Shop drive

Abstract

Angle gear (100, 200) with an input shaft (102, 202) and an output shaft (104, 204) and a power split with at least two load paths between the input shaft (102, 202) and the output shaft (104, 204), wherein each of the load paths comprises exactly one gear section (106, 206, 208) between an input gear (103, 203) of the input shaft (102, 202) and an output gear (105, 205) of the output shaft (104, 204), and wherein the input gear (103, 203) and the output gear (105, 205) are each designed as a bevel gear.

Description

Field of invention The invention relates to an angle gear and a use of an angle gear. State of the art Angle gears are known from the prior art that transfer a load from an input shaft to an output shaft arranged at an angle to the input shaft. US Patent 2,565,539 A shows a transmission with two load paths using bevel gears and several spur gears. US Patent 4,607,538 A shows a simple load transmission between two bevel gears using an internally toothed, tapered belt. However, existing state-of-the-art solutions have limitations regarding the maximum transmissible load. Increasing the size of the meshing gears on the input and output shafts is not always straightforward. There is therefore a need to improve bevel gears, in particular to increase the maximum load that can be transmitted or to reduce the geometric dimensions of a bevel gear while maintaining the maximum transmissible load. Disclosure of the invention One object of the invention is to provide an improved bevel gear. In particular, an improved bevel gear should be able to transmit a higher maximum load. The problem is solved with an angle gear according to claim 1. Advantageous further developments and embodiments are described in the dependent claims and in this description. One aspect of the invention relates to a bevel gear with an input shaft and an output shaft as well as a power split with at least two load paths between the input shaft and the output shaft, wherein each of the load paths comprises exactly one toothed part between an input gear of the input shaft and an output gear of the output shaft. Another aspect concerns the use of an angle gear in one of the typical embodiments described herein. Typically, each gear section of the at least two load paths meshes with a bevel gear as the input gear of the input shaft and with a bevel gear as the output gear of the output shaft. This allows for an increase in the maximum transmissible load. Typically, at least two of the gear sections are arranged symmetrically around the bevel gear of the input shaft. Typically, at least two of the gear sections are arranged symmetrically around the bevel gear of the output shaft. The terms input shaft and output shaft are used in this description to refer to the two shafts to which further gearboxes, motors, consumers, or similar devices can be connected. Accordingly, a shaft described as an "output shaft" may also be designed as an input shaft or used as an input shaft, and vice versa. The terms input shaft and input gear, on the one hand, and output shaft and output gear, on the other, are interchangeable in typical embodiments. In typical embodiments, there is no intermediate coupling between the load paths. Typically, there is no direct meshing between the input shaft and the output shaft, or between the input gear and the output gear. Typically, there is no direct meshing between the input gear of the input shaft and the output gear of the output shaft. In typical embodiments, each load path is coupled exclusively to the input shaft and the output shaft. In a typical embodiment, the gear teeth are each designed as a bevel gear. Typically, at least one of the gear teeth is designed as a bevel gear. Typically, at least one of the bevel gears is designed as a hollow bevel gear. In typical embodiments, the gear teeth are designed as a bevel gear, hollow bevel gear, spur gear, crown gear, or generally as a gear. In typical embodiments, the uniform engagement of the input gear of the input shaft and the output gear of the output shaft simplifies their bearing arrangement, since at least essentially only axial forces occur in the bearings of the input shaft and the output shaft. In typical embodiments, the axes of the gear teeth are coaxial, or the gear teeth are arranged on a common axis or positioned as evenly as possible between the input and output shafts, for example, with an angle of 120°, 130°, or 140° between the tooth contacts of two gear teeth. This allows for very simple backlash adjustment and also aids load distribution. In typical embodiments, the common axis is floatingly mounted. In further embodiments, the bearings of the gear teeth are coupled in their axial movement. In still other embodiments, the bearings of the gear teeth on the axis are designed as plain bearings. In this way, particularly with gear teeth designed as bevel gears, a reliable and even distribution of the load or transmitted torque across the gear teeth is possible. In typical designs, a preload is applied to the bearings of at least two gear teeth arranged on a single axis. The axis is typically floating. This allows for minimal backlash and even load distribution across the gear teeth, even with inaccuracies in the gear teeth themselves. By adjusting the preload of the bearings of the gear teeth against each other, a typical bevel gear can be set, for example, from low backlash to zero backlash. In typical embodiments of bevel gears, the gear ratio is 1. A gear ratio of 1 allows the common axis or axes of the gear teeth to be arranged on planes of symmetry of the input and output shafts. In other embodiments, the gear ratio is not equal to 1, in particular 1.5, 2, 3, or 4. In typical embodiments, the gear teeth are arranged for mutual or uniform load balancing. Typically, a uniform power distribution across at least two load paths is achieved with a coupled floating bearing arrangement for the gear teeth. Mutual load balancing is typically achieved by supporting a common axis, on which the gear teeth are mounted, with axial sliding bearings. In typical embodiments, at least two of the load paths have at least substantially the same stiffness. In some embodiments, a self-adjusting sliding bearing is additionally or alternatively provided to achieve uniform load distribution.In exemplary embodiments with at least two, in particular three or four, load paths and a hollow bevel gear, an even load distribution is achieved, particularly by the self-adjusting hydrodynamic sliding bearing of the hollow bevel gear, which compensates for the lower mechanical torsional stiffness of the hollow bevel gear with the stiffness of the load path of the at least one bevel gear, in particular two or three bevel gears. Typically, the load paths are utilized at least substantially equally. At least substantially equal utilization of the paths corresponds to at least substantially equal proportions of the maximum transmissible torque. In typical embodiments, the load path utilization differs by more than 1%, more than 5%, more than 10%, or more than 20% between the load paths.Particularly in embodiments with at least one gear section as a hollow bevel gear, the load path utilization can differ by more than 20% between the load paths. In typical embodiments, the load path utilization differs by less than 30%, less than 20%, less than 10%, less than 7%, or less than 5% between the load paths. In a typical embodiment, at least two of the gear components are arranged coaxially. Typically, at least two gear components are mounted on a common axis. Typically, at least one of the two gear components mounted on a common axis is floatingly mounted. Floating mounting on a common axis typically achieves automatic backlash adjustment. Automatic backlash adjustment facilitates load balancing between the gear components. In a typical embodiment, the gear components, and in particular the input and output gears, feature axially force-reduced teeth. An example of an axially force-reduced tooth design is a curved tooth design with zero helix angle at the center of the tooth, a herringbone tooth design, a Zerol® tooth design, or a spur tooth design.Axial force-reduced gearing can support load balancing or ensure that a more uniform load distribution is not hindered by differing axial forces. Another way to describe axial force-reduced gearing is "at least essentially force-free or force-compensated in the tooth width direction." This applies, for example, to spur gearing, herringbone gearing, and Zerol® gearing. In a typical embodiment, at least one or all of the gear teeth are supported by a sliding bearing. In other embodiments, rolling bearings are provided for supporting at least one or all of the gear teeth. In a typical embodiment, a sliding bearing for a gear component or a common shaft is designed as a hydrodynamic sliding bearing. Other sliding bearings used in typical embodiments include PTFE sliding bearings, hydrostatic sliding bearings, or plastic sliding bearings. Typically, at least one of the gear components is made of plastic. Typically, the gear components and the bevel gears of the input and output shafts are made of plastic. In a typical embodiment, the bevel gear is made at least substantially entirely of plastic. In a typical embodiment, at least one of the gear teeth is made of metal. In a typical embodiment, the bevel gear is made at least substantially entirely of metal. In a typical embodiment, at least one of the parts of the bevel gear is made of ceramic. In a typical embodiment, at least two of the gear teeth are identical. In typical embodiments, two gear teeth are designed as identical bevel gears, thus enabling the use of identical parts or the same stiffness of the load paths. In a typical embodiment, at least two of the gear teeth are designed differently. In typical embodiments, two gear teeth, in particular two bevel gears, and a third gear tooth with a larger diameter, in particular a hollow bevel gear, are present, which allows for better use of the installation space and higher power density. In typical embodiments, two gear teeth, in particular two bevel gears, and a third gear tooth with a smaller diameter, in particular a third bevel gear, also allow for better utilization of the installation space and higher power density. In embodiments with four or more gear teeth, in particular at least three bevel gears and a hollow bevel gear, better utilization of the installation space and higher torque can be achieved across the multitude of power flows. In another embodiment, two load paths are present, and the two gear teeth are designed as a bevel gear and a bevel ring gear. This allows the axes of the load paths to be designed coaxially, simplifying the bearing arrangement of the input and output shafts. In particular, the lateral forces cancel each other out, and the bearing only has to absorb a pure axial force. In typical designs, two gear teeth are implemented as two bevel gears with different diameters, which better fills the available space. Typical advantages of these embodiments can include higher power density or torque density, particularly through better utilization of the installation space with at least two gear teeth. Especially in embodiments that allow axially adjustable preload of gear teeth mounted on a common axis (which also includes physically interrupted axes), low-backlash adjustment is possible. Particularly through the floating bearing arrangement, which may optionally be preloaded around a central position by a spring, self-balancing of the load between the gear teeth is possible. In typical embodiments, the input gear and output gear are designed as identical bevel gears, which allows the use of identical parts and a symmetrical connection of the load paths. In typical embodiments, the input gear and output gear are designed as different bevel gears, thus enabling a simple gear ratio other than 1. In certain embodiments, a low load on the input and output shafts due to gear forces is achieved, for example, by canceling axial forces between two gear teeth or by using gears with reduced axial forces. From a purely physical standpoint, these forces result from the arrangement of the device components relative to one another. In particular, reducing or eliminating axial forces in these embodiments allows for simplified bearing arrangements for the input or output shaft, or enables the connection of additional gear units, especially coaxial gear units, such as planetary gear units mounted on the output side, to either of these shafts. Angle gears (100, 200) of typical embodiments have a power split with three load paths, each with a toothed part, in particular with exactly one toothed part, between the input shaft and the output shaft. In typical embodiments of angle gearboxes with three power paths, two of the gear parts (206) are designed as identical bevel gears and the third gear part (208) is designed as a hollow bevel gear. In designs of bevel gears with a plain bearing on at least one of the input and output shafts, a more compact design can be achieved, bearing fatigue can be avoided, better system damping can be achieved, and inaccuracies can be compensated for by the lubricating film. These points can be particularly advantageous, for example, in continuous operation applications. Brief description of the drawings The invention will now be explained in more detail with reference to the accompanying drawings, where the figures show: Fig. 1 a schematic view of a bevel gear according to an embodiment of the invention; Fig. 2 a schematic section of the bevel gear of Fig. 1 along the section plane AA shown in Fig. 1; Fig. 3 a schematic view of the bevel gear of Figs. 1 and 2; Fig. 4 a schematic section of the bevel gear of Figs. 1, 2 to 3; Fig. 5 a schematic perspective view of the bevel gear of Figs. 1, 2, 3 to 4; Fig. 6 a schematic rear view of a typical embodiment of a bevel gear according to the invention with a toothed part designed as a hollow bevel gear, with section planes AA, BB and CC shown; Fig. 7 a schematic section of the bevel gear of Fig. 6 along the section plane AA shown in Fig. 6; Fig.Fig. 8 a schematic section of the bevel gear of Fig. 6 according to the section plane BB shown in Fig. 6; Fig. 9 a schematic section of the bevel gear of Fig. 6 according to the section plane CC shown in Fig. 6; Fig. 10 a schematic side view of the bevel gear of Fig. 6 with the gear section designed as a hollow bevel gear, with a section plane DD indicated; Fig. 11 a schematic section of the bevel gear of Figs. 6 and 10 according to the section plane DD shown in Fig. 10; Fig. 12 a schematic perspective view of the bevel gear of Figs. 6, 7, 8, 9, 10 to 11. Description of the embodiments shown in the figures Typical embodiments of the invention are described below with reference to the figures. In describing typical embodiments, the same reference numerals may be used in different figures and for different embodiments to represent identical or similar parts, in order to make the description clearer. However, this does not mean that corresponding parts of the invention are limited to the variants shown in the embodiments. Figure 1 schematically shows an exemplary embodiment of a bevel gear 100 according to the invention with a gear ratio of 1. The bevel gear 100 has an input shaft 102 (example, one-piece) with a bevel gear 103 and an output shaft 104 (example, one-piece) with a bevel gear 105. The input shaft 102 is not directly connected to the output shaft 104. The bevel gear 103 of the input shaft 102 does not mesh with the bevel gear 105 of the output shaft 104. In the embodiment shown in Fig. 1, the gears or bevel gears of the input and output shafts are integrally formed with the respective shafts. In other embodiments, the gears are pushed on, pressed on, or otherwise connected to the respective shafts in a torque-transmitting manner. The exemplary embodiment shown in Fig. 1 has two load paths. Each load path has exactly one toothed section 106 between an input gear of the input shaft 102 and an output gear of the output shaft 104. Each toothed section 106 forms one load path. In the exemplary embodiment shown in Fig. 1, the gear teeth 106 are arranged coaxially and mounted on a common axis 130. Hydrodynamic sliding bearings (not explicitly shown in Fig. 1) are provided for mounting the gear teeth 106 on the common axis 130. In the typical embodiment shown in Fig. 1, the gear components are supported by hydrodynamic plain bearings. In other typical embodiments, the support is provided by non-hydrodynamic plain bearings or by rolling bearings. For example, when the gear components are supported by mutually preloaded rolling bearings, the common axis can be axially slidable to achieve load balancing between the load paths. Figure 2 schematically shows a sectional view of the embodiment of the typical bevel gear 100 of Figure 1 in section AA of Figure 1. The schematic sectional view shows the input shaft 102, which includes a bevel gear 103 integrally formed with a stub shaft as the input gear and is supported by a bearing 120. The output shaft 104 also includes a bevel gear 105 integrally formed with a stub shaft as the output gear and is supported by a bearing 122. The gear part 106 visible in Fig. 2 and also the second gear part not shown in Fig. 2 are mounted on the axis 130 as described above in connection with Fig. 1. In the exemplary embodiment shown in Figures 1 and 2, the input and output shafts are arranged at a right angle to each other, as in typical embodiments. In other typical embodiments, the input and output shafts are arranged at an angle of at least substantially 90° to each other. Typically, the input and output shafts are arranged at an angle greater than 90°, greater than 120°, or greater than 140° to each other. Typically, the input and output shafts are arranged at an angle of less than 90°, less than 80°, or less than 70° to each other. Figure 3 schematically shows an exemplary embodiment of Figures 1 and 2 in a side view. The bevel gear 103 of the input shaft 102 is clearly not meshing with the bevel gear 105 of the output shaft 104. One of the two load paths formed by the gear teeth 106 is visible in Figure 3. Torque is introduced via the input shaft 102 and distributed at least substantially evenly across the existing load paths with the gear teeth 106. The torque is transmitted from the input shaft 102 to the load paths with the gear teeth 106 and is further transmitted by the gear teeth to the output shaft 104. Figure 4 schematically shows an exemplary section CC through the side view of Figure 3. The view shows the common axis 130 of the coaxially arranged gear teeth 106 and their bearings 124. The common axis 130 is floatingly mounted in a housing (not shown). The gear teeth 106 can be preloaded against each other or with respect to the input shaft 102 or output shaft 104 (shown in Figure 1) by means of the rolling bearings 124. The reference numerals already shown and explained in Figs. 1, 2 to 3 are not explained again for Figs. 4 and 5. Figures 6, 7, 8, 9, 10, 11 to 12 show a further exemplary embodiment of a bevel gear with a ratio of 1. Figure 6 shows an exemplary embodiment with an input shaft 202 with an input gear 203 and an output shaft 204 with an output gear 205 in a rear view of a typical bevel gear 200. In the embodiment shown in Fig. 6, two gear teeth 206 are provided as bevel gears. A further, third gear tooth 208 is designed as a hollow bevel gear in the typical embodiment shown in Fig. 6. Figure 7 shows the bearing 220 of the input shaft 202 of the embodiment shown in Figure 6. Figure 7 also shows the bearing 222 of the output shaft 204 and the bearing 224 of the gear part 208. The input gear 203 of the input shaft 202 meshes with the two toothed parts 206 (only one meshing point with a bevel gear 206 is visible in Fig. 7; further details are shown in Figs. 8 and 9) and the toothed part 208. Likewise, the output gear 205 of the output shaft 204 meshes with the two toothed parts 206 (shown in detail in Figs. 8 and 9) and the toothed part 208. The input shaft 202 and the output shaft 204 are not in direct interaction, and the toothed parts mesh exclusively with the input gear 203 of the input shaft 202 and the output gear 205 of the output shaft 204. The embodiment shown in Figs. 6, 7, 8, 9, 10, 11 to 12 features a triple power split to three load paths. The two gear teeth 206, designed as bevel gears, are arranged above and below, and symmetrically to, the central axis of the input shaft 202 and the output shaft 204. The third gear tooth 208 is designed as a hollow bevel gear and is rotationally symmetrical to this central axis. All axes of the gear teeth 206 and 208 lie in the plane of symmetry of the input shaft 202 and the output shaft 204. In the embodiment of Fig. 6-11, the force flow is automatically and evenly distributed across the three gear teeth by means of a hydrodynamic sliding bearing; in addition, the clearance can be adjusted to the respective operating point (continuous operation) by axially adjusting the hollow bevel gear and the two other gear teeth. Figures 8 and 9 show the respective bearing arrangement 226, exemplified as a sliding bearing arrangement, of the gear parts 206. In typical embodiments, mutual or uniform load balancing is achieved by arranging at least two or all gear teeth on a plane of symmetry shared by the input and output shafts. Wherever the term "on the plane of symmetry" is used herein, it typically refers to the arrangement of the axis of rotation of the respective gear tooth in the plane of symmetry. In some embodiments, a floating, for example hydrodynamic or hydrostatic, bearing arrangement for a common shaft is provided. By designing the bearings 226 and 224 of the gear components 206 and 208 as hydrodynamic plain bearings, the force flow is automatically and evenly distributed across the three gear components 206 and 208 in this variant, thereby increasing the transmissible load of the gearbox by approximately a factor of three. Furthermore, the backlash can be adjusted to the respective operating point by axially adjusting the hollow bevel gear 208 and the two gear components 206. It is also conceivable to automate the backlash adjustment via a hydrostatic or hydrodynamic plain bearing, resulting in a torsional backlash of less than 1 arcmin down to zero backlash at the respective operating point. Figures 8, 9, 10 to 11 show schematic sectional views and schematic views of the embodiment shown in Figures 6 and 7. Figure 11 illustrates the uniform distribution of the tooth engagements around the output gear 205 of the output shaft. In particular, the toothed parts 206 and 208 are arranged in one plane on different sides of the output gear. Figure 12 schematically shows a perspective view of the embodiment shown in Figures 6, 7, 8, 9, 10 to 11. The invention is not limited to the exemplary embodiments; rather, the scope of the invention is determined by the claims. In particular, more than three load paths or other translations are also possible, which, however, have not been shown in the exemplary embodiments in the figures for the sake of clarity.

Claims

Angle gear (100, 200) with an input shaft (102, 202) and an output shaft (104, 204) and a power split with at least two load paths between the input shaft (102, 202) and the output shaft (104, 204), wherein each of the load paths comprises exactly one gear section (106, 206, 208) between an input gear (103, 203) of the input shaft (102, 202) and an output gear (105, 205) of the output shaft (104, 204), and wherein the input gear (103, 203) and the output gear (105, 205) are each designed as a bevel gear. Angle gear (100, 200) according to claim 1, wherein the gear parts (106, 206, 208) are each designed as a bevel gear. Angle gear (100 200) according to one of the preceding claims, wherein the gear parts (106, 206, 208) are arranged for mutual and / or uniform load compensation. Angle gear (100, 200) according to one of the preceding claims, wherein at least two of the gear parts (106) are arranged coaxially. Angle gear (100, 200) according to one of the preceding claims, wherein the gear parts (106, 206, 208) have axial force-reduced gear teeth. Angle gear (100, 200) according to one of the preceding claims, wherein at least one of the gear parts (106, 206, 208) is mounted by means of a sliding bearing. Angle gear (100, 200) according to claim 6, wherein the sliding bearing is hydrodynamically designed. Angle gear (100, 200) according to one of the preceding claims, wherein at least one of the gear parts (106, 206, 208) is made of plastic. Angle gear (100, 200) according to one of the preceding claims, wherein at least two of the gear parts (106, 206, 208) are identical. Angle gear (100, 200) according to one of the preceding claims, wherein at least two of the gear parts (106, 206, 208) are designed differently. Angle gear (100, 200) according to one of the preceding claims, with a power split with three load paths, each with a toothed part between the input shaft (102, 202) and the output shaft (104, 204). Angle gear (100, 200) according to claim 11, wherein two of the gear parts (206) are designed as identical bevel gears and the third gear part (208) is designed as a hollow bevel gear. Angle gear (100, 200) according to one of the preceding claims, wherein bearings (124) of at least two gear parts (106, 206, 208) arranged on a common, in particular floating, axis (130) are preloaded against each other.

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