POWER TRANSMISSION DEVICE WITH BRAKE STRUCTURE

Abstract

A power transmission device (1) comprising: a transmission (10) comprising a housing (11) and a power transmission assembly (12) arranged in the housing (11), wherein the housing (11) comprises a bushing (111); a motor assembly (20) comprising a motor body (21) and a rotating shaft (22) projecting from a front face of the motor body (21), the rotating shaft (22) being inserted into the bushing (111) and connected to the power transmission assembly (12); and a brake assembly (30) which is installed on the rotating shaft (22) and positioned in the bushing (111) and is configured to generate a braking force on the rotating shaft (22), wherein the transmission (10) further comprises a limiting frame (112) and a limiting block (113) located within the bushing (111), wherein the brake assembly (30) comprises a brake block (31), a brake ring (32) and a brake spring (33), wherein the brake block (31) extends through the rotating shaft (22) and is positioned in the limiting frame (112), the brake ring (32) is arranged on the brake block (31) and is designed to encircle the rotating shaft (22), and the brake spring (33) is arranged around the brake ring (32) and abuts against the limiting block (113), and wherein the brake block (31) comprises a locking block (311), wherein a spacer groove (320) is defined on the brake ring (32) and the locking block (311) is accommodated in the spacer groove (320).

Description

BACKGROUND OF THE REVELATION Technical Area

[0001] The technical field relates to a brake structure and specifically to a power transmission device with a brake structure. Description of the related technique

[0002] Electric lifting columns have been widely used in industrial, medical, and educational settings, particularly in applications such as workbenches and hospital beds that require quiet operation and smooth height adjustment. Additionally, the electric lifting column uses a motor to drive the lead screw, screw thread, worm gear, or other mechanisms for power transmission, and the lifting speed is controlled by the arrangement of the braking structure.

[0003] Furthermore, most engine brake modules of related technology are installed at the rear of the engine. However, this installation method requires reserving installation space and avoiding interference with other mechanical parts. Consequently, this results in limitations in the arrangement of parts and increases the overall length of the engine assembly. Therefore, the inventor's research motivation is to find a way to brake the engine and achieve the desired space savings by positioning it at the rear of the engine.

[0004] In view of the aforementioned disadvantages, the inventor, based on his expert knowledge and extensive research, proposes this revelation to solve the problems of the related technology.

[0005] US Patent 11,788,611 B1 describes an actuator with a worm gear positioning mechanism comprising: a shell housing; a motor with a worm rod; a gear assembly with a guide spindle rod, a worm gear, and a bearing, wherein the worm gear has an annular element with an inner circumferential surface; an outer tube with an outer circumferential surface attached to the inner circumferential surface, wherein the worm gear is positioned radially between the worm rod and the outer tube; and a telescopic tube arranged in the outer tube, comprising an inner tube and a screw nut, wherein the screw nut is movably screwed to the guide spindle rod to make the inner tube linearly movable relative to the outer tube. SUMMARY OF THE REVELATION

[0006] One objective of this disclosure is to provide a power transmission device with a braking structure in which the overall length and volume of the motor are reduced while maintaining the braking effect.

[0007] This disclosure relates to a power transmission device comprising a gearbox, a motor assembly, and a brake assembly. The gearbox includes a housing and a power transmission assembly arranged within the housing, and the housing includes a bushing. The motor assembly includes a motor body and a drive shaft projecting from a front face of the motor body. The drive shaft is inserted into the bushing and connected to the power transmission assembly. The brake assembly is installed on the drive shaft and positioned within the bushing, and the brake assembly exerts a braking force on the drive shaft.

[0008] In one embodiment of this disclosure, the transmission further comprises a limiting frame and a limiting block located within the bushing. The brake assembly includes a brake block, a brake ring, and a brake spring. The brake block extends through the rotating shaft and is positioned on the limiting frame. The brake ring is arranged on the brake block and surrounds the rotating shaft. The brake spring surrounds the brake ring and is held in place by the limiting block to prevent it from disengaging from the rotating shaft.

[0009] In one embodiment of this disclosure, the brake block includes a locking block, wherein a spacer groove is defined on the brake ring, and the locking block is accommodated in the spacer groove.

[0010] In one embodiment of this disclosure, the housing includes an annular plate located on an outer side of the bushing. The motor body includes a projecting surface located on a lower side of the rotating shaft, and the projecting surface is attached to the annular plate and seals the bushing.

[0011] In one embodiment, the motor assembly also includes a bearing. The bearing is arranged on the protruding surface and abuts the brake block.

[0012] In one embodiment of this disclosure, the brake ring contains several arc-shaped parts and the arc-shaped parts are attached to one another and arranged in a ring shape on an outer circumference of the rotating shaft.

[0013] In one embodiment of this disclosure, several anti-slip patterns are arranged on an outer circumference of the brake ring to increase friction with the brake spring.

[0014] In one embodiment of this disclosure, several grooves are arranged on an inner wall surface of the brake ring to store lubricating oil. The grooves extend from the upper surface of the arc-shaped part to the lower side of the arc-shaped part.

[0015] In one embodiment of this disclosure, the brake ring includes a flange on the side facing its engine body.

[0016] In contrast to related technologies, the power transmission device with a brake structure in this disclosure incorporates a brake block positioned between the motor body and the brake ring. This prevents the brake ring from interfering with the bearing at the front of the motor, thus preventing bearing damage. Consequently, the brake ring is isolated from the front motor bearing and is positioned as intended. Furthermore, the gearbox housing can lock the brake spring and prevent it from disengaging from the drive shaft. Additionally, the brake assembly in this disclosure is located within the gearbox housing, which saves space at the rear of the motor and reduces its overall volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The features of the disclosure that are considered novel are precisely set forth in the attached claims. However, the disclosure itself can best be understood by reference to the following detailed description of the disclosure, which describes a number of exemplary embodiments of the disclosure, together with the accompanying drawings; these show: Fig. 1 a schematic view of the application of the power transmission device with a brake structure in this disclosure; Fig. 2 a perspective schematic exploded view of the power transmission device with a brake structure in this disclosure; Fig. 3 a perspective schematic exploded view of the brake structure in this disclosure; Fig. 4 a cross-sectional view of the brake assembly in this disclosure; Fig. 5 a perspective schematic exploded view of the brake ring in this revelation Fig. 6 a cross-sectional view of the blocking block combined in the housing, in this disclosure; and Fig. 7 a cross-sectional view of the power transmission device with a brake structure in this disclosure. DETAILED DESCRIPTION

[0018] The technical content of this disclosure, accompanied by a detailed description of embodiments and relevant drawings, will become apparent as follows. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than limiting.

[0019] See Fig. Figure 1, which is a schematic view of an application of the power transmission device with a braking structure in this disclosure. This disclosure is a power transmission device 1 with a braking structure that is applied to an electric lifting column 2 for controlling the vertical movement of the electric lifting column 2 to adjust the height of a worktable or a hospital bed.

[0020] It should be noted that in this embodiment, the power transmission device 1 with the brake structure is provided on both the front and rear sides of the electric lifting column 2 to increase the lifting speed of the electric lifting column 2. In some embodiments, the electric lifting column 2 may only be provided with one power transmission device 1 with the brake structure.

[0021] See Fig. Figure 2, which is a perspective schematic exploded view of the power transmission device with the brake structure in this disclosure. The power transmission device 1 with the brake structure in this disclosure comprises a gearbox 10, a motor assembly 20, and a brake assembly 30. The gearbox 10 comprises a housing 11 and a power transmission assembly 12, which is arranged in the housing 11. The housing 11 comprises a bushing 111, a limiting frame 112, and a limiting block 113, which are located inside the bushing 111.

[0022] The motor assembly 20 comprises a motor body 21 and a rotating shaft 22, which projects from the front of the motor body 21. The rotating shaft 22 is inserted into the bushing 111 and connected to the power transmission assembly 12. It should be noted that the rotor, stator, coil winding, etc., which are located inside the motor body 21, are not described in detail here.

[0023] The brake assembly 30 is installed on the rotating shaft 22 and positioned in the bushing 111, and the brake assembly 30 exerts a braking force on the rotating shaft 22. Specifically, the brake assembly 30 includes a brake block 31, a brake ring 32, and a brake spring 33. Furthermore, the housing 11 contains an annular plate 114 located on the outer side of the bushing 111. The motor body 21 includes a protruding surface 211 located on the lower side of the rotating shaft 22. The protruding surface 211 is attached to the annular plate 114 and seals the bushing 111.

[0024] Furthermore, in one embodiment of this disclosure, the motor assembly 20 also includes a bearing 23 and a screw thread 24. The bearing 23 is arranged on the projecting surface 211 and abuts the brake block 31. The screw thread 24 is arranged on the rotating shaft 22 and connected to the power transmission assembly 12.

[0025] See Fig. 3, Fig. 4 to Fig. Figure 5, which are a perspective schematic exploded view of the brake assembly in this disclosure, a cross-sectional view of the brake assembly in this disclosure, and a perspective schematic exploded view of the brake ring in this disclosure. The brake block 31 of the brake assembly 30 in this disclosure includes a locking block 311. Additionally, the brake block 31 extends through the rotating shaft 22 and is positioned on the limiting frame 112 of the housing 11. Furthermore, a spacer groove 320 is defined on the brake ring 32. The brake ring 32 is arranged on the brake block 31 and surrounds the rotating shaft 22. Consequently, the locking block 311 is located in the spacer groove 320 to prevent the brake ring 32 from rotating together with the rotating shaft 22. In addition, the brake spring 33 surrounds the brake ring 32 and is held in place by the limiting block 113 to prevent it from disengaging from the rotating shaft 22.

[0026] In more detail, the brake ring 32 comprises several arc-shaped parts 321. These arc-shaped parts 321 are arranged side-by-side in a ring-like pattern on the outer circumference of the rotating shaft 22. Additionally, the brake ring 32 includes a flange 3211 on the side facing the motor body 21. Several anti-slip patterns 3212 are arranged on the outer circumference of the brake ring 32 to increase friction with the brake spring 33. The anti-slip patterns 3212 are arranged to prevent slippage and to prevent the brake spring 33 from slipping or disengaging.

[0027] Furthermore, several grooves 3213 are arranged on the inner wall surface of the brake ring 32 for holding lubricating oil. The grooves 3213 extend from the upper surface of the arc-shaped part 321 to the lower side of the arc-shaped part 321. The lubricating oil is deposited between the contact surfaces of the rotating shaft 22 and the brake ring 32 to provide lubrication and cooling effects when friction occurs between them.

[0028] Furthermore, the brake spring 33 is a compression spring that corresponds to the shape of the brake ring 32. The brake spring 33 can be a right-handed coil spring, which causes the brake spring 33 and the brake ring 32 to contract radially when the rotating shaft 22 rotates in the opposite direction. Conversely, the brake spring 33 and the brake ring 32 can expand radially when the rotating shaft 22 rotates forward.

[0029] See Fig. 6 and Fig.Figure 7 shows a cross-sectional view of the locking block combined in the housing described in this disclosure, and a cross-sectional view of the power transmission device with a brake structure described in this disclosure. The brake assembly 30 of the power transmission device 1 described in this disclosure is located on the front of the motor assembly 20. Additionally, the brake block 31 of the brake assembly 30 is positioned on the limiting frame 112. It should be noted that arranging the brake assembly 30 on the front of the motor assembly 20 can reduce the overall length and volume of the motor assembly 20 while maintaining the intended braking function.

[0030] When the power transmission device 1 of this disclosure is in use, the rotating shaft 22, located on the front of the motor assembly 20, is equipped with a screw thread 24 and inserted into the bushing 111 of the gearbox 10 to be connected to the power transmission assembly 12. Accordingly, the rotating shaft 22 is driven to rotate by the components in the motor body 21.

[0031] It is worth noting that when the rotating shaft 22 rotates in the opposite direction, the brake spring 33 and the brake ring 32 shrink radially. Then the inner wall surface of each arc-shaped part 321 is in frictional contact with the surface of the shaft 22 to exert a braking effect and reduce the rotational speed.

[0032] If, however, the direction of rotation of the rotating shaft 22 is opposite to the direction of rotation of the brake spring 33, the rotating shaft 22 causes each arcuate part 321 and the brake spring to expand radially. Then, no arcuate part 321 touches the surface of the rotating shaft 22. As a result, the rotating shaft 22 can rotate within the brake ring 32, thus maintaining the transmission speed of the rotating shaft 22.

Claims

[1] A power transmission device (1) comprising: a transmission (10) comprising a housing (11) and a power transmission assembly (12) arranged in the housing (11), wherein the housing (11) comprises a bushing (111); a motor assembly (20) comprising a motor body (21) and a rotating shaft (22) projecting from a front face of the motor body (21), the rotating shaft (22) being inserted into the bushing (111) and connected to the power transmission assembly (12); and a brake assembly (30) which is installed on the rotating shaft (22) and positioned in the bushing (111) and is configured to generate a braking force on the rotating shaft (22), wherein the transmission (10) further comprises a limiting frame (112) and a limiting block (113) located within the bushing (111), wherein the brake assembly (30) comprises a brake block (31), a brake ring (32) and a brake spring (33), wherein the brake block (31) extends through the rotating shaft (22) and is positioned in the limiting frame (112), the brake ring (32) is arranged on the brake block (31) and is designed to encircle the rotating shaft (22), and the brake spring (33) is arranged around the brake ring (32) and abuts against the limiting block (113), and wherein the brake block (31) comprises a locking block (311), wherein a spacer groove (320) is defined on the brake ring (32) and the locking block (311) is accommodated in the spacer groove (320). [2] The power transmission device (1) according to claim 1, wherein the housing (11) comprises an annular plate (114) located on an outer side of the bushing (111), the motor body (21) comprises a projecting surface (211) located on a lower side of the rotating shaft (22), and the projecting surface (211) is attached to the annular plate (114) and is configured to seal the bushing (111). [3] The power transmission device (1) according to claim 2, wherein the motor assembly (20) further comprises a bearing (23) and the bearing (23) is arranged on the projecting surface (211) and abuts the brake block (31). [4] The power transmission device (1) according to claim 1, wherein the brake ring (32) comprises several arc-shaped parts (321) and the arc-shaped parts (321) are attached to one another and are arranged in a ring shape on an outer circumference of the rotating shaft (22). [5] The power transmission device (1) according to claim 4, wherein several anti-slip patterns (3212) are arranged on an outer circumference of the brake ring (32). [6] The power transmission device (1) according to claim 5, wherein several grooves (3213) are arranged on an inner wall surface of the brake ring (32) to store a lubricating oil, and the grooves (3213) extend from an upper surface of the arc-shaped part (321) to a lower side of the arc-shaped part (321). [7] The power transmission device (1) according to claim 1, wherein several anti-slip patterns (3212) are arranged on an outer circumference of the brake ring (32). [8] The power transmission device (1) according to claim 1, wherein several grooves (3213) are arranged on an inner wall surface of the brake ring (32) to store a lubricating oil, and the grooves (3213) extend from an upper surface of the arc-shaped part (321) to a lower side of the arc-shaped part (321).

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