Drive device having a ring gear composed of segments, in particular identical segments
The drive device with segmented gear rings uses radially positioned connecting screws and hardened flange areas to prevent gaps and maintain smooth operation at varying temperatures, addressing the issue of operational smoothness and durability.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SEW EURODRIVE GMBH & CO KG
- Filing Date
- 2025-11-10
- Publication Date
- 2026-06-25
AI Technical Summary
Existing drive devices with segmented gear rings experience operational smoothness issues due to gap formation in the toothed area at varying temperatures, particularly at high temperatures where the gear ring expands radially, leading to tensile stresses and impaired smoothness.
The drive device incorporates connecting screws positioned radially outer and closer to the teeth, with hardened flange areas, to prevent gap formation by transmitting force effectively to the gear teeth, and uses centering screws for alignment without pressing adjacent segments together, ensuring a rotationally fixed connection.
This design maintains smooth operation at varying temperatures by preventing gaps in the toothed area, reducing tensile stresses, and enhancing the durability and torque transmission capability of the gear ring.
Smart Images
Figure EP2025082434_25062026_PF_FP_ABST
Abstract
Description
[0001] Drive device with a gear ring composed of segments, in particular identical segments to each other
[0002] Description:
[0003] The invention relates to a drive device with a gear ring composed of segments, in particular identical segments.
[0004] It is generally known that a gear ring can be assembled from ring segments.
[0005] From DE 102016010 084 A1, a segmented gear with helical teeth is known as the closest prior art.
[0006] A segmented gear is known from DE 102022 002 624 A1.
[0007] A segmented gear ring is known from EP 0 140 018 A1.
[0008] The invention is therefore based on the objective of further developing a drive device with improved smoothness of operation.
[0009] According to the invention, the problem is solved in the drive device according to the features specified in claim 1.
[0010] Important features of the invention for the drive device with a gear ring composed of, in particular, identical segments are that the respective segment has an inner ring section,
[0011] Struts, an outer ring section with teeth, in particular external teeth, in particular helical teeth, and a first flange area which is arranged at the circumferentially forward end area of the segment,
[0012] ISI \ EIDOPAT 10.11 .2025 has a second flange area, which is arranged at the circumferentially rear end area of the segment, connecting screws and centering screws, wherein the inner ring section is arranged radially inside the outer ring section and wherein both the first flange area and the second flange area each, as well as the struts each, connect the inner ring section to the outer ring section, wherein both the connecting screws each and the centering screws each project through the first and the second flange area, wherein, in particular in the radial direction, the connecting screws are arranged closer to the teeth than the centering screws and / or wherein the connecting screws are arranged radially outside the centering screws.
[0013] According to the invention, a drive device with a segmented gear ring, driven by a pinion, can be designed with improved smoothness of operation even at varying operating temperatures. This is because the radially outer arrangement of the connecting screws, positioned as close as possible to the toothed area, prevents or significantly reduces the formation of gaps in the toothed area. Since, at high temperatures, particularly in the part that holds the gear ring, such as a drum or similar component, the gear ring tends to expand radially outwards, potentially creating gaps between the segments, especially at the radially outer edge, and thus in the toothed area, these gaps are prevented by the connecting screws.
[0014] The resulting tensile stresses in the gear area only imperceptibly impair the smoothness of running, whereas the gaps would significantly impair the smoothness of running.
[0015] It is also beneficial that not only the gear teeth but also the respective flange area is hardened, with the hardening depth in the flange area preferably exceeding the hardening depth in the gear teeth area. In an advantageous embodiment, the first and / or second flange area has a hardened surface. The advantage here is that the force applied by the connecting bolts propagates into the radial spacing area covered by the external gear teeth, thus preventing wear in this area.
[0016] In an advantageous embodiment, the first and / or the second flange area has a hardening depth of more than 1.5 millimeters, in particular wherein the radial spacing area covered by the hardened area, especially by the hardened surface, overlaps with the radial spacing area covered by the inner ring section and overlaps with the radial spacing area covered by the outer ring section. It is advantageous that the force introduced by the connecting screws is transmitted up to the gear teeth area and prevents the gap from forming there by pulling the end of the segment towards the adjacent segment, and that no intermediate unhardened and therefore more elastic sections reduce or weaken the force applied to the flange area by the connecting screws.
[0017] In an advantageous embodiment, the inner ring section is connected to a drum, in particular by means of screws, on which the gear ring is mounted, thus ensuring a rotationally fixed connection between the inner ring section and the drum. An advantage of this design is that the drum can operate at either a low or high temperature, allowing the gear ring to be operated at both temperatures.
[0018] In an advantageous embodiment, the pinion's teeth engage with the teeth, particularly helical teeth, of the gear ring. This is advantageous because it improves smooth running of the drive device, as gaps in the toothing area are avoided.
[0019] According to the invention, the axial direction is aligned parallel to the axis of rotation of the gear ring, and the radial distance is referenced to this axis of rotation, as is the circumferential direction. In an advantageous embodiment, no centering screws are arranged radially within each connecting screw. It is advantageous that the connecting screws are arranged as radially far out as possible, close to the teeth.
[0020] In an advantageous embodiment, each of the centering screws has a cylindrical section arranged between two threaded sections, with a nut, in particular a screw nut, being screwed onto each threaded section. An advantage of this is that tightening the nuts allows for symmetrical tightening.
[0021] In an advantageous embodiment, each of the connecting screws has a cylindrical section, at the first end of which a screw head adjoins and at the second end of which a threaded section adjoins, onto which a nut, in particular a nut, is screwed. It is advantageous that the connecting screw can be tightened securely, so that the screw head and the nut of the connecting screw press against the flange areas.
[0022] In an advantageous embodiment, the cylindrical section of each connecting screw, particularly in the screw direction, is shorter than the sum of the wall thicknesses of the first flange region and the wall thicknesses of the second flange region. It is advantageous that the nut and the screw head of each connecting screw press against the flange regions of the nearest adjacent segments.
[0023] In an advantageous embodiment, the cylindrical section of the respective centering screw, particularly in the screw direction, is longer than the sum of the wall thicknesses of the first flange region and the wall thicknesses of the second flange region. An advantage of this is that the centering function can be performed without pressing the flange regions of the nearest adjacent segments together.
[0024] In an advantageous embodiment, the segment is made of a steel, in particular an austenitic-ferritic spheroidal graphite cast iron, especially ADI. An advantage of this is that it can transmit a high torque. In an advantageous embodiment, the segment, including its inner ring section, outer ring section, struts, and flange regions, is formed in one piece, in particular as a single unit. An advantage of this is that the segment can withstand a high torque.
[0025] In an advantageous embodiment, no connecting screw is arranged radially within each centering screw. It is advantageous that the connecting screws are arranged radially outwards, i.e., as close as possible to the toothing.
[0026] In an advantageous embodiment, the maximum outer diameter of the cylindrical section of the respective connecting screw is smaller than the maximum outer diameter of the cylindrical section of the respective centering screw. This is advantageous because the surface pressure on the centering screw is kept low, thus preventing overloading of the centering screw.
[0027] In an advantageous embodiment, the distance between two adjacent connecting screws is smaller than the distance between two adjacent centering screws. The advantage here is that the tightening force can be transferred with minimal loss to press the toothed areas of the two adjacent segments together.
[0028] In a preferred embodiment, the segments are arranged one behind the other in the circumferential direction, each segment touching its nearest neighboring segments. An advantage of this is that the toothed ring can be manufactured in a simple manner.
[0029] In an advantageous embodiment, the normal direction of the respective flat surface of the front or rear flange region to the axis of rotation of the gear ring has an angle of less than 90° and / or an angle which is equal in magnitude to the difference between 90° and the helix angle of the helical gearing, and / or the flange regions are inclined in accordance with the helix angle of the helical gearing. It is advantageous that the flange regions are inclined and thus inclined in accordance with the gearing. Further advantages will become apparent from the dependent claims. The invention is not limited to the combination of features of the claims.For the person skilled in the art, further meaningful combination possibilities of claims and / or individual claim features and / or features of the description and / or the figures arise, in particular from the problem statement and / or the task arising from comparison with the prior art.
[0030] The invention will now be explained in more detail with reference to schematic illustrations:
[0031] Figure 1 shows a drive device according to the invention with a gear ring composed of identical segments 1 in a front view.
[0032] Figure 2 shows segment 1 in side view.
[0033] Figure 3 shows segment 1 in oblique view.
[0034] Figure 4 shows a connecting screw in side view.
[0035] Figure 5 shows a centering screw in side view.
[0036] As shown in the figures, the drive device has a gear ring composed of circumferentially arranged segments 1, which is mounted on a drum 3 that has a temperature higher than the ambient temperature. The gear ring has external teeth and is driven via a pinion 2 that meshes with the external teeth.
[0037] The segments that are closest to each other are aligned relative to each other by means of centering screws and connected to each other by means of connecting screws.
[0038] As a result of the increased temperature of drum 3, the outer diameter of drum 3 increases, and a gap could form between the nearest adjacent segments 1. Such gaps are particularly problematic in the area of the external teeth.
[0039] Preferably, the segments 1 are made of a steel, in particular of an austenitic-ferritic cast iron with spheroidal graphite, especially ADI.
[0040] Each segment 1 has an inner ring section 20, which is connected via struts 23 to an outer ring section 22 with helical teeth arranged radially outside the inner ring section 20. The ring axis of the inner ring section 20 is aligned coaxially with the ring axis of the outer ring section 22 and coaxially with the axis of rotation of the gear ring.
[0041] At the circumferentially front and rear end regions of segment 1, a flange region 21 is arranged, which connects the inner ring section 20 with the outer ring section 22 and has a greater hardening depth, in particular case hardening depth, than the rest of segment 1.
[0042] Preferably, the hardening depth exceeds 1.5 millimeters.
[0043] The external teeth are preferably designed as helical teeth. Therefore, the flange areas 21 at the circumferentially forward and rear ends are inclined at the helix angle of the external teeth.
[0044] The flange area 21 of each segment 1 is connected to the flange area 21 of a segment 1 that is closest to that segment 1. The two flange areas are in contact with each other, and both centering screws and connecting screws protrude through the two flange areas, particularly in the tangential direction.
[0045] The centering screws are inserted through second bores 30, which have a larger clear diameter than the first bores 31 provided for the insertion of the connecting screws.
[0046] Each connecting screw has a cylindrical section 41 which adjoins a screw head 40 and which, on its side facing away from the screw head 40, adjoins a threaded section 42. A nut is screwed onto the threaded section 42, so that after the nut is screwed on, the screw head 40 presses one of the flange regions 21 towards the other flange region 21, which in turn presses from the nut towards the first flange region 21.
[0047] The cylindrical section 41 is preferably shorter than twice the wall thickness of the respective flange region 21. The respective centering screw has a cylindrical section 50 which adjoins a respective threaded section 51 on both sides. This cylindrical section 50 is preferably longer than twice the wall thickness of the respective flange region 21. Although nuts are screwed onto the threaded sections 51 of the respective centering screw, these do not serve, or only to a minor extent, to press the adjacent, contacting flange regions 21 together, but rather primarily or exclusively to align the adjacent, contacting flange regions 21.
[0048] The first bores 31 have a larger radial distance to the axis of rotation of the gear ring than the second bores 30.
[0049] The smallest distance between the first boreholes 31 is smaller than the smallest distance between the second boreholes 30.
[0050] The distance between two adjacent first boreholes 31 is smaller than the distance between two adjacent second boreholes 30.
[0051] Therefore, the connecting screws are arranged in a much closer grid pattern than the centering screws. This prevents a gap in the gear teeth area, as the connecting screws are positioned closer to the gear teeth than the centering screws.
[0052] In particular, the drilling pattern of the four second bores 30 forms a rectangle. In particular, the first bores 31 are at least partially spaced differently from one another.
[0053] In further embodiments of the invention, the first bores 31 are spaced evenly apart. Reference numeral list
[0054] 1 segment, 2 pinions
[0055] 3 Drum
[0056] 20 Inner ring section
[0057] 21 Flange area
[0058] 22 Outer ring section with helical teeth 23 Strut
[0059] 30 second bore
[0060] 31 first borehole
[0061] 40 screw heads
[0062] 41 cylindrical section 42 threaded section
[0063] 50 cylindrical section
[0064] 51 Thread section
Claims
Patent claims:
1. Drive device with a gear ring composed of, in particular, identical segments 1, wherein each segment has an inner ring section, Struts, an outer ring section with teeth, in particular external teeth, in particular helical teeth, and a first flange area arranged at the circumferentially forward end area of the segment, a second flange area arranged at the circumferentially rear end area of the is arranged in segments Connecting screws and comprising centering screws, wherein the inner ring section is arranged radially within the outer ring section and wherein both the first flange region and the second flange region each, as well as the struts each, connect the inner ring section to the outer ring section, characterized in that both the connecting screws each and the centering screws each project through the first and the second flange region, wherein, in particular in the radial direction, the connecting screws are arranged closer to the teeth than the centering screws and / or wherein the connecting screws are arranged radially outside the centering screws.
2. Drive device according to claim 1, characterized in that the first and / or the second flange area has a hardened surface, and / or that the first and / or the second flange area has a hardening depth of more than 1.5 millimeters, in particular wherein the radial spacing area covered by the hardened area, in particular by the hardened surface, overlaps with the radial spacing area covered by the inner ring section and overlaps with the radial spacing area covered by the outer ring section.
3. Drive device according to one of the preceding claims, characterized in that the inner ring section is connected to a drum, in particular by means of screws, on which the gear ring is mounted and with which the inner ring section is thus connected in a rotationally fixed manner, and / or that the toothing of the pinion is in engagement with the toothing, in particular helical toothing, of the gear ring.
4. Drive device according to one of the preceding claims, characterized in that the axial direction is aligned parallel to the axis of rotation of the gear ring and the radial distance is related to this axis of rotation as well as the circumferential direction is related to this axis of rotation.
5. Drive device according to one of the preceding claims, characterized in that no centering screws are arranged radially within each connecting screw.
6. Drive device according to one of the preceding claims, characterized in that each of the centering screws has a cylindrical section which is arranged between two threaded sections, wherein a nut, in particular a screw nut, is screwed onto each threaded section.
7. Drive device according to one of the preceding claims, characterized in that each of the connecting screws has a cylindrical section, at the first end of which a screw head adjoins and at the second end of which a threaded area adjoins, onto which a nut, in particular a screw nut, is screwed.
8. Drive device according to one of the preceding claims, characterized in that the cylindrical section of the respective connecting screw, in particular in the screw direction, is shorter than the sum formed from the wall thickness of the first flange area and from the wall thickness of the second flange area.
9. Drive device according to one of the preceding claims, characterized in that the cylindrical section of the respective centering screw, in particular in the screw direction, is longer than the sum formed by the wall thickness of the first flange area and the wall thickness of the second flange area.
10. Drive device according to one of the preceding claims, characterized in that the segment is made of a steel, in particular of an austenitic-ferritic cast iron with spheroidal graphite, in particular ADI.
11. Drive device according to one of the preceding claims, characterized in that the segment together with its inner ring section, outer ring section, its struts and its flange areas is formed in one piece, in particular in one piece.
12. Drive device according to one of the preceding claims, characterized in that no connecting screw is arranged radially within each centering screw.
13. Drive device according to one of the preceding claims, characterized in that the maximum outer diameter of the cylindrical section of the respective connecting screw is smaller than the maximum outer diameter of the cylindrical section of the respective centering screw.
14. Drive device according to one of the preceding claims, characterized in that the distance between two adjacent connecting screws is smaller than the distance between two adjacent centering screws.
15. Drive device according to one of the preceding claims, characterized in that the segments are arranged one behind the other in the circumferential direction, each in contact with its nearest neighboring segments and / or that the normal direction of the respective flat surface of the front or rear flange area to the axis of rotation of the gear ring has an angle of less than 90° and / or has an angle which in magnitude is equal to the difference between 90° and the helix angle of the helical gearing, and / or that the flange areas are arranged inclined according to the helix angle of the helical gearing.