Overload protection rotary actuator and application thereof

Abstract

The invention belongs to the technical field of rotary actuators, and particularly relates to an overload protection rotary actuator and application thereof. The overload protection rotary actuator comprises a power source located at the upstream end of power, a reduction gear set driven by the power source, a rotary output piece located at the downstream end of the power and used for outputting rotary driving force to an acting object, and a shell. The rotary output piece is rotatably assembled on the shell, and the rotary output piece is provided with a gear ring arranged in the circumferential direction; a transition gear is arranged in the reduction gear set; a clutch rack is connected between the transition gear and the gear ring; the two ends of the clutch rack are limited in the shell to slide linearly, and the middle of the clutch rack is provided with an elastic clutch section with the rigidity smaller than that of the two ends. The transition gear is meshed with the clutch section; when the load between the transition gear and the clutch section exceeds the limit, the clutch section is bent to form decoupling. According to the actuator, the overload protection capacity which is large enough can be guaranteed, and the size and the cost of the device cannot be remarkably increased.

Description

Technical Field

[0001] The invention belongs to the technical field of rotary actuators, and in particular relates to an overload protection rotary actuator and application thereof. Background Art

[0002] With the development of smart homes and home appliances, consumers have higher requirements for the functionality, intelligence and safety of home appliances. In particular, the design of home appliances such as smart refrigerators tends to be more compact and beautiful. For example, the space restriction on the top of the refrigerator is very strict for zero-embedded refrigerators.

[0003] In these smart home appliances, rotary actuators play a vital role as core components to achieve key functions such as door opening and closing. However, in actual applications, rotary actuators often face overload situations. For example, when the refrigerator door is obstructed or there is abnormal resistance caused by improper user operation, if there is a lack of effective overload protection mechanism, it may cause problems such as motor burnout and gear damage. In severe cases, it may even cause safety accidents such as pinching the user's fingers. Therefore, it is particularly important to develop a rotary actuator that can respond quickly and effectively protect the system under overload conditions.

[0004] In the prior art, in order to achieve overload protection, an electromagnetic clutch is often used to interrupt power transmission. However, this type of solution has obvious limitations: first, the maximum torque that the electromagnetic clutch can withstand is relatively small. If it is to adapt to the application scenario of large torque, the size of the electromagnetic clutch needs to be increased, which is contrary to the current trend of miniaturization pursued by smart home appliances, especially the trend of thin-film actuators in zero-embedded refrigerators. Secondly, the electromagnetic clutch is expensive and has a complex structure, which increases the difficulty of maintenance. In addition, the response speed and sensitivity of the electromagnetic clutch are prone to instability after long-term use, affecting the user experience. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an overload protection rotary actuator and application thereof.

[0006] The object of the present invention is to provide a solution that can ensure a sufficiently large overload protection capability without significantly increasing the size and cost of the device, especially for products with strict restrictions on installation space, such as zero-embedded refrigerators.

[0007] The overload protection rotary actuator includes a power source located at the upstream end of the power, a reduction gear set driven by the power source, a rotary output member located at the downstream end of the power for outputting a rotary driving force to an object of action, and a housing; the rotary output member is rotatably mounted on the housing, and the rotary output member has a circumferentially arranged ring gear; the reduction gear set has a transition gear; a clutch rack is connected between the transition gear and the ring gear; the two ends of the clutch rack are restricted to slide in a straight line in the housing, and the middle part of the clutch rack has a clutch section with a stiffness smaller than the two ends and elasticity; the transition gear is meshed with the clutch section; when the load between the transition gear and the clutch section exceeds the limit, the clutch section bends in a direction away from the transition gear, causing the clutch section to decouple from the transition gear.

[0008] As a further optimization solution for the overload protection rotary actuator, the power source and the reduction gear set are installed in the housing; the rotary output member is rotatably assembled on the housing, one end of the rotary output member is located in the housing, and the other end is exposed from the housing; the end of the rotary output member located in the housing has a circumferentially arranged gear ring.

[0009] As a further optimization solution for the overload protection rotary actuator, a stop block is provided on the housing and located near the ring gear; one end of the clutch rack is slidably arranged in a channel formed between the stop block and the ring gear; the stop block supports the back side of the clutch rack to keep the clutch rack and the ring gear in meshing state.

[0010] As a further optimization solution for the overload protection rotary actuator, the abutment block has a flat abutment surface on a side adjacent to the gear ring; the abutment surface abuts against the back side of the clutch rack, and a lubricating medium is attached therebetween.

[0011] As a further optimization solution for the overload protection rotary actuator, the housing is further provided with a slide groove, and an end of the clutch rack away from the gear ring is slidably fitted in the slide groove.

[0012] As a further optimization solution for the overload protection rotary actuator, the thickness of the clutch segment in the clutch rack is smaller than that at both ends, so that the clutch segment has a relatively small stiffness.

[0013] As a further optimization solution for the overload protection rotary actuator, a stiffness adjustment groove is cut on the back side of the clutch section in the clutch rack to make the clutch section have relatively small stiffness; the stiffness adjustment groove extends along the length direction of the clutch rack.

[0014] As a further optimization solution for the overload protection rotary actuator, the clutch rack is formed by integrating an injection moldable base material and reinforcing fibers doped in the injection moldable base material; the density of the reinforcing fibers dispersed in the clutch section of the clutch rack is relatively low, so that the clutch section has relatively small stiffness.

[0015] As a further optimization scheme of the overload protection rotary actuator, the power source is a motor; the reduction gear group also includes a worm gear, a first transmission gear, a second transmission gear, a third transmission gear, and a reduction planetary gear group; the worm gear is installed on the output shaft of the motor; the first transmission gear is coaxially connected with the second transmission gear, and the diameter of the first transmission gear is greater than the diameter of the second transmission gear; the first transmission gear is meshed with the worm gear; the third transmission gear is connected between the second transmission gear and the reduction planetary gear group, and transmits the rotational driving force of the second transmission gear to the reduction planetary gear group; the reduction planetary gear group transmits the rotational driving force to the transition gear.

[0016] As a further optimization scheme for the overload protection rotary actuator, a flat accommodating chamber is provided in the shell, and the power source, worm gear, first transmission gear, second transmission gear, third transmission gear, and reduction planetary gear set are arranged in the accommodating chamber; a recessed area is provided on one side outside the shell, and the transition gear and clutch section are arranged in the recessed area.

[0017] As a further optimization scheme of the overload protection rotary actuator, the overload protection rotary actuator is used in a refrigerator to drive the opening and closing of a refrigerator door; the refrigerator includes a refrigerator body and a refrigerator door rotatably connected to the refrigerator body; the overload protection rotary actuator is installed on the top of the refrigerator body, and the rotary output member is assembled at the rotating shaft of the refrigerator door to drive the refrigerator door to rotate.

[0018] Beneficial Effects Compared with the prior art, the overload protection rotary actuator provided by the present invention can effectively protect the rotary drive system in household appliances from overload damage. When the rotating output part encounters an abnormal load, the elastic clutch section of the clutch rack will bend and disengage from the transition gear, thereby quickly interrupting the power transmission, avoiding damage to the motor and the reduction gear set due to overload, and reducing the risk of possible collision and pinching injuries to users. In addition, since the height occupied by the rack clutch structure is extremely small and the thickness of the entire actuator is not increased, the actuator can adapt to various application scenarios with space restrictions, such as smart refrigerators. In addition, by adjusting the structure of the clutch section, such as changing the stiffness adjustment slot, the trigger point of the overload protection can be accurately controlled, and actuators with different overload protection trigger forces can be mass-produced at a very low cost to adapt to different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the overall structure of the overload protection rotary actuator.

[0020] Figure 2 Schematic diagram of the back of a rotary actuator for overload protection.

[0021] Figure 3 Schematic diagram of the internal structure of the rotary actuator for overload protection.

[0022] Figure 4 for Figure 2 A partial enlarged view of .

[0023] Figure 5 It is a schematic diagram of the structure of a clutch rack with a thinned section.

[0024] Figure 6 It is a schematic diagram of the structure of a clutch rack with a stiffness adjustment groove.

[0025] Figure 7 It is a partial structural schematic diagram of the reduction gear set.

[0026] Figure 8 and Fig. 9 It is a schematic diagram of the structure of the reduction planetary gear set.

[0027] Fig.10 A top view of a refrigerator.

[0028] Fig.11 This is a partial enlarged view of the actuator part of the refrigerator.

[0029] In the figure: 1, power source; 3, rotating output member; 4, clutch rack; 9, housing; 21, worm gear; 22, first transmission gear; 23, second transmission gear; 24, third transmission gear; 25, reduction planetary gear set; 29, transition gear; 31, ring gear; 41, clutch section; 81, refrigerator body; 82, refrigerator door; 91, stop block; 92, slide groove. DETAILED DESCRIPTION

[0030] The present invention is further illustrated by the following examples, which are intended to more clearly illustrate the technical solution of the present invention and should not be construed as a limitation.

[0031] First, overload protection of rotary actuators.

[0032] like Figure 1 and Figure 2 The overload protection rotary actuator shown includes a power source 1 located at the upstream end of the power, a reduction gear set driven by the power source 1, a rotary output member 3 located at the downstream end of the power for outputting a rotary driving force to an object, and a housing 9. The housing 9 serves as a supporting and protective component of the overall structure; the power source 1 is used to provide the original driving force; the reduction gear set is used to transmit torque and increase torque by reducing the speed through a series of gears; the rotary output member 3 outputs the final rotary force to the target object to drive it to rotate, such as a rotatable door body in household appliances such as refrigerators and ovens.

[0033] like Figures 1 to 3As shown, the power source 1 and the reduction gear set are installed in the housing 9; the rotary output member 3 is rotatably assembled on the housing 9, one end of the rotary output member 3 is located in the housing 9, and the other end is exposed from the housing 9; the end of the rotary output member 3 located in the housing 9 has a circumferentially arranged ring gear 31. The reduction gear set has a transition gear 29; a clutch rack 4 is connected between the transition gear 29 and the ring gear 31; the two ends of the clutch rack 4 are restricted to slide along a straight line in the housing 9, and the middle part of the clutch rack 4 has a clutch section 41 with less rigidity than the two ends and elasticity; the transition gear 29 is meshed with the clutch section 41; when the load between the transition gear 29 and the clutch section 41 exceeds the limit, the clutch section 41 bends in the direction away from the transition gear 29, so that the clutch section 41 is decoupled from the transition gear 29.

[0034] When the actuator is working normally, the clutch rack 4 maintains a good meshing state with the transition gear 29, so that the power can be smoothly transmitted from the power source 1 to the rotating output member 3. When encountering an abnormal situation that causes an excessive load, the clutch section 41 will deform due to its unique low stiffness and elastic characteristics, thereby getting rid of the meshing relationship with the transition gear 29, releasing the load that exceeds the bearing limit, and realizing overload protection with a high response speed. Moreover, this overload protection structure only takes up a very small thickness of the actuator, and will not become a limiting factor in compressing the thickness of the actuator, and will not cause the thickness of the actuator to be too large and restrict installation in various home appliances.

[0035] like Figure 3 and Figure 4 As shown, a stop block 91 is provided on the housing 9 and adjacent to the gear ring 31; one end of the clutch rack 4 is slidably disposed in a channel formed between the stop block 91 and the gear ring 31; the stop block 91 supports the back side of the clutch rack 4 to keep the clutch rack 4 and the gear ring 31 in meshing state, while also preventing the clutch rack 4 from being unrestrictedly bent and broken when the actuator is subjected to an excessive load.

[0036] Preferably, the abutment block 91 has a flat abutment surface on one side adjacent to the gear ring 31 ; the abutment surface abuts against the back side of the clutch rack 4 , so that the angle of the rack adjacent to the gear ring 31 remains consistent.

[0037] Preferably, the abutting portion between the abutting surface and the back surface of the clutch rack 4 is coated with a lubricating medium, such as lubricating oil or grease.

[0038] like Figure 2As shown, the housing 9 also has a slide groove 92, and the end of the clutch rack 4 away from the gear ring 31 is slidably fitted in the slide groove 92. The slide groove 92 and the stop block 91 limit the deviation of the clutch rack 4 at both ends of the clutch rack 4, thereby ensuring that the clutch rack 4 can only slide on a predetermined path when subjected to overload bending. In addition, the slide groove 92 and the stop block 91 limit the deviation of the clutch rack 4 at both ends of the clutch rack 4, so that the bending of the clutch rack 4 mainly occurs in the clutch section 41, so that the critical point of overload protection triggering can be controlled more accurately, so that the actuator can start the overload protection mechanism under the same load conditions, and improve the consistency and reliability of different batches of products.

[0039] In some embodiments, Figure 5 As shown, the thickness of the clutch segment 41 in the clutch rack 4 is smaller than that of the two ends, so that the clutch segment 41 has a relatively small rigidity.

[0040] In some embodiments, Figure 6 As shown, the back side of the clutch section 41 in the clutch rack 4 is cut to form a stiffness adjustment groove, so that the clutch section 41 has a relatively small stiffness; the stiffness adjustment groove extends along the length direction of the clutch rack 4. By presetting the depth and width of the stiffness adjustment groove, a series of clutch racks 4 with different stiffness can be mass-produced to correspond to overload protection triggering critical points of different strengths, thereby conveniently mass-producing actuators of different specifications to adapt to products with different parameter requirements, such as adapting to refrigerators of different sizes.

[0041] In some embodiments, the clutch rack 4 is formed by an injection moldable base material and reinforcing fibers doped in the injection moldable base material; the density of the reinforcing fibers dispersed in the clutch section 41 of the clutch rack 4 is relatively low, so that the clutch section 41 has a relatively small stiffness. The clutch rack 4 is integrally formed by multi-component injection molding, wherein the injection moldable base material can use thermoplastic plastics such as polyamide, polycarbonate, ABS, and the reinforcing fibers can use glass fiber, carbon fiber and aramid fiber.

[0042] like Figure 2 , Figure 3 , Figure 7 , Figure 8 , Fig. 9As shown, the power source 1 is a motor; the reduction gear set also includes a worm gear 21, a first transmission gear 22, a second transmission gear 23, a third transmission gear 24, and a reduction planetary gear set 25; the worm gear 21 is mounted on the output shaft of the motor; the first transmission gear 22 is coaxially connected with the second transmission gear 23, and the diameter of the first transmission gear 22 is greater than the diameter of the second transmission gear 23; the first transmission gear 22 is meshed with the worm gear 21; the third transmission gear 24 is connected between the second transmission gear 23 and the reduction planetary gear set 25, and transmits the rotational driving force of the second transmission gear 23 to the reduction planetary gear set 25; the reduction planetary gear set 25 transmits the rotational driving force to the transition gear 29. The housing 9 has a flat accommodating chamber, in which the power source 1, the worm gear 21, the first transmission gear 22, the second transmission gear 23, the third transmission gear 24, and the reduction planetary gear set 25 are arranged; the housing 9 has a recessed area on one side outside, in which the transition gear 29 and the clutch section 41 are arranged.

[0043] The worm gear 21 and the first transmission gear 22 form the first stage of reduction, the first transmission gear 22 and the second transmission gear 23 form the second stage of reduction, and the reduction planetary gear set 25 forms the third stage of reduction, forming a high multiple reduction ratio in a compact space, which only occupies a small height. The clutch rack 4 and the reduction gear set are separated to avoid mutual interference and improve the reliability of operation. Figure 8 , Fig. 9 As shown, in the third stage reduction structure formed by the reduction planetary gear set 25, the outer ring gear remains fixed, the sun gear serves as the input end, and the planet carrier serves as the output end.

[0044] Second, overload protection rotary actuator application.

[0045] The above-mentioned overload protection rotary actuator can be widely used in various household appliances. For example, in refrigerators, Fig.10 , Fig.11 As shown, the refrigerator includes a refrigerator body 81 and a refrigerator door 82 rotatably connected to the refrigerator body 81; the overload protection rotary actuator is installed on the top of the refrigerator body 81, and the rotary output member 3 is assembled at the rotating shaft of the refrigerator door 82 to drive the refrigerator door 82 to rotate, so as to drive the refrigerator door 82 to rotate to complete opening and closing.

[0046] When the refrigerator door 82 is opened or closed normally, the clutch rack 4 maintains a good meshing state with the transition gear 29, ensuring that power is smoothly transmitted from the power source 1 to the rotating output member 3. However, if the refrigerator door 82 encounters an obstacle or is subjected to abnormal resistance, resulting in an excessive load, the clutch section 41 in the clutch rack 4 will bend due to overload, causing the clutch rack 4 to slip and decouple from the transition gear 29, preventing the power source 1 and the reduction gear set from being damaged due to overload, and also preventing accidental injury to the user. Once the overload condition is relieved, the clutch rack 4 will immediately resume meshing and continue to support the normal operation of the refrigerator door 82.

[0047] It should also be noted that a protective cover (not shown) is usually provided on the top of the refrigerator body 81 of this type of smart refrigerator to accommodate the actuator, avoid direct exposure of the actuator structure, and improve operational reliability.

[0048] The above embodiments are exemplary, and their purpose is to illustrate the technical concept and features of the present invention so that people familiar with the technology in this field can understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An overload protection rotary actuator, characterized in that: The invention comprises a power source (1) located at an upstream end of the power source, a reduction gear set driven by the power source (1), a rotation output member (3) located at a downstream end of the power source and used to output a rotational driving force to an object, and a housing (9); the rotation output member (3) is rotatably mounted on the housing (9), and the rotation output member (3) has a circumferentially arranged ring gear (31); the reduction gear set has a transition gear (29); a clutch rack (29) is connected between the transition gear (29) and the ring gear (31); 4); the two ends of the clutch rack (4) are restricted to slide in a straight line within the housing (9); the middle of the clutch rack (4) has a clutch section (41) with less rigidity than the two ends and with elasticity; the transition gear (29) is meshed with the clutch section (41); when the load between the transition gear (29) and the clutch section (41) exceeds a limit, the clutch section (41) bends in a direction away from the transition gear (29), so that the clutch section (41) and the transition gear (29) are decoupled.

2. The overload protection rotary actuator according to claim 1, characterized in that: A stop block (91) is provided on the housing (9) and adjacent to the gear ring (31); one end of the clutch rack (4) is slidably disposed in a channel formed between the stop block (91) and the gear ring (31); the stop block (91) supports the back side of the clutch rack (4) to maintain the clutch rack (4) and the gear ring (31) in a meshing state.

3. The overload protection rotary actuator according to claim 2, characterized in that: The abutment block (91) has a flat abutment surface on a side adjacent to the gear ring (31); the abutment surface abuts against the back surface of the clutch rack (4), and a lubricating medium is attached between the two.

4. The overload protection rotary actuator according to claim 2, characterized in that: The housing (9) also has a slide groove (92), and an end of the clutch rack (4) away from the gear ring (31) is slidably fitted in the slide groove (92).

5. The overload protection rotary actuator according to any one of claims 1 to 4, characterized in that: The thickness of the clutch section (41) in the clutch rack (4) is smaller than that of the two ends, so that the clutch section (41) has a relatively small rigidity.

6. The overload protection rotary actuator according to any one of claims 1 to 4, characterized in that: A stiffness adjustment groove is cut on the back side of the clutch section (41) in the clutch rack (4), so that the clutch section (41) has a relatively small stiffness; the stiffness adjustment groove extends along the length direction of the clutch rack (4).

7. The overload protection rotary actuator according to any one of claims 1 to 4, characterized in that: The clutch rack (4) is formed by integrating an injection moldable base material and reinforcing fibers doped in the injection moldable base material; the density of the reinforcing fibers dispersed in the clutch section (41) of the clutch rack (4) is relatively low, so that the clutch section (41) has a relatively low rigidity.

8. The overload protection rotary actuator according to any one of claims 1 to 4, characterized in that: The power source (1) is a motor; the reduction gear set further comprises a worm gear (21), a first transmission gear (22), a second transmission gear (23), a third transmission gear (24), and a reduction planetary gear set (25); the worm gear (21) is mounted on an output shaft of the motor; the first transmission gear (22) is coaxially connected to the second transmission gear (23), and the diameter of the first transmission gear (22) is larger than the diameter of the second transmission gear (23); the first transmission gear (22) is meshed with the worm gear (21); the third transmission gear (24) is connected between the second transmission gear (23) and the reduction planetary gear set (25) to transmit the rotational driving force of the second transmission gear (23) to the reduction planetary gear set (25); and the reduction planetary gear set (25) transmits the rotational driving force to the transition gear (29).

9. The overload protection rotary actuator according to claim 8, characterized in that: The housing (9) has a flat accommodating chamber in its interior, and the power source (1), the worm gear (21), the first transmission gear (22), the second transmission gear (23), the third transmission gear (24), and the reduction planetary gear set (25) are arranged in the accommodating chamber; the housing (9) has a recessed area on one side outside, and the transition gear (29) and the clutch section (41) are arranged in the recessed area.

10. Application of the overload protection rotary actuator according to any one of claims 1 to 9, characterized in that: The overload protection rotary actuator is used in a refrigerator to drive a refrigerator door (82) to open and close; the refrigerator comprises a refrigerator body (81) and a refrigerator door (82) rotatably connected to the refrigerator body (81); the overload protection rotary actuator is mounted on the top of the refrigerator body (81), and the rotary output member (3) is mounted on the rotating shaft of the refrigerator door (82) to drive the refrigerator door (82) to rotate.

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