Rotating shaft mechanism and electronic device

Abstract

The application provides a rotating shaft mechanism and electronic equipment. The rotating shaft mechanism comprises a middle beam, a synchronous gear and first and second swing arms. The synchronous gear comprises first and second gears which are engaged and mounted on the middle beam and connected with the first and second swing arms respectively. The first gear comprises first teeth which comprise first and second ends arranged oppositely in the tooth width direction of the first teeth. The second gear comprises second teeth which comprise third and fourth ends arranged oppositely in the tooth width direction of the second teeth. The third end is located on one side of the synchronous gear with the first end, and the fourth end is located on the other side of the synchronous gear with the second end. The addendum thickness of the first teeth gradually changes from the first end to the second end, and the addendum thickness of the second teeth gradually changes from the third end to the fourth end. The change trend of the addendum thickness of the second teeth is opposite to that of the first teeth. The synchronous structure of the technical scheme has good synchronization effect and can easily realize the synchronous rotation of the structures on both sides of the rotating shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic equipment, and in particular to a rotating shaft mechanism and electronic equipment. BACKGROUND

[0002] With the increasing maturity of flexible folding screen technology, the application of folding terminal products (such as folding mobile phones, folding tablets, folding computers, etc.) is also becoming more and more widespread. In the folding terminal product, a synchronous structure is generally needed to be arranged in the rotating shaft to realize the synchronous rotation of the structures on both sides of the rotating shaft. However, the synchronous effect of the synchronous structure in the existing rotating shaft is poor, which makes it difficult to realize the synchronous rotation of the structures on both sides of the rotating shaft. SUMMARY

[0003] Embodiments of the present application provide a rotating shaft mechanism and electronic equipment, and the synchronous effect of the synchronous structure is good, which makes it easy to realize the synchronous rotation of the structures on both sides of the rotating shaft.

[0004] In a first aspect, the present application provides a rotating shaft mechanism, which comprises:

[0005] a middle beam;

[0006] a synchronous gear comprising a first gear and a second gear, the first gear and the second gear are both mounted on the middle beam and are arranged in sequence along the width direction of the middle beam, and the first gear is engaged with the second gear;

[0007] the first gear comprises a plurality of first teeth, the plurality of first teeth are arranged in sequence along the circumferential direction of the first gear, the first tooth comprises a first end and a second end, and the first end and the second end are arranged opposite to each other in the tooth width direction of the first tooth;

[0008] the second gear comprises a plurality of second teeth, the plurality of second teeth are arranged in sequence along the circumferential direction of the second gear, the plurality of second teeth are used for engaging with the plurality of first teeth, the second tooth comprises a third end and a fourth end, and the third end and the fourth end are arranged opposite to each other in the tooth width direction of the second tooth, the third end and the first end are located on one side of the synchronous gear, and the fourth end and the second end are located on the other side of the synchronous gear;

[0009] the addendum thickness of the first tooth gradually changes from the first end to the second end, the addendum thickness of the second tooth gradually changes from the third end to the fourth end, and the change trend of the addendum thickness of the second tooth is opposite to that of the first tooth; and

[0010] a first swing arm and a second swing arm, the first swing arm and the second swing arm are respectively located on both sides of the width direction of the middle beam, the first swing arm is fixedly connected with the first gear, and the second swing arm is fixedly connected with the second gear.

[0011] It can be understood that in the electronic device with foldable performance, the coincidence degree of the gears in the synchronous assembly is a key factor affecting the motion synchronization between the two housings of the electronic device. If the motion synchronization between the two housings of the electronic device is to be improved, the coincidence degree of the gears in the synchronous assembly needs to be improved to ensure the transmission efficiency and stability of the synchronous assembly.

[0012] The coincidence degree of the gears refers to the ratio of the actual meshing line length to the normal pitch. The coincidence degree is the condition for the gears to continuously mesh. The coincidence degree represents the ratio of the frequency of the simultaneous meshing of two teeth and the meshing of one tooth in the meshing process. The higher the frequency of the simultaneous meshing of two teeth, the higher the coincidence degree, the better the synchronization performance of the synchronous gears, the smaller the load on a single tooth, the more stable the structure of the meshing teeth of the gears, the gears are less likely to bend, and the noise in the rotation process of the gears is smaller. Moreover, the greater the coincidence degree of the gears, the higher the transmission efficiency and stability of the gears.

[0013] In the related art, when the synchronous gears and the middle beam are designed, a design gap needs to be left between the two to ensure that the synchronous gears can be smoothly installed on the middle beam. This design gap can avoid the problem of the synchronous gears being stuck due to the gap between the synchronous gears and the middle beam being too small or too large when the synchronous gears are installed on the middle beam. However, in the actual work of the synchronous gears, the two gears that mesh with each other are prone to not fit tightly, which causes one of the two gears to move towards the middle beam below and reduce or eliminate the design gap with the middle beam, and the other gear also moves towards the middle beam below and reduces or eliminates the design gap with the middle beam, so that the two gears are respectively pushed out to the sides away from each other, causing the involute surfaces of the two gears to change from tangency to misalignment, resulting in an increase in the tooth side gap between the two gears and the inability to fully mesh, which reduces the coincidence degree and meshing effect of the synchronous gears.

[0014] Based on this, in the present embodiment, by gradually changing the addendum thickness of the first tooth from the first end to the second end, gradually changing the addendum thickness of the second tooth from the third end to the fourth end, and making the change trend of the addendum thickness of the second tooth opposite to that of the addendum thickness of the first tooth, the tooth profile of the first tooth and the tooth profile of the second tooth can both have inclined surfaces, and the inclined trend of the inclined surfaces can be oppositely arranged.

[0015] In this arrangement, when the first tooth and the second tooth are engaged, the tooth profile of the first tooth and the tooth profile of the second tooth can be arranged in opposite directions, and the mating surface of the first tooth and the second tooth can be changed from a flat surface to an inclined surface, thereby effectively increasing the mating relative area between the first tooth and the second tooth. The increase in the mating area between the first tooth and the second tooth can make the tooth profile of the first tooth and the tooth profile of the second tooth compactly mate, and the tooth groove of the first tooth and the tooth groove of the second tooth can be further embedded in each other when the tooth profiles of the first tooth and the second tooth are in contact, which is beneficial to make the tooth profile of the next pair of first tooth and second tooth enter engagement before (at least at the same time) the tooth profile of the previous pair of first tooth and second tooth ends engagement, so that the involute surface of the first tooth and the involute surface of the second tooth remain tangent, effectively improve the coincidence degree and engagement effect, and ensure the continuity and stability of transmission. In addition, since the coincidence degree is improved, the synchronization effect between the first gear and the second gear is better, so that the structures on both sides of the rotating shaft mechanism can realize synchronous rotation.

[0016] In a possible implementation, the first tooth further comprises a first tooth top surface connected between the first end and the second end, the first tooth top surface comprises a first top edge located at the first end and a second top edge located at the second end, and the length of the first top edge is different from the length of the second top edge.

[0017] The second tooth comprises a second tooth top surface connected between the third end and the fourth end, the second tooth top surface comprises a third top edge located at the third end and a fourth top edge located at the fourth end, the length of the third top edge is different from the length of the fourth top edge, and the length of the first top edge and the length of the second top edge are in opposite relationship.

[0018] It can be understood that, by making the length of the second top edge different from the length of the first top edge, the tooth width of the first tooth gradually changes in the axial direction of the first gear, so that the first tooth is a tooth with a certain radial displacement, thereby making the mating surface of the first tooth and the second tooth be an inclined surface, which is beneficial to increase the mating area between the first tooth and the second tooth, optimize the engagement effect between the first tooth and the second tooth, and increase the coincidence degree of the synchronous gear.

[0019] In addition, by making the length of the third top edge different from the length of the fourth top edge, the tooth width of the second tooth gradually changes in the axial direction of the second gear, so that the second tooth is a tooth with a certain radial displacement, thereby making the mating surface of the first tooth and the second tooth be an inclined surface, which is beneficial to increase the mating area between the first tooth and the second tooth, optimize the engagement effect between the first tooth and the second tooth, and increase the coincidence degree of the synchronous gear.

[0020] And, by making the length of the third top edge and the length of the fourth top edge in a size relationship opposite to the length of the first top edge and the length of the second top edge, the mating surface of the first tooth and the second tooth can be changed from a flat surface mating to an inclined surface mating, thereby effectively increasing the mating relative area between the first tooth and the second tooth. The increase in the mating area between the first tooth and the second tooth can make the tooth profile of the first tooth and the tooth profile of the second tooth mate well in any cross section, achieving tight fitting of the first tooth and the second tooth. The tight fitting of the first tooth and the second tooth refers to the fitting between the first tooth and the second tooth within a certain range, so that the first gear and the second gear can normally rotate without relative sliding or jumping. This mating method can ensure the transmission accuracy and stability of the gear pair, and avoid vibration, noise and wear caused by improper fitting.

[0021] In a possible implementation, the length of the first top edge is greater than the length of the second top edge, the first tooth has a first draft angle θ1, the length of the first top edge is S1, the length of the second top edge is S2, the tooth width of the first tooth is B1, and the first draft angle θ1, the length of the first top edge S1, the length of the second top edge S2, and the tooth width of the first tooth B1 satisfy the relationship: tanθ1=(S1-S2) / B1.

[0022] It can be understood that by making the first tooth have a first draft angle θ1, when the first gear is prepared, not only can the machining allowance of the first gear be ensured, the frictional resistance between the mold and the surface of the workpiece can be reduced, and the quality of the output first gear parts can be improved. The finished first gear can also be smoothly and quickly ejected from the mold, saving the cost and time of disassembling the first gear from the mold, which is conducive to reducing the machining difficulty of the first gear and reducing the machining cost of the first gear.

[0023] In a possible implementation, the angle range of the first draft angle θ1 can be within an angle range of 3° to 30°.

[0024] It can be understood that by setting the angle range of the first draft angle θ1 within the foregoing range, the first gear can be conveniently demolded from the mold by adjusting the angle size of the draft angle. The greater the angle of the first draft angle θ1, the smaller the force required to disassemble the first gear from the mold, and the shorter the time required to disassemble the first gear from the mold.

[0025] In a possible implementation, the first tooth further comprises a first side surface and a second side surface, both of which are connected between the first end and the second end and oppositely arranged in the circumferential direction of the first gear, the first side surface comprises a first side edge at the first end and a second side edge at the second end, and the second side surface comprises a third side edge at the first end and a fourth side edge at the second end.

[0026] In the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a staggered manner, and the third side edge and the fourth side edge are arranged in a coincident manner, or in the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a coincident manner, and the third side edge and the fourth side edge are arranged in a staggered manner.

[0027] It can be understood that, by arranging the first side edge and the second side edge of the first side surface in a coincident manner in the circumferential direction of the first gear and arranging the third side edge and the fourth side edge of the second side surface in a staggered manner in the circumferential direction of the first gear, the first side surface can be a plane and the second side surface can be an inclined surface with a certain inclination angle. In this arrangement, the first gear can have a structure in which one end has a large tooth thickness and the other end has a small tooth thickness, so that the first gear can have a structure in which a single side edge of the second side surface is radially displaced. By arranging the first gear to be radially displaced on a single side, the first gear can be easily demolded, and the load capacity, wear resistance, machining precision and installation precision of the first gear can be improved, the transmission ratio and speed adaptability of the gear can be optimized, and the gear can have better coincidence and better meshing effect.

[0028] In a possible implementation, the first tooth further comprises a first side surface and a second side surface, both of which are connected between the first end and the second end and oppositely arranged in the circumferential direction of the first gear, the first side surface comprises a first side edge at the first end and a second side edge at the second end, and the second side surface comprises a third side edge at the first end and a fourth side edge at the second end.

[0029] In the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a staggered manner, the third side edge and the fourth side edge are arranged in a staggered manner, and the minimum distance between the first side edge and the third side edge is less than or greater than the minimum distance between the second side edge and the fourth side edge.

[0030] It can be understood that by setting the first side edge and the second side edge of the first side face to be staggered in the circumferential direction of the first gear, and setting the third side edge and the fourth side edge of the second side face to be staggered in the circumferential direction of the first gear, the first side face and the second side face can both be inclined surfaces with a certain inclination angle. In addition, by setting the minimum distance between the first side edge of the first side face and the third side edge of the second side face to be less than or greater than the minimum distance between the second side edge of the first side face and the fourth side edge of the second side face, the extension direction of the first side face and the extension direction of the second side face can be intersected, so as to facilitate the first gear to assume a structure form in which one end has a large tooth thickness and the other end has a small tooth thickness, thereby enabling the first gear to assume a structure in which the first side face and the second side face are both radially displaced. By setting the first gear to be radially displaced on both sides, not only can the first gear be easily demolded, but also the load capacity, wear resistance, machining precision and installation precision of the first gear can be improved, the transmission ratio and speed adaptability of the gear can be optimized, and the synchronous gear can have better coincidence and better meshing effect.

[0031] In a possible implementation, the first end has a different addendum circle radius than the second end.

[0032] It can be understood that by setting the addendum circle radius of the first end to be different from the addendum circle radius of the second end, the first addendum surface can be an inclined surface with a certain inclination, which facilitates the first gear to be demolded from the mold.

[0033] The third end has a different addendum circle radius than the fourth end.

[0034] It can be understood that by setting the addendum circle radius of the third end to be different from the addendum circle radius of the fourth end, the second addendum surface can be an inclined surface with a certain inclination, which facilitates the second gear to be demolded from the mold.

[0035] In a possible implementation, the synchronous gear includes a first rotating shaft, a second rotating shaft, a first limiting piece and a second limiting piece;

[0036] The first rotating shaft and the second rotating shaft are both mounted to the middle beam and oppositely arranged along the width direction of the middle beam, and can rotate relative to the middle beam. The first gear is sleeved on the outer periphery of the first rotating shaft and fixedly connected with the first rotating shaft. The second gear is sleeved on the outer periphery of the second rotating shaft and fixedly connected with the second rotating shaft.

[0037] The first limiting piece is sleeved on one end of the first rotating shaft and one end of the second rotating shaft, and elastically connected between the middle beam and one end of the first gear and one end of the second gear.

[0038] The second limiting member is sleeved on the other end of the second rotating shaft and the other end of the second rotating shaft, and is elastically connected between the middle beam and the other end of the first gear and the other end of the second gear.

[0039] In this arrangement, the first limiting member and the second limiting member can press the two ends of the first gear and the two ends of the second gear in the axial direction, so that the first gear and the second gear can always be engaged, and the axial movement of the first gear and the second gear during engagement can be avoided to prevent the engagement failure of the first gear and the second gear. This facilitates the axial tight fit of the first gear and the second gear, improves the engagement effect of the first gear and the second gear, and has good reliability.

[0040] In one possible implementation, the first limiting member includes a first connecting portion, a first elastic portion, and a second elastic portion. The first connecting portion is connected between the first elastic portion and the second elastic portion. The first elastic portion is wound around the first rotating shaft and extends spirally along the axial direction of the first rotating shaft. The second elastic portion is wound around the second rotating shaft and extends spirally along the axial direction of the second rotating shaft. The rotation direction of the second elastic portion is opposite to that of the first elastic portion.

[0041] It can be understood that by winding the first elastic portion around the first rotating shaft and extending spirally along the axial direction of the first rotating shaft, and winding the second elastic portion around the second rotating shaft and extending spirally along the axial direction of the second rotating shaft, and the rotation direction of the second elastic portion being opposite to that of the first elastic portion, the opposite rotation directions of the first elastic portion and the second elastic portion can adapt to the change trend of the tooth profile of the first tooth and the tooth profile of the second tooth. Thus, the first gear and the second gear can always be engaged, the axial movement of the first gear and the second gear during engagement can be avoided to prevent the engagement failure of the first gear and the second gear. This facilitates the axial tight fit of the first gear and the second gear, improves the engagement effect of the first gear and the second gear, and has good reliability.

[0042] In a second aspect, the present application also provides an electronic device, which includes a first shell, a second shell, and a rotating shaft mechanism as described above, and the rotating shaft mechanism is connected between the first shell and the second shell. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a structural schematic diagram of an electronic device in a folded state according to an embodiment of the present application;

[0044] Figure 2 is a structural schematic diagram of an electronic device in an intermediate state according to an embodiment of the present application;

[0045] Figure 3This is a schematic diagram of the structure of the electronic device provided in the embodiment of this application when it is in the unfolded state;

[0046] Figure 4 yes Figure 1 A partial structural diagram of the rotating shaft mechanism of the electronic device shown;

[0047] Figure 5 yes Figure 4 An exploded view of part of the rotating shaft mechanism shown;

[0048] Figure 6a yes Figure 4 A schematic diagram of the structure of the middle beam of the rotating shaft mechanism at one angle;

[0049] Figure 6b yes Figure 4 A schematic diagram of the structure of the middle beam of the rotating shaft mechanism at another angle;

[0050] Figure 7 yes Figure 6a The exploded view of the central beam is shown;

[0051] Figure 8 yes Figure 4 A partial structural diagram of the first and second rotating components of the rotating shaft mechanism shown.

[0052] Figure 9 yes Figure 4 A schematic diagram of the support plate assembly of the rotating shaft mechanism shown;

[0053] Figure 10 It is along Figure 4 A schematic diagram of the cross-section obtained by cutting along section line AA;

[0054] Figure 11 yes Figure 4 A schematic diagram of a partial structure of the synchronization component of the rotating shaft mechanism shown;

[0055] Figure 12 yes Figure 4 A schematic diagram of a partial structure of the synchronization component of the first embodiment of the rotating shaft mechanism shown;

[0056] Figure 13 yes Figure 12 A schematic diagram of a partial structure of the synchronization component is shown;

[0057] Figure 14a yes Figure 13 The diagram shows a schematic representation of the synchronization component from one angle.

[0058] Figure 14b yes Figure 13 The diagram shows another structural view of the synchronization component.

[0059] Figure 13 is Figure 14a a schematic diagram of a first kind of change trend of the addendum thickness of the first embodiment of the synchronous gear shown in FIG. 1;

[0060] Figure 14b is Figure 15a a schematic diagram of a second kind of change trend of the addendum thickness of the first embodiment of the synchronous gear shown in FIG. 1;

[0061] Figure 4 is Figure 15b a schematic diagram of a third kind of change trend of the addendum thickness of the first embodiment of the synchronous gear shown in FIG. 1;

[0062] Figure 4 is Figure 15c a schematic diagram of a fourth kind of change trend of the addendum thickness of the first embodiment of the synchronous gear shown in FIG. 1;

[0063] Figure 4 is Figure 15d a schematic diagram of a structure of an angle of the first gear of the synchronous gear shown in FIG. 1;

[0064] Figure 4 is Figure 16 a schematic diagram of a structure of an angle of the second gear of the synchronous gear shown in FIG. 1;

[0065] Figure 12 is Figure 17 a schematic diagram of a structure of an angle of the first and second limiters of the synchronous assembly shown in FIG. 1;

[0066] Figure 12 is Figure 18 a schematic diagram of a partial structure of the synchronous assembly of the second embodiment of the rotating shaft mechanism shown in FIG. 1;

[0067] Figure 12 is Figure 19 a schematic diagram of a structure of an angle of the synchronous assembly shown in FIG. 1;

[0068] Figure 4 is Figure 20a a schematic diagram of a structure of another angle of the synchronous assembly shown in FIG. 1;

[0069] Figure 19 is Figure 20b a schematic diagram of a structure of an angle of the first gear of the synchronous gear shown in FIG. 1;

[0070] Figure 19 is Figure 21 a schematic diagram of a structure of an angle of the second gear of the synchronous gear shown in FIG. 1;

[0071] Figure 19 is Figure 22Schematic diagram of the first kind of tooth thickness variation trend of the second embodiment of the synchronization gear shown in the figure;

[0072] Figure 19 is Figure 23a Schematic diagram of the second kind of tooth thickness variation trend of the second embodiment of the synchronization gear shown in the figure;

[0073] Figure 19 is Figure 23b Schematic diagram of the third kind of tooth thickness variation trend of the second embodiment of the synchronization gear shown in the figure;

[0074] Figure 19 is Figure 23c Schematic diagram of the fourth kind of tooth thickness variation trend of the second embodiment of the synchronization gear shown in the figure. DETAILED DESCRIPTION

[0075] For the convenience of understanding, first, the terms involved in the embodiments of the present application are explained.

[0076] And / or: It is only a description of the association relationship of the associated object, indicating that there can be three relationships, for example, A and / or B, which can represent the existence of A alone, the existence of A and B, and the existence of B alone.

[0077] Multiple: refers to two or more than two.

[0078] Connection: should be understood in a broad sense, for example, A is connected with B, which can be that A is directly connected with B, or A is indirectly connected with B through an intermediate medium.

[0079] The specific embodiments of the present application will be described clearly in combination with the drawings.

[0080] The embodiments of the present application provide an electronic device. Wherein, the electronic device can be any device with foldable performance, which can realize unfolding and closing under the operation of the user. The electronic device includes but is not limited to mobile phones, notebook computers, tablet computers, laptop computers, game consoles, personal digital assistants, wearable devices or vehicle-mounted devices, etc.

[0081] It can be understood that when the electronic device is a mobile phone with foldable performance, the mobile phone can include an inner folding mobile phone and an outer folding mobile phone. Among them, due to the folding of the flexible screen of the outer folding mobile phone, the outer folding amplitude is smaller than the inner folding amplitude, so the damage to the flexible screen is relatively weak, and there is almost no folding mark at the folding place after the mobile phone is unfolded, making the entire screen very smooth, thereby greatly improving the quality of the mobile phone, and also increasing the service life of the mobile phone screen.

[0082] Hereinafter, the electronic device will be described by taking an outer folding mobile phone as an example. Of course, in other embodiments, the electronic device can also include, but is not limited to, an inner folding mobile phone, a tablet computer, a game console, an electronic reader, a wearable device, etc., and no strict limitation is made thereto.

[0083] Please refer to Figure 19 , Figure 23d and Figure 19 , Figure 1 is a structural schematic diagram of the electronic device 200 in a folded state provided by an embodiment of the present application, Figure 2 is a structural schematic diagram of the electronic device 200 in an intermediate state provided by an embodiment of the present application, Figure 3 is a structural schematic diagram of the electronic device 200 in an unfolded state provided by an embodiment of the present application.

[0084] Hereinafter, for the convenience of description, the length direction of the electronic device 200 is defined as the X direction, the width direction of the electronic device 200 is defined as the Y direction, and the thickness direction of the electronic device 200 is defined as the Z direction. The X direction, the Y direction and the Z direction are perpendicular to each other in pairs.

[0085] The electronic device 200 can include a flexible display screen 210, a first housing 220, a second housing 230 and a hinge mechanism 100. The hinge mechanism 100 is connected between the first housing 220 and the second housing 230 to realize the rotational connection between the first housing 220 and the second housing 230. The first housing 220 and the second housing 230 can be relatively rotated through the hinge mechanism 100, so that the electronic device 200 is switched between the folded state, the intermediate state and the unfolded state, to meet the use requirements of the user in different scenarios. The first housing 220 and the second housing 230 are also provided with a containing space (not shown in the figure), which is used to contain electronic components such as processors, circuit boards, camera modules and structural components of the electronic device 200. The flexible display screen 210 is connected to the first housing 220, the second housing 230 and the hinge mechanism 100. The flexible display screen 210 can be unfolded or folded through the driving of the first housing 220, the second housing 230 and the hinge mechanism 100.

[0086] Among them, the flexible display screen 210 is an outer folding screen, that is, when the electronic device 200 is in a folded state, the flexible display screen 210 can constitute the appearance display surface of the electronic device 200. The flexible display screen 210 can be a flexible screen that can be folded as a whole, or the flexible display screen 210 can also be a combination of a flexible screen that can be folded in the middle region and a rigid screen at both ends, and no strict limitation is made thereto. Of course, in other embodiments, the flexible display screen 210 can also be an inner folding screen, that is, when the electronic device 200 is in a folded state, the flexible display screen 210 is clamped between the first housing 220 and the second housing 230.

[0087] Exemplarily, the flexible display screen 210 can be an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, a mini organic light-emitting diode display screen, a micro organic light-emitting diode display screen, a micro organic light-emitting diode display screen, or a quantum dot light emitting diodes (QLED) display screen.

[0088] Specifically, the flexible display screen 210 can include a first portion 2110, a second portion 2120, and a foldable portion 2130. The foldable portion 2130 of the flexible display screen 210 is connected between the first portion 2110 of the flexible display screen 210 and the second portion 2120 of the flexible display screen 210, and can be bent to adapt to the unfolding and folding of the electronic device 200. The first portion 2110 of the flexible display screen 210 is connected to the first housing 220, the second portion 2120 of the flexible display screen 210 is connected to the second housing 230, and the foldable portion 2130 of the flexible display screen 210 is arranged opposite to the hinge mechanism 100 in the Z direction.

[0089] In some embodiments, the electronic device 200 can be a foldable electronic device 200 that can be folded once. In other embodiments, the electronic device 200 can be a foldable electronic device 200 that can be folded multiple times (more than twice). In this case, the electronic device 200 can include multiple portions, and adjacent two portions can be relatively close to be folded to the electronic device 200 in a folded state, and adjacent two portions can be relatively far away to be unfolded to the electronic device 200 in an unfolded state.

[0090] Hereinafter, the first housing 220 and the second housing 230 are arranged left and right, so that the electronic device 200 can be folded left and right. However, it should be understood that in other embodiments, the first housing 220 and the second housing 230 can also be arranged up and down, so that the electronic device 200 can be folded up and down.

[0091] As shown in FIG. 2, the electronic device 200 can include a flexible display screen 210, a first housing 220, a second housing 230, a hinge mechanism 100, and a processor 300. Figure 1As shown, the relative rotation of the first housing 220 and the second housing 230 causes the electronic device 200 to be in a folded state. This means that the first housing 220 and the second housing 230 rotate through the pivot mechanism 100 and move closer to each other until they are in contact. When the electronic device 200 is in the folded state, the first housing 220 and the second housing 230 can be in partial or complete contact. At this time, the flexible display screen 210 is located on the outside of the electronic device 200, and the foldable portion 2130 of the flexible display screen 210 is bent. The first portion 2110 and the second portion 2120 of the flexible display screen 210 are positioned opposite each other. The electronic device 200 not only has a smaller size, making it easier for users to store and carry, but it can also display information and allow users to operate the device using half of the flexible display screen 210.

[0092] like Figure 2 As shown, the relative rotation of the first housing 220 and the second housing 230 to bring the electronic device 200 to an intermediate state means that the first housing 220 and the second housing 230 rotate through the pivot mechanism 100 and move away from each other, causing the included angle between the first housing 220 and the second housing 230 to increase; or, the first housing 220 and the second housing 230 rotate through the pivot mechanism 100 and move closer to each other, causing the included angle between the first housing 220 and the second housing 230 to decrease. At this time, the foldable portion 2130 of the flexible display screen 210 still bends, but the bending amplitude of the foldable portion 2130 in the intermediate state is less than the bending amplitude of the foldable portion 2130 in the folded state.

[0093] like Figure 3 As shown, the relative rotation of the first housing 220 and the second housing 230 causes the electronic device 200 to be in an unfolded state. This means that the first housing 220 and the second housing 230 rotate through the pivot mechanism 100 and move away from each other, with the included angle between the first housing 220 and the second housing 230 continuing to increase, approaching or equaling 180 degrees (within the allowable tolerance range). At this time, the foldable portion 2130 of the flexible display screen 210 is flattened, and the first portion 2110 and the second portion 2120 of the flexible display screen 210 are unfolded relative to each other. The electronic device 200 can achieve large-screen display, providing users with richer information and a better user experience.

[0094] Specifically, when the electronic device 200 is in a folded state, the hinge mechanism 100 is also in a folded state. When the electronic device 200 is in an intermediate state, the hinge mechanism 100 is also in an intermediate state. When the electronic device 200 is in an unfolded state, the hinge mechanism 100 is also in an unfolded state.

[0095] Please refer to Figure 1 and Figure 2 , Figure 3 is Figure 4 a partial structure diagram of the rotation shaft mechanism 100 of the electronic device 200 shown in FIG. 1, Figure 5 is Figure 4 an exploded diagram of the partial structure of the rotation shaft mechanism 100 shown in FIG. 2.

[0096] The rotation shaft mechanism 100 can extend along the Y direction from one end of the electronic device 200 to the other end of the electronic device 200, but for the convenience of understanding, only a part of the structure of the rotation shaft mechanism 100 extending along the Y direction is shown in the following and the accompanying drawings, but it should be understood that it is not limited thereto. In addition, the following is described by taking the outer folding of the rotation shaft mechanism 100 as an example, but the improvements made to the rotation shaft mechanism 100 in the following can also be applied to the rotation shaft mechanism 100 capable of realizing inner folding without conflict.

[0097] The rotation shaft mechanism 100 can include a middle beam 10, a first rotating assembly 20, a second rotating assembly 30, a synchronous assembly 40, and a support plate assembly 50. The first rotating assembly 20 and the second rotating assembly 30 are respectively located on both sides of the width direction (i.e., the X direction) of the middle beam 10. The first rotating assembly 20 is rotationally connected with the middle beam 10, and one end of the first rotating assembly 20 away from the middle beam 10 is fixedly connected with a first housing 220. The second rotating assembly 30 is rotationally connected with the middle beam 10, and one end of the second rotating assembly 30 away from the middle beam 10 is fixedly connected with a second housing 230. The synchronous assembly 40 is installed on the middle beam 10 and connected between the first rotating assembly 20 and the second rotating assembly 30, and can realize synchronous rotation of the first rotating assembly 20 and the second rotating assembly 30, so that the first housing 220 and the second housing 230 can realize synchronous rotation. The support plate assembly 50 can include a first support plate 51 and a second support plate 52. The first support plate 51 and the second support plate 52 are respectively located on both sides of the width direction of the middle beam 10. The first support plate 51 is connected between the middle beam 10 and the first rotating assembly 20 and can rotate relative to the middle beam 10. The second support plate 52 is connected between the middle beam 10 and the second rotating assembly 30 and can rotate relative to the middle beam 10. The first support plate 51 and the second support plate 52 can support the flexible display 210 in the folded state, the intermediate state, and the unfolded state of the rotation shaft mechanism 100.

[0098] The rotation direction of the first rotation assembly 20 and the rotation direction of the second rotation assembly 30 are opposite, and the middle beam 10 can maintain a static state during the relative folding and relative unfolding of the first shell 220 and the second shell 230. In other words, during the relative folding and relative unfolding of the first shell 220 and the second shell 230, the position of the middle beam 10 can remain unchanged, that is, the middle beam 10 is relatively static, and the first shell 220 and the second shell 230 can both rotate relative to the middle beam 10. When the first shell 220 rotates relative to the middle beam 10, it can drive the first rotation assembly 20 to rotate relative to the middle beam 10, so that the first rotation assembly 20 drives the second rotation assembly 30 to also rotate relative to the middle beam 10 through the synchronous assembly 40, thereby realizing synchronous rotation of the first rotation assembly 20 and the second rotation assembly 30, that is, synchronous rotation of the first shell 220 and the second shell 230. When the second shell 230 rotates relative to the middle beam 10, it can drive the second rotation assembly 30 to rotate relative to the middle beam 10, so that the second rotation assembly 30 drives the first rotation assembly 20 to also rotate relative to the middle beam 10 through the synchronous assembly 40, thereby realizing synchronous rotation of the second rotation assembly 30 and the first rotation assembly 20, that is, synchronous rotation of the second shell 230 and the first shell 220. At the same time, during the rotation of the first rotation assembly 20 and the second rotation assembly 30 relative to the middle beam 10, the first support plate 51 and the second support plate 52 can also be driven to rotate relative to the middle beam 10, so that the first rotation assembly 20, the first support plate 51, the second rotation assembly 30, the second support plate 52 and the middle beam 10 can cooperate to support the flexible display screen 210 in the folded state, the intermediate state and the unfolded state of the hinge mechanism 100.

[0099] Please refer to Figure 1 and Figure 5 , Figure 4 is Figure 6a the structural diagram of an angle of the middle beam 10 of the hinge mechanism 100 shown in FIG. 1, Figure 6b is Figure 6a the structural diagram of another angle of the middle beam 10 of the hinge mechanism 100 shown in FIG. 1.

[0100] The middle beam 10 can extend in the Y direction and extend from one end of the hinge mechanism 100 to the other end of the hinge mechanism 100 in the Y direction. The middle beam 10 is the most important load-bearing component in the hinge mechanism 100, which can form a kinematic pair connection with the first main swing arm of the first rotation assembly 20 and the second main swing arm of the second rotation assembly 30, and can also provide a certain load-bearing space for the synchronous assembly 40 that realizes the synchronous movement of the first shell 220 and the second shell 230, and the damping mechanism that realizes a good damping feel of the electronic device 200.

[0101] The middle beam 10 can be a one-piece structure. For example, the middle beam 10 can be formed by one-piece molding. It can be understood that the one-piece structure of the middle beam 10 has fewer parts, which is conducive to simplifying the manufacturing process of the middle beam 10 and improving the production and assembly efficiency of the middle beam 10.

[0102] Alternatively, the middle beam 10 can also be a split structure. It can be understood that when the middle beam 10 is a split structure, the middle beam 10 can be split into multiple structures in the Z direction, and the same structure can also be split into multiple structures in the Y direction, so as to simplify the middle beam 10 by layer-by-layer splitting, avoid the problem of reduced strength caused by the overlong extension length of the same structure, and facilitate positioning and assembly.

[0103] Hereinafter, the middle beam 10 will be taken as an example of a split structure, but it should be understood that this is not limiting. In addition, the related description of the split structure of the middle beam 10 hereinafter can be applied to the one-piece structure of the middle beam 10 without conflict.

[0104] Please continue to refer to Figure 4 and Figure 6b The middle beam 10 can have a first rotating groove 11 and a second rotating groove 12. The first rotating groove 11 of the middle beam 10 can be used to mount the first main swing arm of the first rotating assembly 20 and provide a movement space for the rotating action of the first main swing arm relative to the middle beam 10. The second rotating groove 12 of the middle beam 10 can be used to mount the second main swing arm of the second rotating assembly 30 and provide a movement space for the rotating action of the second main swing arm relative to the middle beam 10.

[0105] The first rotating groove 11 of the middle beam 10 and the second rotating groove 12 of the middle beam 10 can be oppositely arranged in the X direction and oppositely arranged or staggered arranged in the Y direction. Among them, the first rotating groove 11 of the middle beam 10 and the second rotating groove 12 of the middle beam 10 are staggered arranged in the Y direction, which means that the first rotating groove 11 of the middle beam 10 and the second rotating groove 12 of the middle beam 10 can be completely staggered arranged in the Y direction, or partially staggered arranged in the Y direction with a certain overlapping part. When the first rotating groove 11 and the second rotating groove 12 are partially staggered arranged in the Y direction, not only can the structures of the first rotating groove 11 and the second rotating groove 12 be independent of each other and not interfere with each other, but also can minimize the size of the middle beam 10 in the X direction, which is conducive to realizing the miniaturization and thinning of the electronic device 200.

[0106] The opening of the first rotating groove 11 of the center beam 10 is located on one side of the center beam 10 along the X direction, for the first main swing arm of the first rotating assembly 20 to extend into the groove. The opening of the second rotating groove 12 of the center beam 10 is located on the other side of the center beam 10 along the X direction, for the second main swing arm of the second rotating assembly 30 to extend into the groove. The extending direction of the first rotating groove 11 of the center beam 10 is opposite to the extending direction of the second rotating groove 12 of the center beam 10. Exemplarily, both the first rotating groove 11 and the second rotating groove 12 can be arc-shaped grooves.

[0107] One first rotating slot 11 can be used to install a first main swing arm of the first rotating assembly 20. One second rotating slot 12 can be used to install a second main swing arm of the second rotating assembly 30. One first rotating slot 11 and one second rotating slot 12 can form a set of rotating slot structures. Depending on the actual application requirements of the rotating shaft mechanism 100, one or more sets of rotating slot structures can be provided on the middle beam 10, and the location of these sets can be selected according to actual application needs without strict limitations.

[0108] Furthermore, the first rotating groove 11 and the second rotating groove 12 of the center beam 10 can be either an integral structure located on the center beam 10 or an assembled structure formed by splicing multiple components in the center beam 10. The following explanation will take the example of the first rotating groove 11 and the second rotating groove 12 of the center beam 10 being an assembled structure formed by splicing multiple components in the center beam 10, but it should be understood that this is not a limitation.

[0109] Please refer to the following: Figure 4 , Figure 6a and Figure 6b , Figure 6a yes Figure 6b The diagram shows an exploded view of the center beam 10. The center beam 10 may include a center beam seat 13 and a center beam cover plate 14.

[0110] The center beam base 13 can extend along the Y direction, from one end of the rotating shaft mechanism 100 to the other end of the rotating shaft mechanism 100 in the Y direction. The center beam base 13 can include a top and a bottom, with the bottom and top of the center beam base 13 arranged opposite each other in the Z direction. The top of the center beam base 13 faces away from the flexible display screen 210, and the bottom of the center beam base 13 faces the flexible display screen 210. The center beam base 13 can be a one-piece structure or an assembled structure. The center beam base 13 can be used to provide a mounting base for the first rotating assembly 20 and the second rotating assembly 30.

[0111] When the middle beam seat 13 is a one-piece structure, the middle beam seat 13 can be a separate structural member that extends from one end of the rotation shaft mechanism 100 to the other end of the rotation shaft mechanism 100 in the Y direction. Exemplarily, the middle beam seat 13 can be formed as a one-piece structure by integral molding.

[0112] It can be understood that the one-piece structure of the middle beam seat 13 has fewer parts, which is beneficial to simplify the manufacturing process of the middle beam seat 13 and improve the production and assembly efficiency of the middle beam seat 13.

[0113] When the middle beam seat 13 is an assembled structure, the middle beam seat 13 can include a plurality of sub-seats. The plurality of sub-seats can be arranged in the Y direction. Each sub-seat extends in the Y direction and has an extension length less than the total extension length of the middle beam seat 13. The plurality of sub-seats can be connected end to end to form the middle beam seat 13 extending from one end of the rotation shaft mechanism 100 to the other end of the rotation shaft mechanism 100.

[0114] It can be understood that, on the one hand, the long middle beam seat 13 is divided into a plurality of sub-seats with shorter lengths, which can effectively avoid the problem of failure due to breakage, fracture, etc. of the middle beam seat 13 in various states such as processing, handling and assembly due to the excessively long extension length, and has high reliability. On the other hand, the long middle beam seat 13 is divided into a plurality of sub-seats with shorter lengths, so that when the middle beam seat 13 is damaged, only the sub-seat at the damaged position needs to be replaced without replacing the entire middle beam seat 13, which is beneficial to avoid material waste and effectively reduce the maintenance cost of the middle beam seat 13.

[0115] The middle beam cover plate 14 is connected to the top of the middle beam seat 13 and extends in the Y direction. The middle beam cover plate 14 can be spliced with the middle beam seat 13 to form the first rotation groove 11 of the middle beam 10 and the second rotation groove 12 of the middle beam 10. The middle beam cover plate 14 can shield part of the structural member arranged in the middle beam 10 to achieve a good appearance effect of the electronic device 200. The number of the middle beam cover plate 14 can be one or more. When the number of the middle beam cover plate 14 is more than one, the plurality of middle beam cover plates 14 can be arranged at intervals in the Y direction.

[0116] Please continue to refer to Figure 7 and Figure 7 The middle beam 10 can also have a first mounting groove 15, a second mounting groove 16, a first shaft hole 17 and a second shaft hole 18. The first mounting groove 15 and the second mounting groove 16 are respectively located on both sides of the width direction (i.e. the Z direction) of the middle beam 10. The first shaft hole 17 and the second shaft hole 18 are respectively located on both sides of the width direction of the middle beam 10.

[0117] The first installation slot 15 can be disposed on the same side of the middle beam 10 as the first rotation slot 11 and spaced apart from the first rotation slot 11 in the Y direction. The first installation slot 15 can be used to install part of the structure of the synchronization assembly 40. Exemplarily, the first installation slot 15 can be located on the middle beam seat 13.

[0118] The number of the first installation slot 15 can be one or more. When the number of the first installation slot 15 is more than one, the plurality of first installation slots 15 can be spaced apart in the length direction (i.e., the Y direction) of the middle beam 10, and each first installation slot 15 can be used to install part of the structure of one synchronization assembly 40.

[0119] The second installation slot 16 can be disposed on the same side of the middle beam 10 as the second rotation slot 12 and spaced apart from the second rotation slot 12 in the Y direction. The second installation slot 16 can be used to install part of the structure of the synchronization assembly 40. Exemplarily, the second installation slot 16 can be located on the middle beam seat 13.

[0120] The number of the second installation slot 16 can be one or more. When the number of the second installation slot 16 is more than one, the plurality of second installation slots 16 can be spaced apart in the length direction of the middle beam 10, and each second installation slot 16 can be used to install part of the structure of one synchronization assembly 40.

[0121] The first shaft hole 17 can be disposed on the same side of the middle beam 10 as the first rotation slot 11 and the first installation slot 15 and spaced apart from the first rotation slot 11 and the first installation slot 15. The extension direction of the first shaft hole 17 can be the same as the length direction (i.e., the Y direction) of the middle beam 10 and can penetrate the middle beam 10 in the length direction of the middle beam 10. The first shaft hole 17 can be used to install the first shaft body 512 of the first support plate 51.

[0122] The number of the first shaft hole 17 can be one or more. When the number of the first shaft hole 17 is more than one, the plurality of first shaft holes 17 can be spaced apart in the length direction of the middle beam 10, and each first shaft hole 17 can be used to install one first shaft body 512 of the first support plate 51.

[0123] Exemplarily, the first shaft hole 17 can be located at the bottom of the middle beam seat 13. The number of the first shaft hole 17 can be two, and the two first shaft holes 17 can be spaced apart in the length direction of the middle beam seat 13.

[0124] The second shaft hole 18 can be disposed on the same side of the middle beam 10 as the second rotating groove 12 and the second mounting groove 16, and is spaced apart from the second rotating groove 12 and the second mounting groove 16. The extending direction of the second shaft hole 18 can be the same as the length direction (i.e., the Y direction) of the middle beam 10, and can penetrate through the middle beam 10 along the length direction of the middle beam 10. The second shaft hole 18 can be used to mount a second shaft body 522 of the second support plate 52.

[0125] The number of the second shaft hole 18 can be one or more. When the number of the second shaft hole 18 is more than one, the multiple second shaft holes 18 can be spaced apart in the length direction of the middle beam 10, and each second shaft hole 18 can be used to mount a second shaft body 522 of the second support plate 52.

[0126] Exemplarily, the second shaft hole 18 can be located at the bottom of the middle beam seat 13. The number of the second shaft hole 18 can be two, and the two second shaft holes 18 can be spaced apart in the length direction of the middle beam seat 13.

[0127] Please refer to Figure 6a and Figure 6a , Figure 6b are Figure 4 the partial structure diagram of the first rotating assembly 20 and the second rotating assembly 30 of the rotating shaft mechanism 100 shown in FIG. 1. In Figure 8 , the first main swing arm of the first rotating assembly 20 and the second main swing arm of the second rotating assembly 30 are not shown. The structures of the first rotating assembly 20 and the second rotating assembly 30 can be the same or different.

[0128] The first rotating assembly 20 can include a first main swing arm (not shown in the figure) and a first fixed frame 21. The first fixed frame 21 is located on one side of the middle beam 10 in the width direction (i.e., the X direction) and is fixedly connected with the first shell 220. The first main swing arm is connected between the middle beam 10 and the first fixed frame 21. The second rotating assembly 30 can include a second main swing arm and a second fixed frame 31. The second fixed frame 31 is located on the other side of the middle beam 10 in the width direction and is fixedly connected with the second shell 230. The second main swing arm is connected between the middle beam 10 and the second fixed frame 31.

[0129] When the first shell 220 and the second shell 230 rotate relative to each other, the first shell 220 can drive the first fixed frame 21 to rotate relative to the middle beam 10, and drive the first main swing arm to synchronously rotate relative to the middle beam 10. The second shell 230 can drive the second fixed frame 31 to rotate relative to the middle beam 10, and drive the second main swing arm to synchronously rotate relative to the middle beam 10, thereby realizing the rotation of the rotating shaft mechanism 100, and realizing the unfolding or folding of the rotating shaft mechanism 100.

[0130] It should be noted that the entire rotating shaft mechanism 100 can have a plurality of first main swing arms, a plurality of second main swing arms, a plurality of first fixed frames 21 and a plurality of second fixed frames 31. When the rotating shaft mechanism 100 has a plurality of first main swing arms, a plurality of second main swing arms, a plurality of first fixed frames 21 and a plurality of second fixed frames 31, the plurality of first main swing arms can be arranged at intervals along the Y direction, the plurality of second main swing arms can be arranged at intervals along the Y direction, the plurality of first fixed frames 21 can be arranged at intervals along the Y direction, and the plurality of second fixed frames 31 can be arranged at intervals along the Y direction. In the following, the connection relationship of the rotating shaft mechanism 100 will be described by taking one first fixed frame 21 and one second fixed frame 31 as an example. The description of one first fixed frame 21 and one second fixed frame 31 below can be applied to other first fixed frames 21 and other second fixed frames 31 without conflict.

[0131] Please continue to refer to Figure 8 and Figure 4 The first fixed frame 21 and the second fixed frame 31 are respectively located on both sides of the middle beam 10 along the X direction, and the first fixed frame 21 and the second fixed frame 31 can rotate relative to the middle beam 10 to realize the folded state and the unfolded state of the rotating shaft mechanism 100. Specifically, the rotation directions of the first fixed frame 21 and the second fixed frame 31 are opposite. When the electronic device 200 is in the unfolded state, the rotating shaft mechanism 100 is also in the unfolded state, and the first fixed frame 21 and the second fixed frame 31 can be flattened relative to each other and jointly support the flexible display screen 210, so that the flexible display screen 210 is more flat and is not easy to be damaged by external force touch, which is beneficial to improve the reliability of the flexible display screen 210. When the electronic device 200 is in the folded state, the rotating shaft mechanism 100 is also in the folded state, and the first fixed frame 21 and the second fixed frame 31 can be folded to be parallel to each other, thereby being able to provide more excellent support performance for the flexible display screen 210.

[0132] The first fixed frame 21 can extend along the Y direction and be connected with the first shell 220 to realize linkage with the first shell 220. That is, when the first shell 220 performs a rotating motion, the first fixed frame 21 will be driven to perform a synchronous rotating motion. In this way, the overall electronic device 200 can have better mechanism tensile capacity and mechanism extrusion capacity.

[0133] The first fixed frame 21 is provided with a first sliding groove 211, a third sliding groove 212 and a third shaft hole 213. The first sliding groove 211 can allow the first main swing arm to slide therein. The extension direction of the first sliding groove 211 can be arranged in parallel with the width direction (i.e., the X direction) of the first fixed frame 21. The shape of the first sliding groove 211 can be matched with the shape of the first main swing arm sliding therein, so that the sliding action of the first main swing arm in the first sliding groove 211 can be more smooth and fluent.

[0134] The first sliding groove 211 can be one or more. When the first sliding groove 211 is more than one, the first sliding grooves 211 can be arranged at intervals in the length direction of the first fixed frame 21, and each of the first sliding grooves 211 can be used for sliding movement of a first main swing arm.

[0135] The third sliding groove 212 can be arranged at intervals with the first sliding groove 211 in the length direction of the first fixed frame 21 (i.e. Y direction), and can be used for sliding movement of the first swing arm 41 of the synchronous assembly 40. The extension direction of the third sliding groove 212 can be arranged in parallel with the width direction of the first fixed frame 21 (i.e. X direction). The shape of the third sliding groove 212 can be matched with the shape of the first swing arm 41 of the synchronous assembly 40 sliding therein, so that the sliding movement of the first swing arm 41 of the synchronous assembly 40 in the third sliding groove 212 can be more smooth and fluent.

[0136] The third sliding groove 212 can be one or more. When the third sliding groove 212 is more than one, the third sliding grooves 212 can be arranged at intervals in the length direction of the first fixed frame 21, and each of the third sliding grooves 212 can be used for sliding movement of a first swing arm 41 of the synchronous assembly 40.

[0137] The third shaft hole 213 can be arranged at intervals with the first sliding groove 211 and the third sliding groove 212 in the length direction of the first fixed frame 21. The extension direction of the third shaft hole 213 can be arranged in parallel with the length direction of the first fixed frame 21, and can penetrate the first fixed frame 21 along the length direction of the first fixed frame 21. The third shaft hole 213 can be used for mounting the third shaft body 513 of the first support plate 51.

[0138] The third shaft hole 213 can be one or more. When the third shaft hole 213 is more than one, the third shaft holes 213 can be arranged at intervals in the length direction of the first fixed frame 21, and each of the third shaft holes 213 can be used for mounting a third shaft body 513 of the first support plate 51.

[0139] Exemplarily, the third shaft hole 213 can be located at the side of the first fixed frame 21 facing the middle beam seat 13. The number of the third shaft hole 213 can be two, and the two third shaft holes 213 can be arranged at intervals in the length direction of the first fixed frame 21.

[0140] Please continue to refer to Figure 8The second fixing frame 31 can be mirror-symmetrical to the first fixing frame 21. The second fixing frame 31 can extend along the Y direction and be connected with the second shell 230 to realize linkage with the second shell 230. That is, when the second shell 230 performs a rotating movement, the second fixing frame 31 will be driven to perform a synchronous rotating movement. Thus, the electronic device 200 as a whole can have better mechanism anti-pulling and anti-extrusion capabilities.

[0141] The second fixing frame 31 is provided with a second sliding groove 311, a fourth sliding groove 312 and a fourth shaft hole 313. The second sliding groove 311 can allow the second main swing arm to slide therein. The extending direction of the second sliding groove 311 can be parallel to the width direction (i.e., the X direction) of the second fixing frame 31. The shape of the second sliding groove 311 can be adapted to the shape of the second main swing arm sliding therein, so that the sliding movement of the second main swing arm in the second sliding groove 311 can be more smooth and fluent.

[0142] The number of the second sliding grooves 311 can be one or more. When the number of the second sliding grooves 311 is more than one, the plurality of second sliding grooves 311 can be arranged at intervals in the length direction of the second fixing frame 31, and each second sliding groove 311 can be used for allowing one second main swing arm to slide therein.

[0143] The fourth sliding groove 312 can be arranged at intervals with the second sliding groove 311 in the length direction (i.e., the Y direction) of the second fixing frame 31 and can allow the second swing arm 42 of the synchronous assembly 40 to slide therein. The extending direction of the fourth sliding groove 312 can be parallel to the width direction (i.e., the X direction) of the second fixing frame 31. The shape of the fourth sliding groove 312 can be adapted to the shape of the second swing arm 42 of the synchronous assembly 40 sliding therein, so that the sliding movement of the second swing arm 42 of the synchronous assembly 40 in the fourth sliding groove 312 can be more smooth and fluent.

[0144] The number of the fourth sliding grooves 312 can be one or more. When the number of the fourth sliding grooves 312 is more than one, the plurality of fourth sliding grooves 312 can be arranged at intervals in the length direction of the second fixing frame 31, and each fourth sliding groove 312 can be used for allowing one second swing arm 42 of the synchronous assembly 40 to slide therein.

[0145] The fourth shaft hole 313 can be arranged at intervals with the second sliding groove 311 and the fourth sliding groove 312 in the length direction of the second fixing frame 31. The extending direction of the fourth shaft hole 313 can be parallel to the length direction of the second fixing frame 31 and can penetrate through the second fixing frame 31 along the length direction of the second fixing frame 31. The fourth shaft hole 313 can be used for mounting the fourth shaft body 523 of the second support plate 52.

[0146] The fourth shaft hole 313 can be one or more. When the fourth shaft hole 313 is more than one, the plurality of fourth shaft holes 313 can be arranged at intervals in the length direction of the second fixed frame 31, and each fourth shaft hole 313 can be used to install a fourth shaft body 523 of the second support plate 52.

[0147] Exemplarily, the fourth shaft hole 313 can be located on the side of the second fixed frame 31 facing the middle beam seat 13. The number of fourth shaft holes 313 can be two, and the two fourth shaft holes 313 can be respectively located at the first and last ends of the second fixed frame 31 along the Y direction.

[0148] Based on the above description, when the first shell 220 and the second shell 230 rotate relative to the middle beam 10 and approach each other, the first fixed frame 21 and the second fixed frame 31 also rotate relative to the middle beam 10 and approach each other, thereby realizing the folding of the electronic device 200. When the first shell 220 and the second shell 230 rotate relative to the middle beam 10 and move away from each other, the first fixed frame 21 and the second fixed frame 31 also rotate relative to the middle beam 10 and move away from each other, thereby realizing the unfolding of the electronic device 200.

[0149] The first and second main swing arms are respectively located on both sides of the middle beam 10 in the X direction, and the rotation directions of the first and second main swing arms are opposite. The first and second main swing arms can control the swing posture of the swing shaft mechanism 100, realize the support of the flexible display screen 210, and improve the strength of the entire swing shaft mechanism 100.

[0150] One end of the first main swing arm is rotationally connected with the middle beam 10, and the other end of the first main swing arm is slidingly connected with the first fixed frame 21. When the first shell 220 rotates relative to the middle beam 10, the first shell 220 drives the first fixed frame 21 to rotate relative to the middle beam 10, and the first main swing arm can be driven to rotate relative to the middle beam 10 through the rotation of the first fixed frame 21 relative to the middle beam 10, and slide relative to the first fixed frame 21.

[0151] Specifically, one end of the first main swing arm is installed in the first rotation groove 11 of the middle beam 10, and the one end of the first main swing arm can slide in the first rotation groove 11 of the middle beam 10. It can be understood that through the sliding movement of the one end of the first main swing arm in the first rotation groove 11 of the middle beam 10, the rotational movement of the first main swing arm relative to the middle beam 10 can be realized, that is, the rotational connection of the first main swing arm with the middle beam 10 can be realized. Exemplarily, the shape of the one end of the first main swing arm can be arc-shaped.

[0152] The other end of the first main swing arm is installed on the first sliding groove 211 of the first fixed frame 21, and the other end of the first main swing arm can slide in the first sliding groove 211 of the first fixed frame 21. When the user folds the first shell 220, the first shell 220 drives the first fixed frame 21 to rotate, and the first fixed frame 21 drives the first main swing arm to slide in the first sliding groove 211 through the first sliding groove 211, thereby realizing the linkage of the first fixed frame 21 and the first main swing arm, so that the first main swing arm can rotate relative to the center beam 10. In other words, the first fixed frame 21 can rotate relative to the center beam 10 and drive the first main swing arm to rotate relative to the center beam 10 to form a rotating chain of "first fixed frame 21-first main swing arm-center beam 10", so that the rotating shaft mechanism 100 can smoothly rotate.

[0153] One end of the second main swing arm is rotatably connected with the center beam 10, and the other end of the second main swing arm is slidably connected with the second fixed frame 31. When the second shell 230 rotates relative to the center beam 10, the second shell 230 drives the second fixed frame 31 to rotate relative to the center beam 10, and the second main swing arm can be driven to rotate relative to the center beam 10 through the rotation of the second fixed frame 31 relative to the center beam 10, and slide relative to the second fixed frame 31.

[0154] Specifically, one end of the second main swing arm is installed on the second rotating groove 12 of the center beam 10, and the one end of the second main swing arm can slide in the second rotating groove 12 of the center beam 10. It can be understood that through the sliding movement of the one end of the second main swing arm in the second rotating groove 12 of the center beam 10, the rotating movement of the second main swing arm relative to the center beam 10 can be realized, that is, the rotatable connection between the second main swing arm and the center beam 10 is realized. Exemplarily, the shape of the one end of the second main swing arm can be arc-shaped.

[0155] The other end of the second main swing arm is installed on the second sliding groove 311 of the second fixed frame 31, and the other end of the second main swing arm can slide in the second sliding groove 311 of the second fixed frame 31. When the user folds the second shell 230, the second shell 230 drives the second fixed frame 31 to rotate, and the second fixed frame 31 drives the second main swing arm to slide in the second sliding groove 311 through the second sliding groove 311, thereby realizing the linkage of the second fixed frame 31 and the second main swing arm, so that the second main swing arm can rotate relative to the center beam 10. In other words, the second fixed frame 31 can rotate relative to the center beam 10 and drive the second main swing arm to rotate relative to the center beam 10 to form a rotating chain of "second fixed frame 31-second main swing arm-center beam 10", so that the rotating shaft mechanism 100 can smoothly rotate.

[0156] Please refer to Figure 4 and Figure 8 , Figure 8 is Figure 9 the structural schematic view of the support plate assembly 50 of the rotating shaft mechanism 100 shown inFigure 10 is along Figure 9 is a sectional view taken along the section line A-A shown in the figure.

[0157] The first support plate 51 and the second support plate 52 are respectively located on both sides of the middle beam 10 along the X direction, and the first support plate 51 and the second support plate 52 can rotate relative to the middle beam 10 to realize the folding state and the unfolding state of the rotating shaft mechanism 100. Specifically, the rotating directions of the first support plate 51 and the second support plate 52 are opposite. When the electronic device 200 is in the unfolded state, the rotating shaft mechanism 100 is also in the unfolded state, and the first support plate 51 and the second support plate 52 can be flattened relative to each other and jointly support the flexible display screen 210, so that the flexible display screen 210 is more flat and is not easy to be damaged due to external force touch, which is beneficial to improve the reliability of the flexible display screen 210. When the electronic device 200 is in the folded state, the rotating shaft mechanism 100 is also in the folded state, and the first support plate 51 and the second support plate 52 can be folded together, thereby being able to provide more excellent support performance for the flexible display screen 210.

[0158] The first support plate 51 can extend along the Y direction and extend from one end along the Y direction of the rotating shaft mechanism 100 to the other end along the Y direction. The first support plate 51 can be connected between the middle beam 10 and the first fixed frame 21. The first support plate 51 can be linked with the first fixed frame 21 and can rotate relative to the middle beam 10. That is, when the first fixed frame 21 performs a rotating motion relative to the middle beam 10, the first support plate 51 will be driven to perform a rotating motion relative to the middle beam 10 synchronously. Thus, the electronic device 200 as a whole can have better mechanism tensile capacity and mechanism extrusion capacity.

[0159] The first support plate 51 can include a first body 511, a first shaft body 512 and a third shaft body 513. The first body 511 can extend along the Y direction and extend from one end along the Y direction of the rotating shaft mechanism 100 to the other end along the Y direction. The first body 511 is located between the middle beam 10 and the first fixed frame 21 and can jointly support the flexible display screen 210 with the middle beam 10 and the first fixed frame 21 in the folding state, the intermediate state and the unfolding state of the rotating shaft mechanism 100, so as to provide a larger support area for the flexible display screen 210, which is beneficial to improve the support stability of the flexible display screen 210.

[0160] The first shaft body 512 can be connected to the first body 511 near one side of the middle beam 10, and the extension direction of the first shaft body 512 can be parallel to the length direction (i.e., the Y direction) of the first body 511. The first shaft body 512 can be installed in the first shaft hole 17 of the middle beam 10 to realize the rotational connection between the first support plate 51 and the middle beam 10. The number of the first shaft body 512 can be one or more. When the number of the first shaft body 512 is more than one, the plurality of first shaft bodies 512 can be arranged at intervals in the length direction (i.e., the Y direction) of the first body 511, and each first shaft body 512 is used to connect with one first shaft hole 17 of the middle beam 10. For example, the number of the first shaft body 512 can be two, and the two first shaft bodies 512 are connected to the first body 511 and arranged at intervals in the length direction of the first body 511.

[0161] The third shaft body 513 can be connected to the first body 511 near one side of the first fixed frame 21, and the extension direction of the third shaft body 513 can be parallel to the length direction of the first body 511. The third shaft body 513 can be arranged opposite to the first shaft body 512 in the width direction (i.e., the X direction) of the first body 511. The third shaft body 513 can be installed in the third shaft hole 213 of the first fixed frame 21 to realize the rotational connection between the first support plate 51 and the first fixed frame 21. The number of the third shaft body 513 can be one or more. When the number of the third shaft body 513 is more than one, the plurality of third shaft bodies 513 can be arranged at intervals in the length direction of the first body 511, and each third shaft body 513 is used to connect with one third shaft hole 213 of the first fixed frame 21. For example, the number of the third shaft body 513 can be two, and the two third shaft bodies 513 are connected to the first body 511 and arranged at intervals in the length direction of the first body 511.

[0162] When the user folds the first shell 220, the first shell 220 drives the first fixed frame 21 to rotate, and the first fixed frame 21 drives the first support plate 51 to rotate relative to the middle beam 10. In other words, the first fixed frame 21 can rotate relative to the middle beam 10 and drive the first support plate 51 to rotate relative to the middle beam 10 to form a rotation chain of “first fixed frame 21-first support plate 51-middle beam 10”, so that the rotation shaft mechanism 100 can rotate smoothly.

[0163] The second support plate 52 can be mirror-symmetrical to the first support plate 51. The second support plate 52 can extend along the Y direction and extend from one end along the Y direction of the rotation shaft mechanism 100 to the other end along the Y direction. The second support plate 52 can be connected between the middle beam 10 and the second fixed frame 31. The second support plate 52 can be linked with the second fixed frame 31 and can rotate relative to the middle beam 10. That is, when the second fixed frame 31 performs a rotating motion relative to the middle beam 10, the second support plate 52 will be driven to perform a rotating motion relative to the middle beam 10 synchronously. Thus, the electronic device 200 as a whole can have better mechanism tensile capacity and mechanism extrusion capacity.

[0164] The second support plate 52 can include a second body 521, a second shaft body 522, and a fourth shaft body 523. The second body 521 can extend along the Y direction and extend from one end along the Y direction of the rotation shaft mechanism 100 to the other end along the Y direction. The second body 521 is located between the middle beam 10 and the second fixed frame 31 and can support the flexible display screen 210 together with the middle beam 10 and the second fixed frame 31 in the folded state, the intermediate state, and the unfolded state of the rotation shaft mechanism 100, so as to provide a larger support area for the flexible display screen 210 and improve the support stability of the flexible display screen 210.

[0165] The second shaft body 522 can be connected to the side of the second body 521 close to the middle beam 10, and the extension direction of the second shaft body 522 can be parallel to the length direction (i.e., the Y direction) of the second body 521. The second shaft body 522 can be installed in the second shaft hole 18 of the middle beam 10 to realize the rotating connection between the second support plate 52 and the middle beam 10. The number of the second shaft body 522 can be one or more. When the number of the second shaft body 522 is more than one, the plurality of second shaft bodies 522 can be arranged at intervals in the length direction of the second body 521, and each second shaft body 522 is used to connect with one second shaft hole 18 of the middle beam 10. For example, the number of the second shaft body 522 can be two, and the two second shaft bodies 522 are connected to the second body 521 and arranged at intervals in the length direction of the second body 521.

[0166] The fourth shaft body 523 can be connected to the second body 521 near one side of the second fixing frame 31, and the extending direction of the fourth shaft body 523 can be parallel to the length direction of the second body 521. The fourth shaft body 523 can be arranged opposite to the second shaft body 522 in the width direction (i.e., the X direction) of the second body 521. The fourth shaft body 523 can be installed in the fourth shaft hole 313 of the second fixing frame 31 to realize the rotational connection between the second support plate 52 and the second fixing frame 31. The number of the fourth shaft body 523 can be one or more. When the number of the fourth shaft body 523 is more than one, the plurality of fourth shaft bodies 523 can be arranged at intervals in the length direction of the second body 521, and each fourth shaft body 523 is used to connect with one fourth shaft hole 313 of the second fixing frame 31. For example, the number of the fourth shaft body 523 can be two, and the two fourth shaft bodies 523 are connected to the first and last ends of the second body 521 along the Y direction.

[0167] When the user folds the second shell 230, the second shell 230 drives the second fixing frame 31 to rotate, and the second fixing frame 31 drives the second support plate 52 to rotate in linkage, so that the second support plate 52 can rotate relative to the middle beam 10. In other words, the second fixing frame 31 can rotate relative to the middle beam 10 and drive the second support plate 52 to rotate relative to the middle beam 10 to form a rotation chain of “second fixing frame 31-second support plate 52-middle beam 10”, so that the rotation shaft mechanism 100 can smoothly rotate.

[0168] Please refer to Figure 4 , Figure 10 is Figure 4 a partial structure diagram of the synchronization assembly 40 of the rotation shaft mechanism 100 shown in FIG. 4.

[0169] The synchronization assembly 40 can include a first swing arm 41, a second swing arm 42, and a synchronization gear 43. The first swing arm 41 and the second swing arm 42 are respectively located on both sides of the width direction of the middle beam 10 and are respectively connected to both sides of the width direction of the synchronization gear 43. When the first swing arm 41 rotates, it drives the synchronization gear 43 to rotate, and the synchronization gear 43 drives the second swing arm 42 to rotate, thereby realizing the synchronous rotation of the first swing arm 41 and the second swing arm 42.

[0170] The first swing arm 41 can include a first swing arm body 411, a first rotating part 412, and a first sliding part 413. The first rotating part 412 is connected to one end of the first swing arm body 411 and can be connected to one side of the synchronization gear 43 to realize the fixed connection between the first swing arm 41 and the synchronization gear 43, so that the first swing arm 41 and the synchronization gear 43 can realize synchronous movement. The connection between the first rotating part 412 and the synchronization gear 43 can be, for example, a screw connection, a bolt connection, or a rivet connection. Figure 11The first rotating part 412 is directly connected with the synchronous gear 43, or the first rotating part 412 is indirectly connected with the synchronous gear 43 through a rotating shaft arranged in the synchronous gear 43. The first sliding part 413 is connected with the other end of the first swing arm body 411. The first sliding part 413 can also be mounted to the third sliding groove 212 of the first fixed frame 21, and the first sliding part 413 can slide in the third sliding groove 212 of the first fixed frame 21. Specifically, the first sliding part 413 can include two first sliding blocks 414, which are respectively located on the two sides of the first swing arm body 411 in the width direction and are oppositely arranged along the Y direction. The two first sliding blocks 414 are respectively mounted to the two sides of the third sliding groove 212 of the first fixed frame 21 along the Y direction.

[0171] The second swing arm 42 can be mirror-symmetrical with the first swing arm 41. The second swing arm 42 can include a second swing arm body 421, a second rotating part 422, and a second sliding part 423. The second rotating part 422 is connected with one end of the second swing arm body 421 and can be connected with the other side of the synchronous gear 43 to realize the fixed connection between the second swing arm 42 and the synchronous gear 43, so that the second swing arm 42 and the synchronous gear 43 can realize synchronous movement. The connection between the second rotating part 422 and the synchronous gear 43 can be direct connection or indirect connection through a rotating shaft arranged in the synchronous gear 43. Figure 11 The second rotating part 422 is directly connected with the synchronous gear 43, or the second rotating part 422 is indirectly connected with the synchronous gear 43 through a rotating shaft arranged in the synchronous gear 43. The second sliding part 423 is connected with the other end of the second swing arm body 421. The second sliding part 423 can also be mounted to the fourth sliding groove 312 of the second fixed frame 31, and the second sliding part 423 can slide in the fourth sliding groove 312 of the second fixed frame 31. Specifically, the second sliding part 423 can include two second sliding blocks 424, which are respectively located on the two sides of the second swing arm body 421 in the width direction and are oppositely arranged along the Y direction. The two second sliding blocks 424 are respectively mounted to the two sides of the fourth sliding groove 312 of the second fixed frame 31 along the Y direction.

[0172] In the following, the synchronous gear 43 in the synchronous assembly 40 and other structures in the synchronous assembly 40 will be described in detail through two different embodiments.

[0173] First embodiment:

[0174] Please refer to Figure 4 , Figure 11 is Figure 11 a part structure schematic diagram of the synchronous assembly 40 of the first embodiment of the rotating shaft mechanism 100. In Figure 12 , for the convenience of understanding, the first swing arm 41 and the second swing arm 42 of the synchronous assembly 40 are not shown.

[0175] The synchronous assembly 40 can further include a first rotating shaft 44 and a second rotating shaft 45. The first rotating shaft 44 and the second rotating shaft 45 are both mounted to the middle beam 10 and are oppositely and spacedly arranged along the width direction (i.e. the X direction) of the middle beam 10. Specifically, the first rotating shaft 44 can be mounted to the first mounting slot 15 of the middle beam 10 and extend along the Y direction and be rotatable relative to the middle beam 10. The second rotating shaft 45 can be mounted to the second mounting slot 16 of the middle beam 10 and extend along the Y direction and be rotatable relative to the middle beam 10. The first rotating shaft 44 and the second rotating shaft 45 can be arranged through the synchronous gear 43 and form a gear shaft structure with the synchronous gear 43, so that the first rotating shaft 44, the second rotating shaft 45 and the synchronous gear 43 synchronously rotate.

[0176] Please refer to Figure 12 , Figure 4 and Figure 12 , Figure 13 are a partial structural schematic view of the synchronous assembly 40 shown in Figure 14a , Figure 14b is an angle structural schematic view of the synchronous assembly 40 shown in Figure 13 , Figure 12 is another angle structural schematic view of the synchronous assembly 40 shown in Figure 14a .

[0177] The synchronous gear 43 can include a first gear 46 and a second gear 47. The first gear 46 can be sleeved on the outer periphery of the first rotating shaft 44 and fixedly connected with the first rotating shaft 44 and coaxially arranged with the first rotating shaft 44. Wherein, the coaxial arrangement of the first gear 46 with the first rotating shaft 44 means that the rotation center line of the first gear 46 coincides with the rotation center line of the first rotating shaft 44. The second gear 47 can be sleeved on the outer periphery of the second rotating shaft 45 and fixedly connected with the second rotating shaft 45 and coaxially arranged with the second rotating shaft 45. Wherein, the coaxial arrangement of the second gear 47 with the second rotating shaft 45 means that the rotation center line of the second gear 47 coincides with the rotation center line of the second rotating shaft 45. When the first rotating shaft 44 sleeved with the first gear 46 and the second rotating shaft 45 sleeved with the second gear 47 are mounted to the middle beam 10, the first gear 46 and the second gear 47 can also be mounted to the middle beam 10 and sequentially arranged in the width direction (i.e. the X direction) of the middle beam 10 and meshed with each other.

[0178] It can be understood that when the first rotating shaft 44 rotates relative to the middle beam 10, the first gear 46 will rotate together. Because of the meshing relationship between the first gear 46 and the second gear 47, the rotation of the first gear 46 will drive the second gear 47 to rotate, and the second gear 47 will drive the second rotating shaft 45 to rotate relative to the base, thereby realizing the synchronous rotation of the first gear 46 and the second gear 47, and the synchronous rotation of the first rotating shaft 44 and the second rotating shaft 45.

[0179] The first gear 46 is also fixedly connected with the first swing arm 41 to link with the first swing arm 41. The second gear 47 is also fixedly connected with the second swing arm 42 to link with the second swing arm 42. Thus, due to the meshing relationship between the first gear 46 and the second gear 47, when one rotates, the other can also rotate synchronously, thereby realizing the opening and closing of the first swing arm 41 and the second swing arm 42, that is, the unfolding and folding of the rotating shaft mechanism 100, and the unfolding and folding of the electronic device 200.

[0180] Please continue to refer to Figure 13 , Figure 14b and Figure 13 , the first gear 46 can include a first gear body 461 and a plurality of first teeth 462. The first gear body 461 can be annular. The inner edge of the first gear body 461 is connected to the outer periphery of the first rotating shaft 44, and the outer edge of the first gear body 461 is connected with the plurality of first teeth 462. The plurality of first teeth 462 can be arranged at intervals along the circumferential direction of the first gear body 461, wherein the circumferential direction of the first gear body 461 is the direction of one turn around the center line of rotation of the first gear 46. That is, the plurality of first teeth 462 can be arranged at intervals along the circumferential direction of the first gear 46, wherein the circumferential direction of the first gear 46 is the direction of one turn around the center line of rotation of the first gear 46. Between two adjacent first teeth 462, a first tooth groove W1 can be formed, and the plurality of first teeth 462 can form a plurality of first tooth grooves W1. Each first tooth groove W1 can be used to accommodate a second tooth 472 of the second gear 47.

[0181] The tooth root of the first tooth 462 can be connected with the first gear body 461, and the tooth top of the first tooth 462 can be away from the first gear body 461. The extension direction of the first tooth 462 can be arranged in parallel with the axial direction of the first gear 46, wherein the axial direction of the first gear 46 is the direction in which the rotation center line of the first gear 46 is located. The first tooth 462 can include a first end 4621 and a second end 4622, which can be oppositely arranged in the tooth width direction (i.e., the Y direction) of the first tooth 462. The tooth width of the first tooth 462 refers to the length of the first tooth 462 in the axial direction of the first gear 46, and the tooth width direction of the first tooth 462 refers to the axial direction of the first gear 46, i.e., the thickness direction of the first tooth 462, that is, the direction from one end face of the first tooth 462 to the other end face of the first tooth 462.

[0182] The second gear 47 can include a second gear body 471 and a plurality of second teeth 472. The second gear body 471 can be annular. The inner edge of the second gear body 471 is connected to the outer periphery of the second rotating shaft 45, and the outer edge of the second gear body 471 is connected with the plurality of second teeth 472. The plurality of second teeth 472 can be arranged in the circumferential direction of the second gear body 471, wherein the circumferential direction of the second gear body 471 is the direction of one round of the rotation center line of the second gear body 471. That is, the plurality of second teeth 472 can be arranged in the circumferential direction of the second gear 47, wherein the circumferential direction of the second gear 47 is the direction of one round of the rotation center line of the second gear 47. The plurality of second teeth 472 can be used to engage with the plurality of first teeth 462. Between two adjacent second teeth 472, a second tooth groove W2 can be formed, and the plurality of second teeth 472 can form a plurality of second tooth grooves W2. Each second tooth groove W2 can be used to accommodate one first tooth 462 of the first gear 46.

[0183] The tooth root of the second tooth 472 can be connected with the second gear body 471, and the tooth top of the second tooth 472 can be away from the second gear body 471. The extension direction of the second tooth 472 can be arranged in parallel with the axial direction of the second gear 47, wherein the axial direction of the second gear 47 is the direction in which the rotation center line of the second gear 47 is located. The second tooth 472 can include a third end 4721 and a fourth end 4722, which can be oppositely arranged in the tooth width direction (i.e., the Y direction) of the second tooth 472. The tooth width of the second tooth 472 refers to the length of the second tooth 472 in the axial direction of the second gear 47, and the tooth width direction of the second tooth 472 refers to the axial direction of the second gear 47, i.e., the thickness direction of the second tooth 472, that is, the direction from one end face of the second tooth 472 to the other end face of the second tooth 472.

[0184] The third end 4721 of the second tooth 472 can be located on the same side as the first end 4621 of the first tooth 462, and the fourth end 4722 of the second tooth 472 can be located on the same side as the second end 4622 of the first tooth 462. That is, the third end 4721 of the second tooth 472 and the first end 4621 of the first tooth 462 are located on one side of the synchronous gear 43, and the fourth end 4722 of the second tooth 472 and the second end 4622 of the first tooth 462 are located on the other side of the synchronous gear 43. The tooth tip thickness of the first tooth 462 gradually changes from the first end 4621 to the second end 4622, and the tooth tip thickness of the second tooth 472 gradually changes from the third end 4721 to the fourth end 4722, and the trend of change of the tooth tip thickness of the second tooth 472 is opposite to that of the first tooth 462.

[0185] The tooth tip thickness of the first tooth 462 refers to the arc length of the tip circle between the two tooth profiles of the first tooth 462 within the end plane (i.e., the plane parallel to the XZ plane) of the first gear 46, that is, the arc length between the two tooth profiles of the first tooth tip surface 4623 of the first tooth 462 that are opposite to each other along the circumferential direction of the first gear 46. The tooth tip thickness of the second tooth 472 refers to the arc length of the tip circle between the two tooth profiles of the second tooth 472 within the end plane (i.e., the plane parallel to the XZ plane) of the second gear 47, that is, the arc length between the two tooth profiles of the second tooth tip surface 4723 of the second tooth 472 that are opposite to each other along the circumferential direction of the second gear 47.

[0186] Please refer to the following: Figure 13 , Figure 14a , Figure 14b and Figure 15a , Figure 15b yes Figure 15c A schematic diagram illustrating the first type of tooth tip thickness variation trend in the first embodiment of the synchronous gear 43. Figure 15d yes Figure 15a A schematic diagram illustrating the second type of tooth tip thickness variation trend in the first embodiment of the synchronous gear 43. Figure 4 yes Figure 15b A schematic diagram illustrating the third variation trend of the tooth tip thickness in the first embodiment of the synchronous gear 43. Figure 4 yes Figure 15c A schematic diagram illustrating the fourth variation trend of the tooth tip thickness in the first embodiment of the synchronous gear 43. Figure 4 In the diagram, the trend of the tooth tip thickness of the first tooth 462 is illustrated by taking the change of the tooth tip thickness of the first tooth tip surface 4623 of the first tooth 462 as an example, and the trend of the tooth tip thickness of the second tooth 472 is illustrated by taking the change of the tooth tip thickness of the second tooth tip surface 4723 of the second tooth 472 as an example, but it is not limited to this.

[0187] It should be understood that the variation trend of the tooth thickness of the second tooth 472 is opposite to that of the first tooth 462, at least including the following cases:

[0188] I. As shown in FIG. 4A, the tooth thickness of the first tooth 462 gradually increases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 gradually decreases from the third end 4721 to the fourth end 4722. Figure 15d

[0189] Exemplarily, the tooth thickness D1 of the first end 4621 can be smaller than the tooth thickness D2 of the second end 4622. The tooth thickness D3 of the third end 4721 can be greater than the tooth thickness D4 of the fourth end 4722. The tooth thickness D1 of the first end 4621 can be the same as the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be the same as the tooth thickness D3 of the third end 4721. Of course, in other application scenarios, the tooth thickness D1 of the first end 4621 can be different from the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be different from the tooth thickness D3 of the third end 4721.

[0190] II. As shown in FIG. 4B, the tooth thickness of the first tooth 462 gradually decreases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 gradually increases from the third end 4721 to the fourth end 4722. Figure 4

[0191] Exemplarily, the tooth thickness D1 of the first end 4621 can be greater than the tooth thickness D2 of the second end 4622. The tooth thickness D3 of the third end 4721 can be smaller than the tooth thickness D4 of the fourth end 4722. The tooth thickness D1 of the first end 4621 can be the same as the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be the same as the tooth thickness D3 of the third end 4721. Of course, in other application scenarios, the tooth thickness D1 of the first end 4621 can be different from the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be different from the tooth thickness D3 of the third end 4721.

[0192] III. As shown in FIG. 4C, the tooth thickness of the first tooth 462 first increases and then decreases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 first decreases and then increases from the third end 4721 to the fourth end 4722. Figures 15a-15d

[0193] ​​​Exemplarily, the addendum D1 of the first end 4621 can be equal to the addendum D2 of the second end 4622. The addendum D3 of the third end 4721 can be equal to the addendum D4 of the fourth end 4722. The addendum D1 of the first end 4621 can be different from the addendum D4 of the fourth end 4722. The addendum D2 of the second end 4622 can be different from the addendum D3 of the third end 4721. Of course, in other application scenarios, the addendum D1 of the first end 4621 can be smaller or larger than the addendum D2 of the second end 4622. The addendum D3 of the third end 4721 can be larger or smaller than the addendum D4 of the fourth end 4722. The addendum D1 of the first end 4621 can be the same as the addendum D4 of the fourth end 4722. The addendum D2 of the second end 4622 can be the same as the addendum D3 of the third end 4721.

[0194] IV. As shown in FIG. 4, the addendum of the first tooth 462 decreases first and then increases from the first end 4621 to the second end 4622, and the addendum of the second tooth 472 increases first and then decreases from the third end 4721 to the fourth end 4722. Figure 15a

[0195] Exemplarily, the addendum D1 of the first end 4621 can be equal to the addendum D2 of the second end 4622. The addendum D3 of the third end 4721 can be equal to the addendum D4 of the fourth end 4722. The addendum D1 of the first end 4621 can be different from the addendum D4 of the fourth end 4722. The addendum D2 of the second end 4622 can be different from the addendum D3 of the third end 4721.

[0196] It should be noted that the change trend of the addendum of the first tooth 462 and the change trend of the addendum of the second tooth 472 are not limited to the above-mentioned several cases, and embodiments capable of satisfying the change trend of the addendum of the second tooth 472 opposite to the change trend of the addendum of the first tooth 462 are within the scope of the present embodiment, and no strict limitation is made.

[0197] It can be understood that in the electronic device 200 with foldable performance, the coincidence degree of the gear in the synchronous assembly 40 is a key factor affecting the motion synchronization between the two housings of the electronic device 200. If it is desired to improve the motion synchronization between the two housings of the electronic device 200, the coincidence degree of the gear in the synchronous assembly 40 needs to be improved to ensure the transmission efficiency and stability of the synchronous assembly 40.

[0198] ​The coincidence degree of the gear refers to the ratio of the actual meshing line length to the normal pitch. The coincidence degree greater than 1 is the condition for the gear to be continuously meshed. The coincidence degree represents the ratio of the frequency of the simultaneous meshing of two teeth and the meshing of one tooth in the meshing process. The higher the frequency of the simultaneous meshing of two teeth, the higher the coincidence degree, the better the synchronization performance of the synchronization gear 43, the smaller the load on a single tooth, the more stable the structure of the meshing teeth of the gear, the gear is less likely to bend, and the noise in the rotation process of the gear is smaller. Moreover, the greater the coincidence degree of the gear, the higher the transmission efficiency and stability of the gear.

[0199] In the related art, when the synchronization gear and the middle beam are designed, a design gap is left between the two to ensure that the synchronization gear can be smoothly installed on the middle beam. This design gap can avoid the problem of the synchronization gear being stuck due to the gap between the synchronization gear and the middle beam being too small or too large when the synchronization gear is installed on the middle beam. However, in the actual work of the synchronization gear, the two gears meshing with each other are prone to not fit tightly, which causes one of the two gears to move towards the middle beam below and reduce or eliminate the design gap with the middle beam, and the other gear also moves towards the middle beam below and reduces or eliminates the design gap with the middle beam, so that the two gears are respectively expanded outward away from each other, causing the involute surfaces of the two gears to change from tangency to misalignment, resulting in an increase in the tooth side gap between the two gears and the inability to completely mesh, which reduces the coincidence degree and meshing effect of the synchronization gear.

[0200] Based on this, in the present embodiment, by gradually changing the addendum thickness of the first tooth 462 from the first end 4621 to the second end 4622, and gradually changing the addendum thickness of the second tooth 472 from the third end 4721 to the fourth end 4722, and the change trend of the addendum thickness of the second tooth 472 is opposite to that of the first tooth 462, the tooth profile of the first tooth 462 and the tooth profile of the second tooth 472 can both have inclined surfaces, and the inclined trend of the inclined surfaces can be oppositely arranged.

[0201] In this arrangement, when the first tooth 462 and the second tooth 472 are engaged, the tooth profile of the first tooth 462 and the tooth profile of the second tooth 472 can be arranged in a cross manner, and the mating surface of the first tooth 462 and the second tooth 472 can be changed from a flat surface to an inclined surface, thereby effectively increasing the mating relative area between the first tooth 462 and the second tooth 472. The increase of the mating area between the first tooth 462 and the second tooth 472 can make the tooth profile of the first tooth 462 and the tooth profile of the second tooth 472 compact, and the tooth groove of the first tooth 462 and the tooth groove of the second tooth 472 can be further embedded in each other when the tooth profiles of the first tooth 462 and the second tooth 472 are in contact, which is beneficial to make the tooth profile of the next pair of first tooth 462 and second tooth 472 enter engagement before (at least at the same time) the tooth profile of the previous pair of first tooth 462 and second tooth 472 ends engagement, so that the involute surface of the first tooth 462 and the involute surface of the second tooth 472 remain tangent, effectively improve the coincidence degree and engagement effect, and ensure the continuity and smoothness of transmission. In addition, due to the improvement of the coincidence degree, the synchronization effect between the first gear 46 and the second gear 47 will be better, so that the structures on both sides of the rotating shaft mechanism 100 can realize synchronous rotation.

[0202] Hereinafter, the structure of the first tooth 462 and the second tooth 472 will be described in detail taking one first tooth 462 and one second tooth 472, and the tooth thickness of the first tooth 462 gradually increases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 gradually decreases from the third end 4721 to the fourth end 4722 as an example. The description of the structure of one first tooth 462 and one second tooth 472 below can be applied to other first teeth 462 and other second teeth 472 without conflict.

[0203] Please refer to Figure 15b , Figure 15c is Figure 15d the structural schematic view of an angle of the first gear 46 of the synchronous gear 43 shown in FIG. 4.

[0204] The first tooth 462 can further include a first tooth top surface 4623, a first side surface 4624, a second side surface 4625, a first end surface 4626 and a second end surface 4627. The first end surface 4626 is an end surface of the first end 4621 of the first tooth 462. The second end surface 4627 is an end surface of the second end 4622 of the first tooth 462. The first end surface 4626 and the second end surface 4627 can be oppositely arranged in the tooth width direction (i.e., the Y direction) of the first tooth 462. The first tooth top surface 4623 is a surface of the first tooth 462 that faces away from the first gear body 461. The first tooth top surface 4623 is connected between the first end 4621 and the second end 4622, i.e., connected between the first end surface 4626 and the second end surface 4627. The first side surface 4624 is a surface of the first tooth 462 that is connected between the first tooth top surface 4623 and the first gear body 461, and the first side surface 4624 can also be connected between the first end 4621 and the second end 4622, i.e., connected between the first end surface 4626 and the second end surface 4627. The second side surface 4625 is another surface of the first tooth 462 that is connected between the first tooth top surface 4623 and the first gear body 461, and the second side surface 4625 can also be connected between the first end 4621 and the second end 4622, i.e., connected between the first end surface 4626 and the second end surface 4627. Among them, the first side surface 4624 can be a surface of the first tooth 462 located on the left side, and the second side surface 4625 can be a surface of the second tooth 472 located on the right side. Of course, in other embodiments, the first side surface 4624 can be a surface of the first tooth 462 located on the right side, and the second side surface 4625 can be a surface of the second tooth 472 located on the left side.

[0205] The first tooth top surface 4623 can include a first top edge A1 located at the first end 4621 and a second top edge A2 located at the second end 4622. Among them, the first top edge A1 can be the intersection line of the first tooth top surface 4623 and the first end surface 4626, and the second top edge A2 can be the intersection line of the first tooth top surface 4623 and the second end surface 4627. The length of the first top edge A1 is not the same as the length of the second top edge A2. Specifically, the length of the first top edge A1 can be less than or greater than the length of the second top edge A2. Exemplarily, the shape of the first tooth top surface 4623 can be an inverted trapezoidal shape.

[0206] It can be understood that by making the length of the second top edge A2 different from the length of the first top edge A1, the tooth width of the first tooth 462 gradually changes in the axial direction of the first gear 46, so that the first tooth 462 is a tooth with a certain radial offset, so that the mating surface of the first tooth 462 that mates with the second tooth 472 can be an inclined surface, which is beneficial to increase the mating area between the first tooth 462 and the second tooth 472, optimize the meshing effect between the first tooth 462 and the second tooth 472, and increase the coincidence degree of the synchronous gear 43.

[0207] One possible implementation, such as Figure 16 As shown, the length of the first top edge A1 can be less than the length of the second top edge A2. The first tooth 462 has a first draft angle θ1, the length of the first top edge A1 is S1, the length of the second top edge A2 is S2, and the tooth width of the first tooth 462 is B1, where the tooth width B1 of the first tooth 462 is the length of the first tooth 462 along the axial direction of the first gear 46. The first draft angle θ1, the length S1 of the first top edge A1, the length S2 of the second top edge A2, and the tooth width B1 of the first tooth 462 satisfy the following relationship:

[0208] tanθ1=(S1-S2) / B1

[0209] It is understandable that by giving the first tooth 462 a first draft angle θ1, during the fabrication of the first gear 46, not only can the machining allowance of the first gear 46 be guaranteed, and the frictional resistance between the mold and the workpiece surface be reduced, thus improving the quality of the produced first gear 46, but the finished first gear 46 can also be smoothly and quickly ejected from the mold, saving the cost and time of removing the first gear 46 from the mold. This helps to reduce the machining difficulty and cost of the first gear 46.

[0210] For example, the angle range of the first draft angle θ1 can be between 3° and 30° (inclusive of the endpoints 3° and 30°). It is understood that setting the angle range of the first draft angle θ1 within the aforementioned range facilitates the demolding of the first gear 46 from the mold by adjusting the angle of the draft angle. Specifically, the larger the angle of the first draft angle θ1, the smaller the force required to remove the first gear 46 from the mold, and the shorter the time required to remove the first gear 46 from the mold.

[0211] Please refer to the following: Figure 16 and Figure 12 In this embodiment, the first side surface 4624 may include a first side edge C1 located at the first end 4621 and a second side edge C2 located at the second end 4622. The first side edge C1 may be the intersection line of the first end face 4626 and the first side surface 4624, and the second side edge C2 may be the intersection line of the second end face 4627 and the first side surface 4624.

[0212] The second side surface 4625 may include a third side surface C3 located at the first end 4621 and a fourth side surface C4 located at the second end 4622. The third side surface C3 may be the intersection line of the first end face 4626 and the second side surface 4625, and the fourth side surface C4 may be the intersection line of the second end face 4627 and the second side surface 4625.

[0213] In the circumferential direction of the first gear 46, the first side edge C1 and the second side edge C2 of the first side surface 4624 can be staggered, and the third side edge C3 and the fourth side edge C4 of the second side surface 4625 can be staggered. The minimum distance between the first side edge C1 of the first side surface 4624 and the third side edge C3 of the second side surface 4625 is less than or greater than the minimum distance between the second side edge C2 of the first side surface 4624 and the fourth side edge C4 of the second side surface 4625.

[0214] In the circumferential direction of the first gear 46, the first side edge C1 and the second side edge C2 of the first side surface 4624 can be staggered, and the third side edge C3 and the fourth side edge C4 of the second side surface 4625 can be staggered. The minimum distance between the first side edge C1 of the first side surface 4624 and the third side edge C3 of the second side surface 4625 is less than or greater than the minimum distance between the second side edge C2 of the first side surface 4624 and the fourth side edge C4 of the second side surface 4625. Figure 16 As shown in the example, the minimum distance between the first side edge C1 and the third side edge C3 is less than the minimum distance between the second side edge C2 and the fourth side edge C4.

[0215] It can be understood that by staggering the first side edge C1 and the second side edge C2 of the first side surface 4624 in the circumferential direction of the first gear 46, and staggering the third side edge C3 and the fourth side edge C4 of the second side surface 4625 in the circumferential direction of the first gear 46, the first side surface 4624 and the second side surface 4625 can both be inclined surfaces with a certain inclination angle. In addition, by making the minimum distance between the first side edge C1 of the first side surface 4624 and the third side edge C3 of the second side surface 4625 less than or greater than the minimum distance between the second side edge C2 of the first side surface 4624 and the fourth side edge C4 of the second side surface 4625, the extension direction of the first side surface 4624 and the extension direction of the second side surface 4625 can be intersected, which facilitates the first gear 46 to have a structure in which one end has a large tooth thickness and the other end has a small tooth thickness, so that the first gear 46 can have a structure in which the first side surface 4624 and the second side surface 4625 are radially displaced on both sides. By setting the first gear 46 to be radially displaced on both sides, not only can the first gear 46 be easily demolded, but also the load capacity, wear resistance, machining precision and installation precision of the first gear 46 can be improved, the transmission ratio and speed adaptability of the gear can be optimized, and the synchronous gear 43 can have better coincidence and better meshing effect.

[0216] In addition, the addendum circle radius R1 of the first end 4621 can be different from the addendum circle radius R2 of the second end 4622. That is, in the radial direction of the first gear 46, the first top edge A1 is arranged to be offset from the second top edge A2, where the radial direction of the first gear 46 is a direction perpendicular to the center line of rotation of the first gear 46. Exemplarily, the addendum circle radius R1 of the first end 4621 can be smaller than the addendum circle radius R2 of the second end 4622.

[0217] It can be understood that, by making the addendum circle radius R1 of the first end 4621 different from the addendum circle radius R2 of the second end 4622, the first addendum surface 4623 can be a bevel surface with a certain inclination. With this arrangement, the first gear 46 can be conveniently demolded from the mold.

[0218] Referring to Figure 14a , Figure 16 is Figure 14a an angle structure diagram of the second gear 47 of the synchronization gear 43 shown in FIG. 4.

[0219] The second tooth 472 can further include a second addendum surface 4723, a third side surface 4724, a fourth side surface 4725, a third end surface 4726, and a fourth end surface 4727. The third end surface 4726 is an end surface of the third end 4721 of the second tooth 472. The fourth end surface 4727 is an end surface of the fourth end 4722 of the second tooth 472. The third end surface 4726 and the fourth end surface 4727 can be arranged opposite to each other in the tooth width direction (i.e., the Y direction) of the second tooth 472. The second addendum surface 4723 is a surface of the second tooth 472 that faces away from the second gear body 471, and the second addendum surface 4723 is connected between the third end 4721 and the fourth end 4722, i.e., connected between the third end surface 4726 and the fourth end surface 4727. The third side surface 4724 is a surface of the second tooth 472 that is connected between the second addendum surface 4723 and the second gear body 471, and the third side surface 4724 can also be connected between the third end 4721 and the fourth end 4722, i.e., connected between the third end surface 4726 and the fourth end surface 4727. The fourth side surface 4725 is another surface of the second tooth 472 that is connected between the second addendum surface 4723 and the second gear body 471, and the fourth side surface 4725 can also be connected between the third end 4721 and the fourth end 4722, i.e., connected between the third end surface 4726 and the fourth end surface 4727. Among them, the third side surface 4724 can be a surface of the second tooth 472 located on the left side, and the fourth side surface 4725 can be a surface of the second tooth 472 located on the right side. Of course, in other embodiments, the third side surface 4724 can be a surface of the second tooth 472 located on the right side, and the fourth side surface 4725 can be a surface of the second tooth 472 located on the left side.

[0220] The second addendum surface 4723 can include a third top edge A3 at the third end 4721 and a fourth top edge A4 at the fourth end 4722. The third top edge A3 can be an intersection line of the second addendum surface 4723 and the third end surface 4726, and the fourth top edge A4 can be an intersection line of the second addendum surface 4723 and the fourth end surface 4727. The length of the third top edge A3 is different from the length of the fourth top edge A4. Specifically, the length of the third top edge A3 can be greater than or less than the length of the fourth top edge A4. Exemplarily, the shape of the second addendum surface 4723 can be an inverted trapezoid.

[0221] It can be understood that, by making the length of the third top edge A3 different from the length of the fourth top edge A4, the tooth width of the second tooth 472 can gradually change in the axial direction of the second gear 47, so that the second tooth 472 is a tooth with a certain radial offset, so that the mating surface of the second tooth 472 that mates with the first tooth 462 can be a bevel, which is beneficial to increase the mating area between the first tooth 462 and the second tooth 472, optimize the meshing effect between the first tooth 462 and the second tooth 472, and increase the coincidence degree of the synchronization gear 43.

[0222] In this embodiment, the size relationship between the length of the third top edge A3 and the length of the fourth top edge A4 is opposite to the size relationship between the length of the first top edge A1 and the length of the second top edge A2. Exemplarily, the length of the third top edge A3 is greater than the length of the fourth top edge A4, and the length of the first top edge A1 is less than the length of the second top edge A2. Alternatively, the length of the third top edge A3 is less than the length of the fourth top edge A4, and the length of the first top edge A1 is greater than the length of the second top edge A2.

[0223] The length of the third top edge A3 can be the same as or different from the length of the first top edge A1. The length of the fourth top edge A4 can be the same as or different from the length of the second top edge A2. For example, the length of the third top edge A3 can be the same as the length of the first top edge A1, and the length of the fourth top edge A4 can be the same as the length of the second top edge A2.

[0224] It is understandable that by making the relationship between the lengths of the third top edge A3 and the fourth top edge A4 opposite to the relationship between the lengths of the first top edge A1 and the second top edge A2, the mating surfaces of the first tooth 462 and the second tooth 472 can be changed from a planar fit to a bevel fit, thereby effectively increasing the relative mating area between the first tooth 462 and the second tooth 472. This increased mating area allows the tooth profiles of the first tooth 462 and the second tooth 472 to fit well at any cross-section, achieving a tight fit between the first tooth 462 and the second tooth 472. This tight fit means that the fit between the first tooth 462 and the second tooth 472 is within a certain range, allowing the first gear 46 and the second gear 47 to operate normally without relative slippage or jump. This fit ensures the transmission accuracy and stability of the gear pair, avoiding vibration, noise, and wear caused by improper fit.

[0225] One possible implementation, such as Figure 17 As shown, the length of the third top edge A3 can be greater than the length of the fourth top edge A4. The second tooth 472 has a second draft angle θ2, the length of the third top edge A3 is S3, the length of the fourth top edge A4 is S4, and the tooth width of the second tooth 472 is B2, where the tooth width B2 of the second tooth 472 is the length of the second tooth 472 along the axial direction of the second gear 47. The second draft angle θ2, the length of the third top edge A3 S3, the length of the fourth top edge A4 S4, and the tooth width B2 of the second tooth 472 satisfy the following relationship:

[0226] tanθ2=(S3-S4) / B2

[0227] Understandably, by giving the second tooth 472 a second draft angle θ2, during the fabrication of the second gear 47, not only can the machining allowance of the second gear 47 be guaranteed, reducing the frictional resistance between the mold and the workpiece surface and improving the quality of the produced second gear 47, but it also allows the finished second gear 47 to be ejected from the mold smoothly and quickly, saving the cost and time of removing the second gear 47 from the mold. This helps to reduce the machining difficulty of the second gear 47 and decrease its machining cost.

[0228] For example, the angle range of the second draft angle θ2 can be between 3° and 30° (inclusive of the endpoints 3° and 30°). It is understood that setting the angle range of the second draft angle θ2 within the aforementioned range facilitates the demolding of the second gear 47 from the mold by adjusting the angle of the draft angle. Specifically, the larger the angle of the second draft angle θ2, the smaller the force required to remove the second gear 47 from the mold, and the shorter the time required to remove the second gear 47 from the mold.

[0229] Please refer to Figure 17 and Figure 12 In the embodiment, the third side surface 4724 can include a fifth side edge C5 located at the third end 4721 and a sixth side edge C6 located at the fourth end 4722. The fifth side edge C5 can be the intersection line of the third end surface 4726 and the third side surface 4724, and the sixth side edge C6 can be the intersection line of the fourth end surface 4727 and the third side surface 4724.

[0230] The fourth side surface 4725 can include a seventh side edge C7 located at the first end 4621 and an eighth side edge C8 located at the second end 4622. The seventh side edge C7 can be the intersection line of the first end surface 4626 and the fourth side surface 4725, and the eighth side edge C8 can be the intersection line of the second end surface 4627 and the fourth side surface 4725.

[0231] In the circumferential direction of the second gear 47, the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 can be arranged in a staggered manner, and the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 can be arranged in a staggered manner. The minimum distance between the fifth side edge C5 of the third side surface 4724 and the seventh side edge C7 of the fourth side surface 4725 is less than or greater than the minimum distance between the sixth side edge C6 of the third side surface 4724 and the eighth side edge C8 of the fourth side surface 4725.

[0232] The fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 are arranged in a staggered manner in the circumferential direction of the second gear 47, which means that the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 are not coincident in the circumferential direction of the second gear 47, but are arranged in sequence. The seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 are arranged in a staggered manner in the circumferential direction of the second gear 47, which means that the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 are not coincident in the circumferential direction of the second gear 47, but are arranged in sequence. For example, as shown in Figure 17 The minimum distance between the fifth side edge C5 and the seventh side edge C7 is greater than the minimum distance between the sixth side edge C6 and the eighth side edge C8.

[0233] It can be understood that by arranging the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 to be staggered in the circumferential direction of the second gear 47, and arranging the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 to be staggered in the circumferential direction of the second gear 47, the third side surface 4724 and the fourth side surface 4725 can both be inclined surfaces with a certain inclination angle. In addition, by making the minimum distance between the fifth side edge C5 of the third side surface 4724 and the seventh side edge C7 of the fourth side surface 4725 smaller or larger than the minimum distance between the sixth side edge C6 of the third side surface 4724 and the eighth side edge C8 of the fourth side surface 4725, the extension direction of the third side surface 4724 and the extension direction of the fourth side surface 4725 can be intersected, which facilitates the second gear 47 to assume a structure in which one end has a large tooth thickness and the other end has a small tooth thickness, so that the second gear 47 can assume a structure in which the third side surface 4724 and the fourth side surface 4725 are both radially displaced. By arranging the second gear 47 to be bilaterally radially displaced, not only can the second gear 47 be easily demolded, but also the load capacity, wear resistance, machining precision and installation precision of the second gear 47 can be improved, the transmission ratio and speed adaptability of the gear can be optimized, and the synchronous gear 43 can have better coincidence and better meshing effect.

[0234] In addition, the addendum circle radius R3 of the third end 4721 can be different from the addendum circle radius R4 of the fourth end 4722. That is, in the radial direction of the second gear 47, the third top edge A3 and the fourth top edge A4 are arranged to be staggered, wherein the radial direction of the second gear 47 is a direction perpendicular to the center line of rotation of the second gear 47. For example, the addendum circle radius R3 of the third end 4721 can be greater than the addendum circle radius R4 of the fourth end 4722.

[0235] It can be understood that by making the addendum circle radius R3 of the third end 4721 different from the addendum circle radius R4 of the fourth end 4722, the second addendum surface 4723 can be an inclined surface with a certain inclination, which facilitates the second gear 47 to be demolded from the mold.

[0236] Please refer to Figure 14b and Figure 17 , Figure 14b is Figure 12 the angle structure diagram of the first limiting member 48 and the second limiting member 49 of the synchronization assembly 40 shown in FIG. 4.

[0237] The synchronous assembly 40 can further include a first limiting member 48 and a second limiting member 49. The first limiting member 48 is sleeved on one end of the first rotating shaft 44 and one end of the second rotating shaft 45, and is elastically connected between one end of the synchronous gear 43 and the middle beam 10. The second limiting member 49 is sleeved on the other end of the first rotating shaft 44 and the other end of the second rotating shaft 45, and is elastically connected between the other end of the synchronous gear 43 and the middle beam 10. The first limiting member 48 and the second limiting member 49 can be structural members with elasticity, which can rebound after being pressed and reset after the pressure is removed.

[0238] Exemplarily, the first limiting member 48 and the second limiting member 49 can be springs, clips or disc springs, etc. The disc spring can be a common disc spring, and the cross-sectional shape of the common disc spring is rectangular, which can have a supporting surface or no supporting surface. Alternatively, the disc spring can be a disc spring with radial grooves. On the basis of the common disc spring, a plurality of uniformly distributed grooves are formed in the radial direction, which can be formed from the inner hole to the outer circle direction, or from the outer circle to the inner hole direction. Alternatively, the disc spring can also be a trapezoidal cross-section disc spring. The cross-section of the spring is trapezoidal, which can be divided into two types: the inner edge thickness is greater than the outer edge thickness type and the inner edge thickness is less than the outer edge thickness type.

[0239] With this arrangement, the first limiting member 48 and the second limiting member 49 can cooperate to press the two ends of the first gear 46 in the axial direction and the two ends of the second gear 47 in the axial direction, so that the first gear 46 and the second gear 47 can always be engaged, avoiding the problem of axial movement of the first gear 46 and the second gear 47 during engagement, which can cause the engagement failure of the first gear 46 and the second gear 47. This is conducive to achieving axial tight fit of the first gear 46 and the second gear 47, improving the engagement effect of the first gear 46 and the second gear 47, and having good reliability.

[0240] Specifically, the first limiting member 48 can include a first connecting portion 481, a first elastic portion 482 and a second elastic portion 483. The first connecting portion 481 can be connected between the first elastic portion 482 and the second elastic portion 483. The first elastic portion 482 is wound around the first rotating shaft 44 and extends in the axial direction of the first rotating shaft 44. The second elastic portion 483 is wound around the second rotating shaft 45 and extends in the axial direction of the second rotating shaft 45. The rotation direction of the second elastic portion 483 is opposite to that of the first elastic portion 482. The rotation direction of the first elastic portion 482 refers to the rotation direction of the helical line of the first elastic portion 482 around the center line of the first rotating shaft 44, and the rotation direction of the second elastic portion 483 refers to the rotation direction of the helical line of the second elastic portion 483 around the center line of the second rotating shaft 45.

[0241] Exemplarily, the first elastic part 482 can be left-handed, i.e., the first elastic part 482 rotates anticlockwise around the first rotating shaft 44. The second elastic part 483 can be right-handed, i.e., the second elastic part 483 rotates clockwise around the second rotating shaft 45. Of course, in other embodiments, the first elastic part 482 can be right-handed, i.e., the first elastic part 482 rotates clockwise around the first rotating shaft 44. The second elastic part 483 can be left-handed, i.e., the second elastic part 483 rotates anticlockwise around the second rotating shaft 45.

[0242] It can be understood that, by arranging the first elastic part 482 around the first rotating shaft 44 and extending helically along the axial direction of the first rotating shaft 44, and arranging the second elastic part 483 around the second rotating shaft 45 and extending helically along the axial direction of the second rotating shaft 45, and the rotation direction of the second elastic part 483 is opposite to that of the first elastic part 482, the opposite rotation directions of the first elastic part 482 and the second elastic part 483 can adapt to the opposite trends of the tooth profile of the first gear 462 and the tooth profile of the second gear 472, so that the first gear 46 and the second gear 47 can always be engaged, avoiding the axial movement of the first gear 46 and the second gear 47 during engagement, thereby avoiding the problem of engagement failure of the first gear 46 and the second gear 47, and facilitating the axial tight fit of the first gear 46 and the second gear 47, improving the engagement effect of the first gear 46 and the second gear 47, and improving the reliability.

[0243] The second limiting part 49 can include a second connecting part 491, a third elastic part 492, and a fourth elastic part 493. The second connecting part 491 can be connected between the third elastic part 492 and the fourth elastic part 493. The third elastic part 492 is arranged around the second rotating shaft 45 and extends helically along the axial direction of the second rotating shaft 45. The fourth elastic part 493 is arranged around the second rotating shaft 45 and extends helically along the axial direction of the second rotating shaft 45. The rotation direction of the fourth elastic part 493 is opposite to that of the third elastic part 492.

[0244] The rotation direction of the third elastic part 492 refers to the rotation direction of the helical line of the third elastic part 492 around the center line of the first rotating shaft 44, and the rotation direction of the fourth elastic part 493 refers to the rotation direction of the helical line of the fourth elastic part 493 around the center line of the second rotating shaft 45.

[0245] For example, the third elastic portion 492 can rotate clockwise, that is, the third elastic portion 492 rotates clockwise around the first rotation axis 44. The fourth elastic portion 493 can rotate counterclockwise, that is, the fourth elastic portion 493 rotates counterclockwise around the second rotation axis 45. Of course, in other embodiments, the third elastic portion 492 can rotate counterclockwise, that is, the third elastic portion 492 rotates counterclockwise around the first rotation axis 44. The fourth elastic portion 493 can rotate clockwise, that is, the fourth elastic portion 493 rotates clockwise around the second rotation axis 45.

[0246] It is understandable that by having the third elastic part 492 wound around the first rotating shaft 44 and extend spirally along the axial direction of the first rotating shaft 44, and the fourth elastic part 493 wound around the second rotating shaft 45 and extend spirally along the axial direction of the second rotating shaft 45, and by having the rotation direction of the fourth elastic part 493 opposite to that of the third elastic part 492, the opposite rotation directions of the third elastic part 492 and the fourth elastic part 493 can be adapted to the changing trends of the tooth profiles of the first tooth 462 and the second tooth 472. This ensures that the first gear 46 and the second gear 47 can always maintain meshing, avoiding the problem of axial movement of the first gear 46 and the second gear 47 during meshing, which could lead to meshing failure. This further facilitates the axial tight fit of the first gear 46 and the second gear 47, improves the meshing effect of the first gear 46 and the second gear 47, and enhances reliability.

[0247] Furthermore, in this embodiment, the rotation direction of the first elastic portion 482 can be opposite to that of the third elastic portion 492. The rotation direction of the second elastic portion 483 can be opposite to that of the fourth elastic portion 493. For example, the rotation direction of the first elastic portion 482 can be left-handed, the rotation direction of the third elastic portion 492 can be right-handed, the rotation direction of the second elastic portion 483 can be right-handed, and the rotation direction of the fourth elastic portion 493 can be left-handed. Alternatively, the rotation direction of the first elastic portion 482 can be right-handed, the rotation direction of the third elastic portion 492 can be left-handed, the rotation direction of the second elastic portion 483 can be left-handed, and the rotation direction of the fourth elastic portion 493 can be right-handed.

[0248] Second embodiment:

[0249] Please refer to the following: Figure 18 , Figure 18 and Figure 12 , Figure 19 yes Figure 20a A partial structural diagram of the synchronization component 40 of the second embodiment of the rotating shaft mechanism 100 shown. Figure 20b yes Figure 19 The diagram shows a structural schematic of the synchronization component 40 at one angle. Figure 4 yes Figure 20a A schematic diagram of the synchronization component 40 from another angle.Figure 19 In the drawings, the first swing arm 41 and the second swing arm 42 of the synchronization assembly 40 are not shown for the convenience of understanding.

[0250] In the present embodiment, the same contents as the first embodiment will not be described again, and the first gear 46 and the second gear 47 are both single-side radial displacement, which will be described in detail below. In addition, the description of the synchronization assembly 40 below can be applied to the first embodiment above without conflict.

[0251] Specifically, in the circumferential direction of the first gear 46, the first side edge C1 and the second side edge C2 of the first side face 4624 can be arranged in a staggered manner, and the third side edge C3 and the fourth side edge C4 of the second side face 4625 can be arranged in a coincident manner. Alternatively, in the circumferential direction of the first gear 46, the first side edge C1 and the second side edge C2 of the first side face 4624 can be arranged in a coincident manner, and the third side edge C3 and the fourth side edge C4 of the second side face 4625 can be arranged in a staggered manner.

[0252] In the drawings, the first swing arm 41 and the second swing arm 42 of the synchronization assembly 40 are not shown for the convenience of understanding.

[0253] In the drawings, the first swing arm 41 and the second swing arm 42 of the synchronization assembly 40 are not shown for the convenience of understanding. Figure 20b and Figure 19 , Figure 19 is Figure 20a a structural schematic view of an angle of the first gear 46 of the synchronization gear 43 shown in the drawings. In the circumferential direction of the first gear 46, the first side edge C1 and the second side edge C2 of the first side face 4624 are arranged in a coincident manner, and the third side edge C3 and the fourth side edge C4 of the second side face 4625 are arranged in a staggered manner.

[0254] It can be understood that, by setting the first side edge C1 and the second side edge C2 of the first side surface 4624 to coincide in the circumferential direction of the first gear 46, and setting the third side edge C3 and the fourth side edge C4 of the second side surface 4625 to be misaligned in the circumferential direction of the first gear 46, the first side surface 4624 can be a plane, and the second side surface 4625 can be an inclined surface with a certain inclination angle. In this arrangement, the first gear 46 can be easily demolded, and the load capacity, wear resistance, machining precision and installation precision of the first gear 46 can be improved, and the transmission ratio and speed adaptability of the gear can be optimized, which is beneficial to the synchronization gear 43 to have better coincidence and good meshing effect.

[0255] In addition, the addendum circle radius R1 of the first end 4621 can be the same as the addendum circle radius R2 of the second end 4622. That is, in the radial direction of the first gear 46, the first top edge A1 and the second top edge A2 are arranged to coincide, wherein the radial direction of the first gear 46 is perpendicular to the center line of rotation of the first gear 46.

[0256] It can be understood that, by setting the addendum circle radius R1 of the first end 4621 to be the same as the addendum circle radius R2 of the second end 4622, the first addendum surface 4623 can be a plane, and the first addendum surface 4623 can have better planeness.

[0257] In the embodiment, in the circumferential direction of the second gear 47, the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 can be misaligned, and the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 can be arranged to coincide. Alternatively, in the circumferential direction of the second gear 47, the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 can be arranged to coincide, and the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 can be misaligned.

[0258] In the embodiment, in the circumferential direction of the second gear 47, the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 can be misaligned, and the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 can be arranged to coincide. Alternatively, in the circumferential direction of the second gear 47, the fifth side edge C5 and the sixth side edge C6 of the third side surface 4724 can be arranged to coincide, and the seventh side edge C7 and the eighth side edge C8 of the fourth side surface 4725 can be misaligned.

[0259] In a possible implementation, please refer to Figure 21 andFigure 21 , Figure 19 yes Figure 20b The diagram shows a structural schematic of the second gear 47 of the synchronizing gear 43 at an angle. In the circumferential direction of the second gear 47, the fifth side C5 and the sixth side C6 of the third side 4724 can be arranged to overlap, and the seventh side C7 and the eighth side C8 of the fourth side 4725 can be arranged to be staggered.

[0260] It is understandable that by aligning the fifth side C5 and the sixth side C6 of the third side 4724 in the circumferential direction of the second gear 47, and by misaligning the seventh side C7 and the eighth side C8 of the fourth side 4725 in the circumferential direction of the second gear 47, the third side 4724 can be a plane, and the fourth side 4725 can be an inclined plane with a certain angle. This arrangement facilitates the second gear 47 to have a structure with a large tooth thickness at one end and a small tooth thickness at the other end, allowing the second gear 47 to exhibit a single-sided radial displacement structure on a single side of the fourth side 4725. By setting the second gear 47 to single-sided radial displacement, not only can the second gear 47 be easily demolded, but its load-bearing capacity, wear resistance, machining accuracy, and installation accuracy can also be improved. This optimizes the gear's transmission ratio and speed adaptability, and helps the synchronous gear 43 to have better overlap and meshing performance.

[0261] Furthermore, the tip circle radius R3 of the third end 4721 can be the same as the tip circle radius R4 of the fourth end 4722. That is, in the radial direction of the second gear 47, the third tip edge A3 and the fourth tip edge A4 are arranged to coincide, wherein the radial direction of the second gear 47 is perpendicular to the rotation center line of the second gear 47.

[0262] It is understandable that by making the tip circle radius R3 of the third end 4721 different from the tip circle radius R4 of the fourth end 4722, the second tip surface 4723 can be made flat, thus giving the second tip surface 4723 better flatness.

[0263] Please refer to the following: Figure 22 , Figure 22 , Figure 19 and Figure 23a , Figure 23b yes Figure 23c A schematic diagram illustrating the first type of tooth tip thickness variation trend in the second embodiment of the synchronous gear 43. Figure 23d yes Figure 23a A simplified schematic diagram illustrating the second type of tooth tip thickness variation trend in the second embodiment of the synchronous gear 43. Figure 19 yes Figure 23b A schematic diagram illustrating the third type of tooth tip thickness variation trend in the second embodiment of the synchronous gear 43. Figure 19 yesFigure 23c A schematic diagram illustrating the fourth type of tooth tip thickness variation trend in the second embodiment of the synchronous gear 43. Figure 19 In the diagram, the trend of the tooth tip thickness of the first tooth 462 is illustrated by taking the change of the tooth tip thickness of the first tooth tip surface 4623 of the first tooth 462 as an example, and the trend of the tooth tip thickness of the second tooth 472 is illustrated by taking the change of the tooth tip thickness of the second tooth tip surface 4723 of the second tooth 472 as an example, but it is not limited to this.

[0264] It should be understood that in this embodiment, the trend of the change in the tooth tip thickness of the second tooth 472 is opposite to the trend of the change in the tooth tip thickness of the first tooth 462, including at least the following situations:

[0265] 1. As Figure 23d As shown, the tooth tip thickness of the first tooth 462 can gradually increase from the first end 4621 to the second end 4622, and the tooth tip thickness of the second tooth 472 can gradually decrease from the third end 4721 to the fourth end 4722.

[0266] For example, the tooth tip thickness D1 of the first end 4621 can be less than the tooth tip thickness D2 of the second end 4622. The tooth tip thickness D3 of the third end 4721 can be greater than the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D1 of the first end 4621 can be the same as the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D2 of the second end 4622 can be the same as the tooth tip thickness D3 of the third end 4721. Of course, in other application scenarios, the tooth tip thickness D1 of the first end 4621 can be different from the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D2 of the second end 4622 can be different from the tooth tip thickness D3 of the third end 4721.

[0267] II. Figure 19 As shown, the tooth tip thickness of the first tooth 462 can gradually decrease from the first end 4621 to the second end 4622, and the tooth tip thickness of the second tooth 472 can gradually increase from the third end 4721 to the fourth end 4722.

[0268] For example, the tooth tip thickness D1 of the first end 4621 can be greater than the tooth tip thickness D2 of the second end 4622. The tooth tip thickness D3 of the third end 4721 can be less than the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D1 of the first end 4621 can be the same as the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D2 of the second end 4622 can be the same as the tooth tip thickness D3 of the third end 4721. Of course, in other application scenarios, the tooth tip thickness D1 of the first end 4621 can be different from the tooth tip thickness D4 of the fourth end 4722. The tooth tip thickness D2 of the second end 4622 can be different from the tooth tip thickness D3 of the third end 4721.

[0269] III. Figures 23a-23dAs shown, the tooth thickness of the first tooth 462 increases first and then decreases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 decreases first and then increases from the third end 4721 to the fourth end 4722.

[0270] Exemplarily, the tooth thickness D1 of the first end 4621 can be equal to the tooth thickness D2 of the second end 4622. The tooth thickness D3 of the third end 4721 can be equal to the tooth thickness D4 of the fourth end 4722. The tooth thickness D1 of the first end 4621 can be different from the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be different from the tooth thickness D3 of the third end 4721. Of course, in other application scenarios, the tooth thickness D1 of the first end 4621 can be less than or greater than the tooth thickness D2 of the second end 4622. The tooth thickness D3 of the third end 4721 can be greater than or less than the tooth thickness D4 of the fourth end 4722. The tooth thickness D1 of the first end 4621 can be the same as the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be the same as the tooth thickness D3 of the third end 4721.

[0271] IV. As Figure 23a Figure 23b Figure 23c Figure 23d As shown, the tooth thickness of the first tooth 462 increases first and then decreases from the first end 4621 to the second end 4622, and the tooth thickness of the second tooth 472 decreases first and then increases from the third end 4721 to the fourth end 4722.

[0272] Exemplarily, the tooth thickness D1 of the first end 4621 can be equal to the tooth thickness D2 of the second end 4622. The tooth thickness D3 of the third end 4721 can be equal to the tooth thickness D4 of the fourth end 4722. The tooth thickness D1 of the first end 4621 can be different from the tooth thickness D4 of the fourth end 4722. The tooth thickness D2 of the second end 4622 can be different from the tooth thickness D3 of the third end 4721.

[0273] It should be noted that the change trend of the tooth thickness of the first tooth 462 and the change trend of the tooth thickness of the second tooth 472 are not limited to the above-mentioned several cases, and embodiments capable of satisfying the change trend of the tooth thickness of the second tooth 472 opposite to the change trend of the tooth thickness of the first tooth 462 are within the scope of the present embodiment, and no strict limitation is made.

[0274] With reference to the above two embodiments, it should be understood that the structural improvement of the synchronous assembly 40 of the rotating shaft mechanism 100 provided by the embodiments of the present application is not only applicable to the outer folding scenario of the electronic device 200, but also applicable to the inner folding scenario of the electronic device 200. When the synchronous assembly 40 is applied to the inner folding scenario of the electronic device 200, the synchronous assembly 40 can include more gears than the two gears described above. For example, the synchronous assembly 40 can include four gears, two first gears 46 and two second gears 47, wherein the first gears 46 and the second gears 47 are alternately arranged and sequentially meshed. The structural arrangement of the first gears 46 and the second gears 47 can refer to the description above, and will not be described here again. Of course, in other embodiments, the synchronous assembly 40 can also include six gears, three first gears 46 and three second gears 47, wherein the first gears 46 and the second gears 47 are alternately arranged and sequentially meshed.

[0275] It should be noted that the embodiments of the present application do not limit the number of gears in the synchronous assembly 40, as long as the synchronous assembly 40 includes an even number of gears, and the first gears 46 and the second gears 47 are alternately arranged and sequentially meshed.

[0276] The above has carried on the detailed introduction to the embodiments of the present application, and the principle and implementation mode of the present application are described by applying specific examples in this paper. The above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed; in view of the above, the content of the specification should not be understood as the limitation of the present application.

Claims

1. A rotation shaft mechanism characterized by comprising: The rotating shaft mechanism comprises: a middle beam; a synchronous gear comprising a first gear and a second gear, the first gear and the second gear are both mounted on the middle beam and arranged in sequence along the width direction of the middle beam, the first gear is engaged with the second gear; the first gear comprises a plurality of first teeth, the plurality of first teeth are arranged in sequence along the circumferential direction of the first gear, the first tooth comprises a first end and a second end, the first end and the second end are arranged oppositely in the tooth width direction of the first tooth; the second gear comprises a plurality of second teeth, the plurality of second teeth are arranged in sequence along the circumferential direction of the second gear, the plurality of second teeth are used for engaging with the plurality of first teeth, the second tooth comprises a third end and a fourth end, the third end and the fourth end are arranged oppositely in the tooth width direction of the second tooth, the third end and the first end are located on one side of the synchronous gear, and the fourth end and the second end are located on the other side of the synchronous gear; the addendum thickness of the first tooth gradually changes from the first end to the second end, the addendum thickness of the second tooth gradually changes from the third end to the fourth end, and the change trend of the addendum thickness of the second tooth is opposite to that of the first tooth; and a first swing arm and a second swing arm, the first swing arm and the second swing arm are respectively located on both sides of the width direction of the middle beam, the first swing arm is fixedly connected with the first gear, and the second swing arm is fixedly connected with the second gear.

2. The rotation shaft mechanism according to claim 1, wherein The first tooth further comprises a first tooth top surface, the first tooth top surface is connected between the first end and the second end, the first tooth top surface comprises a first top edge located at the first end and a second top edge located at the second end, and the length of the first top edge is different from that of the second top edge; the second tooth comprises a second tooth top surface, the second tooth top surface is connected between the third end and the fourth end, the second tooth top surface comprises a third top edge located at the third end and a fourth top edge located at the fourth end, the length of the third top edge is different from that of the fourth top edge, and the size relationship between the length of the first top edge and the length of the second top edge is opposite to that between the length of the third top edge and the length of the fourth top edge.

3. The rotation shaft mechanism according to claim 2, wherein The length of the first top edge is greater than that of the second top edge, the first tooth has a first draft angle θ1, the length of the first top edge is S1, the length of the second top edge is S2, the tooth width of the first tooth is B1, and the first draft angle θ1, the length S1 of the first top edge, the length S2 of the second top edge, and the tooth width B1 of the first tooth satisfy the relationship: tan θ1= (S1-S2) / B1.

4. The rotation shaft mechanism according to claim 3, wherein The angle range of the first draft angle θ1 is within the angle range of 3°~30°.

5. A pivot mechanism according to any one of claims 1 to 4, wherein The first tooth further comprises a first side surface and a second side surface, both of which are connected between the first end and the second end and oppositely arranged in the circumferential direction of the first gear, the first side surface comprises a first side edge at the first end and a second side edge at the second end, and the second side surface comprises a third side edge at the first end and a fourth side edge at the second end. In the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a staggered manner, and the third side edge and the fourth side edge are arranged in a coincident manner, or in the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a coincident manner, and the third side edge and the fourth side edge are arranged in a staggered manner.

6. A pivot mechanism according to any one of claims 1 to 4, wherein The first tooth further comprises a first side surface and a second side surface, both of which are connected between the first end and the second end and oppositely arranged in the circumferential direction of the first gear, the first side surface comprises a first side edge at the first end and a second side edge at the second end, and the second side surface comprises a third side edge at the first end and a fourth side edge at the second end. In the circumferential direction of the first gear, the first side edge and the second side edge are arranged in a staggered manner, and the third side edge and the fourth side edge are arranged in a staggered manner, and the minimum distance between the first side edge and the third side edge is less than or greater than the minimum distance between the second side edge and the fourth side edge.

7. The rotation mechanism according to any one of claims 1 to 4, wherein The addendum circle radius of the first end is different from the addendum circle radius of the second end.

8. The rotation mechanism according to any one of claims 1 to 4, wherein The synchronous gear comprises a first rotating shaft, a second rotating shaft, a first limiting member and a second limiting member. The first rotating shaft and the second rotating shaft are both mounted to the middle beam and oppositely arranged in the width direction of the middle beam, and can rotate relative to the middle beam, the first gear is sleeved on the outer periphery of the first rotating shaft and fixedly connected with the first rotating shaft, and the second gear is sleeved on the outer periphery of the second rotating shaft and fixedly connected with the second rotating shaft. The first limiting member is sleeved on one end of the first rotating shaft and one end of the second rotating shaft and elastically connected between the middle beam and one end of the first gear and one end of the second gear. The second limiting member is sleeved on the other end of the second rotating shaft and the other end of the second rotating shaft and elastically connected between the middle beam and the other end of the first gear and the other end of the second gear.

9. The rotation mechanism according to claim 8, wherein The first limiting member comprises a first connecting portion, a first elastic portion and a second elastic portion, the first connecting portion is connected between the first elastic portion and the second elastic portion, the first elastic portion is spirally arranged around the first rotating shaft and extends in the axial direction of the first rotating shaft, the second elastic portion is spirally arranged around the second rotating shaft and extends in the axial direction of the second rotating shaft, and the rotation direction of the second elastic portion is opposite to that of the first elastic portion.

10. An electronic device, comprising: The electronic device comprises a first shell, a second shell and the rotating shaft mechanism as claimed in any one of claims 1-9, and the rotating shaft mechanism is connected between the first shell and the second shell.

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