Ring gear with spacer, device with surrounding housing

Abstract

A ring gear (2) with a spacer (3) is proposed, wherein the ring gear (2) is designed with an internal toothing (7) for torque transmission in a gearbox and the spacer (3) distances the ring gear (2) from a contact surface (4) of a further component (5), wherein the spacer (3) is a component separate from the ring gear (2) and is positively connected to the ring gear (2) and bears against an end face contact surface (6) of the ring gear (2), wherein the end face contact surface (6) is arranged radially outside the internal toothing (7) of the ring gear (2) and the spacer (3) has at least one locking lug (8) for positive locking connection (14) with the ring gear (2).

Description

[0001] The invention relates to a ring gear of a transmission with a spacer to the housing, in order to maintain the ring gear at a distance in the axial direction from a contact surface of the housing. The spacer contacts both the ring gear or an end face of the ring gear and the contact surface of the housing, which is also designed as an end face. The spacer is connected to the ring gear as a separate component via a captive connection.

[0002] US 2022 / 0 275 857 A1 shows a ring gear for torque transmission with a one-piece molded flange, via which the ring gear can be attached to another component.

[0003] DE 10 2014 202 494 A1 discloses a planetary gearbox, in particular for wind turbines, comprising at least one gearbox stage with two parallel connected and power-splitting planetary stages, wherein at least one of the two planetary stages comprises a ring gear operatively connected to a housing, on the inner circumferential surface of which at least three planet gears are arranged.

[0004] DE 10 2017 130 657 A1 shows a gearbox arrangement for a vehicle and a use of an elastic ring in a gearbox arrangement for a vehicle.

[0005] DE 10 2023 104 475 A1 discloses a ring gear carrier for a transmission of a vehicle electric drive. Furthermore, an assembly for a transmission of a vehicle electric drive, comprising a housing, a ring gear and such a ring gear carrier, is shown.

[0006] The JP S61 - 211 560 A shows a gearbox with a ring gear.

[0007] The task is to improve the well-known ring gear.

[0008] The problem is solved according to the invention by a ring gear with a spacer, wherein the ring gear with its internal teeth is designed for torque transmission in a gearbox and the spacer distances the ring gear from a contact surface of a further component, in that the spacer as a component separate from the ring gear is positively connected to the ring gear and rests on an end face contact surface of the ring gear, wherein the end face contact surface is arranged radially outside the internal teeth of the ring gear.

[0009] The spacer component is positively and preferably captive connected to the ring gear component. The positive connection is preferably a detachable snap-fit ​​connection. This allows the spacer to be clipped onto the ring gear and ensures it remains firmly connected to the gear during assembly. Once assembled, the spacer positions the ring gear away from a stop surface, thus ensuring correct positioning within the gearbox.

[0010] The positive locking connection preferably creates a rotationally fixed connection between the ring gear and the spacer. Alternatively, rotation between the ring gear and the spacer can also be provided, but while maintaining the positive locking in the axial direction.

[0011] It is advantageous if the spacer is designed as a single, ring-shaped component. This allows for a circumferential spacer between the ring gear and a contact surface, formed by another component. Ideally, with ring-shaped bodies, three contact surfaces evenly distributed around the circumference result in a wobble-free and thus clearly defined overall contact. These three contact surfaces can be axially offset from the individual spacer. Alternatively, three spacers can be positively connected to the ring gear, with these being equally evenly distributed around the circumference of the ring gear – however, this method requires more effort for assembly and component provision.

[0012] The end face of the ring gear, against which the spacer comes into contact after the positive-locking connection is complete, is arranged radially outside the internal teeth of the ring gear. The ring gear, as part of a transmission, has internal teeth that can mesh with other gears. Thus, the ring gear is a ring-shaped component. Radially outside the internal teeth, the ring gear has a circumferential annular collar, which has at least one end face contact surface on an axial side of the ring gear. Due to the annular collar being set off from the internal teeth, the contact surface can be positioned within the axial extent of the internal teeth. In other words, the extent of the internal teeth extends beyond the position of the contact surface for the spacer. Advantageous embodiments of the invention are the subject of the dependent claims and are explained in more detail below.

[0013] According to the invention, the spacer has at least one locking lug for a positive-locking connection with the ring gear. The at least one locking lug secures the positive-locking connection in at least one axial direction, meaning it locks at least one degree of freedom in the axial direction of the components relative to each other. In the case of an annular spacer, several locking lugs distributed regularly or irregularly around the circumference can be formed integrally by the spacer. The locking lug can engage in a groove formed by the ring gear complementary to the engagement contour of the locking lug and secure both components relative to each other. Thus, several locking lugs can engage in a common groove, several locking lugs can engage in their own separate grooves, or only one locking lug can engage in only one groove.

[0014] Advantageously, the spacer is made of plastic. This plastic is suitable for use in a gearbox and for the surrounding environment and contact with gear oil. At the same time, the plastic must possess the necessary dimensional stability so that the spacing provided by the spacer is not altered by gear oil and / or temperature during gearbox operation, thus ensuring that the spacing remains reliably consistent. Only then is the correct positioning of the internal teeth relative to the meshing gears guaranteed with high precision. As a result, the axial engagement lengths of the teeth can be reduced, which ensures a constant contact length during operation. This means that the overall length of the components containing the teeth can be reduced due to the lower variance in engagement lengths during operation. Excess lengths required to ensure the engagement lengths can be significantly reduced.

[0015] Furthermore, the ring gear has at least one groove for positive locking with the spacer. The groove can be formed in the ring gear, preferably as a circular arc in cross-section, with the opening of the groove oriented radially inwards or outwards.

[0016] Alternatively, for the engagement with the locking nose, it is also possible to form a radially inward or outward directed step in the form of a radial step instead of a typical groove shape, whereby the formation of such a step is reminiscent of an undercut.

[0017] In one embodiment of the invention, the radial positioning of the positive-locking connection is arranged in the axial direction within the axial extent of the internal teeth of the ring gear. Advantageously, this achieves a wide tooth profile and simultaneously saves weight.

[0018] Another embodiment provides that the ring gear has external teeth whose axial extent lies within that of the internal teeth. This external toothing allows the ring gear to be joined, for example, to a complementary internal toothing of a housing, thus ensuring the ring gear is fixed within the gearbox. Alternatively, a parking pawl can engage with such external teeth to block the rotation of the ring gear, or another gear can engage with it, either driving or being driven by the ring gear.

[0019] In an advantageous embodiment, the end-face contact surface is positioned radially between the external and internal teeth. This advantageously allows for a wider tooth profile while simultaneously reducing weight, and the spacer is isolated from the influence of the internal teeth. The internal teeth do not need to have the engagement contour required for a positive-locking connection with the spacer.

[0020] In a preferred embodiment, the end-face contact surface is arranged axially within the axial extent of the internal teeth of the ring gear. Thus, the end-face contact surface does not project beyond the length of the teeth. This distance can therefore be accommodated by the axial extent of the spacer.

[0021] Another embodiment provides that the contact surface of the additional component is arranged axially within the axial extent of the internal teeth of the ring gear. Thus, as an alternative to the previously mentioned embodiment, the material of the additional component can be designed to extend axially to such an extent that the spacer requires as little installation space as possible in its axial dimension.

[0022] In one embodiment of the invention, the additional component is a housing surrounding the gearbox. Once the ring gear and the spacer have been joined, the ring gear is ready for insertion into the gearbox. The gearbox is located within a housing and utilizes a ring gear, stationary relative to the housing, with its internal teeth for meshing with other gearbox components (gears). Therefore, it is advantageous if the housing provides the contact surface for the additional component, against which the spacer rests, thus reliably positioning the ring gear within the gearbox relative to the other gears. Character description

[0023] Further embodiments of the invention are explained in more detail with reference to the figures. These show: Fig. 1 a ring gear according to the invention with a spacer, Fig. 2 the spacer according to the invention made of Fig. 1 and Fig. 3 the installation situation of the ring gear according to the invention Fig. 1.

[0024] The Fig. Figure 1 shows a ring gear 2 according to the invention with a spacer 3. The two components 2 and 3 thus form an assembly 1 as a device after being joined together, which can be inserted into a housing 13 (not shown here). This is illustrated in the Fig. 3 explained further.

[0025] The ring gear 2 has an external toothing 10 on an outer cylindrical surface, which engages with a complementary internal toothing 15 of a housing 13. The ring gear 2 has a "double-T" cross-section. Furthermore, the ring gear 2 has an internal toothing 7 as a running tooth for engaging a planet gear, so that the planet gear can roll in the internal toothing 7. The internal toothing 7 has an axial extension 12, which extends from one end face of the internal toothing 7 to the axially opposite end face of the internal toothing 7. The external toothing 10 also has an axial extension 11, which extends from one end face of the external toothing 10 to the axially opposite end face of the external toothing 10. Offset from these two end faces of the external toothing 10, the end-face contact surface 6 of the ring gear 2 is formed on an axial side, against which the spacer 3 comes to rest.The end-face contact surface 6 is ideally flat all around and has no further steps. Alternatively, this end-face contact surface 6 can be stepped in the circumferential direction; however, at least three partial end-face contact surfaces should be provided for contact with the spacer 3 so that the spacer 3 cannot wobble relative to the ring gear 2.

[0026] In this embodiment, the positive locking connection 14 is achieved by a fully circumferential groove 9 formed by the ring gear 2, into which at least one locking lug 8 of the spacer 3 engages. The at least one locking lug 8 engages in the groove 9 and secures the spacer 3 to the ring gear 2 in the radial and axial directions. No positive locking element is provided in the circumferential direction. The end-face contact surface 6 is provided to determine the axial position between the ring gear 2 and the spacer 3. If the at least one locking lug 8 has a specific arc length in the circumferential direction, the locking is achieved in the radial direction.

[0027] The Fig. Figure 2 shows the spacer 3 according to the invention. Fig. 1. A more detailed illustration of the at least one locking lug 8 reveals that there are multiple locking lugs 8, which are arranged regularly distributed around the circumference. In this embodiment, 18 locking lugs 8 are uniformly spaced from one another around the circumference and are formed integrally with the spacer 3. All locking lugs 8 have the same geometric shape. It is thus clear that this arrangement of the locking lugs 8 enables the spacer 3 to be centered on the ring gear 2.

[0028] The Fig. Figure 3 shows the installation situation of the ring gear 2 according to the invention. Fig. 1.

[0029] The two interlocking gear teeth 10 and 15 prevent the ring gear 2 from rotating, instead locking it securely within the housing 13. The housing 13 also features a contact surface 4 designed for the spacer 3. The positioning of the contact surfaces 4 and 6 within the axial extension 12 of the internal gear teeth 7 is clearly visible. This allows the engagement length between the internal gear teeth 7 and a planet gear to be designed independently of the shape of the spacer 3 and its contact surfaces 4 and 6. This nesting arrangement saves installation space and allows components 2 and 3 to be arranged very compactly within the housing 13. The axial extension of the spacer 3 makes it possible to install identical ring gears 2 in different housings 13.By means of the radial positioning of the contact surface 6 shown here, radially inside and thus away from the external toothing 10 as well as radially outside and thus away from the internal toothing 7, the spacer 3 can be “hidden” radially between the toothings, which means that this assembly 1 can be represented in a very compact form. Reference symbol list 1 assembly 2. Ring gear 3 spacers 4 Mounting surface (additional component) 5. Another component 6. End face contact surface (ring gear) 7 Internal teeth (ring gear) 8 locking tab 9 Nut 10 External teeth (ring gear) 11 Axial expansion (external teeth of the ring gear) 12 Axial extension (internal gearing) 13 cases 14 Form-fit connection 15 Internal teeth (housing)

Claims

[1] Ring gear (2) with spacer (3) wherein the ring gear (2) is designed with an internal toothing (7) for torque transmission in a gearbox and the spacer (3) spaces the ring gear (2) apart from a contact surface (4) of a further component (5), wherein the spacer (3) is positively connected to the ring gear (2) as a component separate from the ring gear (2) and bears against an end face contact surface (6) of the ring gear (2), wherein the end face contact surface (6) is arranged radially outside the internal toothing (7) of the ring gear (2). characterized by that the spacer (3) has at least one locking lug (8) for positive locking connection (14) with the ring gear (2). [2] Ring gear (2) with spacer (3) according to claim 1, characterized by , that the spacer (3) is made of plastic. [3] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by, that the ring gear (2) has at least one groove (9) for positive locking connection (14) with the spacer (3). [4] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the radial positioning of the positive locking connection (14) is arranged in the axial direction within the axial extension (12) of the internal teeth (7) of the ring gear (2). [5] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the ring gear (2) has an external toothing (10) which in its axial extent (11) is within the axial extent (12) of the internal toothing (7). [6] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the end face contact surface (6) is placed radially between the external toothing (10) and the internal toothing (7). [7] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the end face contact surface (6) is arranged in the axial direction within the axial extent (12) of the internal teeth (7) of the ring gear (2). [8] Ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the contact surface (4) of the further component (5) is arranged in the axial direction within the axial extent (12) of the internal toothing (7) of the ring gear (2). [9] Device with a ring gear (2) with spacer (3) according to one of the preceding claims, characterized by , that the further component (5) is a housing (13) surrounding the gearbox.

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