Transmission assembly with planetary stage and spur gear stage

The integration of the second housing part as an axial abutment for the planet carrier bearing in the gear arrangement addresses the complexity and cost issues of existing designs, achieving reduced weight and axial space requirements.

WO2025124838A1PCT designated stage expired Publication Date: 2025-06-19ZF FRIEDRICHSHAFEN AG +1
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Patent Information

Application Number
PCT/EP2024/082651
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2023-12-14
Filing Date
2024-11-18
Publication Date
2025-06-19

AI Technical Summary

Technical Problem

Existing gear arrangements with planetary and spur gear stages require separate means to secure the planet carrier bearing, leading to increased structural complexity, weight, manufacturing costs, and axial space requirements.

Method used

The gear arrangement integrates a first housing part and a second housing part, where the second housing part forms an axial abutment for the planet carrier bearing, eliminating the need for separate securing means and allowing for reduced structural complexity.

Benefits of technology

This design reduces the structural complexity, weight, manufacturing costs, and axial space requirements by eliminating the need for separate securing means for the planet carrier bearing, while maintaining the functionality of the gear arrangement.

✦ Generated by Eureka AI based on patent content.

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  • Figure EP2024082651_19062025_PF_FP_ABST
    Figure EP2024082651_19062025_PF_FP_ABST
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Abstract

The invention relates to a transmission assembly (201) with a planetary stage, a spur gear stage, a first housing part (103), and a second housing part (115), wherein the planetary stage has a ring gear which is joined to the first housing part (103), the second housing part (115) is joined to the first housing part (103), the first housing part (103) forms a receiving area for at least one outer ring of at least one planet carrier bearing (105) of the planetary stage, and the second housing part (115) forms a receiving area for at least one outer ring of at least one bearing (207) of a hub (113) of the spur gear stage. The second housing part (115) forms an axial counter bearing for the at least one outer ring of the bearing (207) of the hub (113).
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Description

[0001] Gear arrangement with planetary stage and spur gear stage

[0002] The invention relates to a transmission arrangement according to the preamble of claim 1 and a method according to claim 10.

[0003] Gear arrangements with a planetary stage and a spur gear stage are known from the prior art. The planetary stage has a rotatably mounted planet carrier with planet gears that mesh with a housing-fixed ring gear and a rotatable sun gear. The sun gear is non-rotatably connected to a hub of the spur gear stage via a sun shaft. The hub has a first spur gear that meshes with a second spur gear. The planet carrier bearings are axially fixed by means of a disc-shaped element screwed into the first housing part.

[0004] Toward the spur gear stage, the planet carrier is mounted in a first housing section by means of a double-row roller bearing in an X arrangement. The first housing section is bolted to the ring gear and a second housing section. The second housing section contains the spur gear stage.

[0005] The invention is based on the object of providing a transmission arrangement with a planetary gear stage and a spur gear stage that is improved over the prior art. This object is achieved by a transmission arrangement according to claim 1 and a method according to claim 10. Preferred developments emerge from the subclaims and the following description.

[0006] The gear arrangement according to the invention comprises, in addition to the planetary stage and the spur gear stage, a first housing part and a second housing part. The first housing part and / or the second housing part are preferably each designed as a single piece. Both housing parts are separate pieces and are therefore not integrally connected to one another. The gear arrangement is preferably a wind turbine gearbox or part of such a gearbox. The planetary stage has a ring gear that is joined to the first housing part. The ring gear and the first housing part are thus connected to one another by means of a joint. The joint is preferably a screw connection.

[0007] The second housing part is joined to the first housing part, i.e., connected by means of a joint. This joint is also preferably designed as a screw connection.

[0008] The first housing part forms a receptacle for at least one outer ring of at least one planet carrier bearing of the planetary stage. A planet carrier of the planetary stage is rotatably mounted in the first housing part by means of the at least one planet carrier bearing. The at least one outer ring is fixed in the receptacle of the first housing part.

[0009] The second housing part forms a bearing mount for at least one outer ring of at least one bearing of a hub of the spur gear stage. The hub is rotatably mounted in the second housing part by means of the at least one bearing. The at least one outer ring of the at least one bearing is fixed in the bearing mount.

[0010] Instead of the aforementioned annular means, the second housing part according to the invention forms an axial abutment for the at least one outer ring of the planet carrier bearing. The at least one outer ring of the planet carrier bearing is thus axially fixed by the second housing part. The second housing part limits the axial displacement of the at least one outer ring of the planet carrier bearing in an axial direction.

[0011] Preferably, the second housing part limits the displaceability of the at least one outer ring of the planet carrier bearing in the direction of the spur gear stage. For this purpose, the second housing part preferably forms an annular surface against which the at least one outer ring of the planet carrier bearing abuts during an axial movement or a movement in the direction of the spur gear stage, or against which the at least one outer ring of the planet carrier bearing bears. In the opposite direction, i.e. axially away from the spur gear stage, the displaceability of the at least one outer ring of the planet carrier bearing is preferably limited by a shoulder formed by the first housing part or by a retaining ring that is embedded in a groove in the first housing part.

[0012] The inventive design of the gear assembly is advantageous because it eliminates the need for a separate means for securing the at least one outer ring of the planet carrier bearing. The first housing part and the second housing part can be integrated into one another. This reduces the structural complexity of the housing. This is advantageous with regard to weight, manufacturing costs, and axial space requirements.

[0013] The second housing part preferably forms part of a housing of the spur gear stage. In a preferred development, the second housing part is screwed to the first housing part. For this purpose, the second housing part has one or more holes. A first screw is received in one of these holes. A thread of the first screw engages with a corresponding thread of the first housing part. Preferably, the hole in the second housing part that receives the first screw is designed as a through hole. A head of the screw is then located at an opening of the hole, which is arranged opposite the thread of the first housing part. The second housing part is therefore screwed to the first housing part by means of the first screw.

[0014] If the head of the first screw is located inside the spur gear stage, i.e. within a housing of the spur gear stage, which is preferably formed at least partially by the first housing part and the second housing part, the head of the screw is no longer accessible after assembly of the spur gear stage. The first screw would therefore have to be screwed into the thread of the first housing part before assembly of the spur gear stage. To avoid this and thereby simplify assembly of the spur gear stage, the hub is preferably further developed with one or more through-holes. These are each at least partially aligned with one of the holes in the second housing part in at least one position of the hub. In particular, one of the holes in the hub is aligned with the hole in the second housing part in which the first screw is accommodated in at least one position of the hub. Since the hub is rotatably mounted, its position is characterized by its angle of rotation.Different positions of the hub differ from each other in the angle of rotation that the hub takes in the respective position.

[0015] To be aligned, the center axes of the holes must be parallel to each other. Generally, two holes are at least partially aligned if their center axes are parallel to each other and the outline of one of the holes, in an axial parallel projection, lies within or coincides with the outline of the other hole. Preferably, the one or more holes of the second housing part are each concentrically aligned with one of the holes of the hub in at least one position of the hub. In a concentric alignment, the center axes of the holes coincide.

[0016] The new design allows a screwing tool to be inserted through one or more holes in the hub. Using the screwing tool, the first screw can be screwed into the thread of the first housing part after the hub has already been assembled.

[0017] In a further preferred embodiment, the hub and the second housing part border a cavity. This cavity runs between the hub and the second housing part.

[0018] According to the further development, the one or more holes in the hub and the one or more holes in the second housing part open into the cavity. This ensures that the space between the one or more holes in the hub and the one or more holes in the second housing part is freely accessible for the screwing tool.

[0019] In a preferred embodiment, at least part of the head of the first screw is located in the aforementioned cavity. In particular, a screw head drive of the first screw can be located in the cavity. Thus, the head or the screw head drive of the first screw is accessible to the screwing tool via the one or more holes in the hub.

[0020] In a further preferred embodiment, a cylindrical portion of said cavity extends between the portion of the head of the first screw and at least one of the holes of the hub that, when the hub is in position, are at least partially aligned with the hole in the second housing part in which the first screw is received. The cylindrical portion of the cavity corresponds to the portion of the cavity occupied by the screwing tool when it is inserted through the hole in the hub and engaged with the head of the first screw or the screw head drive to screw the first screw into the thread of the first housing half.

[0021] Preferably, the arrangement is further developed with a gear that is fixed to the hub in a rotationally fixed manner. The gear and the hub are arranged coaxially to one another and rotatable about a common axis of rotation. To ensure that the one or more holes in the hub are not covered by the gear, the gear according to the further development has one or more through holes, each of which is at least partially aligned with one of the one or more holes in the hub. The screwing tool can then be inserted through a pair of aligned holes in the gear and the hub and engaged with the head or screw head drive of the first screw.

[0022] Two aligned holes in the gear and the hub can be provided exclusively for inserting the screwing tool and can therefore remain free. In a preferred embodiment, at least one pair of at least partially aligned holes in the gear and the hub also serves to fix the gear on the hub. Thus, a second screw is received in at least one of the one or more holes in the gear. A hole in the hub that is aligned with at least one of the one or more holes in the gear has a thread with which a thread of the second screw engages, i.e., into which the second screw has been screwed.

[0023] Preferably, the arrangement is further developed with a third housing part. This is joined to the first housing part. For example, the third housing part is a housing cover.

[0024] The third housing part has one or more through holes, each of which is at least partially aligned with one of the one or more holes in the second housing part. The one or more holes in the third housing part are preferably closed or closable by means of removable covers. The holes in the third housing part make it possible to place the third housing part on the first housing part using assembly aids according to a method according to the invention described further below. The assembly aids are each at least partially passed through one of the one or more holes in the third housing part.

[0025] In a further preferred embodiment, the hub is arranged at least partially axially between the second housing part and the third housing part. Thus, the second housing part and the third housing part extend on different axial sides of the hub. In particular, the hub can be rotatably mounted in the first housing part and / or the third housing part by means of appropriate bearings.

[0026] A method according to a first aspect of the invention for assembling the above-described arrangement, whose second housing part is further developed with one or more holes, provides that the first screw is inserted into one of the holes in the second housing part. The hub is rotated into a position in which the hole in the second housing part, into which the first screw was inserted, is at least partially aligned with one of the holes in the hub. The screwing tool is inserted through this hole in the hub and engaged with the screw or its head. This allows the screw to be screwed into the thread of the first housing part in a further step. The steps of "inserting the first screw" and "rotating the hub" can be carried out in any order.The screwing tool is inserted after turning the hub and engaged with the screw or its head so that the first screw can then be screwed in.

[0027] If the arrangement is further developed with a gear fixed to the hub in a rotationally fixed manner, the screwing tool is also inserted through a hole in the gear which is at least partially aligned with the hole in the hub through which the screwing tool is inserted.

[0028] A method according to a second aspect of the invention serves for assembling the above-described arrangement further developed with a second screw received in one of the one or more holes of the gear. According to the invention, one or more, preferably exactly three, assembly aids are used. These each have a thread that can be engaged with a thread in one of the one or more holes of the hub. Threaded rods, for example, can be used as assembly aids.

[0029] According to the invention, the one or more assembly aids are screwed into the respective thread of the one or more holes in the hub. The assembly aids are screwed in far enough that they pass through the respective hole in the hub, come into contact with the second housing part, and are consequently clamped against the second housing part. As a result, the hub and the second housing part are clamped against each other via the at least one bearing of the hub.

[0030] The clamping ensures that the components of an assembly consisting of the one or more screwed-in assembly aids clamped against the second housing part, the hub, the at least one bearing of the hub, and the second housing part are immovably fixed relative to one another. In the clamped and mutually fixed state, the assembly can be inserted into the first housing part and, according to a preferred embodiment, joined to the first housing part.

[0031] In detail, in a preferred development, the first housing part and the second housing part are joined together.

[0032] In a further preferred embodiment, the third housing part is joined to the first housing part after the first housing part and the second housing part have been joined together, and while the one or more assembly aids are screwed in and clamped against the second housing part. In the clamped state, the one or more assembly aids are each guided at least partially through one of the one or more holes in the third housing part.

[0033] Subsequently, i.e. after the third housing part has been joined to the first housing part, the one or more assembly aids are removed through the respective hole of the third housing part in a preferred further development.

[0034] In a preferred embodiment, the method steps according to the second aspect of the invention are carried out before the method steps according to the first aspect of the invention.

[0035] The figures depict gear arrangements. Corresponding reference numbers indicate identical or functionally equivalent features. Specifically, the figures show:

[0036] Fig. 1 shows a gear arrangement known from the prior art; and

[0037] Fig. 2 shows a gear arrangement according to the invention.

[0038] The gear assembly 101 shown in Fig. 1, which is known from the prior art, has a first housing part 103. The first housing part 103 forms a bearing receptacle for a planet carrier bearing 105, with which a planet carrier 107 is rotatably mounted in the first housing part 103, and is screwed to a ring gear of a planetary stage, to which the planet carrier 107 also belongs.

[0039] The planet carrier bearing 105 is designed as a double-row tapered roller bearing in an X arrangement. To secure the outer rings of the planet carrier bearing 105, a ring 109 is screwed to the first housing part 103. The ring 109 forms an axial abutment against the outer rings of the planet carrier bearing 105.

[0040] A sun shaft 111 of the same planetary stage, to which the planet carrier 107 also belongs, is non-rotatably connected to a hub 113 of a downstream planetary stage, which has a gear 114 belonging to a spur gear stage. The hub 113 is rotatably mounted in a second housing part 115 by means of tapered roller bearings in an O-arrangement. To fix the bearings of the hub 113, a ring 117 is screwed to the end face of the hub 113.

[0041] The two rings 109, 117 are located in a space between the planetary stage and the spur gear stage. Since they are no longer accessible after the planetary stage and spur gear stage have been assembled, they must be pre-assembled. This requires the planetary stage and spur gear stage to be assembled separately before the first housing section 103 and the second housing section 115 can be screwed together.

[0042] The embodiment 201 of the invention shown in Fig. 2 differs from the gear assembly 101 of Fig. 1, among other things, in that the second housing part 115 assumes the function of the ring 109. Accordingly, the second housing part 115 according to Fig. 2 forms an axial abutment for an outer ring of the planet carrier bearing 105.

[0043] The gear 114 meshes with a pinion 203 arranged on an output shaft 205. The output shaft 205 is not mounted in the second housing part 115, but in the first housing part 103. In detail, the first housing part 103 forms a bearing seat for an outer ring of a planetary stage-side bearing 207 of the output shaft 205. An opposite bearing 209 of the output shaft 205 is arranged in a housing cover 211 screwed to the first housing part 103. The housing cover 211 closes an opening in the first housing part 103 and forms a bearing receptacle for an outer ring of the bearing 209. The two bearings 207, 209 of the output shaft 205 are configured in an O-arrangement.

[0044] The second housing part 115 is screwed to the first housing part 103 by means of screws 213. The heads of the screws 213 are located in a cavity enclosed by the first housing part 103 and the housing cover 211. They are concealed by the hub 113.

[0045] To ensure that the screws 213 are still accessible for assembly, the hub 113 has holes 215. By rotating the hub 113, the holes 215 can be positioned so that they are each concentrically opposite a screw 213. This allows a screwing tool to be passed through the holes 215 and engaged with the head of the respective screw 213.

[0046] The holes 215 of the hub 113 also serve to screw the gear 114 to the hub 113. For this purpose, they have an internal thread which engages with an external thread of a screw 217.

[0047] Threaded rods can be screwed into the internal threads of holes 215 as assembly aids. These are screwed in far enough that they come into contact with the second housing part 115 and exert a force on the second housing part 115. This fixes the first housing part 115 and the hub 113 together and allows them to be inserted together into the first housing part.

[0048] The housing cover 211 has through holes 219. The holes 219 are each arranged so that their center axis coincides with the center axis of a screw 213. If the hub 113 is appropriately positioned, the center axes also coincide with the center axis of a hole 215. The holes 219 allow the housing cover 211 to be placed on the first housing part 103 while the threaded rods are screwed in. The housing cover 211 is placed so that the threaded rods are each inserted into one of the holes.

[0049] Once the hub 113 is supported by one or more bearings in the second housing part 215 and in the housing cover 211, the threaded rods can be unscrewed and removed through the holes 219. The holes 219 are then closed with a plug 221.

[0050] Reference symbol

[0051] Gear assembly housing part planet carrier bearing planet carrier ring

[0052] Sunwave

[0053] hub

[0054] gear

[0055] Housing part

[0056] ring

[0057] Gear arrangement

[0058] pinion

[0059] Output shaft

[0060] warehouse

[0061] warehouse

[0062] Housing cover

[0063] screw

[0064] Hole

[0065] screw

[0066] Through-hole plug

Claims

Patent claims 1. A gear arrangement (201) with a planetary stage, a spur gear stage, a first housing part (103), and a second housing part (115); wherein the planetary stage has a ring gear that is joined to the first housing part (103); wherein the second housing part (115) is joined to the first housing part (103); wherein the first housing part (103) forms a receptacle for at least one outer ring of at least one planet carrier bearing (105) of the planetary stage; wherein the second housing part (115) forms a receptacle for at least one outer ring of at least one bearing (207) of a hub (113) of the spur gear stage; characterized in that the second housing part (115) forms an axial abutment for the at least one outer ring of the at least one bearing (207) of the hub (113).

2. Arrangement (201) according to claim 1; characterized in that the second housing part (115) has one or more holes; wherein a first screw (213) is received in one of the holes of the second housing part (115), the thread of which screw engages with a thread of the first housing part (103); wherein the hub (113) has one or more through holes (215); and wherein the one or more holes of the second housing part (115) are each at least partially aligned with one of the holes (215) of the hub (113) in at least one position of the hub (113).

3. Arrangement (201) according to the preceding claim; characterized in that the one or more holes (215) of the hub (113) and the one or more holes of the second housing part (115) open into a cavity adjacent to the hub (113) and the second housing part (115).

4. Arrangement (201) according to the preceding claim; characterized in that at least a part of a head of the first screw (213) is located in the cavity.

5. Arrangement (201) according to the preceding claim; characterized in that a cylindrical part of the cavity extends between the part of the head of the first screw (213) and the respective hole (215) of the hub (113).

6. Arrangement (201) according to one of claims 2 to 5; characterized by a gear (114) which is fixed in a rotationally fixed manner on the hub (113) and which has one or more through holes, each of which is at least partially aligned with one of the one or more holes (215) of the hub (113).

7. Arrangement (201) according to the preceding claim; characterized in that in at least one of the one or more holes of the gear (114) a second screw (217) is received, the thread of which engages with a thread in one of the one or more holes (215) of the hub (113).

8. Arrangement (201) according to one of the preceding claims; characterized by a third housing part (211) which is joined to the first housing part (103) and has one or more through holes (219) which are each at least partially aligned with one of the one or more holes of the second housing part (115).

9. Arrangement (201) according to the preceding claim; characterized in that the hub (113) is arranged at least partially axially between the second housing part (115) and the third housing part (211).

10. A method for assembling an arrangement (211) according to one of claims 2 to 9, comprising the steps - inserting the first screw (213) into one of the holes of the second housing part (115); - rotating the hub (113) into a position in which one of the holes (215) of the hub (113) is at least partially aligned with the hole of the second housing part (115); - inserting a screwing tool through the hole (215) of the hub (113); - Engaging the screwing tool with the first screw (213); and - Screw the first screw (213) into the thread of the first housing part (103).

11. Method according to the preceding claim for assembling an assembly (201) according to one of claims 6 to 8; characterized in that the screwing tool is inserted through one of the one or more holes of the gear (114) which is at least partially aligned with the hole (215) of the hub (113).

12. A method for assembling an arrangement (211) according to one of claims 7 to 9; characterized in that one or more assembly aids are each screwed into a thread in one of the one or more holes (215) of the hub (113) and clamped against the second housing part (115).

13. Method according to the preceding claim; characterized in that an arrangement consisting of the one or more assembly aids screwed in and clamped against the second housing part (115), the hub (113), the at least one bearing (207) of the hub (113) and the second housing part (115) are joined to the first housing part (103).

14. Method according to the preceding claim; characterized in that the first housing part (103) and the second housing part (115) are joined together, while the one or more assembly aids are screwed in and clamped against the second housing part (115).

15. Method according to one of the preceding two claims for assembling an arrangement according to claim 8; characterized in that the third housing part (211) is joined to the first housing part (103) after the first housing part (103) and the second housing part (115) have been joined to one another, and while the one or more assembly aids are screwed in and clamped against the second housing part (115); wherein the one or more assembly aids are each passed at least partially through one of the one or more holes (219) of the third housing part (211).

16. Method according to the preceding claim; characterized in that the one or more assembly aids are removed through the respective hole (219) of the third housing part (211) after the third housing part (211) has been joined to the first housing part (103).

17. A method for assembling an arrangement (211) according to one of claims 7 to 9; characterized in that the arrangement (211) is assembled according to a method according to one of claims 12 to 16 and subsequently according to a method according to claim 10 or 11.

Citation Information

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