagon is used (solid lines in <FIG>), and the connecting rib <NUM> disposed around the hexagon is perpendicular to the extrusion force F; and referring to <FIG>, when being subjected to the extrusion force F, the elastic member <NUM> may be compressed along the X-axis direction and may be deformed. As the extrusion force F increases, a deformation quantity of the elastic member <NUM> increases. When the extrusion force F acting on the elastic member <NUM> reaches a critical point t (point t in <FIG>), the elastic member <NUM> may bulge outward along a direction intersecting the X-axis to be deformed (dashed lines in <FIG>), and the connecting rib <NUM> of the elastic member <NUM> may be deformed along a plurality of directions (which is not limited to deformation along the X-axis direction only). That is, the concave cam assembly <NUM> continues to extrude the elastic member <NUM> to exceed the critical point t, and the deformation quantity of the elastic member <NUM> includes deformation along the X-axis direction and deformation along the direction intersecting the X-axis direction. According to the principle of buckling analysis, the extrusion force F acting on the elastic member <NUM> remains unchanged, and in this case, a torsion force of the rotating shaft <NUM> is stable.

In some implementations, the critical point t (that is, the extrusion force F acting on the elastic member <NUM> becomes a constant force) is reached, before the protruding part <NUM> rotates to a connection point between the recessed part <NUM> and the flat grinding area <NUM>. In this way, even if a surface of the flat grinding area <NUM> is not flat, when the protruding part <NUM> and the flat grinding area <NUM> come into contact and rotate relative to each other, and the extrusion force F acting on the elastic member <NUM> is a constant force, the cam wheel <NUM> and the concave wheel <NUM> are extruded by a reaction force of a same magnitude, so that the concave wheel <NUM> and the cam wheel <NUM> are relatively stable, and then the first body <NUM> and the second body <NUM> maintain an opening/closing angle needed by the user. A critical point t of the elastic member <NUM> is in a specific relationship with a hollowed-out shape, a material, a thickness, an angle θ between the connecting rib <NUM> of the elastic member <NUM> and the extrusion force F (refer to <FIG>), and the like. A material, a wall thickness, a hollowed-out shape, and the like that are selected by the elastic member <NUM> may be comprehensively calculated based on the extrusion force F needed by the elastic member <NUM>, so that the elastic member <NUM> can produce a proper extrusion force F, or a material, a wall thickness, a hollowed-out shape, and the like of the elastic member <NUM> may be designed based on whether the elastic member <NUM> needs to reach a constant force interval. When the rotating shaft <NUM> is applied to a specific terminal device <NUM>, a function of the rotating shaft <NUM> is implemented. In addition, the elastic member <NUM> is always in an elastic deformation area of the elastic member <NUM> in a process of being deformed by the extrusion force F, and no plastic deformation occurs. Therefore, plastic deformation and elastic attenuation of the disc spring 41a in the related technology do not occur.

A range of the constant force interval (which is a width when the extrusion force F along an axial direction deformation quantity in <FIG> is a constant force) also has a specific relationship with the angle θ between the connecting rib <NUM> and the extrusion force F. In some implementations, when conditions such as a wall thickness and a material of the elastic member <NUM> are the same, and a range of an angle θ is <NUM>°-<NUM>°, a range of the constant force interval is the largest; or when an angle θ is less than <NUM>°, a range of the constant force interval increases as an angle θ increases; or when an angle θ is greater than <NUM>°, a range of the constant force interval decreases as an angle θ increases. An angle θ between the connecting rib <NUM> and the extrusion force F may be selected according to an actual application requirement of the rotating shaft, that is, a hollowed-out shape and an arrangement direction of the hollowed-out shape are selected according to needs.

A material of the elastic member <NUM> may be metal, metal alloy, or plastic. The elastic member <NUM> made of metal or metal alloy has stronger toughness and can be used more frequently. The elastic member <NUM> of the plastic material may be used to form the elastic member <NUM> through injection molding, and processing costs are low. In some implementations, the elastic member <NUM> can be used more than <NUM>,<NUM> times.

The rotating shaft <NUM> further includes a friction sheet <NUM>, and roughness of a surface of the friction sheet <NUM> is relatively large. The friction sheet <NUM> includes a fourth through hole <NUM>. The fourth through hole <NUM> is in a flat shape, and a shape of the fourth through hole <NUM> matches with a shape of the rod part <NUM>. The friction sheet <NUM> is fixedly connected to the rod part <NUM>. The friction sheet <NUM> is located between the concave wheel <NUM> and the first fastening plate <NUM>. Surfaces that are of the friction sheet <NUM> and that connect to the concave wheel <NUM> and the first fastening plate <NUM> have specific roughness. Because the concave wheel <NUM> is fixedly connected to the first fastening plate <NUM>, the friction sheet <NUM> is fixedly connected to the central shaft <NUM>. The friction sheet <NUM> is disposed to increase a friction force between the friction sheet <NUM> and adjacent elements (namely, the concave wheel <NUM> and the first fastening plate <NUM>). When an included angle is formed between the first body <NUM> and the second body <NUM>, because of existence of gravity of the first body <NUM> or the second body <NUM>, the first body <NUM> or the second body <NUM> has a recovery tendency along the direction of gravity, a friction force may be increased, and the recovery resistance of the first body <NUM> or the second body <NUM> along the direction of gravity can be increased, thereby improving stability when the first body <NUM> and the second body <NUM> are opened or closed. Further, the friction sheet <NUM> is disposed to reduce a distance between the fastener <NUM> and the concave cam assembly <NUM>, further reduce a width of the elastic member <NUM> along the X-axis direction, increase a reaction force acting on the concave cam assembly <NUM> by the elastic member <NUM>, and further increase a friction force of each element on a surface perpendicular to the X-axis direction, thereby further improving stability when the first body <NUM> and the second body <NUM> are opened or closed.

Surfaces that are of the concave wheel <NUM> and the first fastening plate <NUM> and that connect to the friction sheet <NUM> may also be provided with a groove or a protrusion that matches with the surface roughness of the friction sheet <NUM>, so that a proper friction force is produced when the rotating shaft <NUM> is rotating and when the first body <NUM> or the second body <NUM> maintains a specific included angle.

The friction sheet <NUM> may alternatively be located between the cam wheel <NUM> and the fastener <NUM>, for example, located between the fastener <NUM> and the elastic member <NUM> or located between the elastic member <NUM> and the concave cam assembly <NUM>. The friction sheet <NUM> is disposed to reduce a distance between the fastener <NUM> and the concave cam assembly <NUM>, further reduce a width of the elastic member <NUM> along the X-axis direction, increase a reaction force acting on the concave cam assembly <NUM> by the elastic member <NUM>, and further increase a friction force of each element on a surface perpendicular to the X-axis direction, thereby improving stability when the first body <NUM> and the second body <NUM> are opened or closed.

The rotating shaft <NUM> provided in this application uses the elastic member <NUM> that is of the integrated structure and that is in the hollowed-out shape, and may be assembled to the central shaft <NUM> at one time, and therefore mounting is simple, thereby improving mounting efficiency. The elastic member <NUM> replaces the disc spring group 40a including the plurality of disc springs 41a, so as to fundamentally avoid problems of low efficiency and high error rate that are caused by assembling the plurality of disc springs 41a, and no additional automated assembly device needs to be disposed. In addition, the elastic member <NUM> of the integrated structure may avoid a torsion force fluctuation in a direction perpendicular to an axial direction when a plurality of disc springs 41a or springs are used in a related technology. A structure of the elastic member <NUM> in this application is more conducive to ensuring stability after the first body <NUM> and the second body <NUM> are opened. In addition, the elastic member <NUM> is always in an elastic deformation area of the elastic member <NUM> in a process of being deformed by the extrusion force F, and no plastic deformation occurs. Therefore, plastic deformation and elastic attenuation of the disc spring 41a in the related technology do not occur, and a use frequency is improved. In addition, based on the structure of the elastic member <NUM> in this application, when the extrusion force F acting on the elastic member <NUM> exceeds a critical point t, the elastic member <NUM> features a constant force.

Claim 1:
A rotating shaft, comprising:
a central shaft (<NUM>, 10a);
a first bracket (<NUM>, 20a), rotatably mounted on the central shaft;
a second bracket (<NUM>, 30a), fixedly connected to the central shaft;
an elastic member (<NUM>, 60a, 60b, 60c), disposed on the central shaft; and
a concave cam assembly (<NUM>, 50a), disposed on the central shaft, wherein the concave cam assembly is configured to enable the elastic member to be deformed; and wherein
when the first bracket rotates relative to the second bracket, the concave cam assembly generates an extrusion force acting on the elastic member, so that the elastic member in a hollowed-out shape is deformed, and then a specific included angle is formed between the first bracket and the second bracket;
wherein the central shaft comprises a fastening part (<NUM>), a blocking part (<NUM>), and a rod part (<NUM>) that are fixedly connected, and the blocking part is located between the rod part and the fastening part; and the second bracket is fastened to the fastening part, the rod part sequentially passes through the first bracket, the concave cam assembly, and the elastic member, and the first bracket is held against the blocking part, wherein the rotating shaft further comprises a fastener (<NUM>), and the fastener is fastened to a side of the rod part facing away from the blocking part, and is held against a surface of the elastic member facing away from the concave cam assembly;
characterised in that the elastic member is a hollow cylinder of an integrated structure, and a plurality of hollowed-out holes (<NUM>, 63a, 63b, 63c) and a plurality of connecting ribs (<NUM>, 65a, 65b, 65c) are disposed on a cylinder wall of the elastic member, and the plurality of hollowed-out holes are interleaved with the plurality of connecting ribs and are disposed at intervals to form the elastic member.