A full-chain backlash-free transmission mechanism

Abstract

This invention discloses a full-chain backlash-eliminating transmission mechanism, belonging to the field of mechanical equipment. It forms two transmission chains by setting a first transmission unit and a second transmission unit between the power input and power output components. Through the corresponding arrangement of gear transmission components such as helical gears and double gears in the two transmission chains, and the placement of backlash-eliminating force-applying components on the corresponding helical gears, the backlash is eliminated along the entire transmission chain. The full-chain backlash-eliminating transmission mechanism of this invention has a compact structure and flexible design, capable of meeting the dynamic backlash elimination requirements of the entire chain under different design forms. It ensures the accuracy and stability of the transmission mechanism, reduces noise caused by backlash, meets the requirements of high torque and high reduction ratio settings, is easy to miniaturize, has strong compatibility, is easy to process and assemble, and can effectively reduce the application cost of the transmission mechanism, possessing good practical value and application prospects.

Description

Technical Field

[0001] This invention belongs to the field of mechanical equipment, and specifically relates to a full-chain backlash elimination transmission mechanism. Background Technology

[0002] Gear transmission mechanisms are very common in mechanical equipment, playing an important role in transmission devices such as gearboxes. However, during actual installation and operation, due to machining and assembly tolerances of the gears and backlash between the meshing teeth, gear transmission mechanisms generally have a backlash error.

[0003] Currently, traditional methods to reduce backlash in gear transmissions involve improving the machining accuracy of the gear teeth and the gears themselves, and imposing higher requirements on the machining accuracy and form and position tolerances of the rotating shaft and gearbox bearing holes. While these methods can improve the backlash problem of transmission mechanisms to some extent, they inevitably lead to increased manufacturing costs. Moreover, with the operation of the transmission system, most of the gear teeth will wear, which will cause backlash and transmission backlash to gradually increase, failing to fundamentally solve the backlash problem of transmission mechanisms.

[0004] To better address the aforementioned issues, researchers have proposed a series of technical solutions to resolve transmission backlash problems in the existing technology, but these solutions still have certain shortcomings and limitations.

[0005] For example, in existing patents CN201921490608.1 and CN201220054180.8, two coaxially mounted spur gears of the same specification are connected by tension springs and snap rings, allowing them to rotate relative to each other in the circumferential direction, thus meshing the engaged teeth and eliminating the backlash in single-stage gear transmission. In existing patents CN201821309568.1 and CN202120866599.2, compression springs and disc springs are used respectively to spread two coaxially mounted helical gears of the same specification, which are circumferentially positioned by a shaft key, within a limited range. This causes a slight change in the actual meshing tooth thickness of the helical gears, filling the meshing helical teeth in real time to eliminate backlash. While the aforementioned solutions, using a double-layer elastic gear combination to eliminate transmission backlash, can achieve some effect, they require modifications to the size and structure, significantly increasing the difficulty of overall machining and assembly. Secondly, in the above structure, the transmitted torque is limited by the spring force while ensuring backlash elimination. With limited size and a small spring, the transmission rigidity of the transmission mechanism is insufficient. Furthermore, adjusting the backlash elimination force requires repeated disengagement and engagement of the double-plate gear and the ordinary gear, leading to operational inconvenience. In addition, the aforementioned double-layer elastic combination gear must mesh with one ordinary rigid gear and cannot mesh with another similar combination gear, resulting in significant application limitations. Moreover, when the aforementioned double-layer elastic combination gear meshes with two ordinary rigid gears simultaneously, interference may occur, preventing its continuous multi-stage use or its use as an intermediate gear. It can only reduce backlash in a single stage transmission and cannot achieve backlash elimination across the entire transmission chain.

[0006] In the existing patent CN202011614190.8, a full-chain helical gear and the aforementioned double-layer elastic helical gear are used in combination, and the axial preload of the ordinary helical gear shaft compression spring is applied to eliminate the backlash of each gear. However, due to the high difficulty and long cycle of helical gear processing, its processing cost will increase significantly; in addition, the minimum tooth thickness of helical gears is much larger than that of spur gears. When using them for multi-stage high reduction ratio transmission, the structure of the transmission mechanism will be larger, making it unsuitable for use in situations with strong volume constraints or in working conditions where helical gear transmission is not appropriate.

[0007] Furthermore, in many cases, the transmission output shaft does not need to perform a full rotation or too many rotations. Under such requirements, the existing patent CN201420455365.9 uses the same structure as the above-mentioned elastic double-layer gear to eliminate backlash. Its elastic gear part becomes a non-circular sector gear disk, and its side edge exposes the spring adjustment position, which can adjust the backlash without repeatedly disengaging and meshing with ordinary gears, thus eliminating backlash to a certain extent. However, for the above structure, its processing and assembly process is very complicated, and it can usually only reduce the backlash of a single stage transmission, which has obvious application limitations. Summary of the Invention

[0008] In view of one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides a full-chain backlash elimination transmission mechanism, which can realize the overall backlash elimination in a multi-stage transmission process, ensure transmission accuracy, simplify the structure of the transmission mechanism, facilitate the processing and assembly of the transmission mechanism, and reduce the assembly and application costs of the transmission mechanism.

[0009] To achieve the above objectives, the present invention provides a full-chain backlash-free transmission mechanism, comprising a power input component, a power output component, and a transmission module disposed between the two.

[0010] The power input component is a worm gear;

[0011] The transmission module includes a first transmission unit and a second transmission unit. The two transmission units mesh with the worm gear via helical gears, and the two transmission units form two transmission chains between the worm gear and the power output component; and at least one transmission unit includes at least two gears.

[0012] The transmission module includes at least one double gear, which consists of two gears, one of which is a helical gear and the other is a helical gear with the opposite rotation direction to the helical gear or a non-helical gear without self-locking.

[0013] Accordingly, at least some of the helical gears and at least one double gear in the transmission module are axially movable, and a backlash-eliminating force-applying element is provided for at least one axially movable helical gear to provide axial backlash-eliminating force for the helical gear.

[0014] As a further improvement of the present invention, the reduction ratios of the two transmission units are the same.

[0015] As a further improvement of the present invention, the worm gear is a single-start worm gear or a multi-start worm gear;

[0016] and / or

[0017] The power output component is an output gear or an output rack.

[0018] As a further improvement of the present invention, the double gear includes a helical gear and a non-helical gear, and the ratio of the number of teeth of the helical gear to the number of teeth of the non-helical gear is not equal to 1.

[0019] As a further improvement of the present invention, the non-helical gear is a spur gear or a bevel gear.

[0020] As a further improvement of the present invention, the gap-eliminating force-applying component is an elastic component capable of elastic deformation.

[0021] As a further improvement of the present invention, the elastic element includes, but is not limited to, compression spring, tension spring, disc spring or diaphragm spring;

[0022] and / or

[0023] A planar thrust bearing or shim is provided between the backlash-eliminating force-applying component and the end face of the corresponding helical gear.

[0024] As a further improvement of the present invention, the axially displaceable helical gear satisfies the following relationship:

[0025] 2arcsin(h 20 *tanα / d)≥0.9β

[0026] In the formula, β is the magnitude of the slewing backlash; h 20 h is the distance the helical gear can move axially; 10 α is the tooth height of the helical gear; α is the helix angle of the helical gear; d is the pitch circle diameter of the helical gear.

[0027] As a further improvement of the present invention, the power output component is an output gear;

[0028] Both transmission units are identical double gears, namely, a first double gear and a second double gear axially spaced on the same side of the worm;

[0029] The two double gears each include a helical gear meshing with the worm and a spur gear meshing with the output gear; and

[0030] The two double gears can move axially respectively, and each double gear is provided with a backlash elimination force application component, and the force application directions of the two backlash elimination force application components are opposite.

[0031] As a further improvement of the present invention, the power output component is an output rack;

[0032] The two transmission units are respectively located on both sides of the radial direction of the worm; and

[0033] The first transmission unit includes two meshing helical gears, and the second transmission unit includes two identical double gears and a spur gear disposed between the two double gears. The double gears include a helical gear and a spur gear disposed coaxially. One double gear meshes with the worm gear with its helical gear, and the other double gear meshes with the output rack with its helical gear. The two double gears are respectively meshed with independent spur gears by their spur gears.

[0034] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0035] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0036] (1) The full-chain backlash elimination transmission mechanism of the present invention forms two transmission chains by setting a first transmission unit and a second transmission unit between the power input component and the power output component. Then, through the corresponding setting of gear transmission components such as helical gears and double gears in the two transmission chains, and the setting of backlash elimination force application components for the corresponding helical gears, the backlash is eliminated in the entire transmission chain. This ensures the transmission accuracy and stability of the transmission mechanism, meets the requirements of low noise, high torque and high reduction ratio of the transmission mechanism, and the entire mechanism is easy to miniaturize, easy to process and assemble, and has a low setting cost.

[0037] (2) The full-chain backlash elimination transmission mechanism of the present invention can meet the setting requirements under different setting conditions by optimizing the specific form and material of the backlash elimination force application component, simplifying the setting form and setting process of the backlash elimination force application component; at the same time, by setting the planar thrust bearing or shim, the change in the shape of the backlash elimination force application component caused by the rotation of the helical gear can be further avoided, fully ensuring the reliability of the backlash elimination force application component setting and extending the service life of the entire transmission mechanism.

[0038] (3) The full-chain backlash elimination transmission mechanism of the present invention can realize the design of transmission mechanism under different structural forms by optimizing the specific configuration of the two transmission units and the form of the power output component, meet the configuration and use requirements of different application environments, meet the full-chain backlash elimination requirements of the transmission mechanism under different use environments, and improve the applicability and compatibility of the transmission mechanism.

[0039] (4) The full-chain backlash elimination transmission mechanism of the present invention has a compact structure and flexible design. It can meet the full-chain dynamic backlash elimination under different design forms, ensure the transmission accuracy and stability of the transmission mechanism, reduce the noise caused by the existence of backlash, meet the setting requirements of high torque and high reduction ratio, is easy to miniaturize, has strong compatibility, is easy to process and assemble, can effectively reduce the application cost of the transmission mechanism, and has good practical value and application prospects. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a front structural schematic diagram of the full-chain backlash elimination transmission mechanism in Embodiment 1 of the present invention;

[0042] Figure 2 This is a side view of the backlash-free transmission mechanism in Embodiment 1 of the present invention;

[0043] Figure 3 This is a schematic diagram of the tooth meshing relationship of the full-chain backlash elimination transmission mechanism in Embodiment 1 of the present invention;

[0044] Figure 4 This is a front structural schematic diagram of the full-chain backlash elimination transmission mechanism in Embodiment 2 of the present invention;

[0045] Figure 5 This is a side view of the backlash-free transmission mechanism in Embodiment 2 of the present invention;

[0046] Figure 6 This is a schematic diagram of the tooth meshing relationship of the full-chain backlash elimination transmission mechanism in Embodiment 2 of the present invention;

[0047] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0048] 10. Motor; 20. Input worm gear; 30. First double gear; 40. Second double gear; 50. Output gear; 60. Housing; 70. First compression spring; 71. Second compression spring; 130. First planar thrust bearing; 140. Second planar thrust bearing; 201. First worm gear tooth surface; 202. Second worm gear tooth surface; 301. First helical gear; 3011. First helical tooth surface; 302. First spur gear; 3021. First spur tooth surface; 401. Second helical gear; 4011. Second helical tooth surface; 402. Second spur gear; 4021. Second spur tooth surface; 501. First output tooth surface; 502. Second output tooth surface;

[0049] 150, Fifth helical gear; 160, Third double gear; 170, Fifth spur gear; 180, Fourth double gear; 190, Output rack; 200, Sixth helical gear; 240, Shim; 1601, Third helical gear; 1602, Third spur gear; 1801, Fourth helical gear; 1802, Fourth spur gear. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] Example:

[0056] In a preferred embodiment of the present invention, the full-chain backlash-eliminating transmission mechanism includes a power input component, a power output component, a first transmission unit and a second transmission unit disposed between the two, and a backlash-eliminating force-applying component corresponding to at least one transmission unit. By matching the two transmission units with the power input component and the power output component respectively, two transmission chains are formed between the power input component and the power output component, thereby realizing power transmission. Simultaneously, through the setting and function of the backlash-eliminating force-applying component, the transmission backlash between the two transmission chains during power transmission can be accurately eliminated, thereby ensuring the reliability and accuracy of the transmission mechanism in the power transmission process.

[0057] Specifically, in the preferred embodiment, the power input component is a worm gear, which is further preferably a single-start worm gear or a multi-start worm gear. Meanwhile, the power output component is further preferably a gear or a rack.

[0058] Simultaneously, at least one transmission unit includes at least two gears, and the output rotation directions of the gears meshing with the power output component in both transmission units are the same. In actual installation, both transmission units preferably include at least two gears, and the first-stage gears of both transmission units are more preferably helical gears, with the output directions of the last-stage gears being the same.

[0059] Furthermore, the transmission module consisting of two transmission units includes at least one double gear, which in turn includes at least one helical gear, and at least one double gear in the transmission module is axially movable. In actual installation, the axial movement of the double gear can be achieved using mature methods such as optical shafts and slide rails, which will not be elaborated here. Moreover, when the double gear includes two helical gears, the helix directions of the two helical gears should be opposite; when the double gear includes only one helical gear, the other gear is a non-helical gear without self-locking capability, preferably a spur gear or a bevel gear.

[0060] By using a double gear, it can move axially and rotate along the tooth groove of the meshing helical gear, so that all gears in the entire transmission chain are in a meshing state. The backlash of the double gear itself can be eliminated by axial movement, and the method of eliminating backlash by axial movement of the double gear will not affect the meshing relationship of other gears in the entire transmission chain, thus achieving the effect of eliminating backlash.

[0061] Furthermore, in the preferred embodiment, the backlash-eliminating force-applying component is an elastically deformable component, which is configured to correspond to the helical gear. Through elastic deformation, it applies an axial preload to the corresponding helical gear, driving the helical gear to move axially. In actual implementation, the number of backlash-eliminating force-applying components can be one or more; more preferably, the backlash-eliminating force-applying component can be one or more of a tension spring, compression spring, disc spring, and diaphragm spring.

[0062] In a preferred embodiment, the backlash-eliminating force-applying component is preferably disposed on the double gear. When the worm is fixed, the end face of the gear teeth meshing with the worm exceeds the central axis of the worm, and the gears in the entire transmission chain do not move axially, the sum of the limit angles of clockwise rotation and counterclockwise rotation of the double gear in the current position is the rotational backlash of the entire transmission chain. The size of this rotational backlash is represented by the symbol β, and the limit angle of rotation is a scalar.

[0063] Correspondingly, the magnitude of the backlash β that can be eliminated is determined by the tooth height h of the helical gear. 10 The helix angle α, the pitch circle diameter d, and the distance h that the helical gear can move axially are all factors to consider. 20 And the structural limitation on the height h that the double gear can float. 21 A joint decision.

[0064] Backlash elimination of the entire chain can be achieved when the axially movable helical gear satisfies the following relationship.

[0065] 2arcsin(h 20 *tanα / d)≥0.9β

[0066] Furthermore, for double gears, the following relationship can be satisfied for different matching meshing forms:

[0067] When the helical gear portion of the double gear has a tooth height of h 11 When the other helical gear is engaged, the axial movement distance h of the helical gear is... 20 The following relationship must be satisfied:

[0068] 0.95(h 10 +h 11 )>h 20

[0069] h 21 ≥0.9h 20

[0070] When the helical gear portion of the double gear engages with the worm, the axial movement distance h of the helical gear is... 20 The following relationship must be satisfied:

[0071] 0.95h 10 >h 20

[0072] h 21 ≥0.9h 20

[0073] Furthermore, in a preferred embodiment, the double gear includes helical gears and non-helical gears, and the ratio of their tooth counts is not equal to 1. This is because if the ratio of the number of teeth of the helical gears to the non-helical gears is equal to 1, during the assembly process, the angle γ between the tooth tips of any two adjacent gears and the shaft center is equal but not constant, resulting in large fluctuations in the sum of backlash in the entire transmission chain. Under a limited structure, it may be impossible to completely eliminate backlash. Conversely, if the tooth count ratio is not equal to 1, the angle γ between the tooth tips of any two adjacent gears and the shaft center varies randomly, causing the backlash and β in the entire transmission chain to also be in a state of change, making it easier for the meshing state of the double gears to meet the condition of completely eliminating backlash.

[0074] The technical solutions of the present invention will be further explained and illustrated below through two specific embodiments.

[0075] Example 1:

[0076] In this embodiment, the structure of the full-chain backlash-free transmission mechanism is as follows: Figures 1-3 As shown, the system includes an input worm gear 20 driven by a motor 10; correspondingly, two transmission units and a power output component are respectively disposed in the housing 60, with the first-stage gears of the two transmission units meshing with the input worm gear 20 extending into the housing 60, and the last-stage gears of the two transmission units meshing with the power output component.

[0077] Meanwhile, in this embodiment, the two transmission units are the same double gears, namely the first double gear 30 and the second double gear 40. The two double gears are arranged on the same side of the input end worm 20 and are spaced apart in the axial direction of the input end worm 20. The two double gears respectively include a helical gear and a spur gear arranged coaxially, namely the first helical gear 301 and the first spur gear 302, and the second helical gear 401 and the second spur gear 402.

[0078] More specifically, the first helical gear 301 and the second helical gear 401 are respectively meshed with the input end worm gear 20; correspondingly, the power output component is the output gear 50, which meshes with the first spur gear 302 and the second spur gear 402 respectively.

[0079] In actual installation, the two double gears are positioned and installed in the housing 60 by their own structure and by the optical shaft or bearing. In this embodiment, the input worm 20-first double gear 30-output gear 50 constitute the first transmission chain, and the input worm 20-second double gear 40-output gear 50 constitute the second transmission chain.

[0080] like Figure 2As shown in the figure, there are two backlash elimination force application components in this embodiment. One of the backlash elimination force application components is a first compression spring 70 corresponding to the first double gear 30. One end of the spring is mounted on the housing 60, and the other end acts axially on the end face of the first double gear 30, providing an axial force to the first double gear 30. This causes the first double gear 30 to be subjected to axial force and generate axial displacement, which in turn causes the first helical gear 301 to rotate along the tooth groove of the input end worm 20. Correspondingly, another backlash-eliminating force-applying component is a second compression spring 71 corresponding to the second double gear 40. One end of the spring is mounted on the housing 60, and the other end acts axially on the end face of the second double gear 40, providing an axial force to the second double gear 40. This causes the second double gear 40 to undergo axial displacement under the action of axial force, which in turn causes the second helical gear 401 to rotate along the tooth groove of the input end worm 20, thereby driving the other gears on the two transmission chains to rotate and thus completing the backlash elimination action. It can also overcome the axial force exerted by the input end worm 20 on the first double gear 30 and the second double gear 40 during the transmission process.

[0081] In this embodiment, the two double gears need to be axially displaced separately, and each is equipped with a backlash-reducing force-applying component that can provide axial backlash reduction force. This is because if only one of the first double gear 30 and the second double gear 40, which simultaneously meshes with the input worm 20, can be axially displaced—for example, only the first double gear 30—then during transmission, the input worm 20 will exert a large axial force on both double gears. The first compression spring 70 cannot resist this axial force, causing the first double gear 30 to move only in the direction of this axial force and unable to dynamically float to compensate for backlash. Moreover, the first compression spring 70 cannot be simply replaced with a compression spring with greater elasticity; otherwise, the first double gear 30 will provide a large normal force to the input worm 20, and in severe cases, the input worm 20 will be unable to rotate due to the large normal force.

[0082] Preferably, to reduce the influence of gear rotation on the shape of the first compression spring 70, a first planar thrust bearing 130 is provided between the end faces of the first compression spring 70 and the first double gear 30; correspondingly, a second planar thrust bearing 140 is provided between the end faces of the second compression spring 71 and the second double gear 40, such as... Figure 2 As shown in the image.

[0083] Furthermore, to further illustrate the backlash elimination process of the transmission mechanism in this embodiment, in conjunction with, as shown in the example below... Figure 3 The meshing relationship of each tooth surface shown is explained.

[0084] Specifically, the elastic force of the first compression spring 70 acts directly on the first double gear 30. The first helical tooth surface 3011 of the first helical gear 301 meshes with the first worm tooth surface 201 of the input worm 20 and rotates counterclockwise along the helical tooth surface of the input worm 20. Correspondingly, the first spur gear 302 meshes with the first output tooth surface 501 of the output gear 50 with its first spur tooth surface 3021, driving the output gear 50 to rotate. At the same time, the second output tooth surface 502 of the output gear 50 meshes with the second spur tooth surface 4021 on the second double gear 40, driving the second double gear 40 to rotate. Then, the second helical tooth surface 4011 meshes with the second worm tooth surface 202 on the input worm 20. At this time, all meshing tooth surfaces on the two transmission chains are in close contact, and the axial components of the normal forces on the first worm tooth surface 201 and the second worm tooth surface 202 are opposite, as shown by the positions of the two meshing points in the figure. Thus, it can be seen that the two transmission chains clamp the input end worm gear 20.

[0085] Throughout the transmission process, the sum of the transmission backlash in the entire transmission chain changes. However, under the action of the axial floating displacement of the first double gear 30, real-time compensation can be achieved, so that there is no rotational error in the entire transmission process, thus eliminating the backlash.

[0086] Obviously, in actual setup, the output gear 50 can also be replaced with a rack as needed. The backlash elimination process is similar to that described above and will not be described in detail here.

[0087] Example 2:

[0088] In this embodiment, such as Figures 4-6 As shown, compared with the scheme in Embodiment 1, the two transmission units at this time include two gear sets respectively disposed on both radial sides of the input end worm 20, which form two transmission chains between the input end worm 20 and the output rack 190.

[0089] Specifically, one transmission chain includes two meshing helical gears, namely a fifth helical gear 150 and a sixth helical gear 200, which mesh with the input worm gear 20 and the output rack 190, respectively. Simultaneously, the other transmission chain includes a third double gear 160, a fourth double gear 180, and a fifth spur gear 170. Each double gear includes a coaxially arranged spur gear and a helical gear, namely a third helical gear 1601 and a third spur gear 1602, and a fourth helical gear 1801 and a fourth spur gear 1802. The third helical gear 1601 meshes with the side of the input worm gear 20 opposite to the fifth helical gear 150, and the fourth helical gear 1801 meshes with the output rack 190. The third spur gear 1602, the fifth spur gear 170, and the fourth spur gear 1802 mesh sequentially, forming... Figure 4 The two transmission chains shown.

[0090] More specifically, the two transmission units have the same reduction ratio. The gears of the first transmission unit meshing with the power output component and the gears of the second transmission unit meshing with the power output component rotate in the same direction. The output rack 190 is simultaneously driven by two helical gears on the two transmission chains. In actual installation, each gear and rack is preferably positioned and installed within the housing 60 by its own structure, a mating optical shaft, bearings, or guide rails.

[0091] In this embodiment, the force-applying component for eliminating backlash is preferably a first compression spring 70 corresponding to the sixth helical gear 200. One end of the first compression spring 70 is connected to the housing 60, and the other end acts axially on the end face of the sixth helical gear 200. Preferably, a gasket 240, more preferably a polytetrafluoroethylene gasket, is provided between the first compression spring 70 and the end face of the sixth helical gear 200 to prevent the first compression spring 70 from deforming when the sixth helical gear 200 rotates, thus affecting its force-applying effect.

[0092] In addition, in this embodiment, the sixth helical gear 200 is configured to reciprocate axially, and at least one double gear is also configured to reciprocate axially, thereby compensating for backlash through the axial floating displacement of the double gear. During actual operation, the sixth helical gear 200 moves along the helical tooth surface of the output rack 190 and rotates, driving the rotation of other gears and racks on both transmission chains, as well as the axial movement and rotation of the corresponding double gear, thereby achieving the goal of eliminating backlash.

[0093] To further explain the backlash elimination process of the transmission mechanism in this embodiment, combined with Figure 6 The meshing relationship of each tooth surface shown will be explained in detail. Furthermore, due to... Figure 6 The text involves a large number of "tooth surfaces," and for ease of reading and understanding, each feature will not be named separately here. The following textual descriptions and... Figure 6 The diagram numbers in the illustrations can accurately explain the meshing relationship in this embodiment.

[0094] exist Figure 6 In the above-mentioned axial backlash elimination force-applying component, the first compression spring 70, directly acts on the sixth helical gear 200, which is subjected to axial force. Its tooth surface 2001 meshes with the tooth surface 1502 of the fifth helical gear 150. After the two tooth surfaces come together, the fifth helical gear 150 is simultaneously subjected to axial force. The other tooth surface 1501 of the fifth helical gear 150 abuts against a tooth surface 203 on the input end worm gear 20, and the other tooth surface 2002 of the sixth helical gear 200 meshes with the tooth surface 1901 of the output rack 190. The output rack 190 tends to move horizontally to the right as the sixth helical gear 200 rotates. In this way, the other tooth surface 1902 on the output rack 190 abuts against the tooth surface 18011 of the fourth helical gear 1801 of the fourth double gear 180 on another transmission chain and drives it to rotate slightly.

[0095] Correspondingly, the fourth spur gear 1802 of the fourth double gear 180 abuts against a tooth surface 1701 of the fifth spur gear 170 with its tooth surface 18021, causing it to rotate slightly. The other tooth surface 1702 of the fifth spur gear 170 abuts against the tooth surface 16021 of the third spur gear 1602 of the previous meshing third double gear 160, causing it to rotate slightly. Meanwhile, the tooth surface 16011 of the third helical gear 1601 abuts against the other tooth surface 204 of the input worm gear 20 through rotation and axial movement. At this time, the axial components of the normal forces on the meshing tooth surfaces 203 and 204 of the worm gear are opposite, such as... Figure 6 As indicated by the arrow above, this can be seen as the two transmission chains clamping the input worm gear 20.

[0096] It is easy to see that, because the backlash-eliminating force-applying component can avoid or compensate for backlash during gear rotation and meshing, the backlash in the transmission structure given in this embodiment has been completely eliminated. When the input worm 20 is driven to rotate unidirectionally by the motor 10, the rotation direction of one gear and the movement direction of the rack in the entire rotation chain are as follows: Figure 6 As shown by the up arrow.

[0097] The full-chain backlash elimination transmission mechanism of this invention has a compact structure and flexible design. It can meet the requirements of full-chain dynamic backlash elimination under different design forms, ensure the transmission accuracy and stability of the transmission mechanism, reduce noise caused by backlash, meet the setting requirements of high torque and high reduction ratio, is easy to miniaturize, has strong compatibility, is easy to process and assemble, can effectively reduce the application cost of the transmission mechanism, and has good practical value and application prospects.

[0098] Those skilled in the art will readily understand that the above description is merely 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 scope of protection of the present invention.

Claims

1. A full-chain backlash-free transmission mechanism, comprising a power input component, a power output component, and a transmission module disposed between the two, characterized in that, The power input component is a worm gear; The transmission module includes a first transmission unit and a second transmission unit. The two transmission units mesh with the worm gear via helical gears, and the two transmission units form two transmission chains between the worm gear and the power output component. Both transmission units are identical double gears, namely, a first double gear and a second double gear axially spaced on the same side of the worm; Both double gears include a helical gear meshing with the worm and a spur gear meshing with the power output component. The ratio of the number of teeth of the helical gear to the number of teeth of the spur gear is not equal to 1. The two double gears can move axially respectively, and each double gear is provided with a backlash elimination force application component. The backlash elimination force application component is an elastic component capable of elastic deformation, and the force application directions of the two backlash elimination force application components are opposite; the meshing tooth surfaces on the two transmission chains are in close contact, and the axial components of the normal force acting on the worm tooth surface by the two helical gears are opposite. A helical gear capable of axial displacement satisfies the following relationship: wherein β is the back lash of the gear; h 20 is the axial movement distance of the helical gear; h 10 is the tooth height of the helical gear; is the height that the double helical gear can float due to structure; α is the helix angle of the helical gear; d is the pitch diameter of the helical gear; Throughout the transmission process, the sum of the transmission backlashes in the entire transmission chain changes. However, under the action of the axial floating displacement of the first double gear, real-time compensation can be achieved, so that there is no rotational error in the entire transmission process, thus eliminating the backlash.

2. The full-chain backlash-free transmission mechanism according to claim 1, characterized in that, The two transmission units have the same reduction ratio.

3. The full-chain backlash-free transmission mechanism according to claim 1, characterized in that, The worm gear can be a single-start worm gear or a multi-start worm gear.

4. The full-chain backlash-free transmission mechanism according to claim 1 or 3, characterized in that, The power output component is an output gear or an output rack.

5. The full-chain backlash-free transmission mechanism according to claim 1, characterized in that, The elastic element is a compression spring or a tension spring.

6. The full-chain backlash-free transmission mechanism according to claim 1 or 5, characterized in that, A planar thrust bearing or shim is provided between the backlash-eliminating force-applying component and the end face of the corresponding helical gear.

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