Electric holder support and projection equipment

Abstract

The invention discloses an electric cradle head support and projection equipment, the electric cradle head support comprises a support shell, a chassis, a driving part and a gear slipping mechanism, the gear slipping mechanism comprises a first gear, a second gear, a damping locking part and a rotating shaft assembly, the first gear, the second gear and the damping locking piece are arranged on the rotating shaft assembly in a stacked and sleeved mode, the first gear and the second gear are clamped between the support shell and the damping locking piece, and the first gear and the second gear are connected in a damping rotating mode. The driving part is arranged in the support shell and is in transmission connection with the first gear, the chassis is arranged at the bottom of the support shell and is rotationally connected with the support shell, and the second gear is in transmission connection with the chassis. The electric holder support and the projection equipment are simple in structure and beneficial to compressing the height of the whole electric holder support.

Description

Technical Field

[0001] The present invention relates to the technical field of projection equipment, and in particular to an electric pan / tilt stand and projection equipment. Background Art

[0002] Since the projection equipment often needs to be tilted toward the projection screen, the projected image will be deformed into a trapezoid, which greatly affects the user's viewing experience. Therefore, the general method is to add an electric pan / tilt head to the projection equipment to drive the projection optical machine to rotate relative to the bracket, so that the projection direction of the optical machine reaches a suitable projection angle, so that the shape of the projection image can be improved.

[0003] However, since users often manually rotate the projector to further adjust the projection angle during use, this may damage the drive motor inside the projector during the rotation process. A general practice is to set a damping structure between the multiple layers of rotating disks to achieve an electric and manual integrated design. However, this structure is relatively complex and will result in a high thickness of the rotating structure, which is not conducive to compression. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes an electric pan-tilt bracket and a projection device, which have a simple structure and are conducive to compressing the height of the entire electric pan-tilt bracket.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention discloses an electric pan-tilt head bracket, comprising a bracket shell, a chassis, a driving member and a gear sliding mechanism, wherein the gear sliding mechanism comprises a first gear, a second gear, a damping locking member and a rotating shaft assembly, wherein the first gear, the second gear and the damping locking member are respectively stacked and sleeved on the rotating shaft assembly, the first gear and the second gear are clamped between the bracket shell and the damping locking member, and the first gear and the second gear are rotationally connected in a damping manner; the driving member is arranged in the bracket shell and is transmission-connected to the first gear, the chassis is arranged at the bottom of the bracket shell and is rotationally connected to the bracket shell, and the second gear is transmission-connected to the chassis.

[0007] Preferably, a first groove is formed on a side of the first gear facing away from the second gear, the shaft assembly penetrates into the first groove, and at least a portion of the damping locking member is located in the first groove.

[0008] Preferably, a second groove is formed on a side of the second gear close to the first gear, the shaft assembly passes through the second groove, and at least a portion of the first gear extends into the second groove.

[0009] Preferably, the gear slipping mechanism also includes a pressure plate, which is fixed in the bracket shell, one end of the rotating shaft assembly abuts against the inner wall of the bracket shell, and the other end abuts against the pressure plate; the first gear and the second gear are clamped between the pressure plate and the bracket shell.

[0010] Preferably, the rotating shaft assembly includes a center rod and a rotating cylinder, one end of the center rod abuts against the inner wall of the bracket shell, and the other end abuts against the pressure plate; the rotating cylinder is sleeved with the center rod and is rotatably connected to the center rod, and the first gear, the second gear and the damping locking member are respectively stacked and sleeved on the outer wall surface of the rotating cylinder.

[0011] Preferably, the center rod is circumferentially clamped to the bracket shell and / or the pressure plate, and the second gear and the damping locking member are circumferentially clamped to the rotating drum to rotate synchronously with the rotating drum.

[0012] Preferably, a first flange is formed at the end of the rotating drum away from the damping locking member, the first flange abuts between the second gear and the pressure plate, and the first gear and the second gear are clamped between the first flange and the damping locking member.

[0013] Preferably, the damping locking member includes a nut, an elastic member, a first gasket and a second gasket, and the nut, the elastic member, the first gasket and the second gasket are respectively sleeved and fixed on the rotating shaft assembly, the elastic member is clamped between the first gear and the nut, the first gasket is clamped between the first gear and the second gear, the second gasket is clamped between the elastic member and the first gear, and the second gasket is clamped with the rotating shaft assembly in the circumferential direction so as to rotate synchronously with the rotating shaft assembly.

[0014] Preferably, the electric pan / tilt head bracket also includes a first connecting member, a second connecting member, a bearing and a gear plate, the first connecting member is fixedly connected to the top side of the inner wall of the bracket shell, the second connecting member and the chassis are coaxially rotatably connected to the bracket shell, and the second connecting member is arranged on the bottom side of the inner wall of the bracket shell, the gear plate is fixedly connected to the side of the second connecting member away from the chassis, and the second gear is meshed with the gear plate; the first connecting member is provided with a limit block along the circumferential direction, and the limit block abuts against the first wall surface of the bearing; the second connecting member is provided with a clamping plate protruding upward along the circumferential direction, and the clamping plate abuts against the second wall surface of the bearing; the first wall surface and the second wall surface of the bearing are rotatably connected.

[0015] In a second aspect, the present invention discloses a projection device, comprising a projector body and the electric pan / tilt stand described in the first aspect, wherein the projector body is connected to the stand housing and can rotate relative to the stand housing.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the electric pan-tilt head bracket and projection equipment proposed in the present invention, wherein a gear slipping mechanism is arranged between the driving member and the chassis, and the gear slipping mechanism comprises at least two gears stacked in the height direction, so that rotational damping is formed between the two gears, and the relationship between the damping force and the output torque of the driving member is reasonably controlled, so that an electric and manual integrated rotation structure can be further realized, so that stable transmission can be achieved when the driving member outputs electricity, and slipping can be achieved when manually rotated, thereby avoiding damage to the driving member when the projector body is manually rotated; wherein the two gears in the gear slipping mechanism are respectively connected to the driving member and the chassis for transmission, and the two gears and the damping locking member are stacked with each other, the structure is simple and is conducive to compressing the height of the entire electric pan-tilt head bracket.

[0017] In a further solution, a first groove capable of accommodating at least a portion of the damping locking member is formed on a side of the first gear facing away from the second gear, and a second groove capable of accommodating at least a portion of the first gear is formed on a side of the second gear close to the first gear. By stacking such structures, the height of the entire rotating structure can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a projection device according to a preferred embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A partial cross-sectional schematic diagram of an electric pan / tilt bracket of a projection device;

[0020] Figure 3 yes Figure 2 Schematic diagram of the exploded view of the electric gimbal bracket;

[0021] Figure 4 yes Figure 3 The enlarged schematic diagram of point A in the middle;

[0022] Figure 5 yes Figure 1 Schematic diagram of the exploded structure of the electric pan / tilt bracket of the projection equipment;

[0023] Figure 6 yes Figure 5 The enlarged schematic diagram of point B in the middle;

[0024] Figure 7 yes Figure 1 Schematic diagram of the internal top side structure of the electric pan / tilt bracket of the projection equipment;

[0025] Figure 8 yes Figure 1 A schematic diagram of the internal bottom structure of the electric pan / tilt bracket of a medium projection device;

[0026] Fig. 9 yes Figure 7 Schematic diagram of the exploded structure of the gear slip mechanism of the electric pan / tilt bracket;

[0027] Fig.10 yes Figure 7 Schematic diagram of the assembly structure of the gear sliding mechanism of the electric pan / tilt bracket;

[0028] Fig.11 yes Fig.10 Enlarged schematic diagram of point C in the middle.

[0029] Description of Figure Numbers:

[0030] 100. Electric PTZ bracket;

[0031] 10. bracket housing; 11. upper housing; 12. lower housing;

[0032] 20. Chassis;

[0033] 30. driving member; 31. output gear;

[0034] 40. Gear slip mechanism; 41. First gear; 411. First groove; 42. Second gear; 421. Second groove; 43. Damping locking member; 431. Nut; 432. Elastic member; 433. First gasket; 434. Second gasket; 435. Third gasket; 44. Rotating shaft assembly; 441. Center rod; 4411. Stop end; 442. Rotating drum; 4421. First flange; 45. Pressing plate;

[0035] 50. first connecting member; 51. limiting block;

[0036] 60. Second connecting member; 61. Clamping plate;

[0037] 70. bearing; 71. first wall surface; 72. second wall surface;

[0038] 80. Gear plate;

[0039] 91. Fixed disk; 92. Ring disk;

[0040] 200. Projector body. DETAILED DESCRIPTION

[0041] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0042] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and circuit / signal communication.

[0043] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] like Figure 1 As shown, a preferred embodiment of the present invention discloses a projection device and an electric pan-tilt bracket thereof, wherein the projection device includes an electric pan-tilt bracket 100 and a projector body 200, and structures such as a lens, an optical machine, and a fan are all arranged in the projector body 200. The projector body 200 is connected to the electric pan-tilt bracket 100 and can rotate relative to the electric pan-tilt bracket 100 to adjust the pitch angle.

[0046] Combination Figure 2 The electric pan / tilt bracket 100 includes a bracket housing 10, a chassis 20, a driving member 30 and a gear sliding mechanism 40. The projector body 200 is connected to the bracket housing 10 and can rotate relative to the bracket housing 10. The driving member 30 is disposed in the bracket housing 10, and the chassis 20 is disposed at the bottom of the bracket housing 10 and is rotatably connected to the bracket housing 10; wherein the driving member 30 is transmission-connected to the gear sliding mechanism 40, and the gear sliding mechanism 40 is transmission-connected to the chassis 20. The chassis 20 at least partially extends out of the bottom of the bracket housing 10 to contact the desktop, thereby supporting the projection device.

[0047] Furthermore, the electric pan-tilt bracket 100 further includes a first connecting member 50, a second connecting member 60, a bearing 70 and a gear plate 80. Figures 3 to 6The bracket housing 10 can be divided into an upper shell 11 and a lower shell 12, and the two are fixedly assembled by fasteners such as screws. The driving member 30, the gear sliding mechanism 40, and the first connecting member 50 are fixed to the inner wall of the upper shell 11 respectively, and the second connecting member 60, the gear plate 80 and the chassis 20 are fixed to each other and coaxially connected to the lower shell 12. The gear plate 80 rotates synchronously with the chassis 20. The chassis 20 is located at the bottom of the lower shell 22 to support the entire projection device. The second connecting member 60 is provided on the inner wall of the lower shell 12. The gear plate 80 is fixedly connected to the side of the second connecting member 60 away from the lower shell 12, and the gear plate 80 is meshed with the gear sliding mechanism 40. One of the first connecting member 50 and the second connecting member 60 is fixedly connected to the first wall surface 71 of the bearing 70, and the other is fixedly connected to the second wall surface 72 of the bearing 70, and the first wall surface 71 of the bearing 70 is connected to the second wall surface 72 of the bearing 70.

[0048] Specifically, combined Figure 6 and Figure 7 The first connecting member 50 is provided with a limit block 51 along the circumferential direction to limit the bearing 70 therein, and the limit block 51 abuts against the first wall surface 71 of the bearing 70; Figure 8 , the second connecting member 60 is provided with a clamping plate 61 protruding upward along the circumferential direction, and the clamping plate 61 abuts against the second wall surface 72 of the bearing 70; the first wall surface 71 and the second wall surface 72 can rotate relative to each other almost without friction. In this specific embodiment, the bearing 70 is a radial bearing divided into an inner part and an outer part, and the inner part and the outer part of the bearing are connected by ball rotation, wherein the first wall surface 71 is the outer wall surface of the bearing 70, and the second wall surface 72 is the inner wall surface of the bearing 70, and the multiple clamping plates 61 protruding along the circumferential direction tightly press the inner wall surface of the bearing 70 in the radial direction; in other embodiments, the bearing 70 can also adopt an axial bearing divided into an upper part and a lower part, and the upper part and the lower part of the bearing are connected by ball rotation.

[0049] The first connecting member 50 may be a component independent of the upper shell 11 or a structure integrated with the upper shell 11 ; the second connecting member 60 may be a component independent of the chassis 20 or a structure integrated with the chassis 20 .

[0050] In this specific embodiment, based on the larger diameter of the gear plate 80, the electric pan-tilt bracket 100 also includes a fixed plate 91 and a circular ring plate 92. The fixed plate 91 is used to pad under the gear plate 80, and the circular ring plate 92 is used to pad above the gear plate 80 to prevent the gear plate 80 from tilting when subjected to uneven force and affecting the meshing of the gear plate 80 with the gear sliding mechanism 40.

[0051] The gear slip mechanism 40 can transmit torque in the electric mode on the one hand, and reduce the torque transmitted to the driving member 30 in the manual rotation mode on the other hand. Fig. 9The gear sliding mechanism 40 includes a first gear 41, a second gear 42, a damping locking member 43 and a shaft assembly 44. The first gear 41, the second gear 42 and the damping locking member 43 are respectively stacked and sleeved on the shaft assembly 44. The first gear 41 and the second gear 42 are clamped between the bracket housing 10 and the damping locking member 43, and the first gear 41 and the second gear 42 are connected in a damping rotation manner. The output gear 31 of the driving member 30 is meshed with the first gear 41, and the second gear 42 is meshed with the gear plate 80. The driving member 30 may be, for example, a motor.

[0052] Refer to Figure 4 A first groove 411 is formed on the side of the first gear 41 away from the second gear 42, the shaft assembly 44 penetrates into the first groove 411, and at least a portion of the damping locking member 43 is located in the first groove 411. A second groove 421 is formed on the side of the second gear 42 close to the first gear 41, the shaft assembly 44 penetrates into the second groove 421, and at least a portion of the first gear 41 extends into the second groove 421. By providing the first groove 411 and / or the second groove 421, the height of the stacked gear structure can be effectively reduced. The material of the first gear 41 and the second gear 42 is preferably an alloy material to better avoid damage between the two gears due to friction.

[0053] Combination Figures 9 to 11 The gear sliding mechanism 40 also includes a pressure plate 45, which is fixed in the bracket shell 10. One end of the rotating shaft assembly 44 abuts against the inner wall of the bracket shell 10, and the other end abuts against the pressure plate 45; and the pressure plate 45 presses the second gear 42 to limit the positions of the first gear 41 and the second gear 42 to prevent them from falling; further, the pressure plate 45 is fixed to the upper shell 11 by fasteners such as screws, so that the first gear 41 and the second gear 42 are clamped between the pressure plate 45 and the upper shell 11.

[0054] Refer to Figure 4 The rotating shaft assembly 44 includes a center rod 441 and a rotating cylinder 442. The center rod 441 passes through the first gear 41 and the second gear 42, and passes through the first groove 411 and the second groove 421, so that one end of the center rod 441 abuts against the inner wall of the upper shell 11, and the other end abuts against the pressure plate 45; the rotating cylinder 442 is sleeved with the center rod 441 and is rotatably connected with the center rod 441, and the first gear 41, the second gear 42 and the damping locking member 43 are respectively stacked and sleeved on the outer wall surface of the rotating cylinder 42.

[0055] The center rod 441 is clamped to the upper shell 11 and / or the pressure plate 45 in the circumferential direction, so that the center rod 441 is restricted in both the circumferential direction and the axial direction and does not rotate. In this embodiment, the upper end of the center rod 441 is a rotation-stopping end 4411, and the rotation-stopping end 4411 is clamped to the upper shell 11 in the circumferential direction. The center of the first gear 41 has a circular hole, which can be relatively rotatably sleeved on the rotating cylinder 442; and the second gear 42 and the damping locking member 43 are clamped to the rotating cylinder 442 in the circumferential direction to rotate synchronously with the rotating cylinder 442.

[0056] A first flange 4421 is formed at the end of the rotating drum 442 away from the damping locking member 43 . The first flange 4421 abuts between the second gear 42 and the pressure plate 45 and will not fall off. The first gear 41 and the second gear 42 are clamped between the first flange 4421 and the damping locking member 43 .

[0057] The damping locking member 43 includes a nut 431, an elastic member 432, a first gasket 433 and a second gasket 434. The nut 431, the elastic member 432, the first gasket 433 and the second gasket 434 are respectively sleeved and fixed on the shaft assembly 44. The elastic member 432 is clamped between the first gear 41 and the nut 431, and the first gasket 433 is clamped between the first gear 41 and the second gear 42 to prevent the mutual friction surface between the first gear 41 and the second gear 42 from being too large and causing damage; the second gasket 434 is clamped between the elastic member 432 and the first gear 41, and the second gasket 434 is circumferentially engaged with the shaft assembly 44 to rotate synchronously with the shaft assembly 44; the damping friction force between the first gear 41 and the second gear 42 can be controlled by the tightening stroke of the nut 431. In this specific embodiment, the damping locking member 43 further includes a third gasket 435 , which is clamped between the nut 431 and the elastic member 432 , and the third gasket 435 is circumferentially engaged with the shaft assembly 44 to rotate synchronously with the shaft assembly 44 .

[0058] The output gear 31 of the driving member 30 meshes with the first gear 41 , and the second gear 42 meshes with the gear plate 80 , so that the gear slip mechanism 40 can transmit torque in electric mode and reduce the torque transmitted to the driving member 30 in manual mode.

[0059] In the electric rotation mode, the torque output by the driving member 30 to the first gear 41 is smaller than the friction torque between the first gear 41 and the second gear 42, so that the first gear 41 and the second gear 42 will not rotate relative to each other. At this time, the projector body 200, the bracket shell 10, the driving member 30, the gear sliding mechanism 40, the first connecting member 50, and the first wall 71 of the bearing 70 are relatively stationary, and these structures as a whole rotate relative to the second wall 72 of the bearing 70, the gear plate 80, the second connecting member 60, the fixed plate 91, the annular plate 92, and the chassis 20, thereby realizing electric rotation.

[0060] In the manual rotation mode, the user applies force to the projector body 200 or the bracket shell 10, and the force is transmitted to the first gear 41 and the second gear 42 through the upper shell 11, the center rod 441, and the rotating cylinder 442 to drive the first gear 41 and the second gear 42 to move circumferentially along the gear plate 80. Since the second gear 42 is meshed with the gear plate 80, the second gear 42 will inevitably be subjected to the torque of the reaction force of the gear plate 80 when moving circumferentially around the gear plate 80. The reaction force torque from the gear plate 80 is greater than the friction torque between the first gear 41 and the second gear 42, but less than the rotational torque of the output shaft of the driving member 30. Therefore, the second gear 42 rotates relative to the first gear 41 (that is, the two slip in the circumferential direction). At the same time, the first gear 41 is stationary relative to the driving member 30, and the second gear 42 can move relative to the gear plate 80 (at this time, the second gear 42 is rotating while also revolving around the gear plate 80, that is, the second gear 42 is meshed on the gear plate 80 and moves axially therefrom). At this time, the projector body 200, the bracket shell 10, the driving part 30, the first gear 41, the first connecting part 50, and the first wall 71 of the bearing 70 remain relatively stationary, and these structures rotate relative to the second wall 72 of the bearing 70, the gear plate 80, the second connecting part 60, the fixed plate 91, the annular plate 92, and the chassis 20, thereby achieving manual rotation.

[0061] The projection device and electric pan-tilt head bracket thereof provided by the preferred embodiment of the present invention comprise at least two gears stacked in the height direction, so that rotational damping is formed between the two gears, and the relationship between the damping force and the output torque of the driving member is reasonably controlled, thereby realizing an electric pan-tilt head bracket integrated with electric and manual operation, so that not only stable transmission can be achieved when the driving member outputs electric power, but also slipping can be achieved when manually rotated, thereby avoiding damage to the driving member when the projection device is manually rotated.

[0062] The background section of the present invention may contain background information about the problem or environment of the present invention, rather than describing the prior art by others. Therefore, the content contained in the background section is not an admission by the applicant that the prior art is available.

[0063] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of mutual contradiction, the technical personnel in this field can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope defined by the attached claims.

Claims

1. An electric pan / tilt bracket, characterized in that: It includes a support housing, a chassis, a driving member and a gear sliding mechanism, wherein the gear sliding mechanism includes a first gear, a second gear, a damping locking member and a rotating shaft assembly; The first gear, the second gear and the damping locking member are respectively stacked and sleeved on the rotating shaft assembly, the first gear and the second gear are clamped between the bracket housing and the damping locking member, and the first gear and the second gear are connected in a damping rotation manner; The driving member is arranged in the bracket housing and is transmission-connected to the first gear; the chassis is arranged at the bottom of the bracket housing and is rotationally connected to the bracket housing; and the second gear is transmission-connected to the chassis.

2. The electric pan / tilt bracket according to claim 1, characterized in that: A first groove is formed on a side of the first gear away from the second gear, the shaft assembly penetrates into the first groove, and at least a portion of the damping locking member is located in the first groove.

3. The electric pan / tilt bracket according to claim 1, characterized in that: A second groove is formed on a side of the second gear close to the first gear, the shaft assembly passes through the second groove, and at least a portion of the first gear extends into the second groove.

4. The electric pan / tilt bracket according to claim 1, characterized in that: The gear slipping mechanism also includes a pressure plate, which is fixed in the bracket shell. One end of the rotating shaft assembly abuts against the inner wall of the bracket shell, and the other end abuts against the pressure plate; the first gear and the second gear are clamped between the pressure plate and the bracket shell.

5. The electric pan / tilt bracket according to claim 4, characterized in that: The rotating shaft assembly includes a center rod and a rotating cylinder, one end of the center rod abuts against the inner wall of the bracket shell, and the other end abuts against the pressure plate; the rotating cylinder is sleeved with the center rod and is rotatably connected to the center rod, and the first gear, the second gear and the damping locking member are respectively stacked and sleeved on the outer wall surface of the rotating cylinder.

6. The electric pan / tilt bracket according to claim 5, characterized in that: The center rod is circumferentially clamped to the bracket shell and / or the pressure plate, and the second gear and the damping locking member are circumferentially clamped to the rotating drum to rotate synchronously with the rotating drum.

7. The electric pan / tilt bracket according to claim 5, characterized in that: A first flange is formed at the end of the rotating drum away from the damping locking member. The first flange abuts between the second gear and the pressure plate. The first gear and the second gear are clamped between the first flange and the damping locking member.

8. The electric pan / tilt stand according to claim 1, characterized in that: The damping locking member includes a nut, an elastic member, a first gasket and a second gasket. The nut, the elastic member, the first gasket and the second gasket are respectively sleeved and fixed on the rotating shaft assembly. The elastic member is clamped between the first gear and the nut, the first gasket is clamped between the first gear and the second gear, the second gasket is clamped between the elastic member and the first gear, and the second gasket is clamped with the rotating shaft assembly in the circumferential direction so as to rotate synchronously with the rotating shaft assembly.

9. The electric pan / tilt bracket according to claim 1, characterized in that: It also includes a first connecting member, a second connecting member, a bearing and a gear plate, the first connecting member is fixedly connected to the top side of the inner wall of the bracket shell, the second connecting member and the chassis are coaxially rotatably connected to the bracket shell, and the second connecting member is arranged on the bottom side of the inner wall of the bracket shell, the gear plate is fixedly connected to the side of the second connecting member away from the chassis, and the second gear is meshed with the gear plate; the first connecting member is provided with a limit block along the circumferential direction, and the limit block abuts against the first wall surface of the bearing; the second connecting member is provided with a clamping plate protruding upward along the circumferential direction, and the clamping plate abuts against the second wall surface of the bearing; the first wall surface and the second wall surface of the bearing are rotatably connected.

10. A projection device, characterized in that: It comprises a projector body and the electric pan / tilt head bracket according to any one of claims 1 to 9, wherein the projector body is connected to the bracket shell and can rotate relative to the bracket shell.

Images