Worm gear, machining method and related apparatus

Abstract

The present application relates to worm gear transmission technology field, provide worm wheel, processing method and related equipment. Worm wheel includes wheel body and the gear tooth distributed in the outer peripheral wall of wheel body, wherein, the gear tooth is helical tooth, the tooth surface of gear tooth includes flat tooth surface and the arc tooth surface distributed on both sides of flat tooth surface along the direction of tooth. The present application designs the tooth surface of helical tooth of worm wheel to include flat tooth surface and arc tooth surface distributed on both sides of flat tooth surface along the direction of tooth, realizes low load working condition to avoid jamming phenomenon by using flat tooth surface, reduces contact stress under high load working condition through arc tooth surface and flat tooth surface work together, so as to improve the meshing and transmission performance of worm wheel, and improve the service life of worm wheel.

Description

Technical Field

[0001] This invention relates to the field of worm gear transmission technology, and more specifically, to worm gears, processing methods, and related equipment. Background Technology

[0002] Worm gear drives are widely used in mechanical products such as automobiles, aerospace, and machine tools.

[0003] Traditional worm gears feature arc-shaped tooth surfaces, resulting in a line contact between the worm and the arc-shaped tooth surface. This makes them prone to jamming under low-load conditions. Especially in automotive steering systems, where zero backlash is required, a spring mechanism is typically used to allow the worm to float axially on the worm wheel to press the worm and worm wheel together, further increasing the likelihood of jamming in the system.

[0004] With the development of transmission technology, worm gears in the form of helical cylindrical gears are now more commonly used in mechanical products such as steering systems, replacing traditional worm gears. The helical cylindrical gear worm gear and the worm form an interleaved helical gear pair, which has better meshing and transmission performance.

[0005] However, because the tooth surface of a helical cylindrical gear worm gear is designed as a single flat tooth surface, the meshing contact between the worm and the flat tooth surface is a point contact. Under high load conditions, this can easily cause excessive contact stress on the tooth surface of the worm gear, leading to worm gear wear and shortening the worm gear life.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a worm gear, a processing method, and related equipment. The tooth surface of the helical teeth of the worm gear is designed to include a flat tooth surface and arc tooth surfaces distributed on both sides of the flat tooth surface along the tooth direction. This enables the flat tooth surface to avoid jamming under low load conditions, and the arc tooth surface and the flat tooth surface to work together to reduce contact stress under high load conditions, thereby improving the meshing and transmission performance of the worm gear and increasing its service life.

[0008] One aspect of the present invention provides a worm gear, comprising a gear body and gear teeth distributed on the outer peripheral wall of the gear body, wherein: the gear teeth are helical teeth; the tooth surface of the gear teeth includes a flat tooth surface and arc tooth surfaces distributed on both sides of the flat tooth surface along the tooth direction of the gear teeth.

[0009] The aforementioned worm gear has helical teeth, which enables better meshing and transmission performance. The tooth surface is designed to include a flat tooth surface and arc tooth surfaces distributed on both sides of the flat tooth surface along the tooth direction. Under low load conditions, the flat tooth surface can be used to avoid jamming, while under high load conditions, the arc tooth surface and the flat tooth surface work together to reduce contact stress. This improves the meshing and transmission performance of the worm gear and extends its service life. Therefore, the aforementioned worm gear, through the design of the arc tooth surface at both ends and the helical tooth surface at the middle along the tooth direction, can not only avoid the disadvantage of easy wear of the worm gear under high load conditions and improve the worm gear life, but also avoid the disadvantage of easy jamming between the worm gear and the worm under low load conditions and improve the meshing and transmission performance of the worm gear and the worm.

[0010] In some embodiments, the arcuate tooth surface and the flat tooth surface are distributed in the tooth width direction, such that the gear teeth and the helical teeth of the meshing worm have a first meshing state and a second meshing state; in the first meshing state, the helical teeth mesh with the flat tooth surface; in the second meshing state, the helical teeth mesh sequentially with the proximal arcuate tooth surface, the flat tooth surface and the distal arcuate tooth surface; wherein, the first load in the first meshing state is less than the second load in the second meshing state.

[0011] The distribution of the arc tooth surface and the flat tooth surface in the tooth width direction allows the flat tooth surface to participate in meshing under low load conditions to avoid jamming, while under high load conditions, the arc tooth surface and the flat tooth surface participate in meshing together to reduce contact stress.

[0012] In some embodiments, during the first engagement state, the engagement path of the helical teeth and the flat tooth surface forms an engagement line connected by engagement points.

[0013] Under low load conditions, the helical teeth of the worm gear and the flat tooth surface of the worm wheel engage in point contact meshing, achieving smooth, low-noise meshing and transmission, and avoiding jamming.

[0014] In some embodiments, in the second meshing state, the flat tooth surface deforms under the action of the second load, so that the tooth surface of the gear tooth forms an integral arc tooth surface; the meshing path of the helical tooth and the integral arc tooth surface forms a meshing surface connected by the meshing line.

[0015] Under high load conditions, the flat tooth surface located in the middle of the tooth direction is deformed by pressure, forming an integral arc tooth surface with the arc tooth surfaces located at both ends of the tooth direction. The integral arc tooth surface engages with the helical teeth of the worm through line contact, achieving high load-bearing capacity meshing and transmission, and avoiding wear of the worm wheel due to excessive point contact stress.

[0016] In some embodiments, the tooth surface is symmetrical about the normal to the tooth line center point.

[0017] The symmetric design of the worm gear tooth surface about the center point of the tooth line makes it easier to achieve stable and regular meshing and transmission between the worm gear and the worm.

[0018] In some embodiments, the worm gear is made of plastic.

[0019] The tooth surface of plastic worm gears is prone to deformation under high loads. Therefore, designing the tooth surface of plastic worm gears to include flat tooth surfaces and arc tooth surfaces distributed on both sides of the flat tooth surface along the tooth direction can achieve the deformation of the tooth surface into an integral arc tooth surface under high load conditions, which can make line contact meshing with the helical teeth of the worm. This avoids excessive point contact stress under high load conditions, which would lead to tooth surface wear, thereby improving the meshing and transmission performance of the worm gear and extending its service life.

[0020] Another aspect of the present invention provides a worm gear transmission mechanism, including a worm and the worm wheel described above; wherein the helical teeth of the worm mesh with the teeth of the worm wheel.

[0021] The worm gear transmission mechanism, through the design of the arc tooth surface at both ends of the worm wheel and the helical tooth surface of the flat tooth surface in the middle of the tooth direction, can avoid the disadvantage of easy wear of the worm wheel under high load conditions, improve the worm wheel life, and avoid the disadvantage of easy jamming between the worm wheel and worm under low load conditions, thus improving the meshing and transmission performance of the worm gear transmission mechanism.

[0022] In some embodiments, the worm gear is made of plastic and the worm is made of metal.

[0023] By combining a metal worm gear with a plastic worm wheel, low-noise and high-stability meshing transmission is achieved. On the other hand, the characteristic that the tooth surface of the plastic worm wheel is prone to deformation under high load is utilized. Under high load conditions, the tooth surface of the plastic worm wheel is deformed into an integral arc tooth surface under the action of the metal worm, thus achieving line contact meshing with the helical teeth of the worm gear. This avoids excessive point contact stress under high load conditions, which would lead to wear of the worm wheel tooth surface, thereby improving the meshing transmission performance of the worm gear and the service life of the worm wheel.

[0024] Another aspect of the present invention provides a steering system configured with the above-described worm gear transmission mechanism; wherein the worm is buoyant along the axial direction of the worm wheel.

[0025] In the steering system, zero backlash is achieved through the design of the worm gear floating along the axial direction of the worm wheel. With zero backlash between the worm wheel and the worm, the design of the arc tooth surface at both ends of the tooth direction and the helical tooth surface at the middle of the tooth direction of the worm wheel can avoid jamming under low load conditions. Under high load conditions, the arc tooth surface and the flat tooth surface work together to reduce contact stress and improve the service life of the worm wheel.

[0026] Another aspect of the present invention provides a processing method for machining the worm gear described above based on a gear hobbing method; wherein the arc tooth surfaces distributed on both sides of the flat tooth surface include a first arc tooth surface and a second arc tooth surface, and the processing method includes: controlling a hob to cut into the worm gear from a first junction between the first arc tooth surface and the flat tooth surface along the tooth height direction to form the first arc tooth surface; controlling the hob to feed along the tooth direction from the position where the first arc tooth surface is formed to a second junction between the flat tooth surface and the second arc tooth surface to form the flat tooth surface; and controlling the hob to cut out of the worm gear from the position where the flat tooth surface is formed along the tooth height direction to form the second arc tooth surface; wherein, during the hob's movement, the axis of the hob is controlled to be parallel to the normal surface of the worm gear.

[0027] The above-described machining method controls the hob's axis to be parallel to the normal surface of the worm gear during the hob's travel to machine helical tooth shapes. Furthermore, by controlling the hob's feed path, the hob enters along the tooth height direction from the first junction of the first arc tooth surface and the flat tooth surface to cut and shape the first arc tooth surface. The hob continues to feed along the tooth direction to the second junction of the flat tooth surface and the second arc tooth surface to cut and shape the flat tooth surface. Then, the hob exits along the tooth height direction to cut and shape the second arc tooth surface. In this way, the helical tooth surfaces located at both ends of the tooth direction and the flat tooth surface located in the middle of the tooth direction are machined.

[0028] In some embodiments, the hob has a gradually changing tooth thickness; when the hob is controlled to cut into the worm gear, the maximum tooth thickness portion of the hob is located on the same tooth height line as the first junction; when the hob is controlled to feed to the second junction, the maximum tooth thickness portion is fed to the same tooth height line as the second junction.

[0029] When the hob cuts into the worm gear, the maximum tooth thickness is aligned with the first junction on the same tooth height line. The first junction between the flat tooth surface and the first arc tooth surface is located, and the first arc tooth surface with decreasing tooth thickness from the tooth edge to the first junction is machined. When the hob feeds to the second junction, the maximum tooth thickness is fed to the same tooth height line as the second junction to ensure that a flat tooth surface with uniform tooth thickness is machined, and the second junction between the flat tooth surface and the second arc tooth surface is located.

[0030] Another aspect of the present invention provides an electronic device, comprising: a processor; a memory storing executable instructions; wherein, when the executable instructions are executed by the processor, the above-described processing method is implemented.

[0031] Another aspect of the present invention provides a computer-readable storage medium for storing a program that, when executed by a processor, implements the above-described processing method.

[0032] The beneficial effects of this invention compared to the prior art include at least the following: The worm gear of the present invention, through the design of the arc tooth surface at both ends and the helical tooth surface at the middle along the tooth direction, achieves the following: under low load conditions, the flat tooth surface is used to avoid jamming and improve the meshing and transmission performance between the worm gear and the worm. Under high load conditions, the arc tooth surface and the flat tooth surface work together to reduce contact stress and improve the service life of the worm gear.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0035] Figure 1 This diagram shows a schematic representation of the worm gear teeth in an embodiment of the present invention. Figure 2 This diagram illustrates the meshing path formed on the tooth surface of the worm gear under low load conditions in an embodiment of the present invention. Figure 3 This diagram illustrates the meshing path formed on the tooth surface of the worm gear under high load conditions in an embodiment of the present invention. Figure 4 A partial structural schematic diagram of the worm gear transmission mechanism in an embodiment of the present invention is shown; Figure 5 A partial structural schematic diagram of the steering system in an embodiment of the present invention is shown; Figure 6 A schematic diagram showing a comparison of torque consumption in a steering system equipped with the worm gear of the present invention and a conventional type of worm gear with a spiral tooth surface; Figure 7 This diagram illustrates the steps of the processing method in an embodiment of the present invention. Figure 8 This diagram illustrates the tool path of the machining method in an embodiment of the present invention. Figure 9 A schematic diagram of the structure of an electronic device in an embodiment of the present invention is shown. Detailed Implementation

[0036] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to fully and completely convey the concept of the exemplary embodiments to those skilled in the art.

[0037] The accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0038] In the description of this invention, the terms "far," "near," etc., 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 the invention and for 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 limiting the invention. The terms "first," "second," and similar words used in the specific description do not indicate any order, quantity, or importance, but are only used to distinguish different components.

[0039] Furthermore, the process shown in the accompanying drawings is merely illustrative and does not necessarily include all steps. For example, some steps can be broken down, some steps can be combined or partially combined, and the actual execution order may change depending on the actual situation.

[0040] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features in different embodiments can be combined with each other.

[0041] The worm gear provided in this embodiment of the invention includes a gear body and gear teeth distributed on the outer peripheral wall of the gear body, wherein the gear teeth are helical teeth; thus, the worm gear provided in this embodiment of the invention is formed as a worm gear with helical cylindrical gear shape, which can achieve better meshing and transmission performance compared with a spur tooth worm gear.

[0042] Figure 1 The structure of the worm gear teeth in an embodiment of the present invention is shown; see reference. Figure 1 As shown, the tooth surface of the gear tooth 10 includes a flat tooth surface 11a and an arc tooth surface 11b distributed on both sides of the flat tooth surface 11a along the tooth direction of the gear tooth 10.

[0043] The tooth surface of the worm gear 10 is designed to include a flat tooth surface 11a and an arc tooth surface 11b distributed on both sides of the flat tooth surface 11a along the tooth direction. Under low load conditions, the flat tooth surface 11a can be used to avoid jamming. Under high load conditions, the arc tooth surface 11b and the flat tooth surface 11a work together to reduce contact stress, thereby improving the meshing and transmission performance of the worm gear and increasing its service life.

[0044] Therefore, the worm gear provided in this embodiment of the invention, through the design of the helical tooth surface with the arc tooth surface 11b at both ends and the flat tooth surface 11a in the middle along the tooth direction, can avoid the disadvantage of easy wear of the flat tooth surface under high load conditions and improve the worm gear life, and can also avoid the disadvantage of easy jamming of the arc tooth surface under low load conditions and improve the meshing and transmission performance of the worm gear and worm.

[0045] In some embodiments, the arc tooth surface 11b and the flat tooth surface 11a are distributed in the tooth width direction, such that the gear teeth 10 and the helical teeth of the meshing worm have a first meshing state and a second meshing state; in the first meshing state, the helical teeth mesh with the flat tooth surface 11a; in the second meshing state, the helical teeth mesh sequentially with the proximal arc tooth surface 11b, the flat tooth surface 11a and the distal arc tooth surface 11b; wherein, the first load in the first meshing state is less than the second load in the second meshing state.

[0046] In this context, "proximal end" and "distal end" refer to the worm gear. During the meshing process between the worm gear and the worm wheel, the part of the tooth that first contacts the helical tooth along the tooth direction of the tooth 10 is called the proximal end, and vice versa.

[0047] The distribution of the arc tooth surface 11b and the flat tooth surface 11a in the tooth width direction allows the flat tooth surface 11a to participate in meshing under low load conditions (i.e., the first meshing state) to avoid jamming, while under high load conditions (i.e., the second meshing state), the arc tooth surface 11b and the flat tooth surface 11a jointly participate in meshing to reduce contact stress.

[0048] In a specific example, the tooth width B of the flat tooth surface 11a is set to 3mm, but it is not limited to this. In different mechanical products, the tooth width B of the flat tooth surface 11a can be adjusted accordingly, for example, set to 1.5mm, 6mm, etc., as long as the distribution of the arc tooth surface 11b and the flat tooth surface 11a in the tooth width direction is set to meet the requirement that the flat tooth surface 11a participates in meshing under low load conditions, and the arc tooth surface 11b and the flat tooth surface 11a participate in meshing together under high load conditions.

[0049] The first load (i.e., low load) in the first meshing state as described in this embodiment of the invention is typically less than 40 Nm, and the second load (i.e., high load) in the second meshing state is typically greater than 40 Nm, but is not limited thereto. There can also be an intermediate meshing state between the first and second meshing states; in the intermediate meshing state, the flat tooth surface 11a mainly participates in the meshing, supplemented by the arc tooth surface 11b. Since the load in the intermediate meshing state (typically around 40 Nm) is neither too low nor too high, the method of mainly using the flat tooth surface 11a and supplemented by the arc tooth surface 11b will not bring excessive contact stress to the worm gear, nor will it cause jamming between the worm gear and the worm.

[0050] Figure 2 This illustrates the meshing path formed on the tooth surface of the worm gear under low load conditions in an embodiment of the present invention; see reference. Figure 2 As shown, in the first meshing state, the helical teeth of the worm and the meshing path 20 of the flat tooth surface 11a form a meshing line connected by the meshing points.

[0051] Under low load conditions, the helical teeth of the worm gear and the flat tooth surface 11a of the worm wheel make point contact meshing to achieve smooth, low-noise meshing and transmission, and avoid jamming.

[0052] Figure 3 This illustrates the meshing path formed on the tooth surface of the worm gear under high load conditions in an embodiment of the present invention; combined with Figure 1 and Figure 3 As shown, in the second meshing state, the flat tooth surface 11a deforms under the action of the second load, so that the tooth surface of the gear tooth 10 forms an integral arc tooth surface 11'; the meshing path 30 of the helical tooth and the integral arc tooth surface 11' forms a meshing surface connected by the meshing line.

[0053] Under high load conditions, the flat tooth surface 11a located in the middle of the tooth direction is deformed by pressure, forming an integral arc tooth surface 11' with the arc tooth surfaces 11b located at both ends of the tooth direction. The integral arc tooth surface 11' engages with the helical teeth of the worm through line contact, achieving meshing and transmission with high load capacity, and avoiding wear of the worm wheel due to excessive point contact stress.

[0054] Furthermore, in this embodiment of the invention, the tooth surface of the gear tooth 10 is symmetrical about the normal plane passing through the center point of the tooth line of the gear tooth 10. This is more conducive to achieving stable and regular meshing and transmission between the worm gear and the worm.

[0055] In the above embodiments, the worm gear may be made of plastic, and the gear teeth 10 are formed as plastic gear teeth.

[0056] The tooth surface of the plastic gear tooth 10 is prone to deformation under high load. Therefore, by designing the tooth surface of the gear tooth 10 to include a flat tooth surface 11a and an arc tooth surface 11b distributed on both sides of the flat tooth surface 11a along the tooth direction of the gear tooth 10, the tooth surface can be deformed into an integral arc tooth surface under high load conditions, thereby achieving line contact meshing with the helical teeth of the worm gear. This avoids excessive point contact stress under high load conditions, which would lead to tooth surface wear of the gear tooth 10, thereby improving the meshing and transmission performance of the worm gear and increasing its service life.

[0057] Figure 4 This diagram illustrates a partial structure of the worm gear transmission mechanism in an embodiment of the present invention; combined with... Figure 1 and Figure 4 As shown, this embodiment of the invention also provides a worm gear transmission mechanism, including a worm 40 and a worm wheel 100 as described in the above embodiment; wherein the helical teeth 44 of the worm 40 mesh with the gear teeth 10 of the worm wheel 100.

[0058] The worm gear transmission mechanism, through the design of the helical tooth surfaces 11b at both ends of the tooth direction and the flat tooth surface 11a in the middle of the tooth direction of the worm gear 100, can avoid the disadvantage of easy wear of the worm gear 100 under high load conditions, improve the service life of the worm gear 100, and avoid the disadvantage of easy jamming between the worm gear 100 and the worm 40 under low load conditions, thereby improving the meshing and transmission performance of the worm gear transmission mechanism.

[0059] In some embodiments, the worm gear 100 is made of plastic and the worm 40 is made of metal.

[0060] By engaging a metal worm 40 with a plastic worm wheel 100, low-noise and high-stability meshing transmission is achieved. Furthermore, the deformation of the plastic worm wheel 100's tooth surface under high load conditions is utilized. Under high load, the tooth surface of the worm wheel 100 deforms into an integral arc-shaped tooth surface under the action of the worm 40, thus achieving line contact meshing with the helical teeth 44 of the worm 40. This avoids excessive point contact stress under high load conditions, preventing wear on the worm wheel 100's tooth surface, thereby improving meshing transmission performance and extending the service life of the worm wheel 100.

[0061] This invention also provides a steering system equipped with the above-described worm gear transmission mechanism; wherein the worm is buoyant along the axial direction of the worm wheel.

[0062] In the steering system, zero backlash is achieved through the design of the worm gear floating along the axial direction of the worm wheel. With zero backlash between the worm wheel and the worm, the helical tooth surface design of the worm wheel with the arc tooth surface 11b at both ends of the tooth direction and the flat tooth surface 11a in the middle of the tooth direction, as described in the above embodiment, can avoid jamming under low load conditions. Under high load conditions, the arc tooth surface 11b and the flat tooth surface 11a work together to reduce contact stress and improve the service life of the worm wheel.

[0063] Figure 5 This invention illustrates a partial structure of the steering system in an embodiment of the invention, primarily showing the position of the worm gear within the steering system; see reference... Figure 5 As shown, the steering system includes an input shaft 51 connected to the steering wheel and an output shaft 52 connected to the wheel. A worm gear 40 (not specifically shown in the figure) is connected to the power steering motor of the steering system. A worm wheel 100 is sleeved on the output shaft 52 and supported at both ends by bearings 53, transmitting the power steering torque from the power steering motor to the output shaft 52.

[0064] Traditional worm gears have an arc-shaped tooth surface. As mentioned above, the meshing contact between the worm and the arc-shaped tooth surface is a line contact, which is prone to jamming under low load conditions. During the experiment, the torque value ΔT was used to measure the torque consumed by the worm and worm wheel due to jamming. Specifically, the output waveform of the assist motor's torque can be monitored and plotted using software. The waveform shows a regular torque output sub-waveform that matches the worm-wheel meshing transmission cycle. Each sub-waveform has a maximum point (which can be identified as the separation torque between the worm and worm wheel) and a fluctuating torque segment immediately following the separation torque and located between the separation torque and the subsequent stable output torque. The torque value of this fluctuating torque segment can be determined as the torque value ΔT consumed by the worm and worm wheel due to jamming. ΔT = Torque1 - Torque2, where Torque1 is the separation torque and Torque2 is the output torque.

[0065] Figure 6 The diagram illustrates a comparison of torque consumption in a steering system equipped with the worm gear of this invention and a conventional type of spiral toothed worm gear; see reference. Figure 6 As shown, traditional spiral tooth worm gears are prone to jamming under low load conditions, with a measured ΔT value of 1.0+. However, the worm gear of this invention, based on a helical tooth surface design including spiral tooth surfaces at both ends of the tooth direction and a flat tooth surface in the middle of the tooth direction, has a measured ΔT value of only 0.5+, which can effectively improve the jamming phenomenon under low load conditions and improve the transmission performance of the steering system.

[0066] Furthermore, embodiments of the present invention also provide a processing method for processing the worm gear described in any of the above embodiments. The structure and principle of the worm gear described in any of the above embodiments can be applied to the following processing method embodiments. In the following processing method embodiments, the already explained structure and principle of the worm gear will not be repeated.

[0067] Figure 7 The main steps of the processing method in this embodiment of the invention are shown. Figure 8 The tool path of the machining method in this embodiment of the invention is shown; combined with Figure 1 , Figure 7 and Figure 8 As shown, the machining method provided in this embodiment of the invention is based on gear hobbing to machine the worm gear 100 described above. The arc tooth surfaces 11b distributed on both sides of the flat tooth surface 11a include a first arc tooth surface 11b1 and a second arc tooth surface 11b2. The machining method specifically includes: S610, control the hob 700 to cut into the worm gear 100 from the first junction 710 between the first arc tooth surface 11b1 and the flat tooth surface 11a along the tooth height direction T of the gear tooth 10 until the first arc tooth surface 11b1 is formed.

[0068] Before the hob 700 cuts into the worm gear 100, the hob 700 can be controlled to travel along the tooth direction to the first junction 710.

[0069] S620, control the hob 700 to feed along the tooth direction E from the position of forming the first arc tooth surface 11b1 to the second junction 720 of the flat tooth surface 11a and the second arc tooth surface 11b2, so as to form the flat tooth surface 11a. S630, control the hob 700 to cut the worm gear from the position of the forming flat tooth surface 11a along the tooth height direction T to form the second arc tooth surface 11b2.

[0070] After the hob 700 cuts out of the worm gear 100, the hob 700 can be controlled to leave the worm gear 100 along the tooth direction.

[0071] Furthermore, during the travel of the hob 700, i.e. the hobbing process, the hob 700 is linked with the worm gear 100: the hob 700 rotates and feeds along the tooth direction of the worm gear 100 (i.e., the axis of the hob 700 is controlled to be parallel to the normal surface of the worm gear 100), while the worm gear 100 itself is also rotating. The machining of the full circumference of the worm gear 100 is formed by its own rotation and the cutting of the high-speed rotating hob 700, thus achieving the machining of the helical tooth 10.

[0072] The above-described machining method, through the control of the tool path of the hob 700, causes the hob 700 to cut into the first junction 710 between the first arc tooth surface 11b1 and the flat tooth surface 11a along the tooth height direction T to cut and form the first arc tooth surface 11b1. The hob 700 is then controlled to continue feeding along the tooth direction E to the second junction 720 between the flat tooth surface 11a and the second arc tooth surface 11b2 to cut and form the flat tooth surface 11a. Then the hob 700 is cut out along the tooth height direction T to cut and form the second arc tooth surface 11b2. In this way, the helical tooth surface machining of the arc tooth surface 11b located at both ends of the tooth direction and the flat tooth surface 11a located in the middle of the tooth direction is realized.

[0073] Continue to combine Figure 1 , Figure 7 and Figure 8 As shown, in some embodiments, the hob 700 has a gradually decreasing tooth thickness, which typically decreases from the tooth root to the tooth tip. When the hob 700 cuts into the worm gear 100, the maximum tooth thickness portion of the hob 700 is positioned on the same tooth height line as the first junction 710, so as to locate the first junction 710 between the flat tooth surface 11a and the first arc tooth surface 11b1, and to machine the first arc tooth surface 11b1 whose tooth thickness decreases from the tooth edge to the first junction 710. When the hob 700 is fed to the second junction 720, the maximum tooth thickness portion is fed to the same tooth height line as the second junction 720, so as to ensure that a flat tooth surface 11a with uniform tooth thickness is machined, and to locate the second junction 720 between the flat tooth surface 11a and the second arc tooth surface 11b2.

[0074] Thus, by using the above-described processing method, a gear tooth 10 with an oblique tooth shape having an arc tooth surface 11b located at both ends of the tooth direction and a flat tooth surface 11a located in the middle of the tooth direction can be formed based on the hobbing method.

[0075] The machined worm gear 100 features a helical tooth surface design with arc tooth surfaces 11b at both ends and a flat tooth surface 11a in the middle along the tooth direction. Under low load conditions, the flat tooth surface 11a is used to avoid jamming and improve meshing and transmission performance. Under high load conditions, the arc tooth surface 11b and the flat tooth surface 11a work together to reduce contact stress and improve service life.

[0076] This invention also provides an electronic device, including a processor and a memory, wherein the memory stores executable instructions, and when the executable instructions are executed by the processor, the processing method described in any of the above embodiments is implemented.

[0077] The electronic device of this invention can be deployed in a machine tool or in a remote control device to control the tool path of a hob. It enables the hob to machine a gear tooth with an arc tooth surface at both ends and a flat tooth surface in the middle of the tooth direction. The machined worm gear, through the design of the arc tooth surface at both ends and the flat tooth surface in the middle of the tooth direction, can avoid jamming and improve meshing and transmission performance under low load conditions by using the flat tooth surface. Under high load conditions, the arc tooth surface and the flat tooth surface work together to reduce contact stress and improve service life.

[0078] Figure 9 The structure of the electronic device in an embodiment of the present invention is shown; see reference Figure 9 As shown, the electronic device 800 is manifested in the form of a general-purpose computing device, and its components include, but are not limited to: at least one processor 810, at least one memory 820, and a bus 830 connecting different platform components (including memory 820 and processor 810).

[0079] The memory 820 stores program code, which can be executed by the processor 810, causing the processor 810 to perform the steps of the processing method described in any of the above embodiments.

[0080] The memory 820 may include a readable medium in the form of volatile memory cells, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0081] The memory 820 may also include programs / utilities having one or more program modules, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0082] Bus 830 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0083] Electronic device 800 can also communicate with one or more external devices, such as keyboards, pointing devices, Bluetooth devices, etc. These external devices enable users to interact with electronic device 800. Electronic device 800 can also communicate with one or more other computing devices, including routers and modems. This communication can be performed via input / output (I / O) interfaces. Furthermore, electronic device 800 can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter can communicate with other modules of electronic device 800 via bus 830. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 800, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0084] This invention also provides a computer-readable storage medium for storing a program that, when executed, implements the processing method described in any of the above embodiments. In some possible implementations, various aspects of this invention can also be implemented as a program product comprising program code, which, when run on a terminal device, causes the terminal device to execute the processing method described in any of the above embodiments.

[0085] The storage medium of this invention can be executed by a processor deployed in a machine tool or by a processor deployed in a remote control device. When executed by the processor, the storage medium is used to control the tool path of the hob, thereby realizing the machining of a gear tooth with an arc tooth surface at both ends and a flat tooth surface in the middle of the tooth direction based on the hob machining method. The worm gear is designed with arc tooth surfaces at both ends and a flat tooth surface in the middle along the tooth direction. Under low load conditions, the flat tooth surface is used to avoid jamming and improve meshing and transmission performance. Under high load conditions, the arc tooth surface and the flat tooth surface work together to reduce contact stress and improve service life.

[0086] The storage medium may be a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device. However, the storage medium of the present invention is not limited thereto, and may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0087] The storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media include, but are not limited to: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0088] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable signal medium may also be any readable medium other than a readable storage medium, capable of transmitting, propagating, or transmitting a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable signal medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0089] The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or they can be connected to external computing devices, such as through an Internet service provider.

[0090] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A worm gear, comprising a gear body and gear teeth distributed on the outer peripheral wall of the gear body, characterized in that: The gear teeth are helical teeth; The tooth surface of the gear includes a flat tooth surface and arc tooth surfaces distributed on both sides of the flat tooth surface along the tooth direction. The distribution of the arc tooth surface and the flat tooth surface in the tooth width direction allows the gear teeth to have a first meshing state and a second meshing state with the helical teeth of the meshing worm. In the first engagement state, the helical teeth engage with the flat tooth surface; In the second engagement state, the helical teeth sequentially engage with the proximal arc tooth surface, the flat tooth surface, and the distal arc tooth surface; Wherein, the first load in the first engagement state is less than the second load in the second engagement state.

2. The worm gear as described in claim 1, characterized in that, In the first meshing state, the meshing path of the helical teeth and the flat tooth surface forms a meshing line connected by the meshing points.

3. The worm gear as described in claim 1, characterized in that, In the second meshing state, the flat tooth surface deforms under the action of the second load, so that the tooth surface of the gear tooth forms an integral arc tooth surface; The meshing path of the helical teeth and the integral arc tooth surface forms a meshing surface connected by meshing lines.

4. The worm gear as described in any one of claims 1 to 3, characterized in that, The tooth surface is symmetrical about the normal to the tooth line center point.

5. The worm gear as described in claim 1, characterized in that, The worm gear is made of plastic.

6. A worm gear transmission mechanism, characterized in that, Includes a worm gear and a worm wheel as described in any one of claims 1 to 5; The helical teeth of the worm mesh with the gear teeth.

7. The worm gear transmission mechanism as described in claim 6, characterized in that, The worm gear is made of plastic, and the worm is made of metal.

8. A steering system, characterized in that, It is equipped with the worm gear transmission mechanism as described in claim 6 or 7; The worm can float along the axial direction of the worm wheel.

9. A processing method, characterized in that, The worm gear as described in any one of claims 1 to 5 is manufactured using the gear hobbing method; The arc-shaped tooth surfaces distributed on both sides of the flat tooth surface include a first arc-shaped tooth surface and a second arc-shaped tooth surface, and the machining method includes: The hob is controlled to cut into the worm gear from the first junction of the first arc tooth surface and the flat tooth surface along the tooth height direction of the gear teeth until the first arc tooth surface is formed; The hob is controlled to feed from the position where the first arc tooth surface is formed, along the tooth direction, to the second junction of the flat tooth surface and the second arc tooth surface, so as to form the flat tooth surface; and The hob is controlled to cut the worm gear along the tooth height direction from the position where the flat tooth surface is formed, so as to form the second arc tooth surface; During the travel of the hob, the axis of the hob is controlled to be parallel to the normal plane of the worm gear.

10. The processing method as described in claim 9, characterized in that, The hob has a gradually changing tooth thickness; When the hob cuts into the worm gear, the maximum tooth thickness of the hob is aligned with the first junction on the same tooth height line. When the hob is fed to the second boundary, the maximum tooth thickness portion is fed to the same tooth height line as the second boundary.

11. An electronic device, characterized in that, include: processor; A memory, wherein executable instructions are stored; When the executable instructions are executed by the processor, the processing method as described in claim 9 or 10 is implemented.

12. A computer-readable storage medium for storing a program, characterized in that, When the program is executed by the processor, it implements the processing method as described in claim 9 or 10.

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