Worm speed reduction transmission device

Abstract

The invention discloses a worm speed reduction transmission device which comprises a shell assembly, a main worm assembly, an auxiliary worm assembly and a half shaft assembly, wherein the main worm assembly and the auxiliary worm assembly are installed in the shell assembly. The half shaft assembly is composed of an input half shaft and an output half shaft, the reduction ratio adjusting assembly comprises a driving gear ring and a driven gear ring, the driving gear ring is fixedly connected with the input half shaft, and the driven gear ring is fixedly connected with the output half shaft; the first transmission gears are evenly distributed along the inner circumference of the driving gear ring and meshed with the driving gear ring. The second transmission gears are evenly distributed along the inner circumference of the driven gear ring and meshed with the driven gear ring. An eccentric wheel is arranged on the first transmission gear, an adjusting groove is formed in the eccentric wheel, the shaft rod is arranged in the adjusting groove in a sliding mode, electromagnetic blocks are arranged at the two ends of the adjusting groove and on the shaft rod, and the position of the shaft rod in the adjusting groove is controlled through the electromagnetic blocks to change the eccentric distance so that the transmission ratio can be continuously adjusted. The large reduction ratio and the self-locking characteristic of worm transmission are kept, and meanwhile the requirements of load change and speed adjustment are met.

Description

Technical Field

[0001] This invention relates to transmission technology, and more particularly to a worm gear reducer transmission. Background Technology

[0002] Worm gear reducers are used in applications requiring large reduction ratios and self-locking functions because they can achieve a large transmission ratio in a single stage.

[0003] Existing technology, such as Chinese patent application CN112388666A, discloses a robot shoulder joint device. In this patent, a worm gear pair is used to realize the lateral swing of the robot arm, and the self-locking characteristic of the worm gear transmission is used to lock the joint position when power is off.

[0004] The transmission ratio of a traditional worm gear pair is determined by the number of worm threads and the number of teeth on the worm wheel. Once manufactured, the reduction ratio is a fixed value. It is impossible to dynamically adjust the output speed and torque according to actual load changes, speed requirements, or process specifications. If the transmission characteristics need to be changed, the machine must be stopped and the corresponding worm wheel or worm component replaced.

[0005] To address the issue of a fixed speed ratio, existing technologies typically employ multi-motor switching at the drive source, or use tandem gear transmission mechanisms at the front / rear ends, or continuously variable transmissions (CVTs). While these methods can achieve a certain range of speed regulation, they increase the complexity of the transmission chain and are often difficult to implement in situations with severely limited installation space. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention proposes a worm gear reducer that uses electromagnetic adjustment of the eccentricity to achieve continuous adjustment of the transmission ratio without changing the number of worm threads or the number of worm wheel teeth.

[0007] The technical solution of this invention is implemented as follows: A worm gear reducer includes a housing assembly, a main worm gear assembly and a secondary worm gear assembly installed inside the housing assembly, and a half-shaft assembly, characterized in that... The half-shaft assembly consists of an input half-shaft and an output half-shaft. The reduction ratio adjustment component includes a driving gear ring and a driven gear ring. The driving gear ring is fixedly connected to the input half-shaft, and the driven gear ring is fixedly connected to the output half-shaft. Multiple first transmission gears are evenly distributed along the inner circumference of the driving gear ring and mesh with it, and multiple second transmission gears are evenly distributed along the inner circumference of the driven gear ring and mesh with it. in, An eccentric wheel is provided on the first transmission gear, and an adjustment groove is provided on the eccentric wheel. The shaft is slidably disposed in the adjustment groove. Electromagnetic blocks are provided at both ends of the adjustment groove and on the shaft. The electromagnetic blocks control the position of the shaft in the adjustment groove to change the eccentricity.

[0008] In this invention, the reduction ratio adjustment assembly further includes a connecting rod, one end of which is slidably connected to a shaft, and the other end is rotatably connected to a second transmission gear via a rotating shaft. An overrunning clutch is provided between the second transmission gear and the rotating shaft for unidirectional power transmission.

[0009] In this invention, the electromagnetic blocks are equidistantly arranged along the circumference of the shaft to provide a stable magnetic field force to maintain the shaft in the set position in the adjustment groove.

[0010] In this invention, the first transmission gear and the second transmission gear are provided in multiple sets, and the initial phase angle between the eccentric wheel in each set and the first transmission gear differs by 360° / n, where n is the number of sets.

[0011] In this invention, the overrunning clutch is configured to transmit power to the second transmission gear only when the connecting rod swings in the first direction, and to allow free rotation when it swings in the second direction.

[0012] In this invention, the adjusting groove is a radially extending straight groove or an arc-shaped groove, used to guide the shaft to move radially to adjust the eccentricity. The connecting rod is provided with a through groove, and the end of the shaft is located in the through groove and can slide therein.

[0013] In this invention, the housing assembly includes a first housing, a second housing, and a third housing connected in sequence, with the main worm gear assembly and the auxiliary worm gear assembly installed inside the second housing.

[0014] In this invention, the secondary worm gear assembly includes a second worm and a second worm wheel, with the second worm wheel mounted on the main worm to achieve two-stage worm gear transmission.

[0015] In this invention, the total transmission ratio of the driving gear ring and the driven gear ring satisfies the following formula: Among them, Z a Indicates the number of teeth on the driving gear ring; Z d Indicates the number of teeth on the driven gear ring; Z p1 Z represents the number of teeth on the first transmission gear; p2 Indicates the number of teeth on the second transmission gear; n a Indicates the rotational speed of the driving gear; n d The value represents the rotational speed of the driven gear ring; r represents the radius of the second transmission gear; k represents the transmission coefficient of the connecting rod; and e represents the eccentricity between the shaft and the center of the eccentric wheel.

[0016] In this invention, the center positions of the first transmission gear and the second transmission gear are fixed, and they can only rotate around their own axes.

[0017] The worm gear reducer transmission device according to the present invention has the following beneficial effects: This invention maintains the large reduction ratio and self-locking characteristics of traditional worm gear transmissions, and adjusts the eccentricity between the eccentric wheel and the shaft through electromagnetic control, thereby continuously changing the transmission ratio between the input shaft and the output shaft of the main worm gear. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the worm gear reducer transmission device of the present invention; Figure 2 This is a schematic diagram of the internal structure of the worm gear reducer of the present invention; Figure 3 This is a schematic diagram of the internal structure of the worm gear reducer of the present invention; Figure 4 This is a partial structural schematic diagram of the worm gear reducer transmission device of the present invention; Figure 5 This is a schematic diagram of the reduction ratio adjustment component of the present invention; Figure 6 This is a schematic diagram of the reduction ratio adjustment component of the present invention from another angle; Figure 7 This is a partial structural schematic diagram of the reduction ratio adjustment component of the present invention; Figure 8 This is an exploded view of the reduction ratio adjustment component of the present invention.

[0019] The reference numerals in the attached drawings are as follows: 10-outer shell assembly, 101-first shell, 102-second shell, 103-third shell, 20-main worm gear assembly, 201-first worm wheel, 202-first worm, 30-secondary worm gear assembly, 301-second worm wheel, 302-second worm, 40-half shaft assembly, 401-first half shaft, 402-second half shaft, 50-reduction ratio adjustment assembly, 501-driving gear ring, 502-driven gear ring, 503-first transmission gear, 504-second transmission gear, 505-eccentric wheel, 506-adjustment groove, 507-shaft, 508-electromagnetic block, 509-connecting rod, 510-through groove, 511-rotating shaft, 512-overrunning clutch. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] Reference Figures 1 to 8 As shown in the figure, this embodiment proposes a worm gear reduction transmission device, including a housing assembly 10, in which a main worm gear assembly 20 and a secondary worm gear assembly 30 are installed.

[0022] The housing assembly 10 includes a first housing 101, a second housing 102, and a third housing 103 connected sequentially to each other. The main worm gear assembly 20 consists of a first worm wheel 201 and a first worm 202; the auxiliary worm gear assembly 30 consists of a second worm wheel 301 and a second worm 302. The second worm wheel 301 is mounted on the first worm 202, and power is transmitted to the main worm gear assembly 20 via the auxiliary worm gear assembly 30.

[0023] In this embodiment, power is generated by the second worm 302 driving the second worm wheel 301, which meshes with it, to rotate. Since the second worm wheel 301 is directly mounted on the first worm 202, the rotation of the second worm wheel 301 drives the first worm 202 to rotate synchronously. The first worm 202 drives the first worm wheel 201, which meshes with it, to rotate, thereby transmitting power to the output end. The power passes through two stages of worms: the secondary worm assembly 30 and the main worm assembly 20. The worm gear meshing transmission achieves two-stage speed reduction, ultimately resulting in a lower speed and higher torque at the output end.

[0024] Specifically, traditional worm gear structures can achieve a large transmission ratio, but when extremely high transmission ratios (exceeding 100:1) are required, the number of worm gear teeth must be extremely large or the number of worm threads must be extremely small, resulting in a very small helix angle and low overall transmission efficiency. In this embodiment, through the mutual transmission between the main worm assembly 20 and the auxiliary worm assembly 30, an extremely high transmission ratio can be achieved while reducing the diameter of the worm gear, making it suitable for transmission scenarios requiring a large reduction ratio and limited space.

[0025] Furthermore, by superimposing the two-stage self-locking effect of the main worm gear assembly 20 and the auxiliary worm gear assembly 30, it can be ensured that the output end cannot drive the input end in any direction under any circumstances. In this case, the worm gear reducer typically does not require and cannot adjust the reduction ratio. In practical applications, its final output speed is generally changed by external means.

[0026] Common methods include: after stopping the machine, replacing it with a secondary worm assembly 30 with a different number of worm threads / worm wheel teeth. When different working conditions need to be addressed, it is not possible to stop the machine before replacing the secondary worm assembly 30.

[0027] Current technology typically employs dual motors to drive the system by changing the drive source. However, in situations where installation space is limited, such as at the joints of robotic arms or biomimetic robots, high torque needs to be output at low speeds. Worm gear reducers cannot dynamically adjust the reduction ratio, and the installation space is extremely small, making it impossible to accommodate multiple motors or gearboxes.

[0028] Refer again Figures 3 to 4As shown, a half-shaft assembly 40 is also installed inside the housing assembly 10. The half-shaft assembly 40 includes a first half-shaft 401 and a second half-shaft 402 disposed on both sides of the first housing 101, and a second worm gear 301 is mounted on the first half-shaft 401. The first half-shaft 401 and the second half-shaft 402 are connected by a first worm gear 202 and a reduction ratio adjustment assembly 50, so that the power of the first half-shaft 401 can be transmitted to the second half-shaft 402.

[0029] Furthermore, the reduction ratio adjustment component 50 includes a driving gear ring 501 and a driven gear ring 502. The driving gear ring 501 is fixedly connected to the first half-shaft 401, the driven gear ring 502 is fixedly connected to one end of the first worm gear 202, and the other end of the first worm gear 202 is fixedly connected to the second half-shaft 402.

[0030] That is, the first half-shaft 401 drives the second half-shaft 402 to rotate via the driving gear ring 501, the driven gear ring 502 and the first worm gear 202.

[0031] In this embodiment, the inner gear ring of the driving gear ring 501 is meshed with a plurality of first transmission gears 503; the inner gear ring of the driven gear ring 502 is also meshed with a plurality of second transmission gears 504. The centers of the first transmission gears 503 and the second transmission gears 504 are fixed.

[0032] An eccentric wheel 505 is provided on one side of the first transmission gear 503, and an adjusting groove 506 is provided on the eccentric wheel 505. A shaft 507 is slidably connected within the adjusting groove 506. Multiple electromagnetic blocks 508 are circumferentially arranged on the shaft 507, and the electromagnetic blocks 508 are also located at both ends of the adjusting groove 506. The position of the shaft 507 within the adjusting groove 506 is adjusted by controlling the magnitude of the magnetic field between two electromagnetic blocks 508.

[0033] Furthermore, a connecting rod 509 is provided at the end of the shaft 507 away from the adjusting groove 506, and a through groove 510 is provided on the connecting rod 509. The end of the shaft 507 away from the adjusting groove 506 is located in the through groove 510 and can slide within the through groove 510.

[0034] Furthermore, a rotating shaft 511 is mounted on one end of the connecting rod 509. A second transmission gear 504 is rotatably connected to the rotating shaft 511, and the second transmission gear 504 is always in mesh with the internal gear ring of the driven gear ring 502.

[0035] In this embodiment, power is transmitted from the first half-shaft 401 to drive the drive gear ring 501 to rotate, and the drive gear ring 501 drives multiple first transmission gears 503 to rotate. Since the first transmission gears 503 are connected to the eccentric wheel 505, the eccentric wheel 505 also rotates. Simultaneously with the rotation of the eccentric wheel 505, the shaft 507 on it rotates with the eccentric wheel 505. When the shaft 507 rotates along the eccentric wheel 505, it drives the connecting rod 509 to swing along the rotation axis 511 via the through groove 510, that is, to rotate around the center of the second transmission gear 504.

[0036] Furthermore, an overrunning clutch 512 is installed on the second transmission gear 504. The overrunning clutch 512 transmits power in only one direction. That is, when the connecting rod 509 rotates in the direction F1 with the second transmission gear 504 as the center, it can drive the second transmission gear 504 to rotate. When the connecting rod 509 rotates in the direction F2 with the second transmission gear 504 as the center, the rotating shaft 511 and the second transmission gear 504 will rotate freely.

[0037] In this embodiment, the position of the shaft 507 within the adjustment groove 506 is adjusted by controlling the magnitude of the magnetic field between the two electromagnetic blocks 508, thereby changing the eccentricity between the shaft 507 and the center of the eccentric wheel 505. Specifically, a larger eccentricity between the shaft 507 and the center of the eccentric wheel 505 indicates a larger swing amplitude of the connecting rod 509 driven by the eccentric wheel 505 and the shaft 507; conversely, a smaller eccentricity indicates a smaller swing amplitude.

[0038] By adjusting the eccentricity between the shaft 507 and the center of the eccentric wheel 505, the transmission ratio between the driving gear ring 501 and the driven gear ring 502 is changed.

[0039] Furthermore, since the oscillation of the connecting rod 509 is reciprocating and the overrunning clutch 512 only transmits power in one direction, the movement of the second transmission gear 504 is intermittent, meaning that it is driven for half the time.

[0040] The system comprises n identical sets of components (e.g., n=4), evenly distributed around the circumference, with the initial phase angle between the eccentric wheel and the first transmission gear in each set differing by 360° / n. As the driving gear ring 501 rotates, the oscillation phases of each connecting rod 509 also differ by 360° / n sequentially. Therefore, at any given time, at least one or two connecting rods 509 are pushing the second transmission gear 504 in the F1 direction, ensuring a constant torque input to the driven gear ring 502 and achieving continuous and smooth rotation.

[0041] Ensure that the second transmission gear can only be driven in the F1 direction to prevent reverse driving. When the connecting rod 509 moves in the F2 direction, to prevent slippage of the overrunning clutch, the second transmission gear 504 continues to rotate by inertia or the push of other connecting rods, without being subject to reverse resistance.

[0042] Specifically, for each revolution of the eccentric wheel 505, the arc length S traversed by the shaft 507 through the connecting rod 509 in the F1 direction is expressed as: S = k e, where k represents the transmission coefficient of the connecting rod; e represents the eccentricity between the shaft and the center of the eccentric wheel.

[0043] Among them, the shaft 507 causes the second transmission gear 504 to rotate at the corresponding angle in the F1 direction via the connecting rod 509. Represented as: The first transmission gear 503 rotates at the same speed as the eccentric wheel 505, that is, the rotational speed n of the first transmission gear 503 is... p1 Represented as: Considering that the eccentric wheel 505 drives the second transmission gear 504 to rotate only once per revolution, the average speed n of a single set of second transmission gears is... p2 Represented as: When multiple sets of second transmission gears 504 work together, the combined speed of the second transmission gears is equivalent to the average speed of a single set of second transmission gears 504, that is, the speed n of the driven gear ring speed 502. d Represented as: In the above formula, Z a Indicates the number of teeth on the driving gear ring; Z d Indicates the number of teeth on the driven gear ring; Z p1 Z represents the number of teeth on the first transmission gear; p2 Indicates the number of teeth on the second transmission gear; n a Indicates the rotational speed of the driving gear; n d The value r represents the rotational speed of the driven gear ring; r represents the radius of the second transmission gear.

[0044] The total transmission ratio i between the driving gear ring 501 and the driven gear ring 502, as described above, is expressed as follows: In this embodiment, the total transmission ratio i is inversely proportional to the eccentricity e. By adjusting the eccentricity e, stepless speed change between the driving gear ring 501 and the driven gear ring 502 is achieved. In the extreme case, when the eccentricity e = 0, the transmission between the driving gear ring 501 and the driven gear ring 502 is interrupted. Therefore, the maximum eccentricity is limited by the length of the adjustment slot to ensure that the connecting rod does not interfere with surrounding components; while the minimum eccentricity > 0 avoids dead points.

[0045] The electromagnetic blocks 508 at both ends of the adjusting groove 506 control the radial position of the shaft 507 in the groove through magnetic force, thereby changing the distance between the shaft and the center of the eccentric wheel, i.e., the eccentricity e. The larger the eccentricity e, the larger the circumferential radius of the shaft 507, the larger the swing amplitude of the connecting rod 509, the larger the angle through which the second transmission gear rotates in each effective stroke, the larger the input angle obtained by the driven gear ring per revolution, and the higher its speed. Ultimately, increasing the eccentricity e reduces the overall transmission ratio (increases the output speed), while decreasing the eccentricity e increases the transmission ratio (decreases the output speed), thus achieving stepless speed regulation.

[0046] Preferably, multiple electromagnetic blocks 508 are arranged circumferentially at equal intervals on the shaft 507, which can provide sufficient magnetic force to overcome the centrifugal force and friction of the shaft 507 and maintain the set position.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A worm gear reducer, comprising a housing assembly (10), a main worm gear assembly (20) and a secondary worm gear assembly (30) installed inside the housing assembly (10), and a half-shaft assembly (40), characterized in that, The half-shaft assembly (40) consists of an input half-shaft and an output half-shaft. The reduction ratio adjustment assembly (50) includes a driving gear ring (501) and a driven gear ring (502). The driving gear ring (501) is fixedly connected to the input half-shaft, and the driven gear ring (502) is fixedly connected to the output half-shaft. Multiple first transmission gears (503) are evenly distributed along the inner circumference of the driving gear ring (501) and mesh with it, and multiple second transmission gears (504) are evenly distributed along the inner circumference of the driven gear ring (502) and mesh with it. in, An eccentric wheel (505) is provided on the first transmission gear (503), and an adjustment groove (506) is provided on the eccentric wheel (505). The shaft (507) is slidably disposed in the adjustment groove (506). Electromagnetic blocks (508) are provided at both ends of the adjustment groove (506) and on the shaft (507). The electromagnetic blocks (508) control the position of the shaft (507) in the adjustment groove (506) to change the eccentricity.

2. The worm gear reducer according to claim 1, characterized in that, The reduction ratio adjustment assembly (50) also includes a connecting rod (509), one end of which is slidably connected to the shaft (507), and the other end is rotatably connected to the second transmission gear (504) via a rotating shaft (511). An overrunning clutch (512) is provided between the second transmission gear (504) and the rotating shaft (511) for unidirectional power transmission.

3. The worm gear reducer according to claim 1, characterized in that, The electromagnetic blocks (508) are equidistantly arranged along the circumference of the shaft (507) to provide a stable magnetic force to maintain the shaft (507) in the set position in the adjustment groove (506).

4. The worm gear reducer according to claim 1, characterized in that, The first transmission gear (503) and the second transmission gear (504) are provided with multiple sets, and the initial phase angle between the eccentric wheel (505) in each set and the first transmission gear (503) differs by 360° / n, where n is the number of sets.

5. The worm gear reducer according to claim 2, characterized in that, The overrunning clutch (512) is configured to transmit power to the second transmission gear (504) only when the connecting rod (509) swings in the first direction, and to allow freewheeling when swinging in the second direction.

6. The worm gear reducer according to claim 1, characterized in that, The adjusting groove (506) is a radially extending straight groove or arc groove, used to guide the shaft (507) to move radially to adjust the eccentricity. The connecting rod (509) is provided with a through groove (510), and the end of the shaft (507) is located in the through groove (510) and can slide therein.

7. The worm gear reducer according to claim 1, characterized in that, The housing assembly (10) includes a first housing (101), a second housing (102) and a third housing (103) connected in sequence, and the main worm gear assembly (20) and the auxiliary worm gear assembly (30) are installed in the second housing (102).

8. The worm gear reducer according to claim 1, characterized in that, The secondary worm gear assembly (30) includes a second worm (302) and a second worm wheel (301). The second worm wheel (301) is mounted on the main worm (202) to realize two-stage worm gear transmission.

9. The worm gear reducer according to claim 1, characterized in that, The total transmission ratio of the driving gear ring (501) and the driven gear ring (502) satisfies the following formula: Among them, Z a Indicates the number of teeth on the driving gear ring; Z d Indicates the number of teeth on the driven gear ring; Z p1 Z represents the number of teeth on the first transmission gear; p2 Indicates the number of teeth on the second transmission gear; n a Indicates the rotational speed of the driving gear; n d The value represents the rotational speed of the driven gear ring; r represents the radius of the second transmission gear; k represents the transmission coefficient of the connecting rod; and e represents the eccentricity between the shaft and the center of the eccentric wheel.

10. The worm gear reducer according to claim 1, characterized in that, The center positions of the first transmission gear (503) and the second transmission gear (504) are fixed, and they can only rotate around their own axes.

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