METHOD FOR SHAPING A BEVEL GEAR

Abstract

Method for forming a bevel gear (12, 14) with a gear tooth surface (16, 18), the method comprising the following steps: providing an annular gear blank (101); machining a plurality of radially and outwardly extending teeth (20, 22) into the gear tooth surface (16, 18) of the bevel gear (12, 14) (102), each tooth (20, 22) comprising: a tooth tip (26) having a length (50); and a plurality of engagement surfaces (24), wherein each engagement surface (24) comprises a tooth surface (32) and a tooth flank (34) such that the tooth surface (32) at the tooth tip (26) abuts an abutment edge (28); forming at least one chamfer (40) on each tooth (20, 22) at the abutment edge (28) (103), which is formed between the respective engagement surface (24) and the tooth tip (26) by removing a chamfer area (42) at the respective abutment edge (28); applying a heat treatment process to the bevel gear (12, 14) (104);Applying a shot peening process to the bevel gear (12, 14) and to the gear tooth surface (16, 18) (106), wherein the shot peening process causes plastic deformation of the gear tooth surface (16, 18), thereby forming an additional peak of material contained at the chamfer (40) and lying within the chamfer area (42); and finishing the bevel gear (12, 14) by a shearing process, a rolling process, a grinding process, a honing process or a lapping process.

Description

TECHNICAL AREA

[0001] The invention relates to bevel gears, such as those used in vehicles, equipment and the like, and a method for manufacturing and shaping these gears. BACKGROUND

[0002] Bevel gears are used in automotive, equipment, and other similar applications. Common types of bevel gears include helical bevel gears, spiral bevel gears, hypoid bevel gears, and the like. Spiral bevel gears and hypoid bevel gears are typically manufactured by creating the tooth profile, for example, by cutting, milling, hobbing, or forming, such as by forging. The tooth profiles of bevel gears are usually generated using CNC gear milling machines, specialized cutters, and complex programming strategies. SUMMARY

[0003] A bevel gear set and a manufacturing process are provided. The bevel gear set can include a first bevel gear and a second bevel gear. Both the first and second bevel gears can be helical bevel gears. Both the first and second bevel gears can also be hypoid helical bevel gears.

[0004] The first bevel gear can be arranged on a first bevel gear axis. The first bevel gear can have a first gear tooth surface with a plurality of teeth formed on it. Each tooth of the first plurality of teeth extends outwards and radially from the first bevel gear axis.

[0005] The second bevel gear can be arranged on a second bevel gear axis. This second bevel gear can have a second gear tooth surface with a plurality of teeth formed on it. Each tooth of this second plurality of teeth extends outwards and radially from the second bevel gear axis.

[0006] The first set of teeth is designed to engage with the second set of teeth, so that the first set of teeth and the second set of teeth interlock.

[0007] Each tooth of each of the first plurality of teeth and the second plurality of teeth comprises a cusp, a plurality of engagement surfaces, and a chamfer. The cusp may have a length of . The plurality of engagement surfaces may comprise a first engagement surface and a second engagement surface, such that the first engagement surface and the second engagement surface of the respective tooth bear against an abutment edge at the cusp. Each engagement surface may further comprise a tooth face and a tooth flank, such that the tooth face bears against the abutment edge at the cusp.

[0008] The chamfer can be formed at an abutment edge and can extend along the tooth tip length. The chamfer can be dimensioned such that it has a first chamfer dimension that is essentially equivalent to the tooth tip length and a second chamfer dimension.

[0009] The individual bevel gears of the bevel gear set can be formed by the manufacturing process disclosed herein, which comprises the following steps: providing an annular gear blank; machining a plurality of radially and outwardly extending gear teeth in the gear tooth surface of the bevel gear by a milling process; forming at least one chamfer on each tooth, such that each chamfer is arranged on an abutment edge, between the respective engagement surface and the tooth tip, by an automated brushing process; applying a heat treatment process to the bevel gear; finishing the bevel gear; and applying a shot peening process to the bevel gear.

[0010] The aforementioned features and advantages, as well as further features and advantages of the present teachings, will become clearly evident from the following detailed description of some of the best types and further embodiments of the present teachings with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Fig. Figure 1 is a schematic perspective view of an exemplary spiral bevel gear set.

[0012] Fig. Figure 2 is a schematic plan of an exemplary spiral hypoid bevel gear set.

[0013] Fig. Figure 3 is a schematic cross-section of an exemplary gear tooth.

[0014] Fig. Figure 4 is a schematic perspective view of a selected plurality of teeth on an exemplary bevel gear set, in which the teeth are in mesh.

[0015] Fig. 5A is a schematic cross-sectional view with an exemplary gear tooth, designed with a chamfer between each of the respective tooth flanks and the respective tooth tip.

[0016] Fig. 5B is a schematic perspective view with an exemplary gear tooth, designed with a chamfer between each of the respective tooth flanks and the respective tooth tip.

[0017] Fig. Figure 6 is a schematic perspective view of a selected plurality of teeth on an exemplary bevel gear set, wherein the selected plurality of teeth is formed with a chamfer between the tooth flanks of each tooth and the respective tooth tip.

[0018] Fig. Figure 7 is a schematic view of a selected plurality of teeth on an exemplary bevel gear set, wherein the teeth are in exemplary engagement, and wherein the selected plurality of teeth is formed with a chamfer between the tooth flanks of each tooth and the respective tooth tip.

[0019] Fig. Figure 8 is a flowchart illustrating the process for forming an exemplary bevel gear. DETAILED DESCRIPTION

[0020] Although the present disclosure relates to specific applications or industries, those knowledgeable in the relevant field can recognize the broader applications of this disclosure. With basic knowledge of the field, it is evident that terms such as "above," "below," "upwards," "downwards," etc., are used only descriptively in the figures and do not represent any limitations on the scope of the disclosure as defined in the attached claims. All numerical designations, such as "firstly" or "secondly," are purely illustrative and do not limit the scope of the disclosure in any way.

[0021] Features shown in one figure can be combined with, replaced by, or modified by features shown in other figures. Unless otherwise stated, no features, elements, or limitations are mutually exclusive. Furthermore, none of the features, elements, or limitations are essential for operation. All specific configurations shown in the figures are purely illustrative and do not limit the claims or description in any way.

[0022] Referring to the drawings, in which the same reference numbers refer to the same components in the different views, a bevel gear set is described. 10 and a method for manufacturing 100 This was provided.

[0023] The bevel gear set 10 can a first bevel gear 12and a second bevel gear 14 include the first bevel gear 12 can be on a first bevel gear axis 29 be arranged. The first bevel gear 12 can via a first gear tooth surface 16 , with an initial multitude of teeth formed on it 20 , possess. Each tooth of the first set of teeth 20 extends outwards and radially from the first bevel gear axis 29 The second bevel gear 14 can be mounted on a second bevel gear axis 30 be arranged. The second bevel gear 14 can be accessed via a second gear tooth surface 18 , with a second multitude of teeth formed on it 22 , possess. Each tooth of the second set of teeth 22 extends outwards and radially from the second bevel gear axis 30 The first set of teeth 20 is designed to fit into the second set of teeth 22to intervene so that the first multitude of teeth 20 and the second set of teeth 22 interlock 46 .

[0024] Both the first bevel gear 12 as well as the second bevel gear 14 can be a spiral bevel gear ( Fig. 1) Spiral bevel gears typically have a generally ring-shaped gear body with a gear tooth surface 16 , 18 , which have a multitude of radially outward-facing or helical teeth 20 , 22 exhibits the shape of the gear tooth. 20 , 22 of the first bevel gear 12 and the second bevel gear 14 It can be, for example, straight, spiral, or a hypoid gear.

[0025] The first bevel gear 12 and the second bevel gear 14 , when used as a spiral bevel gear ( Fig. 1) Designed, they can be shaped as a right-hand spiral bevel gear or a left-hand spiral bevel gear, depending on the application. In a left-hand spiral bevel gear, the outer half of a tooth is inclined obliquely counterclockwise from an axial plane through the center of the tooth ( Fig. 1) In a right-hand spiral bevel gear, the outer half of a tooth is inclined obliquely clockwise from an axial plane through the center of the tooth ( Fig. 2).

[0026] Furthermore, when designed as a spiral bevel gear set 10 , as shown in Fig. 1, are the first bevel gear axis 29 and the second bevel gear axis 30 They are designed to cross over each other. An example application of such a configuration is in a vehicle differential, where the drive direction from the drive shaft must be rotated essentially orthogonally to drive the wheels.

[0027] The first bevel gear 12 and the second bevel gear 14 can be designed as a spiral hypoid bevel gear, as shown in an example in Fig. 2. While hypoid gears generally have a similar shape to helical bevel gears, hypoid gears have helical teeth that are curved and chamfered, with the pitching surface of the tooth being a hyperboloid of revolution. Hypoid gears operate on non-crossing axes. As such, when designed as helical hypoid bevel gears... 12 , 14 , as shown in Fig. 2, are the first bevel gear axis 29 and the second bevel gear axis 30Non-crossing. An example application for such a configuration can be found in a vehicle differential in larger trucks, SUVs, and the like, since helical hypoid bevel gear sets are capable of transmitting higher torque than strictly helical bevel gear sets. The greater the offset of the first bevel gear axis, the higher the torque. 29 and the second bevel gear axis 30 The higher the diameter, the higher the transmitted torque between the first bevel gear. 12 and the second bevel gear 14 .

[0028] The first bevel gear 12 and the second bevel gear 14 They can be formed by a face milling process or a gear hobbing process. In the exemplary embodiment, the first bevel gear 12 and the second bevel gear 14The gear blank or workpiece is formed by a face milling process using a multi-flute face mill or similar device. In one example, a gear blank or workpiece is selected and rotated relative to the rotating cutting device to form a groove on the inside of the tooth. The cutting device is then retracted, indexing the blank or workpiece into a position for cutting the next tooth. In another example, the cutting machine rotates both the cutter and the gear blank at predetermined relative speeds without indexing.

[0029] With reference to Fig. 1– Fig. 7. Each tooth can be affected by any of the first set of teeth. 20 and the second multitude of teeth 22 a tooth tip 26 , a multitude of intervention areas 24 , and a chamfer 40 , include.

[0030] The tip of the tooth 26can outside the respective first bevel gear axis 29 and the second bevel gear axis 30 be arranged, and can furthermore be the outermost part of the gear tooth surface 16 , 18 , encompass. The tip of the tooth 26 can also be a length 50 exhibit.

[0031] The multitude of intervention areas 24 can be a first intervention area 24a ( Fig. 3 and Fig. 5) and a second intervention area 24b ( Fig. 3 and Fig. 5) include, so that the first intervention area 24a and the second intervention area 24b of the respective tooth 20 , 22 at the tip of the tooth 26 at an abutment edge 28 is located. Every intervention area 24 can still be a tooth surface 32 and a tooth flank 34 encompass, so that the tooth surface 32 at the tip of the tooth 26 at the abutment edge 28is pending.

[0032] Each tooth 20 , 22 can at least one chamfer 40 exhibit. As in Fig. 5– Fig. As shown in 7, each tooth can 20 , 22 two phases 40 exhibit at least one chamfer. 40 can at an abutment edge 28 be shaped, and can extend along the length of the tooth tip 50 extend the phase 40 can be achieved by removing a chamfer area 42 ( Fig. 5A and Fig. 5B) of the respective tooth 20 , 22 at the abutment edge 28 to be shaped. The chamfered area 42 is defined as the area of ​​the tooth 20 , 22 , which is due to the formation of the phase 40 on the respective tooth 20 , 22 was removed. The chamfer area 42 can have four dimensions, a first chamfer area dimension D1 ( Fig. 5B), a second chamfer area dimension D2 ( Fig. 5B), a third chamfer area dimension D3 ( Fig. 5A, Fig. 5B and Fig. 6) and a fourth chamfer area dimension D4, which corresponds to the surface width of the gear tooth ( Fig. 5B and Fig. 6) corresponds. The first chamfer area dimension D1 can range from approximately 0.10 to approximately 0.40 millimeters. In particular, the first chamfer area dimension D1 can be approximately 0.25 millimeters. The second chamfer area dimension D2 can range from approximately 0.3 to approximately 0.7 millimeters. In particular, the second chamfer area dimension D2 can be approximately 0.5 millimeters.

[0033] The at least one phase 40 can be done on the respective tooth 20 , 22They can be formed through a variety of processes, including, but not limited to, an automated brushing process, a machining process, and a manual or hand process. In one embodiment, the at least one chamfer is 40 by applying an automated brush to the abutment edge 28 of the tooth 20 , 22 along the length 50 of the tooth tip 26 , shaped. The brush can be a metallic brush. Alternatively, the brush can be a non-metallic brush with an abrasive component, such as a nylon bristle brush impregnated with an abrasive such as aluminum oxide or silicon carbide. In another exemplary embodiment, the at least one chamfer 40 formed by a machining process. For example, at least one chamfer can be formed. 40are formed via a computer numerical control machine (CNC), so that the computer numerical control machine (CNC) creates the corresponding chamfer. 40 into the respective tooth 20 , 22 at the corresponding abutment edge 28 cuts, according to a series of predetermined instructions.

[0034] A procedure 100 for forming a bevel gear 12 , 14 with a gear tooth surface 16 , 18 , like the first bevel gear 12 and the second bevel gear 14 of the bevel gear set 10 , is also provided herein and detailed in the flowchart in Fig. 8 described. The process generally comprises the following steps: providing a ring-shaped gear blank; machining a plurality of radially and outwardly extending teeth. 20 , 22 into the gear tooth surface 16 ,18 of the bevel gear 12 , 14 ; Formation of at least one chamfer 40 on each tooth at the abutment edge 28 , formed between the respective intervention surface 24 and the tip of the tooth 26 ; Heat treatment of the bevel gear 12 , 14 ; Application of a shot peening process to the bevel gear; and finishing of the bevel gear 12 , 14 .

[0035] First, in step 101 A ring-shaped gear blank or workpiece is provided. At step 102 A large number of radially and outwardly extending teeth will be used. 20 , 22 through a surface milling process into the gear tooth surface 16 , 18 of the bevel gear 12 , 14The process involves machining the ring-shaped gear blank or workpiece. This is done using a multi-flute face mill or similar tool. In this case, the ring-shaped gear blank or workpiece is positioned relative to the rotating cutting device. The cutting device then cuts into the blank to create a groove on the inside of the tooth. The cutting device is subsequently retracted, and the blank or workpiece is indexed into a position for cutting the next tooth.

[0036] After shaping each corresponding tooth 20 , 22 on the bevel gear 12 , 14 , at steps 101 and 102 , at step 103 , at least one phase 40 on each tooth 20 , 22 shaped. At least one chamfer. 40 is at the abutment edge 28 between the respective intervention area 24and the tip of the tooth 26 shaped. At least one chamfer. 40 can be done on the respective tooth 20 , 22 are formed by an automated brushing process, so that at least one chamfer is formed 40 by applying an automated brush to the abutment edge 28 of the tooth 20 , 22 along the length 50 the tip of the tooth 26 is shaped. The brush can be a metallic brush. Alternatively, the brush can be a non-metallic brush with an abrasive component, such as a nylon bristle brush impregnated with an abrasive such as aluminum oxide or silicon carbide.

[0037] At step 104 will the bevel gear 12 , 14subjected to a heat treatment process. Heat treatment involves the use of heating or cooling, usually at extreme temperatures, to achieve a desired result such as hardening or softening a material. In this example, the respective bevel gear is subjected to this process. 12 , 14 A material is subjected to a heat treatment process to harden it, such as steel or the like. Heat treatment techniques include annealing, surface hardening, precipitation hardening, tempering, normalizing, and quenching.

[0038] After the heat treatment process at step 104 , at step 105 , can the bevel gear 12 , 14Surface finishing can be completed through a metalworking process. It can encompass a wide range of industrial processes used to modify the surface of a manufactured item to improve its appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance, and hardness. Surface finishing can also modify electrical conductivity, remove burrs and other surface defects, and improve the friction characteristics of the gear tooth surface. 16 , 18 rules. In one example, the first and second bevel gears can be 12 , 14 They can be reworked using a surface processing method, such as a shearing process, a rolling process, a grinding process, a honing process and a lapping process.

[0039] At step 106The respective bevel gear 12 , 14 subjected to a shot peening process. Shot peening is a cold metal processing method used to create a comprehensive residual stress layer and modify the mechanical properties of metals and composite materials. Shot peening involves blasting a surface with projectiles—that is, round metal, glass, or ceramic particles—with a force sufficient to cause plastic deformation. This plastic deformation induces compressive residual stress in the surface layer, i.e., the gear tooth surface. 16 , 18 , together with tensile stress inside the respective gear component 12 , 14 The surface is plastically expanded by the irradiation, which impairs the mechanical properties of the surface.

[0040] As in Fig. 3 shown when a bevel gear, such as the first bevel gear disclosed herein, is used. 12and the second bevel gear 14 , which is subjected to a shot peening process, plastic deformation of the material near the abutment edge can occur. 28 an additional peak 36 , i.e., additional material at the abutment edge 28 , cause this additional spike 36 , as in Fig. As shown in section 3, it can change the tooth profile and ultimately the tooth intervention. 46 between the first gear 20 and the second gearing 22 Disruption. The disruption of the dental procedure. 46 between the first gear 20 and the second gearing 22 can have negative effects. For example, an additional spike can 36 , as shown in Fig. 3. undesirable wear of the gear tooth surface 16 , 18 cause, whereby the additional tip 36 meets the tooth profile, i.e., the tooth surface 32 and / or the tooth flank34 of the engaging gear. In another example, an additional tip can be used. 36 , as shown in Fig. 3. Misalignment of the tooth engagement 46 between the first multitude of teeth 20 and the second multitude of teeth 22 cause. In yet another example, an additional spike can 36 , as shown in Fig. 3. Noise, vibration and harshness (NVH) problems in an application such as a vehicle, for example a clicking sound when the auxiliary tip... 36 on the gear tooth surface 16 , 18 of the engaging gear, cause.

[0041] The addition of at least one chamfer 40 to each of the teeth of the first set of teeth 20 and the second multitude of teeth 22 , immediately after the face milling process and before the bevel gear 12 , 14This process, which involves heat treatment and shot peening, addresses these problems. As in Fig. 5A and Fig. 5B shown when a bevel gear, such as the first bevel gear disclosed herein, is used. 12 and the second bevel gear 14 When subjected to the shot peening process, plastic deformation of the material can result in an additional tip. 36 , i.e., additional material deforms on the chamfer 40 , cause. Even if the additional peak 36 , as in Fig. As shown in 5B, the resulting additional tip is formed during the shot peening process. 36 out of Fig. 5B within the area 42 limited. The chamfer area 42 is defined as the area of ​​the tooth 20 , 22 , which is due to the formation of the phase 40 on the respective tooth 20 , 22 at the abutment edge 28was removed. As such, the tooth profile remains unchanged due to the formation of the additional cusp. 36 within the chamfer area 42 , since the additional peak formed 36 , as in Fig. 5B shown, during the dental procedure 46 does not come into contact with the engaging gear tooth. As such, the creation of the chamfer is made possible. 40 Improved service life and reduced wear of the gear, as well as better performance in terms of noise, vibration and harshness (NVH) evaluations in an application such as a vehicle, due to the clicking between the first multitude of teeth. 20 and the second multitude of teeth 22 during the dental procedure 46 is avoided due to the limitation of the additional peak 36 , as shown in Fig. 5B, within the chamfer area 42 .

[0042] The detailed description and the drawings or figures support and describe the present teachings, but the scope of the present teachings is defined solely by the claims. While some of the best methods and further embodiments of the present teachings have been described in detail, there are various alternative designs and embodiments for implementing the present teachings in the appended claims.

Claims

[1] Method for forming a bevel gear with a gear tooth surface, the method comprising the following steps: the provision of a ring-shaped gear blank; machining a plurality of radially and outwardly extending teeth into the gear tooth surface of the bevel gear, wherein each tooth comprises the following: a tooth tip that has a length; and a multitude of engagement surfaces, each engagement surface comprising a tooth surface and a tooth flank, such that the tooth surface at the tooth tip rests against the abutment edge; the formation of at least one chamfer on each tooth at the abutment edge, formed between the respective engagement surface and the tooth tip; the application of a heat treatment process to the bevel gear; the application of a shot peening process to the bevel gear and the gear tooth surface, wherein the shot peening process causes a plastic deformation of the gear tooth surface, thereby forming an additional tip of material, and wherein the additional tip of material is confined at the chamfer; and the finishing of the bevel gear by a shearing process, a rolling process, a grinding process, a honing process and a lapping process. [2] Method according to claim 1, wherein the forming of at least one chamfer on each tooth at the abutment edge further comprises the removal of a chamfer area formed by the corresponding engagement surface and the tooth tip, wherein the chamfer area is dimensioned such that the chamfer area has a first chamfer area dimension, a second chamfer area dimension, a third chamfer area dimension, and a fourth chamfer area dimension. [3] Method according to claim 2, wherein the first chamfer area dimension is arranged along the tooth tip and is from about 0.10 to about 0.40 millimeters. [4] Method according to claim 3, wherein the second chamfer area dimension is arranged along the engagement surface and is from about 0.3 to about 0.7 millimeters. [5] Method according to claim 1, wherein at least one chamfer is formed on each tooth at the abutment edge by an automated brushing process. [6] Method according to claim 5, wherein the at least one chamfer on each tooth is formed by applying a brush to the abutment edge of the tooth along the length of the tooth tip. [7] Bevel gear set comprising: a first bevel gear rotatably arranged on a first bevel gear axis, wherein the first bevel gear has a first gear tooth surface, wherein a first plurality of teeth is formed on a first gear tooth surface, such that each tooth on the first plurality of teeth extends outwards and radially from the first gear link axis; a second bevel gear rotatably arranged on a second bevel gear axis, wherein the second bevel gear has a second gear tooth surface, wherein a second plurality of teeth is formed on a second gear tooth surface, such that each tooth on the second plurality of teeth extends outwards and radially from the second bevel gear axis; wherein each tooth of the first multitude of teeth and of the second multitude of teeth comprises the following: a tooth tip that has a length; a plurality of engagement surfaces, each engagement surface comprising a tooth face and a tooth flank, such that the tooth face at the tooth tip rests against the abutment edge; and at least one chamfer formed at the abutment edge, extending along the length of the tooth tip; and wherein the first multitude of teeth is designed to engage with the second multitude of teeth, so that the first multitude of teeth and the second multitude of teeth interlock. [8] Bevel gear set according to claim 7, wherein each chamfer on each tooth is formed on the abutment edge of the corresponding tooth by removing a chamfer area formed by the corresponding engagement surface and the tooth tip, wherein the chamfer area is dimensioned such that the chamfer area has a first chamfer area dimension, a second chamfer area dimension, a third chamfer area dimension, and a fourth chamfer area dimension. [9] Bevel gear set according to claim 8, wherein the first chamfer area dimension is arranged along the tooth tip and is from about 0.10 to about 0.40 millimeters. [10] Bevel gear set according to claim 9, wherein the second chamfer area dimension is arranged along the engagement surface and is of about 0.3 to about 0.7 millimeters.

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