Gearbox with a D-shaped housing cover, gearbox series with such gearboxes and method for manufacturing such a gearbox series

Abstract

Gearbox (101) with at least one planetary stage (103) and at least one spur gear stage (105); wherein a shaft (109) of the planetary stage (103) and a first shaft (111) of the spur gear stage (105) are connected to one another in a rotationally fixed manner; wherein a housing (121a, 121b) of the spur gear stage (105) forms at least one bearing seat for a second shaft (117) of the spur gear stage; wherein the gear (101) has a housing bell (119) with which a housing of the planetary stage (103) and the housing (121a, 121b) of the spur gear stage (105) are fixed to one another; wherein the housing bell (119) encapsulates the bearing seat in a fluid-tight manner; wherein the housing (121a, 121b) of the spur gear stage (105) has a first parting line which runs between a first housing part (121a) and a second housing part (121b); wherein the first shaft (111) is rotatably mounted in the first housing part (121a); ​​wherein the first housing part (121a) forms a first part of the bearing seat for the second shaft (117); wherein the second housing part (121b) forms a second part of the bearing seat; a first part of a second, flat parting line runs between the first housing part (121a) and the housing bell (119); wherein a second part of the second parting line runs between the second housing part (121b) and the housing bell (119); and wherein the housing bell (119) forms a surface along the second parting line with a circular part (303) and a protuberance (305) radially outwards; wherein the protuberance (305) covers at least part of the bearing seat; characterized in that the housing bell (119) is designed in at least two pieces; a first piece having the annular part (303) and a second piece having the protuberance (305).

Description

[0001] The invention relates to a transmission according to the preamble of claim 1, a transmission series according to claim 6 and a method according to claim 7.

[0002] Wind turbine gearboxes typically have a spur gear stage on the output side, which is connected downstream of a planetary stage. The following section focuses on the housing coupling between the two gearbox stages. The housing coupling secures a spur gear stage housing to a planetary stage housing. The housing coupling must be adapted to the geometric conditions of the spur gear stage and the planetary stage. This makes it difficult to reuse components across gearboxes. For example, a changed axis position of an output shaft requires a specially adapted housing coupling.

[0003] JP 2007-146 666 A discloses a transmission with a planetary gear stage and a downstream spur gear stage. The housing of the spur gear stage is constructed in several parts.

[0004] The invention is based on the object of providing a transmission that does not have the disadvantages inherent in the prior art solutions. In particular, the degree of component reusability across transmissions is to be increased.

[0005] This object is achieved by a transmission according to claim 1, a transmission series according to claim 6 and a method according to claim 7. Preferred developments are contained in the subclaims.

[0006] The transmission comprises at least one planetary stage and at least one spur gear stage. A planetary stage is a gear stage, i.e. a section of a transmission which in turn forms a transmission, with a ring gear, a planet carrier, one or more planet gears and a sun gear. The planet gears are rotatably mounted in the planet carrier and each mesh with the ring gear and / or the sun gear. Two of the three components, ring gear, planet carrier and sun gear, are rotatably mounted, while the third component is arranged in a rotationally fixed manner. For example, the ring gear can be integrated in a transmission housing in a rotationally fixed manner, while the planet carrier and the sun gear are rotatably mounted. One of the two rotatably mounted components is rotationally fixedly connected to an input, such as an input shaft of the planetary stage, and the other rotatably mounted component is connected to an output, such as an output shaft.The input and output of the planetary stage are arranged coaxially to each other, i.e. they have a common axis of rotation.

[0007] A spur gear stage is a gear stage with gears that are exclusively designed as spur gears and mounted for rotation. In particular, all gears in the spur gear stage can have external teeth. The axes of rotation of the gears are fixed and run parallel to each other. An output shaft of the spur gear stage is usually arranged offset from an input shaft.

[0008] In this case, a shaft of the planetary stage and a first shaft of the spur gear stage are connected to one another in a rotationally fixed manner. The shaft of the planetary stage is preferably an output shaft of the planetary stage. Accordingly, the first shaft of the spur gear stage is preferably an input shaft of the spur gear stage. A rotationally fixed connection refers to a connection that does not allow any rotation of the connecting partners relative to one another. In particular, the shaft of the planetary stage and the first shaft of the spur gear stage can be connected to one another in one piece.

[0009] A housing of the spur gear stage forms a first bearing seat for a second shaft of the spur gear stage. The second shaft is different from the first shaft. In particular, both shafts have an axial offset relative to each other.

[0010] A bearing seat is a means for receiving and securing a bearing. In this case, a bearing is received and secured, with which the second shaft is rotatably mounted in the housing. The first bearing seat is preferably designed as a through-bore, i.e., a circular cylindrical, continuous recess with two openings. Such a bearing seat serves to receive and secure an outer ring of the bearing with which the second shaft is mounted in the housing.

[0011] The gearbox features a bell housing as a housing coupling between the planetary stage and the spur gear stage. The bell housing secures the planetary stage housing and the spur gear stage housing to each other. The bell housing is therefore a connecting piece between the planetary stage housing and the spur gear stage housing. In particular, the bell housing can have the basic shape of a hollow body with a first opening and a second opening. The planetary stage housing is secured to the first opening. Similarly, the spur gear stage housing is secured to the second opening.

[0012] The housing bell preferably has the basic shape of a hollow solid of revolution. The basic shape of a solid refers to the shape of an original solid from which the former is created by eliminating individual areas, for example by inserting recesses, and / or by adding individual areas.

[0013] The first bearing seat is encapsulated in a fluid-tight manner by the bell housing. The bell housing covers the first bearing seat in such a way that no fluid, especially no oil contained in the transmission, can escape into the environment. This implies that the first bearing seat opens into the bell housing.

[0014] The invention eliminates the need for a separate cover for the first bearing seat. Such a cover would require modification of the housing bell, which would be detrimental to the intended reusability.

[0015] In a preferred embodiment, a fluid-tight connection exists between the housing bell and the housing of the spur gear stage, on the one hand, and between the housing bell and the housing of the planetary gear stage, on the other hand. Preferably, the housing of the planetary gear stage, the housing bell, and the housing of the spur gear stage form a common cavity containing gear oil, which is fluid-tightly encapsulated from the environment by the housing of the planetary gear stage, the housing bell, and the housing of the spur gear stage.

[0016] In a further preferred embodiment, the second shaft of the spur gear stage is an input or output shaft. This implies that a second shaft end, opposite the first shaft end, protrudes from the housing of the spur gear stage. The second shaft end is located on a side of the housing opposite the first bearing seat. Conversely, the housing bell is arranged on a side of the housing opposite the second shaft end.

[0017] The housing of the spur gear stage is constructed in two pieces. A first, preferably fluid-tight, parting line runs between a first housing part of the spur gear stage housing and a second housing part of the spur gear stage housing. The first shaft is rotatably mounted in the first housing part. The first housing part is therefore used exclusively to support the first shaft. This means that the bearings with which the first shaft is rotatably mounted are fixed exclusively in the first housing part. The first bearing seat, on the other hand, is formed jointly by the first housing part and the second housing part. The first housing part thus forms a first part of the first bearing seat and the second housing part a second part of the first bearing seat. The first parting line runs through the bearing seat.

[0018] The above statements regarding the first bearing seat and the two-piece design of the housing of the spur gear stage preferably apply analogously to a second bearing seat of the second shaft of the spur gear stage. Thus, the second bearing seat serves to accommodate and secure another bearing, with which the second shaft is rotatably mounted in the housing of the spur gear stage. The first housing part of the housing of the second spur gear stage forms a first part of the second bearing seat. A second part of the second bearing seat is formed by the second housing part of the housing of the spur gear stage. The first parting line also runs through the second bearing seat.

[0019] The first housing section of the spur gear stage housing forms a base body, while the second housing section forms a removable cover. Since the base body and the cover together form the bearing seats of the second shaft, the second shaft can be removed for maintenance purposes once the cover has been removed. This allows for maintenance or replacement of the second shaft while the gearbox is installed in the tower of a wind turbine.

[0020] Preferably, the transmission is further developed such that the parting line and a rotational axis of the second shaft lie in a common plane. This plane includes the parting line and the rotational axis.

[0021] A second parting line runs between the housing of the spur gear stage and the housing bell. The second parting line extends over both the first housing part of the spur gear stage housing and the second housing part of the spur gear stage housing. This means that a first part of the second parting line runs between the first housing part and the housing bell; a second part of the second parting line runs between the second housing part and the housing bell. The first housing part and the housing bell form the first part of the parting line, while the second housing part and the housing bell form the second part of the parting line. The second parting line is preferably also fluid-tight.

[0022] The second parting line is flat, i.e. it runs in one plane or is contained in the plane.

[0023] Part of the housing bell's surface is circular and forms a radially outwardly directed protrusion. This part of the housing bell's surface forms the second joint with the spur gear stage housing. The protrusion covers at least part of the bearing seat.

[0024] Preferably, the protrusion is further developed in a D-shape. This means that the protrusion has the shape of a circular segment. In particular, the protrusion can be semicircular.

[0025] Since the protrusion at least partially covers the bearing seat, the position of the protrusion also changes with the position of the bearing seat. To increase the degree of reusability of individual parts across transmissions when the position of the second shaft varies depending on the specific application, the housing bell is designed in at least two pieces according to the invention. A first piece of the housing bell has the circular part of the surface, and a second piece has the protrusion. Using such a refinement, the transmission series described below can be created.

[0026] A transmission series is defined as a number of individual transmissions. These transmissions form the series, meaning the series is identical to the entire series.

[0027] The transmission series comprises a first transmission and a second transmission, each with a two-piece bell housing. The second piece of the bell housing of the first transmission and the second piece of the bell housing of the second transmission are identical in design. This makes it possible to use the second piece across all transmissions within the transmission series.

[0028] The first pieces of the housing bells of the first gear and the second gear each have a receptacle for securing the second piece. The positioning of the receptacle for securing the second piece of the housing bell of the first gear and the receptacle for securing the second piece of the housing bell of the second gear differ. Otherwise, the first piece of the housing bell of the first gear and the first piece of the housing bell of the second gear are preferably identical in construction.

[0029] The different position of the holder for securing the second piece of the housing bell allows adaptation to different positions of the second shaft. Due to the different position of the holder, a cross-gearbox use of the first piece of the housing bell is not possible. However, a method according to the invention enables a cross-gearbox use of a blank from which the first piece of the housing bell is manufactured. This method provides that the first piece of the housing bell of the first gearbox is manufactured from a first blank and the first piece of the housing bell of the second gearbox is manufactured from a second blank. The first blank and the second blank are identical in construction. As part of the production of the first piece of the respective housing bell from the blank, the holder for securing the second piece is manufactured. The position of the holder can be adapted to suit the specific gearbox.

[0030] Preferred embodiments of the invention are illustrated in the figures. Corresponding reference numerals indicate identical or functionally equivalent features. In detail: Fig. 1 a gearbox; Fig. 2 a housing of the spur gear stage of the gearbox; Fig. 3 a one-piece flange of a housing bell; Fig. 4 a two-piece flange; and Fig. 5A and B variants manufactured from a blank.

[0031] In Fig. 1 shows a gearbox 101 in longitudinal section. The gearbox 101 has a planetary stage 103 and a spur gear stage 105. The planetary stage 103 can, as shown in Fig. 1, one or more additional planetary stages may be connected upstream.

[0032] A sun gear 107 of the planetary stage 103 is rotationally fixedly connected to a sun shaft 109, which functions as the output shaft of the planetary stage 103 and is rotationally fixedly connected to a hollow shaft 111 of the spur gear stage 105 via a spline. A first spur gear 113 is arranged on the hollow shaft 111 and rotationally fixedly connected thereto. This first spur gear meshes with a second spur gear 115. The second spur gear 115 is arranged on an output shaft 117 of the transmission and rotationally fixedly connected thereto.

[0033] To securely couple the planetary stage 103 and the spur gear stage 105 to each other, a housing bell 119 is provided. This is integrated in one piece into a rotor-side part of a housing of the planetary stage 103 or the gearbox 101. The housing bell 119 forms a flange to which a housing 121a, 121b of the spur gear stage 105 is screwed. This housing is formed by a base body 121a and a cover 121b. The cover 121b is screwed onto the base body 121a.

[0034] A view of the housing 121a, 121b from the direction of a rotor towards a generator, that is to say in the image plane of Fig. 1 viewed from left to right is in Fig. 2. Here, it can be seen that the base body 121a and the cover 121b together form a bearing seat for a rotor-side bearing of the output shaft 117. The base body 121a and the cover 121b are connected to each other along a flat separating surface.

[0035] The flange of the bell housing is in Fig. 3 with the reference number 301. Shown here is a plan view of the flange 301 in the axial direction from the generator towards the rotor, i.e. in the image plane of Fig. 1 viewed from right to left. The flange 301 has a circular portion 303 and a crescent-shaped or D-shaped portion 305.

[0036] The circular part 303 is aligned coaxially with a rotational axis of the sun shaft 109. An axis of symmetry of the circular part 303 is thus identical to the rotational axis.

[0037] The D-shaped part 305 is designed as a protuberance radially outwards and covers a rotor-side, i.e. the part in the image plane of Fig. 1, the bearing seat of the output shaft 117, arranged on the left, forms a fluid-tight seal. For this purpose, there is a fluid-tight connection between the D-shaped part 305 and the cover 121b of the housing 121a, 121b of the spur gear stage 105. Furthermore, there is a fluid-tight connection between the annular part 303 of the flange 301 and the base body 121a of the housing 121a, 121b of the gear stage 105. A fluid-tight connection surface between the flange 301 and the housing 121a, 121b extends completely around the axis of rotation of the sun shaft 109 and is self-contained.

[0038] Fig. 4 shows a flange 301 of a two-piece housing bell 119. A first piece of the housing bell 119 forms the circular part 303, a second piece the D-shaped part 305. Between the two pieces runs a flat separating surface which is aligned parallel to the axis of rotation of the sun shaft 109.

[0039] The angular position of the first part of the housing flange 109 is determined by the interface to the planetary stage 103 and is therefore not variable. A solution to reuse the first part 103 across the entire transmission is described in the Fig. 5a and Fig. 5b indicated. Fig. Figure 5a shows a first part of the housing flange 119 with the annular part 101 of the flange 301, in which the parting plane between the first part and the second part runs horizontally. This corresponds to the Fig. 4. To manufacture such a part, the shape of the parting surface is machined from a rotationally symmetrical blank. The shape of the parting surface is therefore variable. This makes it possible to adjust the angular position of the parting surface, as shown in Fig.5b. This also allows the position of the second piece of the housing bell 119, and thus the position of the D-shaped part 305 of the flange 301, to be varied and adapted to a changed position of the output shaft 117. Reference symbol 101 Gearboxes 103 planetary stage 105 Spur gear stage 107 Sun gear 109 Sun Wave 111 Hollow shaft 113 first spur gear 115 second spur gear 117 Output shaft 119 Case bell 121a base body 121b lid 301 flange 303 circular part 305 D-shaped part

Claims

[1] Gearbox (101) with at least one planetary stage (103) and at least one spur gear stage (105); wherein a shaft (109) of the planetary stage (103) and a first shaft (111) of the spur gear stage (105) are connected to one another in a rotationally fixed manner; wherein a housing (121a, 121b) of the spur gear stage (105) forms at least one bearing seat for a second shaft (117) of the spur gear stage; wherein the gear (101) has a housing bell (119) with which a housing of the planetary stage (103) and the housing (121a, 121b) of the spur gear stage (105) are fixed to one another; wherein the housing bell (119) encapsulates the bearing seat in a fluid-tight manner; wherein the housing (121a, 121b) of the spur gear stage (105) has a first parting line which runs between a first housing part (121a) and a second housing part (121b); wherein the first shaft (111) is rotatably mounted in the first housing part (121a); ​​wherein the first housing part (121a) forms a first part of the bearing seat for the second shaft (117); wherein the second housing part (121b) forms a second part of the bearing seat; a first part of a second, flat parting line runs between the first housing part (121a) and the housing bell (119); wherein a second part of the second parting line runs between the second housing part (121b) and the housing bell (119); and wherein the housing bell (119) forms a surface along the second parting line with a circular part (303) and a protuberance (305) radially outwards; wherein the protrusion (305) covers at least part of the bearing seat; characterized by , that the housing bell (119) is designed in at least two pieces; a first piece having the annular part (303) and a second piece having the protuberance (305). [2] Transmission (101) according to claim 1; characterized by that the housing bell (119) is fluid-tightly connected to the housing (121a, 121b) of the spur gear stage (105) and to the housing of the planetary stage (103). [3] Transmission (101) according to one of the preceding claims; characterized by that the second shaft (117) is an input or output shaft. [4] Transmission (101) according to one of the preceding claims; characterized by that the parting line and an axis of rotation of the second shaft (117) lie in a common plane. [5] Transmission (101) according to one of the preceding claims; characterized by that the protrusion (305) has the shape of a circular segment. [6] Transmission series with a first transmission (101) according to one of the preceding claims and a second transmission (101) according to one of the preceding claims; characterized by , that the second piece of the housing bell (119) of the first gear (101) and the second piece of the housing bell (119) of the second gear (101) are of identical construction; wherein the first piece of the housing bell (119) of the first gear (101) and the first piece of the housing bell (119) of the second gear (101) differ with regard to the positioning of a receptacle for fixing the second piece of the housing bell (109). [7] Method for manufacturing a transmission series according to the preceding claim; characterized by , that the first piece of the housing bell (119) of the first gear (101) is made from a first blank and the first piece of the housing bell (119) of the second gear (101) is made from a second blank; wherein the first blank and the second blank are identical in construction.

Images