Transmission housing, in particular for planetary transmission, and production method

Abstract

The invention relates to a transmission housing, in particular for a planetary transmission, comprising a ring gear (10) having an inner toothing in at least some sections and a housing cover (20) for covering the ring gear (10) in the longitudinal axial direction, the ring gear (10) and the housing cover (20) being connectable on the end sides and each having an end-side joining surface (11, 21) on which the ring gear (10) and the housing cover (20) are joined together in the longitudinal axial direction and on which the ring gear (10) and the housing cover (20) are joined together in the longitudinal axial direction. The ring gear (10) and the housing cover (20) are integrally bonded to each other, in particular by means of heating element welding or infrared welding or ultrasonic welding or rotary friction welding.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201810147068.0, filed on February 12, 2018, entitled "Transmission housing and manufacturing method, especially for planetary gear transmission". Technical Field

[0002] This invention relates to a transmission housing, particularly for planetary gear transmissions, having a gear ring and a housing cover for covering the gear ring in the longitudinal direction. Furthermore, the invention also relates to a method for manufacturing such a transmission housing. Background Technology

[0003] A transmission housing is disclosed in EP 2 644 309 B1, comprising a gear ring and a housing cover. The gear ring is segmentally provided with internal teeth and is covered longitudinally by the housing cover. An overlap region is formed between the housing cover and the gear ring, in which the gear ring and housing cover are coaxially interlocked. The gear ring has a transparent material suitable for laser processing, allowing the housing cover to be joined to the gear ring by laser radiation welding.

[0004] The known connection between the gear ring and the housing cover necessitates the use of a laser-resistant transparent material for the gear ring. Simultaneously, the housing cover must possess a laser-absorbing material. Furthermore, these two materials, which are affected differently by the laser, must be compatible to allow them to be welded together. In particular, the two materials with different laser properties must have similar melting temperatures to enable welding.

[0005] This significantly limits the material selection for components used in the transmission housing. Furthermore, it is necessary to extrude the housing cover and gear ring before welding to ensure sufficient contact between the mating surfaces. This extrusion is particularly difficult to achieve in components manufactured using injection molding techniques, thus increasing production costs. Manufacturing costs are also negatively impacted by the need for laser facilities for laser radiation welding, which require significant investment. Additional costs arise technically with laser radiation welding when welding circular transmission housings because the mating components must be rotated. Summary of the Invention

[0006] Therefore, the object of the present invention is to describe a transmission housing that can be manufactured simply, inexpensively, and reliably. In particular, the object of the present invention is to describe a method for manufacturing a transmission housing that reduces production costs and technical manufacturing expenses.

[0007] According to the present invention, this task is solved in terms of the transmission housing by the subject matter of claims 1 and 10, and in terms of the manufacturing method by the subject matter of claims 3 and 11.

[0008] Therefore, the present invention is based on the idea of ​​describing a transmission housing, particularly for planetary gear transmissions, having a gear ring with at least partially internal teeth and a housing cover for covering the gear ring in the longitudinal direction, wherein the gear ring and the housing cover can be connected at their ends and each has a mating surface at its ends, on which the gear ring and the housing cover are material-locked to each other. This material-locked connection can be achieved, in particular, by welding with heating elements, infrared welding, ultrasonic welding, or rotary friction welding.

[0009] The difference between this invention and the prior art lies in that, according to this invention, the connection between the gear ring and the housing cover is achieved on the end side. This has the following advantages: During manufacturing, an additional welding method can be used, which enables the material-locking connection of different materials. The selection of materials for the components of the transmission housing is thus significantly improved. Therefore, limitations regarding laser penetration are no longer necessary. Furthermore, the mating parts required for establishing the material-locking connection are obtained at a significantly lower investment cost compared to laser equipment. Simultaneously, the end-side connection allows for higher tolerances in the manufacturing of the individual mating parts, thereby reducing the overall production cost of the transmission housing.

[0010] Preferably, in this invention, the mating surfaces of the gear ring and the housing cover are adjacent to end-side open recesses that surround the outer periphery. These recesses together form an annular groove that accommodates the welded protrusion. This has the advantage that the welded protrusion does not protrude beyond the outer diameter of the transmission housing. This simplifies manufacturing and further ensures high dimensional accuracy of the transmission housing.

[0011] In the method for manufacturing a transmission housing according to the present invention, particularly the transmission housing previously described, the following method steps are performed sequentially in time:

[0012] - Provides a toothed ring and a housing cover with at least segmented internal teeth, wherein the toothed ring and the housing cover each have at least one end-side splicing surface;

[0013] - The splicing surfaces are heated by heating elements or infrared radiators, thereby melting the gear ring and housing cover sections at their ends; and

[0014] - The gear ring and housing cover are coaxially joined to form a material-locking connection between the joint surfaces.

[0015] The manufacturing method according to the present invention differs from the prior art in that the following sub-steps are combined in a single working step:

[0016] - This ensures that the mating components, especially the gear ring and the housing cover, come into contact; and

[0017] - The materials are locked together to connect the splicing and mating parts.

[0018] In this invention, the splicing surfaces are first heated to prepare them for a material-locking connection. Subsequently, the contact and material-locking connection of the splicing mating parts are performed simultaneously by bringing the heated and molten splicing surfaces into contact with each other. This has several advantages. Firstly, to melt the splicing surfaces, a corresponding heat source can be applied to multiple splicing mating parts simultaneously. Multiple toothed rings and multiple housing covers, in particular, can be heated simultaneously on their splicing surfaces, thereby melting them.

[0019] The coaxial splicing of the fused joint surfaces further allows for manufacturing tolerances, enabling the original components—the gear ring and the housing cover—to be manufactured with greater manufacturing tolerances. This reduces the cost of manufacturing each individual splice mating component, which is beneficial for lower manufacturing costs.

[0020] Preferably, the splicing surface is heated by a heating element or an infrared radiator. When using a heating element, it is particularly advantageous to arrange the heating element in contact with the splicing surface. This has the following advantages: melting can be achieved under a certain mechanical pressure, resulting in uniform and rapid melting of the splicing surface. In contrast, using an infrared radiator allows for non-contact heating of the splicing surface, thus preventing molten material from adhering to the heating element.

[0021] In a preferred embodiment of the method according to the invention, the splicing surfaces are pressed against each other under pressure during coaxial splicing until the splicing surfaces cool and the material locks securely together. In other words, the splicing surfaces are preferably pressed against each other until the material lock connection is sufficiently strong, so that the splicing mating parts also maintain their orientation relative to each other after the pressure is released.

[0022] In a preferred embodiment, the splicing surfaces can be heated to above the respective melting points of the plastics used to form the gear ring and / or the housing cover. Specifically, the temperature parameters for heating the splicing surfaces are adjusted accordingly based on the plastics used for the gear ring and / or the housing cover. It is advantageous, in any case, to introduce a large amount of heat energy into the splicing surfaces, thereby melting them.

[0023] The spliced ​​surfaces can be heated for a predetermined duration, which is pre-selected based on the type and effect of the radiating element used to heat the spliced ​​surfaces. The radiating element, such as a heating element or an infrared radiator, acts on the spliced ​​surfaces for the predetermined duration. This duration depends on the type of radiating element (heating element or infrared radiator). Furthermore, the pre-selected duration of heating the spliced ​​surfaces depends on the amount of heat energy applied by the radiating element. Finally, the duration of heating depends on the plastic used for the material to be melted.

[0024] In another preferred embodiment of the manufacturing method according to the invention, a splicing device is provided for coaxially splicing the gear ring and the housing cover. The gear ring and the housing cover can be inserted into the splicing device and loaded with a splicing force by two pneumatic cylinders and / or servo motor shafts. The splicing force is preferably pre-adjusted according to the size of the splicing surfaces. Using the splicing device (which applies the splicing force to the gear ring and the housing cover) ensures that the spliced ​​mating parts, i.e., the gear ring and the housing cover, are spliced ​​together with the same force in principle. This improves the process reliability of the manufacturing method. In particular, it ensures that a stable and substantially identical connection of the spliced ​​mating parts is achieved with consistent quality throughout the production batch.

[0025] Preferably, in the method according to the invention, the gear ring and housing cover are cooled over a predetermined time period after being joined while maintaining the joining force. The predetermined time period may depend on the material used and the size of the transmission housing.

[0026] In the preferred embodiment of the transmission housing and manufacturing method described above, the splicing surfaces on the end sides are oriented perpendicular to the rotation axis of the gear ring. In other words, the gear ring and housing cover are preferably joined by butt welding or by butt welding.

[0027] Another aspect of the invention relates to a transmission housing, particularly for a planetary gear transmission, having a gear ring at least partially having internal teeth and a housing cover for covering the gear ring in the longitudinal direction. The gear ring and the housing cover are coaxially fitted together to form an annular overlapping region. In the overlapping region, the mating surfaces of the gear ring and the housing cover are in contact with each other. According to the invention, the gear ring and the housing cover each have a tapered mating surface in the overlapping region, and are connected to each other along the mating surface material in a locking manner, particularly by rotational friction welding.

[0028] Using a tapered splice face allows for a simple and efficient way to create an interference fit between mating components. This ensures that the splice faces are securely connected in the overlapping area, enabling rapid and efficient material locking, especially through rotary friction welding. The tapered splice face also allows for easy orientation of components during manufacturing. This accelerates the manufacturing process and reduces overall production costs.

[0029] In particular, one type of transmission housing, according to the invention, comprises the following steps performed sequentially in time:

[0030] - Provides a toothed ring and a housing cover with at least segmented internal teeth, wherein the toothed ring and the housing cover have complementary conical splicing surfaces;

[0031] - The gear ring and housing cover are coaxially spliced ​​to establish surface contact between the tapered splicing surfaces, forming an overlapping area;

[0032] - In particular, the overlapping area is heated by rotary friction welding, so that the gear ring and the housing cover are connected in a material-locking manner in the overlapping area.

[0033] The complementary conical splicing surfaces enable a simple and minimally oriented surface-to-surface compression connection between the splicing surfaces. This provides excellent contact between the splicing surfaces, allowing heat to be transferred between the two splicing mats. This facilitates welding the splicing mats.

[0034] The complementary conical splicing surfaces essentially form a self-centering device, thus eliminating the need for costly pre-positioning. Furthermore, the conical splicing surfaces create tolerance compensation, allowing for the manufacture of mating components, particularly gear rings and housing covers, with relatively large manufacturing tolerances. Overall, the manufacturing process is not only accelerated in this manner but also performed at a lower cost.

[0035] In a preferred variation of the method according to the invention, a compression connection is formed between the splicing surfaces of the toothed ring and the housing cover during the establishment of surface contact. In other words, the toothed ring and the housing cover are spliced ​​together with a splicing force, thereby establishing a compression connection. This improves the subsequent welding process.

[0036] In all the aforementioned variations of the transmission housing or manufacturing method according to the invention, in a preferred embodiment, the housing cover is formed via an engine bearing cover or an adapter element, which is configured to connect the transmission housing and the engine. In this manner, the transmission housing can be directly connected to the engine, thereby achieving a compact design and simplified process control in overall production.

[0037] Preferably, the adapter element is welded to or can be welded to the gear ring on the transmission side. On the engine side, the adapter element can have a universal connector for connection to different engines, especially electric motors. The adapter element thus forms a universal interface for different engines. In this way, the transmission housing can be connected to different engines via the adapter element, and the standardization of individual components can positively impact production costs. The transmission housing can therefore be used, in particular, for different structural series of engine-transmission combinations. In other words, the transmission housing can be used in a manner compatible with the entire structural series (modular principle).

[0038] Typically, the connection between the gear ring and the housing cover, especially the material-locking connection, does not necessarily have to be achieved only at the end side. The invention also includes embodiments in which, in addition to the material-locking connection at the end side, at least circumferentially extending face segments of the gear ring and the housing cover overlap, particularly with the housing cover at least partially embedded in the gear ring. The overlapping face segments form an overlapping region. Further material-locking connections can be provided in the overlapping region. In this respect, the embodiments of the invention described above can be combined with each other. Attached Figure Description

[0039] The present invention will now be described in detail with reference to the illustrative accompanying drawings and embodiments. Wherein:

[0040] Figure 1 and 2 Cross-sectional views are shown through the connection region of the transmission housing according to a preferred embodiment of the invention, wherein the gear ring and the housing cover are connected to each other at the end sides;

[0041] Figure 3 A cross-sectional view is shown through the overlapping region of the transmission housing according to a preferred embodiment of the invention, wherein the gear ring and the housing cover have complementary tapered splicing surfaces;

[0042] Figure 4 A perspective view of an engine transmission housing assembly according to a preferred embodiment is shown, wherein the gear ring and the housing cover have mating surfaces arranged sequentially in a mating manner;

[0043] Figure 5 Showing through according to Figure 4 A cross-sectional view of the engine and transmission housing assembly;

[0044] Figure 6 A perspective view of an engine transmission housing assembly according to a preferred embodiment is shown, wherein an annular groove for receiving a welded protrusion is formed between the gear ring and the housing cover; and

[0045] Figure 7 Showing through according to Figure 6 Cross-sectional view of the engine and transmission housing assembly. Detailed Implementation

[0046] exist Figure 1-3 The diagram schematically illustrates different possibilities for the material locking connection between the gear ring 10 and the housing cover 20 of the transmission housing 1. According to... Figure 1 and 2In this embodiment, the gear ring 10 and the housing cover 20 are butt-connected. For this purpose, the gear ring 10 and the housing cover 20 each have end-side mating surfaces 11 and 21, which are arranged sequentially in a butt-connected manner and are connected to each other by means of a welded protrusion 40. To prevent the welded protrusion 40 from extending on the outer periphery of the gear ring 10 and thus affecting the outer dimensions of the transmission housing 1, it is preferable that the gear ring 10 and the housing cover 20 each have recesses 12 and 22. Adjacent recesses 12 and 22 are directly adjacent to the mating surfaces 11 and 21 and extend on the outer periphery of the gear ring 10 or the housing cover 20. The recesses 12 and 22 are preferably constructed complementaryly to form an annular groove 30 in the connected state of the gear ring 10 and the housing cover 20. The annular groove 30 preferably extends around the outer periphery of the gear ring 10 or the housing cover 20. A variant of the mating connection with an annular groove 30 is exemplarily shown in… Figure 2 As shown in the image.

[0047] The material-locking connection between the gear ring 10 and the housing cover 20 is preferably achieved by welding. Specifically, the gear ring 10 and the housing cover 20 are each made of plastic material. The material-locking connection is established by heating the plastic material. In this regard, a heating element welding method or an infrared welding method can be used for the material-locking connection. In both cases, the mating surfaces 11, 21 are first heated until they reach or exceed the melting temperature of the plastic material of the gear ring 10 or the housing cover 20. As a result, the material in the region of the mating surfaces 11, 21 melts. The molten mating surfaces are then coaxially joined together, thereby achieving a material-locking connection between the molten mating surfaces.

[0048] Alternatively, the splicing surfaces 11 and 21 can be joined together before heating, particularly by pressing them against each other with a splicing force. The pressed splicing surfaces 11 and 21 can then be heated, for example, by rotary friction welding. This also establishes a welded joint. Rotary friction welding offers the advantage that the arching of the weld bulge 40 is avoided through direct contact with the heating element rotating around the weld. In this respect, it is possible to abandon the practice of... Figure 2 The annular groove 30 is shown in the figure.

[0049] Alternatively, the gear ring 10 and the housing cover 20 may be joined by ultrasonic welding. For this purpose, at least one joint surface 11 or 21 is provided with an energy conductor. The energy conductor may, for example, be an edge along the geometry of the joint surface. The energy conductor is used to concentrate the ultrasonic waves in the material, thereby suitably introducing energy into the region of the joint surface. Preferably, in ultrasonic welding, an ultrasonic generator that generates ultrasonic waves is placed on the end side of the housing cover. The ultrasonic waves pass through the housing cover and thus reach the joint surfaces 11, 21 between the housing cover 20 and the gear ring 10.

[0050] exist Figure 3 The diagram schematically shows the overlapping area 31 between the housing cover 20 and the gear ring 10. The gear ring 10 and the housing cover 20 each have complementary mating surfaces 11 and 21, which are each conically constructed. The conical shapes of the mating surfaces 11 and 21 are complementary, allowing them to slide alternately. In this way, the gear ring 10 and the housing cover 20 can be easily positioned relative to each other. Furthermore, the mating surfaces 11 and 21 are brought into contact under pressure by applying a mating force axially, i.e., a compression connection is established. The compression connection is advantageous, and a weld protrusion 40 is subsequently created by rotary friction welding, whereby the molten and material-locked mating surfaces 11 and 21 are interconnected.

[0051] Figure 4-7 The diagram shows an assembly consisting of a transmission housing 1 and an engine 5, with the engine connected to the transmission housing 1 via an engine adapter 2. The engine adapter 2 is formed via a housing cover 20, which is welded to the gear ring 10 of the transmission housing 1. The engine 5 is configured as an electric motor and has corresponding electrical contacts 51 at its end opposite the transmission housing 1. (As can be seen from...) Figure 5 and 7 As seen in the cross-sectional view, engine 5 is equipped with engine shaft 52, which extends into engine adapter 2. Engine shaft 52 can be connected to transmission shaft.

[0052] The engine adapter 2 is formed through the housing cover 20 and has an engine-side end on which the engine adapter 2 is constructed so that the engine adapter can be connected to different engines 5. In particular, the engine adapter can be connected to two or more different engine sizes. The engine adapter 2 thus forms a platform for a modular system in which multiple engines 5 with different power intensities can be connected to the transmission housing 1.

[0053] Gear ring 10 according to Figure 4-7 All embodiments include an internal toothed portion 13. The internal toothed portion 13 extends over the entire length of the distal end section of the toothed ring 10, wherein the toothed ring 10 has a greater wall thickness in the distal end section. An overlapping region 31 connects the distal end section proximally, and in the overlapping region, the toothed ring 10 has a reduced wall thickness. The outer diameter of the toothed ring 10 is the same in the distal end section and in the proximal end section (overlapping region 31).

[0054] The engine adapter 2 or housing cover 20 also has a proximal section and a distal section. In the proximal section, the engine adapter 2 has an outer diameter corresponding to the outer diameter of the gear ring 10. In the distal section corresponding to the overlapping region 31, the engine adapter has an outer diameter substantially corresponding to the inner diameter of the gear ring 10 in the proximal section. In this regard, cylindrical mating surfaces 11, 21 are constructed between the engine adapter 2 or housing cover 20 and the gear ring 10. The engine adapter 2 or housing cover 20 moves into the gear ring 10, so that the mating surfaces 11, 21 overlap and form the overlapping region 31.

[0055] Through the overlapping area, the gear ring 10 and the engine adapter 2 or housing cover 20 are interlocked by means of a rotating friction welding material. Specifically, a rotating friction welding device is guided around the outer periphery of the overlapping area 31, thereby heating the material of the mating surfaces 11, 21. Heating is performed in a manner exceeding the melting point of the material used for the gear ring 10 or housing cover 20, thereby forming a material-locked connection between the gear ring 10 and the housing cover 20 in the area of ​​heat input.

[0056] according to Figure 6 and 7 Implementation examples and according to Figure 4 and 5 The difference in the embodiments is that, according to Figure 4 and 5 In one embodiment, the proximal end section of the engine adapter 2 is connected to the distal end section of the engine adapter 2 via an annular surface extending perpendicular to the longitudinal axis of the gear ring.

[0057] The threshold, relatively speaking, is based on Figure 6 and 7 In this embodiment, an inclined annular surface is provided, which is substantially tapered relative to the longitudinal axis of the gear ring 10. This creates an annular groove 30 between the proximal end section of the engine adapter 2 and the proximal end section of the gear ring 10 or the overlapping region 31. The annular groove 30 has a cross-sectional shape substantially corresponding to a right triangle. The annular groove 30 allows for the containment of material flowing from the gear ring 10 during rotary friction welding. Therefore, it is ensured that the outer diameter of the transmission housing 10 remains unchanged relative to its unwelded state after the welding process.

[0058] According to Figure 4-7 In all embodiments, especially Figure 4 and 6As can be clearly seen, the annular surface between the proximal and distal regions of the engine adapter 2 and the complementary annular surface of the gear ring 10 extend on different planes. In other words, the annular surfaces are not arranged in a continuous row along the entire periphery of the gear ring 10 or the engine adapter 20, but are locally offset along the axial direction of the gear ring 10. This enables the rotational orientation of the engine adapter 2 relative to the gear ring 10, thus simultaneously achieving anti-torsion.

[0059] List of reference numerals

[0060] 1 Transmission housing 2 Engine adapter 5 engine 10 Gear ring 11 splicing surface of gear ring 12 Recesses on the ring gear 13 Internal teeth 20 housing cover 21 The splicing surface of the shell cover 22 Recess on the housing cover 30 Annular groove 31 Overlapping areas 40 Welded raised part

Claims

1. A method for manufacturing a transmission housing, the method comprising the following steps performed sequentially in time: - Provides a toothed ring (10) with at least segmented internal teeth and a housing cover (20), wherein, The toothed ring (10) and the housing cover (20) each have at least one splicing surface (11, 21) on one end side. - The splicing surfaces (11, 21) are heated by heating elements or infrared radiators, thereby melting the toothed ring (10) and the housing cover (20) segmentally at their ends; and - The toothed ring (10) and the housing cover (20) are coaxially spliced ​​to form a material-locking connection between the splicing surfaces (11, 21).

2. The method according to claim 1, Its features are, The splicing surfaces (11, 21) are pressed against each other under pressure during coaxial splicing until the splicing surfaces (11, 21) cool down and the materials are locked together in a fixed manner.

3. The method according to claim 1 or 2, Its features are, The splicing surfaces (11, 21) are heated to exceed the respective melting points of the plastics used to form the toothed ring (10) and / or the housing cover (20).

4. The method according to any one of claims 1 to 3, Its features are, The splicing surfaces (11, 21) are heated for a predetermined duration, wherein the duration is pre-selected based on the type and effect of the radiating element used to heat the splicing surfaces (11, 21).

5. The method according to any one of claims 1 to 4, Its features are, The gear ring (10) and the housing cover (20) are placed into the splicing device and are loaded with splicing force by two pneumatic cylinders and / or servo motor shafts, wherein the splicing force is pre-adjusted according to the size of the splicing surfaces (11, 21).

6. The method according to any one of claims 1 to 5, Its features are, The toothed ring (10) and the housing cover (20) are cooled over a predetermined time period while maintaining the splicing force after being spliced, wherein the predetermined time period depends on the materials and structural dimensions used.

7. The method according to any one of claims 1 to 6, Its features are, The splicing surfaces (11, 21) on the end sides are oriented perpendicular to the rotation axis of the gear ring (10).

8. In particular, a transmission housing for a planetary gear transmission, the transmission housing having a gear ring (10) having internal teeth in at least a portion and a housing cover (20) for covering the gear ring in the longitudinal direction, wherein, The gear ring (10) and the housing cover (20) are coaxially fitted together to form an annular overlapping area (31), in which the splicing surfaces (11, 21) of the gear ring (10) and the housing cover (20) are in contact with each other. Its features are, The gear ring (10) and the housing cover (20) have conical splicing surfaces (11, 21) in the overlapping area (31), and are connected to each other in a material-locking manner along the splicing surfaces (11, 21), especially by rotational friction welding.

9. The transmission housing according to claim 8, Its features are, The splicing surfaces (11, 21) of the toothed ring (10) and the housing cover (20) are adjacent to the end-side open recesses (12, 22) that surround the outer periphery, wherein the recesses (12, 22) together form an annular groove (30) that accommodates the welded protrusion (40).

10. A method for manufacturing a transmission housing, particularly according to claim 8, the method comprising the following steps performed sequentially in time: - Provides a toothed ring (10) with at least segmented internal teeth and a housing cover (20), wherein, The toothed ring (10) and the housing cover (20) have complementary conical splicing surfaces (11, 21). - The gear ring (10) and the housing cover (20) are coaxially spliced ​​to establish surface contact between the tapered splicing surfaces (11, 21), wherein an overlapping area (31) is formed; and - In particular, the overlapping area (31) is heated by rotary friction welding, so that the gear ring (10) and the housing cover (20) are material-locked together in the overlapping area (31).

11. The method according to claim 10, Its features are, When establishing surface contact, an extrusion connection is formed between the splicing surfaces (11, 21) of the toothed ring (10) and the housing cover (20).

12. The method according to any one of the preceding claims, Its features are, The housing cover (20) is formed by an engine bearing cover or by an adapter element, which is configured to connect the transmission housing and the engine.

13. The method according to claim 12, Its features are, The adapter element is welded to or can be welded to the gear ring (10) on the transmission side, and has a universal connector on the engine side for connection to different engines, especially electric motors.

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