阅读说明：本技术 带有支承结构的齿轮 (Gear with supporting structure ) 是由 R·拉夫 J·格里姆 G·特里施 于 2021-05-21 设计创作，主要内容包括：本发明涉及带有支承结构的齿轮,其具有转动轴线(101)并包括：具有分布在转动轴线周围的多个齿(210)的齿轮体(200),其中各两个相邻齿在其齿根(211)处通过齿底(220)相互连接。齿轮(100)还具有支承结构(300),其在各自齿底的至少一个或两个关于转动轴线的轴向端处具有支承区,支承区在各自相邻齿之间自齿底延伸离开。支承区(301,302)分别通过过渡区(400-402)直接连接相邻齿和齿底。各自过渡区至少部分且连贯延伸地包围支承区且在其延伸方向上看其横截面具有过渡几何形状。过渡几何形状的几何形状参数在每个支承区沿关于转动轴线的轴向和/或径向稳定变化。本发明还涉及具有这种齿轮的差速器。(The invention relates to a gear with a support structure, having an axis of rotation (101) and comprising: a gear body (200) having a plurality of teeth (210) distributed around a rotational axis, wherein two adjacent teeth are connected to each other at their tooth roots (211) by a tooth bottom (220). The gear (100) also has a bearing structure (300) having bearing zones at least one or both axial ends of the respective tooth bases about the axis of rotation, the bearing zones extending away from the tooth bases between respective adjacent teeth. The support zones (301,302) directly connect adjacent teeth and tooth bottoms via transition zones (400-402), respectively. The respective transition region surrounds the support region at least partially and continuously in an extending manner and has a transition geometry in cross section, as seen in the direction of extension thereof. The geometry parameters of the transition geometry vary steadily in each bearing zone in the axial and/or radial direction with respect to the axis of rotation. The invention also relates to a differential having such a gear.)

1. A gear (100), the gear (100) having an axis of rotation (101), the gear (100) comprising:

-a gear body (200), the gear body (200) having a plurality of teeth (210) distributed around the axis of rotation (101), wherein each two adjacent teeth (210) are interconnected at their tooth roots (211) by a tooth bottom (220), and

-a support structure (300), said support structure (300) having one support zone (301,302) at least one or both axial ends of a respective tooth bottom (220) with respect to said rotation axis (101), said support zone extending away from said tooth bottom (220) between respective adjacent teeth (210),

wherein the bearing zone (301,302) is directly connected to the adjacent tooth (210) and the tooth bottom (220) by a transition zone (400,401,402), respectively, and wherein the respective transition zone (400,401,402) at least partially and continuously surrounds the bearing zone (301,302) and has a transition geometry in cross section, as seen in the direction of extension of the respective transition zone (400,401,402), wherein the geometry of the transition geometry varies steadily at each bearing zone (301,302) along an axial and/or radial direction with respect to the rotational axis (101).

2. Gear (100) according to claim 1, wherein the transition geometry has at least one, preferably a single geometry portion defined by the geometry parameters, and/or wherein the transition geometry or the geometry portion is preferably a rounding, such as a radius or a concave curvature, and/or a bevel, such as a chamfer, and/or an intersection defined according to its shape, such as an intersection defined according to a polynomial function, and/or wherein the transition geometry has at least one radius and/or one chamfer.

3. Gear (100) according to claim 1 or 2, wherein the geometrical dimension is a curvature, a radius (R1-R4, R100) and/or a width or angle of a bevel, in particular a chamfer.

4. Gear (100) according to any one of the previous claims, wherein the respective transition zone (400,401,402) is designed to be steadily varying in geometrical parameters of the transition zone (400,401,402) over the entire transition zone (400,401,402) seen in axial and/or radial direction with respect to the rotation axis (101), wherein the transition zone (400,401,402) preferably has at least one local in axial and/or radial direction in which the geometrical dimension of the transition geometry of the transition zone (400,401,402) remains unchanged.

5. Gear wheel (100) according to any of the previous claims, wherein the geometrical size varies, preferably decreases, uniformly, preferably steadily and/or continuously, in axial and/or radial direction with respect to the rotation axis (101).

6. Gear (100) according to any one of the preceding claims, wherein the transition zone (400,401,402) is substantially U-shaped, parabolic or V-shaped, preferably open towards the axial end of the tooth bottom (220) having the transition zone (400,401,402) and/or towards the radial periphery of the gear (100) with respect to the axis of rotation (101).

7. Gear (100) according to any one of the preceding claims, wherein the transition zone (400,401,402) has a first portion (411) for direct connection between the respective bearing zone (301,302) and a first tooth (210) of adjacent teeth, a second portion (412) for direct connection between the bearing zone (30,302) and a second tooth (210) of adjacent teeth, and a third portion (413) connecting the first portion (411) and the second portion (412), the third portion (413) being for direct connection between the bearing zone (301,302) and the tooth bottom (220) connecting the first tooth and the second tooth (210).

8. Gear (100) according to claim 7, wherein said geometrical dimension preferably continuously decreases in a direction of extension from said first portion (411) towards said third portion (413), and wherein said geometrical dimension preferably continuously decreases in a direction of extension from said second portion (412) towards said third portion (413), and/or wherein said geometrical dimension also continuously varies at the connection of the respective first portion (411) or second portion (412) and third portion (413), respectively.

9. Gear (100) according to any one of the preceding claims, wherein the geometrical size of the transition geometry of the respective transition zone (400,401,402) varies uniformly and/or steadily along an axial and/or radial direction with respect to the rotation axis (101) on opposite sides with respect to the respective bearing zone (301, 302).

10. Gear (100) according to any one of the preceding claims, wherein the dimensions of the respective bearing zone (301,302) vary steadily/continuously, in particular decrease, with respect to the axis of rotation (101) in an axial direction away from the axial end of the tooth bottom (220) with the bearing zone towards the opposite axial end.

11. Gear wheel (100) according to any of the preceding claims, wherein the axial end of the respective bearing zone (301,302) that is axially remote from the tooth bottom (220) with respect to the axis of rotation (101) with the bearing zone (301,302) extends at most over a third of the axial length of the tooth bottom (220) towards the opposite axial end, preferably at most over a quarter of the length of the tooth bottom (220).

12. Gear (100) according to any one of the preceding claims, wherein the respective bearing zone (301,302) extends flat between the respective adjacent teeth (210).

13. Gear (100) according to any one of the preceding claims, wherein the respective bearing zone (301,302) is provided at the respective axial end of the tooth bottom (220) such that a periphery (104) of the gear (100) surrounding the circumference of the gear (100) and preferably exposed to the outside is formed by the respective bearing zone (301,302), preferably by the transition zone (400,401,402), and by the adjacent tooth (210) together.

14. Gear (100) according to any one of the preceding claims, wherein the transition geometry of the respective transition zone (400,401,402) is designed such that the respective transition zone (400,401,402) has a concave curvature in the direction of the respective tooth (210) or the tooth bottom (220).

15. Gear (100) according to any one of the preceding claims, wherein the gear body (200) is designed as a truncated cone preferably extending along the axis of rotation (101) between two end faces (105,106) and further preferably having a cone angle (102) defined between 35 and 70 degrees with respect to the axis of rotation (101), wherein the gear body (200) preferably has a fastening opening (150) on at least one of the two end faces (105,106), wherein the fastening opening (150) is further preferably designed as a through-hole preferably having a defined inner contour of a shaft-hub connection, such as a splined shaft contour, wherein the fastening opening (150) further preferably extends along the axis of rotation (101).

16. A differential having at least one gear wheel (100) according to one of the preceding claims, wherein at least one gear wheel (100) is preferably provided as a differential bevel gear or axle shaft gear.

Technical Field

The present invention relates to a gear wheel with a number of teeth distributed around its axis of rotation. The toothed wheels have a bearing structure which, at least one or both axial ends of the respective tooth base with respect to the axis of rotation, has bearing regions which extend out from the tooth base between adjacent teeth. The invention also relates to a differential having such a gear.

Background

It is known from the prior art to influence the strength of the gear and the product life by means of its structural design. For this purpose, for example, ribs or other forms of reinforcement are provided on the gear.

It is therefore known, for example, to provide a reinforcing structure at least one of the ends of the tooth gap, whereby the mechanical loading of the tooth can be better distributed within the component. Here, the extension of the reinforcing structure between the gear teeth may give the reinforcing structure a "meshed area" (webbed areas) appearance.

For illustration, fig. 12 shows such a gear (800) known from the prior art, with a corresponding reinforcing structure (830). By reinforcing structure 830, material fatigue and cracking in the root (no reference numeral) of tooth (821) may be resisted, thereby extending the life and load carrying capacity of gear 800.

A disadvantage of this known solution is that material fatigue and cracks are particularly resisted because the gear and the reinforcing structure provided thereon are of solid construction and are dimensioned to be large. This may result in increased weight and space requirements for such gears. This is particularly problematic in applications where the installation space is otherwise limited and the component weight also has a significant effect on the efficiency and inertia of the overall system, as in vehicle construction.

Fig. 12 shows sharp edges 840 as the transition from the reinforcing structure 830 to the teeth 821. Furthermore, in the prior art there are gears whose respective reinforcement-to-tooth transitions are formed by a constant and generally small radius (radius) compared to other gear sizes.

However, it has been found that stress peaks occur in the reinforcing structure precisely in the case of such structural transitions (sharp edges, constant radii), so that the service life and the load-bearing capacity of the gear are limited. In the prior art, these adverse effects have hitherto been dealt with by designing the reinforcing structure to be larger in size, with the result that the gear space requirement and the gear weight are further increased.

Disclosure of Invention

The object of the present invention is therefore to provide a gear and also a differential, by means of which the aforementioned disadvantages known from the prior art can be overcome.

The object of the invention is, in particular, to provide a gearwheel and a differential, which are improved in terms of service life, mechanical rigidity and load-bearing capacity, respectively, wherein, in addition, the mechanical stresses occurring in the gearwheel during operation are reduced and evenly distributed, and which can also be used for a number of different applications, wherein despite the increased functionality, weight increases and additional costs in the manufacture of the gearwheel or of the differential are avoided.

A first aspect of the invention relates to a gearwheel having a rotational axis, the gearwheel having a gearwheel body comprising a plurality of teeth distributed around the rotational axis, wherein two respective adjacent teeth are connected to each other at their tooth roots by a tooth bottom.

The gear wheel also has a bearing structure having a bearing region at least one or both axial ends of the respective tooth base with respect to the axis of rotation, the bearing region extending away from the tooth base between respective adjacent teeth.

In this case, the bearing region is directly connected to the adjacent tooth and the tooth base by a transition region.

In this case, the expression "directly connected" is understood, for example, to mean that a direct connection exists, in particular, between the gear structures to be connected to one another, i.e. that, for example, the connection of two structures does not exist (or is provided with an (additional) intermediate structure between them).

The respective transition region then at least partially surrounds the bearing region and extends continuously.

In this case, the expression "continuous extension" is understood, for example, to mean that the extension is continuous, i.e., for example, no structural interruption occurs along its extent.

The transition region has a transition geometry in cross section, as seen in the direction of extension thereof.

In this case, for example, "the direction of extension of the transition regions" may refer to a direction in which the respective transition regions preferably extend consecutively. The "transition region extension direction" can also mean, for example, a direction which extends transversely to the extension of the respective transition region between the respective bearing region and the respective tooth or tooth base. Furthermore, this direction may also be the main direction of extent of the respective transition region, which may be, for example, a direction by means of which the spatial direction of extent of the transition region can be described as optimally as possible (viewed locally/over the entire transition region).

Furthermore, for example, the term "transition geometry" may refer to a geometry which structurally defines a change from a first structure to a second structure (in terms of its shape), i.e. for example a geometry which consists for example of straight lines, curves and/or angles or has only one of the elements. In this case, the transition geometry can also preferably be a geometry which is composed of a plurality of such geometrical basic components in a coherent manner.

In this case, according to the invention, the geometry parameters of the transition geometry vary axially and/or radially along the axis of rotation in each bearing zone, which is preferably stable (steady).

The expression "geometry parameter" may for example refer to the size, arc length, curvature or tortuosity of a curve or a geometry part (geometry element) comprised by the transition geometry. This list is exemplary only.

The expression "continuously variable" (steady change) is understood, for example, to mean that, even if there may be local regions which are not changed in the axial or radial direction, viewed in the axial or radial direction, there is a constant or variable over the entire region. Thus, a constant change may for example mean that the respective geometry parameters of two transition geometries of the same transition zone which are present at two (axially and/or radially) different (and possibly immediately adjacent) points are different from each other. For example, "a stable change in geometry parameters" may also refer to a partial disconnection of a region having changing geometry parameters by a portion in which the geometry parameters remain unchanged (i.e., e.g., smaller-constant-smaller). Alternatively or additionally, "continuously stable changes" can also be understood in the mathematical sense. The geometric parameter can thus be continuously varied in the axial and/or radial direction with respect to the axis of rotation in such a way that the variation of the geometric parameter does not have any abrupt changes, wherein here also the portions without variation can be present in the axial or radial direction.

For example, "axial and/or radial with respect to the axis of rotation" is to be understood such that the directions have a component at least in a respective direction parallel (axial) or perpendicular (radial) to the axis of rotation, so that "axial" preferably extends parallel or obliquely with respect to the axis of rotation, "radial" extends perpendicular or obliquely with respect to the axis of rotation, and "axial and radial" extends obliquely with respect to the axis of rotation.

In other words, the invention can thus be described as follows:

a gearwheel is provided which is intended to rotate about an axis of rotation and comprises a number of teeth, wherein two teeth are connected to each other by (one and the same) tooth root. In particular, high torques can be transmitted, for example, by means of the gear design according to the invention.

The gear also has a support structure. By means of the support structure, it is possible, for example, to increase the gear stiffness and/or to reduce the stresses occurring in the gear during operation.

The bearing structure here has a bearing region at least one or at least two axial ends of the tooth base of two adjacent teeth with respect to the axis of rotation. Thus, the support structures can be provided, for example, in tooth gaps formed between two adjacent teeth, respectively. Preferably, a bearing structure can be provided in each tooth gap of the gear. The support structure can therefore be arranged particularly advantageously on the gear wheel. Thus, the gear can be constructed smaller and lighter, so that a smaller package can be obtained. By being seated at the respective axial ends of the tooth roots, it is simultaneously possible to limit the tooth area available for engagement as little as possible by the support structure, since otherwise free space is used for the provision of the support structure.

The bearing zones extend between respective adjacent teeth away from the root. The bearing region can thus extend away from the tooth root, for example in the radial and/or axial direction with respect to the axis of rotation, in order, for example, to increase the gear diameter (critical for load bearing) and preferably to increase the gear stiffness in this way.

The bearing region is in this case directly (i.e. for example immediately) connected to the adjacent tooth and the tooth base by a transition region. Thus, the extension of the transition zone may be limited, for example, by the teeth and the support structure. Thus, a defined structural transition between the respective tooth and the support structure can be provided by the transition zone. In this case, the transition zone may be provided as the original structure of the gear and/or as an inherent or separate structure of the gear. The transition region can be a gear structure which is exposed to the outside and/or can be identified from the outside. The transition region may preferably extend between edge portions and/or surface portions of the tooth or of the support structure, which may, for example, indicate a change from one structure to another.

The respective transition region at least partially surrounds the bearing region and extends continuously and has a transition geometry in cross section, as viewed in the direction of its extent. The transition geometry can preferably have substantially the same geometric elements or geometric compositions in the axial and/or radial direction.

For each bearing zone, the geometry parameters of the transition geometry vary (preferably steadily, i.e. for example continuously) along the axial and/or radial direction with respect to the axis of rotation. In this case, preferably along an axial and/or radial direction (only/at least) with respect to the axis of rotation, a geometry variable can be provided, which is dependent on the dimensioning of at least one, preferably always the same, component of the axis of rotation, preferably of the component defining the transition geometry. Preferably, the geometry parameters of the respective transition geometry can only be changed along a single axial and/or radial direction with respect to the axis of rotation. The axial direction may be parallel to the axis of rotation, for example. The radial direction may be, for example, perpendicular to the axis of rotation. The axial and/or radial directions may preferably each be oriented towards the gear center.

Thus, for example, the structural transition from the respective tooth to the respective support structure shown in cross-section may preferably be continuously different, for example due to a change (possibly individual) in the transition geometry of each transition zone (e.g. globally). This makes it possible, for example, to design the transition of the tooth to the support structure so that the shape of the gear wheel matches the mechanical loads occurring during operation. Thus, the load on the gear, the flow of force, the expansion and/or the stress on the gear may be distributed (distributed) as evenly as possible. Furthermore, the notch effect emanating from the support structure, such as the stress peaks in the above-described structural transitions, can be reduced. In this way, for example, the maximum stress in the support structure can be significantly reduced compared to a gear without such a transition zone. For example, it may be shown in simulations that a gear with a transition zone may reduce the maximum stress by at least 50% or more compared to a gear subjected to the same load without such a transition zone. Furthermore, the gears may be sized larger only at locations where increased stress is desired. Therefore, the weight of the gear can be reduced. At the same time, more free space may be provided in the tooth space for the gear to mesh with the counter gear, so that the gear does not have to have a larger size despite the provision of the support structure.

The disadvantages known from the prior art are therefore overcome by the present invention by providing a gear, by means of which, for example, torque and power can be transmitted to other gears in the transmission. The gearwheel not only has a first structural element (i.e. the support structure), whereby the rigidity of the gearwheel can be increased and the stresses occurring in the gearwheel during operation can be better absorbed, but it also has other variable structural design elements (i.e. the transition region), whereby the transition from the toothing to the support structure is defined.

According to a preferred embodiment, the transition geometry may have at least one geometry section defined by a geometry parameter. The transition geometry may preferably have only a single such geometry portion. The transition geometry or geometry portion may preferably be rounded, e.g. radius or concave curve, and/or chamfered, e.g. chamfered, and/or defined by its shape (according to a polynomial function).

The transition geometry may preferably have at least one radius and/or chamfer.

In this context, for example, the terms "radius" or "chamfer" can be understood as meaning, respectively, (in the sense of extension) the defined structural elements which are preferably used for corner rounding or edge rounding, in particular at the transition base (e.g. tooth base).

The transition geometry can thus be defined by one or more (composite) geometry sections, and the transition structure can thus be adjusted, for example, according to the gear load. In particular, the above examples of possible designs for the geometry sections are adapted to reduce the notch stress concentration effect caused by abrupt transitions. Furthermore, the gear manufacture is simplified, since the respective geometrical portions can be realized at a very low manufacturing cost. In particular, efficiency advantages can be achieved in the forming process and the service life of the tools used can be extended.

According to a further preferred design, the geometric parameter can be a curvature, a curvature increase, a radius and/or a width or an angle of a bevel, in particular a chamfer.

The term "radius" is understood here to mean, for example, half the value of the diameter of a circle designed for edge rounding and/or the distance between the center of an imaginary circle used for edge rounding and the respective geometric portion.

In this way, the transition geometry can be set in a defined manner and the transition geometry can be adapted to the gear load. Furthermore, by fixing and varying the curvature growth, radius and/or chamfer angle by definition, the effects of notch stress concentrations caused by the support structure can be reduced or avoided.

According to a preferred design, the geometry parameters can be changed to an equal extent in the axial and/or radial direction with respect to the axis of rotation, such as for example equally decreasing and/or increasing. In particular, the geometry parameters can be changed in a stable and/or continuous manner.

The expression "continuously" is understood here, for example, to mean "uniformly" and/or "continuously".

In this way, the transition between the respective gear structures can be designed as smoothly as possible along the transition region extension, so that an improvement in the force flow and a reduction in the stress peaks are achieved.

According to a further preferred embodiment, the transition zones may each have a first portion for direct connection between the respective support zone and a first one of the adjacent teeth. The transition zone may also have a second portion for direct connection between the support zone and a second of the adjacent teeth. In addition, the transition zone may have a third portion connecting the first and second portions for direct connection between the support zone and the tooth bottom connecting the first and second teeth.

The respective transition zone may preferably be substantially U-shaped, V-shaped and/or parabolic, respectively. The respective shape of the respective transition region can be designed such that it is preferably open toward the axial end of the tooth bottom with the transition region and/or preferably toward the radial periphery of the gearwheel about the axis of rotation.

In this case, the geometry parameter may preferably decrease continuously (and/or steadily) along the extension from the first portion to the third portion. Furthermore, the geometric parameter may preferably continuously (and/or steadily) decrease along the extension from the second portion to the third portion. Alternatively or additionally, the geometry parameter may also be continuously (and/or steadily) varied at the connection of the respective first or second portion with the third portion, respectively.

Preferably, the geometry parameters of the transition geometry of the respective transition zone can be changed uniformly and stably along the axial and/or radial direction with respect to the rotation axis on opposite sides with respect to the respective bearing zone.

As a result, stresses can be transferred from the loaded tooth bottom to the support structure in such a gentle manner that stress concentrations are mainly induced in the support structure. This is specifically designed for this stress concentration and therefore prevents material failure in other structures of the gear. Furthermore, the transition zone is wider along the edge of the gear than in the fibers near the bottom of the tooth because it is open towards the gear edge, so the transition structure can exert the greatest influence on stress deflection and concentration. In this way, the gear strength can be additionally improved. In addition, a continuously narrowing transition towards the gear center can be achieved in order to steer the stresses occurring in the gear as gently as possible to prevent stress peaks.

According to a preferred embodiment, the dimensions of the respective bearing region can be varied, for example reduced, steadily and/or continuously in the axial direction with respect to the axis of rotation away from the axial end of the tooth bottom with the bearing region towards the opposite axial end.

Furthermore, the respective bearing region can preferably extend in the axial direction with respect to the rotational axis from the axial end of the tooth base with the bearing region to the opposite axial end over a length of at most one third, preferably at most one fourth, of the axial length of the tooth base.

The tooth base can thus be provided with bearing zones between the teeth in such a way that the surface available for engagement on the tooth flanks is not limited. Meanwhile, the weight increase of the gear can be avoided. Furthermore, the gear wheel is particularly simple to produce and has a corresponding bearing structure because of this design.

According to a preferred embodiment, the respective bearing zone may extend flat between the respective adjacent teeth.

The expression "flat extension" may here be, for example, directed to an extension forming a face (substantially/predominantly, i.e. for example at least 50%, 60%, 70%, 80%, 90% or 95% of the total extension with respect to the respective bearing zone).

The flat extension of the respective bearing region makes it possible to limit the space available in the tooth gap for the engagement as little as possible by the bearing structure, while only a slight increase in the mass of the gear is recorded by the provision of the bearing structure. This flat extension also allows the stresses generated to be relieved over a large area.

According to a further preferred embodiment, the respective bearing zone can be arranged at the respective axial end of the tooth base in such a way that the respective bearing zone (and the transition zone) together with the adjacent tooth form a gear periphery which is surrounded by the gear periphery and is preferably exposed.

The diameter of the gear wheel at its axial end can thus be increased by the bearing structure without causing an overall increase in the gear wheel. In particular, the tooth bottom can be completely surrounded by the gear structure in this way. The stresses occurring precisely at the gear ends can thereby be absorbed and distributed particularly advantageously. It is also possible to provide a direct bearing of two adjacent teeth against each other, so that a structural reinforcement of the gear wheel and a low load on the respective tooth root is obtained. In addition, gear manufacture is simplified because the support structure extends into the gear body from the peripheral edge.

According to a preferred embodiment, the support structure (or in particular the respective support zone) may be at least partially defined by (surrounding it) a transition zone. Additionally or alternatively, the support structure (in particular the respective support zone) may preferably be delimited by a peripheral edge of the gearwheel, such as the periphery described above.

The support structure and the transition region can thus be arranged on the gear wheel in a defined and respectively coordinated manner, so that the two components are arranged in a mutually coordinated manner with respect to the loads occurring during operation. In this way, not only can the force flow between the tooth and the transition region be optimized and possibly notch stress concentration effects reduced, but also the transition of the transition region to the support structure can be selected in a stress and load optimized manner. This can lead to an improvement in the gear stiffness and mechanical load-bearing capacity.

According to a preferred embodiment, the transition geometry of the respective transition region can be formed in each case in such a way that the respective transition region has a concave curvature in the direction of the respective tooth or tooth base.

The transition region can thus be formed, for example, from the outside in the form of a surface (preferably also exposed) which is concavely curved between the tooth, the support structure and/or the tooth base (viewed in a plan view of the tooth base) towards the tooth or tooth base. In addition, a particularly advantageous deflection of the force flow from the tooth or tooth base to the support structure can thus be achieved, so that the load-bearing capacity and the service life can be further increased while the strength of the gear remains unchanged.

According to another preferred embodiment, the gear may have a gear tooth structure for transmitting power to another gear (of the gear transmission mechanism). The teeth of the gears can then be arranged such that they form a straight tooth structure, a helical tooth structure, an arc tooth structure or a quasi-hyperbolic tooth structure of the gear.

Further, the gears may be bevel or bevel gears. The gear body can preferably be designed as a truncated cone. It may preferably extend along the axis of rotation between the two end faces and also preferably have a cone angle defined about the axis of rotation of 35 to 70 degrees.

The gear can thus be used for many different applications and purposes of use and gear manufacture can be simplified.

The gear wheel can preferably be designed such that it, when engaged, is fully engaged with a gear wheel of the same design.

This design ensures that the two toothed wheels can be brought together in a form-fitting manner in order to transmit power, and in particular that no toothed wheel structures interfere with the meshing.

The gear body may preferably also have a fastening opening at least one of the two end faces. In this case, the fastening opening can preferably be designed as a through-hole, which can preferably have a defined inner contour for the shaft-hub connection, such as a splined shaft contour. The fastening opening can preferably extend along the axis of rotation.

The gear wheel can thus be connected to the drive shaft or the driven shaft in a particularly simple and reliable manner. In addition, it is possible to do so that the gear can be used for a large number of different applications.

For this purpose, the gear wheel can also preferably have a rod-shaped or tubular connecting section. Such an embodiment may be advantageous, for example, in the case of an axle gear (axle draft gear). However, the above connection types are only exemplary, and any other connection possibilities are also conceivable.

Another aspect of the invention relates to a differential. Having at least one gear according to the first aspect of the invention. The at least one gear may preferably be provided as a differential bevel gear, a balance bevel gear or an axle shaft gear. The rotational axis of the gear wheels can preferably enclose an angle of between 40 and 100 degrees, in particular 90 degrees, with the rotational axis of the respective counter gear wheel (when engaged).

It is thus possible to provide a differential in which all the advantages mentioned for the gear according to the invention are also obtained. In particular, higher power can be transmitted with the differential while maintaining a constant service life and stability, without simultaneous recording of differential weight gain and/or inertia increase.

Drawings

Further embodiments and advantages of the invention are explained on the basis of the following embodiments in conjunction with the figures of the drawings.

Fig. 1 shows a perspective view of a gear according to an embodiment of the present invention, wherein important aspects of the present invention are emphasized.

Fig. 2 shows a further perspective view of the gear wheel of fig. 1 from a slightly different perspective than the perspective of fig. 1.

Fig. 3 shows a top view of the gear of fig. 1 and section line markings for the sectional views of fig. 5 to 8.

Fig. 4 shows a side view of the gear of fig. 1 and section line markings for the sectional views of fig. 5 to 8.

Fig. 5 shows a side view of the gear of fig. 1 along the section line a-a shown in fig. 3 and 4.

Fig. 6 shows a side view of the gear of fig. 1 along the section line B-B shown in fig. 3 and 4.

Fig. 7 shows a side view of the gear of fig. 1 along the section line C-C shown in fig. 3 and 4.

Fig. 8 shows a side view of the gear of fig. 1 along the section line D-D shown in fig. 3 and 4.

Fig. 9 shows a partially simplified schematic view of the gear of fig. 1.

Fig. 10 shows a simplified cut-away schematic view of the gear of fig. 1 along the tooth bottom.

Fig. 11A to 11G show simplified schematic diagrams of possible transition geometries, with a side view from above and a perspective view from below.

Fig. 12 shows a perspective view of a bevel gear known from the prior art.

Detailed Description

Fig. 1-10 show different views of one embodiment of a gear 100 of the present invention.

Gear 100 has an axis of rotation 101. The alignment of the gear 100 in its working position can preferably be determined by the rotation axis 101. Fig. 1 and 2 illustrate the orientation of the gear 100 when aligned along the axis of rotation 100. Preferably, the gear wheel 100 can be designed to be rotationally symmetrical about the axis of rotation 101, as is shown, for example, in fig. 1 to 8.

The gear 100 may be provided for transmitting power to a mating gear of a gear transmission. The gear 100 can be provided, for example, as a bevel gear for a differential of a motor vehicle, a differential bevel gear or an axle gear, among others. For this reason, the gear 100 may preferably have a tooth structure for power transmission. Here, the gear 100 may have a straight tooth structure, a helical tooth structure, or an arc tooth structure. In fig. 1 to 10, a gear 100, for example, having a straight tooth structure is shown.

The gear 100 has for this purpose a gear body 200 with teeth 210 distributed about the axis of rotation 101. The teeth 210 are preferably evenly distributed over the circumference of the gear 100. Fig. 1 to 8 show this, for example.

The gear body 200 may preferably extend along the axis of rotation 101 between the first end face 105 and the second end face 106, as shown by way of example in fig. 1-8 and 10. The end faces 105,106 may be arranged parallel to each other with a prescribed distance therebetween. The end faces 105,106 can preferably be delimited in the radial direction with respect to the axis of rotation 101 by an imaginary circle having a circle diameter in the range from 60mm to 180 mm.

Fig. 1 to 10 exemplarily show a gear 100 in a bevel gear shape. The gear body 200 may be designed as a truncated cone. The gear body 200 preferably has a smaller diameter at its top side than at its bottom side. In fig. 1 to 10, for example, the top side is formed by the second end face 106, while the bottom side is formed by the first end face 105.

Furthermore, the gear body 200 may preferably have a cone angle 102 of 35 to 70 degrees defined relative to the axis of rotation 101, as is illustrated by way of example in fig. 1 to 9 and in particular in fig. 10. The embodiment should not be construed as limiting the present invention, but the gear body 200 may be arbitrarily designed, for example, may be also designed as a cylinder. The gear 100 may also be a spur gear, an elliptical gear, a worm gear, or a crown gear.

The gear body 200 may preferably have a fastening opening 150 on at least one of the two end faces 105,106 for fastening the gear 100 on the shaft. The fastening opening 150 can be designed here preferably as a through-hole and preferably extends along the axis of rotation 101. Furthermore, the fastening opening 150 can have a defined inner contour for the shaft-hub connection. For example, a spline shaft profile may be provided on a part of the inner surface of the fastening opening 150.

The gear 210 may have any number of teeth 210. The gear 210 illustrated in fig. 1 to 8 has, for example, nine teeth 210.

Two adjacent teeth 210 are each connected to one another at their tooth root 211 by means of a (same) tooth base 220. Fig. 1 to 8 illustrate this.

The cross-sectional shape of the tooth 210 along its extension between the two end faces 105,106 may preferably be determined by an involute. A top rounding 230, which extends over the circumference of the gear wheel, can preferably be provided on the second end face 106. The tooth roots 211 are preferably disposed on opposite sides of the respective tooth 210. Each of the teeth 210 may also preferably have flanks 212 for torque transmission on opposite sides of the respective tooth 210. Each of the flanks 212 may preferably follow the respective tooth root 211 and extend flat therefrom radially outward with respect to the axis of rotation 101. This is illustrated in fig. 1 to 8. The tooth bottom 220 can have, for example, a concave and/or substantially outwardly open U-or V-shape toward the center of the gear in a top view looking at the gear 100. Preferably, a tooth engagement space 213 may be defined between each adjacent tooth 210 and tooth bottom 220, respectively, in which teeth of a mating gear (for power transmission) corresponding to the profile of the tooth 210 may be preferably accommodated. The backlash of the gear 100 can preferably be formed by the respective adjacent tooth 210 and tooth bottom 220. The toothed wheel 100 can preferably have a substantially U-shaped, V-shaped or parabolic tooth gap cross section transversely to the extent of the tooth base 220 (in the axial and/or radial direction with respect to the axis of rotation 101). This is shown by way of example in fig. 1 to 8.

The tooth base 220 may preferably extend between the first end face 105 and the second end face 106 and is preferably defined by the tooth roots 211 of two adjacent teeth 210.

The gear 100 also has a support structure 300 for increasing the stiffness of the gear 100, for example, during operation. Preferably, the tooth spaces formed between the teeth 210 may have the support structures 300, respectively. Preferably, the support structure 300 may be integrally formed with the gear body 200. This is illustrated by way of example in figures 1 to 8 and 10.

The bearing structure 300 has a bearing region 301,302 at least one or both axial ends of the respective tooth base 220 with respect to the axis of rotation 10. For example, fig. 1 to 8 and 10 (for each tooth gap) show a first bearing zone 301 arranged on the first end face 105 and a second bearing zone 302 arranged on the second end face 106. The support structure 300 can be formed here from these two support regions 301, 302.

If the gear body 200 is designed, for example, as a truncated cone, the bearing structure 300 can preferably have bearing regions 301,302 at the axial ends of the tooth bottom 220, at which the gear body 200 has a smaller or larger diameter, so that, for example, the bearing regions 301,302 are arranged (only) on the bottom side or on the top side of the gear body. In fig. 1 to 10, the bearing zones 301,302 are provided, for example, at both axial ends of the tooth base 220.

The respective support regions 301,302 extend away from the tooth base 220 between respective adjacent teeth 210. This is illustrated by way of example in figures 1 to 8 and 10.

In this case, the size of the respective bearing zone 301,302 can preferably be continuously and/or continuously changed, for example reduced and/or increased, in the axial direction with respect to the axis of rotation 101 away from the axial end of the tooth bottom 220 with the bearing zone towards the opposite axial end. This is illustrated by way of example in fig. 1 to 8 and 10, in which case, for example, the bearing zone 301 first decreases continuously with increasing axial distance from the first end face 105 about the axis of rotation 101 and then increases continuously in its circumferential extent (with increasing approach to the tooth bottom 220) before it decreases again. The second bearing zone 302 may, for example, widen with increasing axial distance from the second end face 106, which then decreases again (with increasing proximity to the tooth bottom 220).

Relative to the axis of rotation 101, the respective bearing region 301,302 can extend over a length of at most one third of the axial length of the tooth base 220 in the axial direction with respect to the axis of rotation 101 away from the axial end of the tooth base 220 with the bearing region toward the opposite axial end. Alternatively or additionally, the respective bearing region 301,302 extends with respect to the axis of rotation 101 in the axial direction away from the axial end of the tooth base 220 with the bearing region over a length of at most one quarter of the length of the tooth base 220 toward the opposite axial end. Fig. 1 to 8 and 10 illustrate this point by way of example.

Preferably, the support structure 300 and preferably the respective support regions 301,302 may extend from respective axial ends of the tooth base 220 between the teeth 210 and/or along the tooth base 220 (axially). In particular, the support structure 300 may extend from one axial end of the tooth bottom 220 to the other axial end thereof. The respective support zones 301,302 may preferably extend flat between respective adjacent teeth 210.

The respective bearing region 301,302 can be arranged at the respective axial end of the tooth base 220 in such a way that the respective bearing region 301,302 and the adjacent tooth 210 together form a circumference 104 of the gear 100 which follows the circumference of the gear 100 and is preferably exposed to the outside. This is shown in fig. 1 to 8 and 10, for example, for the first support zone 301.

The respective bearing region 301,302 can preferably be arranged at a defined angle with respect to the tooth base 220. This is shown by way of example in fig. 10.

Preferably, the first bearing zone 301 can be disposed at a first bearing zone angle 304 in the range of 100 to 170 degrees with respect to the tooth bottom 220. Furthermore, with respect to the tooth bottom 220, the second bearing zone 302 can preferably be arranged at a second bearing zone angle 305 in the range of 110 to 170 degrees. The respective bearing zones 301,302 can preferably be arranged on the gear wheel 100 such that they are inclined relative to one another at a bearing angle 306 in the range from 20 to 160 degrees, particularly preferably 100 degrees. This is shown by way of example in fig. 10.

The support zones 301,302 are directly connected to the adjacent tooth 210 and tooth base 220 by respective transition zones 400 to 402. The respective transition region 400 to 402 surrounds the respective support region 301,302 in this case at least in sections and extends continuously. This is illustrated in fig. 1 to 8. For clarity, the transition regions 400-402 are highlighted in color in FIG. 1.

Fig. 1-8 illustrate that, for example, the transition zones 400-402 may at least partially define the support structure 300, and preferably the respective support zones 301, 302. In this case, the respective bearing zone 301,302, the respective transition zone 400 to 402 and the adjacent tooth 210 may together form a periphery 104 extending and exposed as the circumference of the gear 100. The respective transition zones 400 to 402 can preferably extend preferably flat together with the respective support zone 301, 302.

The transition zones 400-402 may preferably be substantially U-shaped, V-shaped, and/or parabolic in shape. The shape of the respective transition region 400 to 402 may preferably open towards the axial end of the tooth bottom 220 with the respective transition region 400 to 402, towards the radial outer circumference of the gear 100 with respect to the axis of rotation 101 and/or towards the circumference 104.

As shown, for example, in fig. 1 to 8, the transition zones 400,401 may have a first portion 411 for direct connection between the associated support zone 301 and a first one of the adjacent teeth 210. The transition zones 400,401 may also have a second portion 412 for direct connection between the belonging support zone 301 and a second tooth of the adjacent teeth 210. The transition zones 400,401 may also have a third portion 413 connecting the first portion 411 and the second portion 412 for direct connection between the support zone 301 and the tooth base 220 connecting the first and second teeth 210.

Thus, for example, the transition region 400 can be provided with a coherent extension over a plurality of portions 411 to 413, while at least partially surrounding the respective support region 301.

Since the gear 100 is rotationally symmetrical about the axis of rotation 101, the transition region 400 can be designed symmetrically with respect to the support structure 300. Preferably, the transition zone 400 may thus extend, for example, from the periphery 104 between one of the respective teeth 210 and the support structure 300, along the support structure 300 and the tooth 210 to the tooth base 220, and from the tooth base back towards the periphery 104 along the support structure 300 and the respective other tooth 210, respectively. The support structure 300 and the respective further tooth 210 extend to the peripheral edge 104. Fig. 1 to 8 illustrate this, but the transition regions 400 to 402 can also have other shapes in plan view.

The transition zones 400 to 402 have a transition geometry in cross section, seen in the direction of their extension. Fig. 5 to 9 show examples of transition geometries by way of example.

The transition geometry may have at least one (or there may be only one or more) geometry sections. For example, the transition geometry or geometry portion may be rounded, such as a radius or a concave curve, such as shown in fig. 5-9. Alternatively or additionally, it is also conceivable for the transition geometry or geometry sections to be oblique edges, such as chamfers, or intersecting lines defined by their shape. For example, the intersection may follow a differential function or a polynomial function. It is also particularly conceivable that the transition geometry preferably has a rounded off chamfer (produced by means of a radius). In fig. 1 to 9, the transition geometry is illustrated by a radius, i.e., by a rounded edge, which transitions, for example, tangentially into the tooth root 211 or tooth base 220. The transition geometry of the respective transition zones 400 to 402 may preferably have substantially the same geometrical portions over the entire extension.

The transition geometry of the respective transition region 400 to 402 can preferably be designed such that the respective transition region 400 to 402 has a concave curvature toward the respective tooth 210 or tooth base 220.

Preferably, the transition zones 400 to 402 between the respective one of the teeth 210, the support structure 300 and the tooth bottom 220 may each have an exposed surface which, in a top view looking at the tooth bottom 220, is concavely curved towards the tooth 210 or the tooth bottom 220. By this exposed surface, either a transition from the tooth bottom 220 to the support structure 300 or a transition from the tooth 210 to the support structure 300 can be formed, as shown, for example, in fig. 1 to 9.

The transition region 400 can bridge, for example, the distance between the support structure 300 and a tooth 210, in particular the flank 212 and/or the bottom 220, which is present in the cross section in the axial direction and in the transverse direction thereof along the direction of extent of the respective transition region 400. This distance can preferably be bridged in both directions by a correspondingly selected geometric section, as shown, for example, in fig. 5 to 9. Fig. 9 shows, in particular, an edge rounding using radii in the transition geometry, which radii (in the sense of the geometry part) have a radius R100 as the distance between the transition geometry and the center point M of the imaginary circle IR used for this purpose. The influence of the design of the transition geometry on the force flow between the respective tooth 210 and the support structure 300 is particularly apparent, for example, from fig. 9, since, for example, the transition structure can be adjusted correspondingly more flexibly and more smoothly. Thus, for example, notch stress concentration effects originating from the support structure 300 can be prevented by a defined contour design of the transition geometry.

The geometry parameters of the transition geometry in this case preferably vary (change) steadily in each bearing zone 301,302 in the axial and/or radial direction with respect to the axis of rotation 101.

The geometry parameters can be curvature, radii R1 to R4, R100 and/or the width or angle of the oblique edges and in particular the chamfers. The geometric parameter may preferably be at least one radius and/or chamfer.

In particular the above-mentioned geometry part of the transition geometry may be defined by a geometry parameter.

The transition geometry of the gear 100 can thus be designed such that the stiffness of the gear 100 is increased in operation and the stresses occurring in operation are reduced in comparison with a gear having a substantially constant geometric dimension in the axial and/or radial direction with respect to the axis of rotation 101.

The geometric shape parameters can be changed, for example, uniformly and continuously along the axial and/or radial direction with respect to the axis of rotation on both sides of the respective bearing zone 301,302, i.e., for example, on opposite sides with respect to the respective bearing zone 301, 302.

The radii of the transition geometries selected as geometry segments for the transition region 401, which are illustrated in fig. 1 to 8 and 10 by way of example, may decrease predominantly in the radial direction towards the gear center, but also have a small component of direction in the axial direction. Thus, for example, the geometry parameters may preferably decrease continuously along the extension from the first portion 411 to the third portion 413. At the same time, the geometrical parameters, such as the radial dimension, may also preferably decrease continuously along the extension from the second portion 412 to the third portion 413. The extension direction of the transition region 401 may be determined here, for example, by a (main) extension direction of the respective first to third portions 411 to 413, which extends, for example, substantially along/with an axial end (orientation) of the respective tooth root 211 or tooth bottom 220. Here, the geometry parameters may also be continuously varied at the connection of the respective first or second part 411, 412 to the third part 413. In particular, it is possible to achieve a continuous and constant course of variation of the geometric parameters of each connection region 400. This makes it possible, for example, to continuously decrease the geometric parameters from the outside toward the gear center.

For the other transition regions 402, corresponding cases can also be found in the exemplary illustrations of fig. 1 to 8 and 10. The radii selected for the transition geometry of the transition region 402 as the geometry section are shown here by way of example to decrease predominantly in the axial direction, but also have a small directional component in the radial direction toward the gear center.

In other words, the geometry parameters may thus for example each increase with the distance from the two axial ends of the gear 100 decreasing axially with respect to the axis of rotation 101. This is illustrated, for example, in fig. 1 to 8 and 10. In this way, for example, the transition from the respective tooth 210 to the support structure 300 is effected as gently as possible.

It is preferably possible here to use radii, for example, with a radius dimension (length dimension) R1-R4 in the range of more than 0mm, in particular more than 0.1mm to 10mm, as the respective geometry section. Alternatively or additionally, chamfers having chamfer angles in the range of 20 to 70 degrees, for example, may be used as the respective geometric portions.

Fig. 5 to 8 show in particular that, for example, no radii R1 to R4 are preferably equally large in the axial and/or radial direction with respect to the axis of rotation 101.

Furthermore, the radius R1 may be set, in particular, the largest with respect to more distant radii, such as the radii R2 to R4, with the smallest axial distance (and radial distance) of the radius R1 from the respective axial end of the gear 100. As the distance from the respective axial end of the gear 100 increases, the radius may then decrease accordingly, for example.

Relative to the initial radius R1, the radius R2 may have a ratio R1/R2 in the range of at least 1 to (at most) 3, the radius R3 may have a ratio R1/R3 in the range of at least 1 to (at most) 10, and/or the radius R4 may have a ratio R1/R4 in the range of at least 1 to (at most) 1000. The respective radius ratio can preferably be determined by a mathematical function, such as a hyperbolic function.

The teeth 210 can preferably be arranged on the gear body 200 such that respective adjacent teeth 210 are variably spaced from each other along the axis of rotation 101. The transition region 400 and 402 can be designed such that the value of the geometry parameter depends on the gap width between the teeth 210 in the axial direction and/or in the radial direction with respect to the axis of rotation 101, wherein the geometry parameter can preferably increase or decrease (preferably but not constantly) with increasing spacing between adjacent teeth 210. Alternatively or additionally, it is of course also conceivable that the transition zone 400-402 may preferably be designed such that the geometry parameter changes with increasing distance between adjacent teeth 210 (viewed as a whole), but that a section of the transition zone 400-402 is still present (for example adjoining the section with the changing geometry parameter and in which the geometry parameter is constant/remains constant or in which they have the same value).

Furthermore, the geometry parameter may preferably be the curvature of the respective geometry section. The curvature increases continuously, steadily and/or continuously from the respective axial end of the gear wheel 100 as the tooth base 220 is approached (axial position with respect to the axis of rotation 101), so that an improvement of the force flow from the tooth 210 to the support structure 300 along the virtual edge between the support structure 300 and the tooth 210 or the tooth base 220 can preferably be achieved. This virtual edge is represented, for example, by outline 840 in fig. 12.

Examples of possible transition zone 400 designs are shown in fig. 11A-11G. They are exemplary only and any other design is also contemplated.

Fig. 11A illustrates a transition region 400 having a transition geometry with a radius of the only geometry portion. The size or value of the radius, i.e. the radius value of the radius, varies in fig. 11A in the axial and/or radial direction with respect to the axis of rotation 101. In the example of fig. 11A, the radius (as a size value) preferably changes stably and continuously.

Fig. 11B illustrates an exemplary transition zone 400 having a transition geometry with a chamfer as the only geometry portion. Fig. 11B shows, by way of example, that the width of the chamfer preferably varies stably and continuously in the axial and/or radial direction with respect to the axis of rotation 101.

Fig. 11C illustrates that the transition geometry of the transition region 400 may also have a geometry portion with a plurality of chamfers of different designs. As shown by way of example, the width of the chamfers provided in the respective geometric parts can preferably be varied in a stable and continuous manner in the axial and/or radial direction with respect to the axis of rotation 101.

Fig. 11D to 11G show by way of example that the transition geometry of the transition region 400 can also be composed of a plurality of geometry sections with different geometry design elements. In the figures, the transition geometry has, for example, at least one geometry section with a radius and at least one geometry section with a chamfer.

Here, only the width of the geometric portion having the chamfer changes in fig. 11D, while the radii of both geometric portions having the radii remain constant. In fig. 11E, the width of the chamfer and the size of the corresponding radius (i.e., radius) are both changing. In fig. 11F and 11G, at least one width of the respective fillets and/or at least one of some (or all) of the radii can be selectively varied.

Of course, when a stable change is observed over the entire region, a plurality of unchanged portions may be included or present. For the sake of overview, this is not explicitly illustrated in the exemplary illustrations in fig. 11A to 11G, but is also covered by the present invention.

It is particularly clear from the above description that almost any number of gear 100 designs can be obtained by the design of the transition zone 400 of the present invention. This allows, for example, a particularly advantageous design of the gear 100 to be selected depending on the respective application.

The gear 100 may preferably be made of metal such as cast iron, steel or aluminum. Alternatively or additionally, the gear 100 can also be made of plastic or ceramic.

At least a portion of the surface of the gear 100 may have been treated, preferably by a surface treatment. Preferably, the transition region 400 and the support structure 300 can have different hardnesses, for example, because of different hardness depths, for example.

Another aspect of the invention relates to a transmission, such as a differential, having at least one of the aforementioned gears 100 according to the invention. The transmission is not shown in the figures, but even if not, it will be readily understood by those skilled in the art.

The invention is not limited by the above-described embodiments, as long as it is covered by the subject matter of the appended claims.

In particular, all features of the embodiments can be combined and interchanged with one another in any way.