Crown gear transmission

Description

[0001] The invention relates to a crown gear transmission according to the preamble of patent claim 1.

[0002] A crown gear transmission consists of a pinion and a crown gear. The pinion can move freely in the axial direction of the pinion via the crown gear teeth without affecting the backlash. The meshing between the pinion and the crown gear must be designed so that the pinion and the crown gear mesh optimally. A defined, optimal backlash between the teeth of the pinion and the crown gear must be ensured, as required for smooth operation. Due to unavoidable variations during production, there is no constant backlash between the flanks of the teeth. A certain amount of backlash is necessary to prevent the teeth from jamming. In principle, a distinction is made between normal backlash, radial backlash, and circumferential backlash.

[0003] Crown gears can be an integral component of crank drives for oscillating positive displacement pumps. The crown gear shaft can either be designed as an eccentric shaft or connected to an eccentric. The rotary motion is converted into an oscillating motion via a connecting rod meshing with the eccentric.

[0004] For crown gear drives, depending on manufacturing tolerances, it is particularly necessary to adjust the so-called circumferential backlash in the meshing between the pinion and the crown gear. The circumferential backlash is the play relative to the pitch circle. The circumferential backlash is the length of the pitch circle arc around which the pinion and the crown gear can rotate relative to each other. The circumferential backlash is influenced by the thickness, spacing, and shape of the individual teeth on the pinion and crown gear, as well as the relative distance between the pinion and the crown gear.

[0005] Fig. 1 shows a crown gear transmission 1 according to the prior art. The crown gear transmission 1 has a housing 2, a pinion shaft 3 mounted rotatably relative to the housing 2, a pinion 4 connected to the pinion shaft 3, a crown gear shaft 5 mounted rotatably relative to the housing 2, and a crown gear 6 connected to the crown gear shaft 5. The pinion 4 and the crown gear 6 are in meshing engagement 7 with each other. The pinion shaft 3 and the pinion 4 are mounted rotatably but stationary relative to the housing 2. Likewise, the crown gear shaft 5 is mounted rotatably but stationary relative to the housing 2. To adjust the backlash between the crown gear 6 and the pinion 4, only the crown gear 6 is displaced in the direction of the crown gear shaft axis 8. The possible displacement is shown by the arrows 9.The adjustment of the circumferential backlash requires a high level of assembly effort if shims are used for the adjustment between the crown gear shaft 5 and the crown gear 6. Furthermore, the realization of a shaft-hub connection between the crown gear 6 and the crown gear shaft 5 that can be displaced axially in the direction of the crown gear shaft axis 8 requires a high level of design effort.

[0006] Fig. 2 shows another crown gear 1 according to the prior art. In the crown gear of the Fig. 2 The crown gear 6, the crown gear shaft 5, and the bearing 10 of the crown gear shaft 5 are displaced in order to adjust the backlash between the crown gear 6 and the pinion 4. This results in considerable design effort. It should be noted that the crown gear shaft 5 is displaced relative to the housing 2. This can be disadvantageous, since the connecting rod guide and / or, for example, sealing points must be designed for this displacement.

[0007] The publication WO 2013 / 067565 A1 relates to a transmission for a muscle-powered vehicle with an auxiliary motor, in particular a pedelec, having a housing mountable on the vehicle and mounted therein a first drive shaft for supplying muscle power, which acts on an approximately coaxial output shaft to drive the vehicle, and approximately at a right angle thereto a second drive shaft for connecting the auxiliary motor, which also acts on the output shaft via an angular gear, wherein the output shaft is a hollow shaft through which the first drive shaft passes and is coupled to it via a first freewheel. The second drive shaft has a pinion and the output shaft has a crown gear, which together form an angular gear in the form of a crown gear transmission. To adjust the play between the pinion and the crown gear, a uniaxial movement takes place, e.g. of the crown gear 21 in its axial direction.

[0008] The publication US 2020 / 0200251 A1 describes an actuator for a component of a land vehicle, comprising an actuator housing that defines an internal volume in which at least one electric motor and an internal mechanical transmission are arranged. The mechanical transmission has at least one first gearwheel having an axis of rotation, wherein the axis of rotation is perpendicular to the axis of rotation of the drive shaft of the actuated shaft. The first gearwheel has axial toothing formed from a toothing extending from bottom to top in the direction of the axis of rotation of the first gearwheel and meshing with the output pinion of the electric motor.

[0009] The invention is based on the object of providing an improved crown gear transmission.

[0010] This object is achieved by a crown gear transmission of the above-mentioned type having the features characterized in patent claim 1. Advantageous embodiments of the crown gear transmission according to the invention are the subject of the dependent patent claims and emerge from the following description of the invention.

[0011] Accordingly, a crown gear transmission according to the invention is provided. The crown gear transmission comprises a housing, a pinion shaft rotatably mounted relative to the housing, a pinion connected to the pinion shaft, a crown gear shaft rotatably mounted relative to the housing, and a crown gear connected to the crown gear shaft. The pinion and the crown gear mesh with one another. Furthermore, the crown gear and the crown gear shaft are arranged rotatably but stationary relative to the housing, and the pinion is displaceable relative to the crown gear in order to adjust a backlash between the crown gear and the pinion. The pinion shaft is rotatably mounted in a flange, and the flange is arranged displaceably relative to the housing. At least one longitudinal fit arranged parallel to the crown gear shaft axis is arranged between the housing and the flange in order to align the pinion shaft.

[0012] Because the pinion is movable relative to the crown gear, the backlash between the crown gear and the pinion can be adjusted despite the crown gear being stationary. The fixed crown gear relative to the housing has the advantage of simplifying the assembly of the crown gear and crown gear shaft. Furthermore, the structural design of the crown gear and crown gear shaft can be simple. Moving other elements such as connecting rods or sealing points is unnecessary and need not be considered in the design. Likewise, it is not necessary to move any bearings for the crown gear shaft.

[0013] The fact that the pinion shaft is rotatably mounted relative to the housing means that the pinion shaft can rotate about its pinion shaft axis, but is supported directly or indirectly by the housing. Specifically, the pinion shaft is supported by a bearing located between the pinion shaft and the housing. Because the pinion is connected to the pinion shaft, the pinion can also rotate relative to the housing about the pinion shaft axis.

[0014] The fact that the crown gear shaft is mounted relative to the housing means that the crown gear shaft can rotate about its axis, but is supported directly or indirectly by the housing. In particular, the crown gear shaft is supported by a bearing located between the crown gear shaft and the housing.

[0015] Because the crown gear is connected to the crown gear shaft, the crown gear can also rotate relative to the housing about the crown gear shaft axis. The meshing refers to the intermeshing of the pinion teeth with the teeth of the crown gear. As previously described, the backlash can be influenced by the distance between the pinion and the crown gear. Therefore, the backlash can be adjusted by shifting the pinion relative to the crown gear.

[0016] The crown gear shaft has a crown gear shaft axis. Furthermore, the pinion can be moved parallel to the crown gear shaft axis. Advantageously, this allows for good gear engagement even after the pinion has been moved, meaning that a large surface area is achieved over which the teeth of the pinion and crown gear overlap.

[0017] According to a further embodiment of the crown gear transmission, the pinion shaft has a pinion shaft axis. Furthermore, the pinion shaft and the crown gear shaft are mounted by the housing in such a way that the pinion shaft axis is perpendicular to the crown gear shaft axis. The arrangement with perpendicular axes also allows for good tooth engagement, i.e., a large surface area is achieved over which the teeth of the pinion and crown gear overlap.

[0018] For example, the pinion shaft is mounted in the flange by means of a roller bearing or a plain bearing. The flange is detachably connected to the housing. The detached flange can be moved relative to the housing. Once moved to the desired position relative to the housing, the flange can be removably reattached. The flange is generally replaceable. This allows a suitable flange to be selected for an initial rough adjustment of the pinion relative to the crown gear. Fine adjustment can then be achieved by moving the flange.

[0019] According to a further embodiment of the crown gear, the flange can be connected to the housing by means of pressure screws and / or tension screws. The detachable connection of the flange to the housing can be achieved by means of tension screws and pressure screws. The pressure screws or tension screws are supported directly or indirectly on the housing.

[0020] With lag screws, the lag screw can slide freely within the flange, i.e., in the area near the head of the screw. For screws with a continuous thread, a sliding hole is drilled in the flange that is at least equal to the outer diameter of the screw. Screws with a smooth area near the head slide automatically within the flange.

[0021] The pressure screws can be used with a housing with an undercut into which the flange engages. Turning the pressure screw in the flange then causes the pressure screw to exert pressure on the housing from the outside, so that the flange, with the part located in the undercut and the pressure screw, clamps the housing. This releasably attaches the flange to the housing.

[0022] According to a further embodiment of the crown gear, a support area of ​​the flange and a support area of ​​the housing are designed such that the flange and the housing can be connected via a force-locking connection. Because the force-locking connection is detachable, the flange can be readjusted with the pinion shaft and pinion and reattached after readjustment.

[0023] According to a further embodiment of the crown gear, a support area of ​​the flange and a support area of ​​the housing are designed such that the flange and the housing can be connected via a partially positive connection. Advantageously, the partially positive connection is also detachable.

[0024] According to a further embodiment of the crown gear, the support area of ​​the flange and / or the support area of ​​the housing has a serrated shape or a wave shape. If the support area of ​​the flange and the support area of ​​the housing have a matching serrated shape or wave shape, then the support area of ​​the flange and the support area of ​​the housing can engage with each other. Accordingly, a partially positive connection is formed between the support area of ​​the flange and the support area of ​​the housing.

[0025] The pinion shaft can be adjusted using the longitudinal fit. This allows the pinion shaft axis to be aligned relative to the crown gear shaft axis.

[0026] According to a further embodiment of the crown gear, the longitudinal fit comprises a groove in the housing, a groove in the flange, and a key arranged in both grooves. The longitudinal fit can be easily formed using the two grooves and the key.

[0027] Further possible implementations of the invention also include combinations of features not explicitly mentioned above or below. Individual aspects may also be added as improvements or additions to the respective basic form of the invention.

[0028] The invention will be explained in more detail below with reference to the drawings, which show Fig. 1 a schematic sectional view of a crown gear transmission according to the prior art, Fig. 2 a schematic sectional view of another crown gear transmission according to the prior art, Fig. 3 a schematic sectional view of a crown gear transmission according to the invention, Fig. 4 a schematic sectional view along the line IV - IV from Fig. 3 , Fig. 5 an enlarged view of area V Fig. 3 , and Fig. 6 another alternative enlarged view of area V from Fig. 3 .

[0029] In the figures, identical or functionally equivalent elements have been given the same reference numerals. Furthermore, it should be noted that the illustrations in the figures are not necessarily to scale. Fig. 1 bis 4 which show a sectional view, the hatching symbolizing a section is partially omitted.

[0030] Fig. 3 shows a schematic sectional view of a crown gear transmission 1 according to the invention. The crown gear transmission 1 has a housing 2, a pinion shaft 3 mounted rotatably relative to the housing 2, a pinion 4 connected to the pinion shaft 3, a crown gear shaft 5 mounted rotatably relative to the housing 2, and a crown gear 6 connected to the crown gear shaft 5. The pinion 4 and the crown gear 6 are in toothed engagement 7 with one another, ie the teeth of the pinion 4 and the teeth of the crown gear 6 mesh with one another.

[0031] The crown gear 6 and the crown gear shaft 5 are arranged so as to be rotatable but stationary relative to the housing 2. Consequently, neither the crown gear 6 nor the crown gear shaft 5 change their spatial position relative to the housing 2 upon rotation about the crown gear shaft axis 8. The crown gear 6 and the crown gear shaft 5 do not change their position relative to the housing 2 either in the radial direction relative to the crown gear shaft axis 8 or in the axial direction relative to the crown gear shaft axis 8. To adjust the backlash between the crown gear 6 and the pinion 4, the pinion 4 is movable.

[0032] The crown gear shaft 5 is supported by a bearing 10. The bearing 10 is arranged between the housing 2 and the crown gear shaft 5. The bearing 10 can be a roller bearing or a plain bearing. The crown gear shaft 5 protrudes from the housing 2 on both sides. Accordingly, the bearing 10 is arranged on a first side 11 of the housing 2 and on a second side 12 of the housing 2 between the crown gear shaft 5 and the housing 2.

[0033] The pinion shaft 3 is rotatably mounted in a flange 13 by means of a bearing 14. The bearing 14 can be a roller bearing or a plain bearing. The bearing 14 determines how the pinion shaft 3 is mounted relative to the flange 13 in the axial and radial directions. The pinion shaft 3 protrudes with one end beyond the housing 2 and the flange 13. At the other end, the pinion shaft 3 protrudes in the other direction beyond the flange 13 and into the housing 2 and is connected to the pinion 4. The bearing 14 is arranged between the flange 13 and a bearing area 15 of the pinion shaft 3.

[0034] The flange 13 is detachably connected to the housing 2. Therefore, the flange 13 can be moved relative to the housing 2 after the connection has been released. As shown in Fig. 3 As shown, the flange 13 is connected to the housing 2 by means of tension screws 16. The tension screws 16 can be aligned such that the tension screw axes 17 of the tension screws 16 screwed into the housing 2 are perpendicular to the surface of the housing 2.

[0035] The holes in the flange 13 through which the tension screws 16 are passed can be elongated. Accordingly, the tension screws 16 are slightly loosened to move the flange 13. The flange 13 is moved into the desired position using the tension screws 16 left in the elongated holes. The tension screws 16 are then tightened again so that the flange 13 is once again firmly but detachably connected to the housing 2. Alternatively or additionally, several holes can be provided in the housing 2 so that the flange 2 can be moved by attaching it to the housing 2 using different holes in the housing 2.

[0036] In an alternative embodiment, the flange 13 can also be connected to the housing 2 by means of pressure screws.

[0037] How Fig. 3 As shown, the pinion 4 is displaceable parallel to the crown gear shaft axis 8 by means of the flange 13. Furthermore, the pinion shaft 3 is mounted by means of the flange 13 in such a way that the pinion shaft axis 18 is perpendicular to the crown gear shaft axis 8.

[0038] To ensure that the pinion shaft axis 18 is perpendicular to the crown gear shaft axis 8, at least one longitudinal fit arranged parallel to the crown gear shaft axis 8 can be arranged between the housing 2 and the flange 13. The longitudinal fit can comprise a groove in the housing 2, a groove in the flange 13, and a key arranged in the two grooves.

[0039] Fig. 4 shows a schematic sectional view along the line IV - IV of Fig. 3 . The viewing direction corresponds to the direction of the arrows marked IV. Pinion 4 and crown gear 6 are visible. In the overlapping area of ​​pinion 4 and crown gear 6, the toothing engagement 7 occurs. The individual teeth of pinion 4 and crown gear 6 are in Fig. 4 not shown. Also shown is the pinion shaft 3 with the bearing area 15. The arrows 9 indicate the direction in which the pinion 4 and the pinion shaft 3 can be displaced in order to adjust the backlash between the crown gear 6 and the pinion 4. The direction of displacement runs along the dashed line 19, which runs parallel to the crown gear shaft axis 8.

[0040] Fig. 5 shows an enlarged view of area V from Fig. 3 . As in Fig. 5 As can be seen, the flange 13 has a flat support area 20 and the housing 2 has a flat support area 21. Because both the support area 20 and the support area 21 are flat, the flange 13 is force-locked to the housing 2 when the flange 13 is pressed onto the housing 2 by means of the tension screw 16.

[0041] Fig. 6 shows another alternative enlarged view of area V from Fig. 3 . As in Fig. 6 As shown, the support area 20 of the flange 13 and the support area 21 of the housing 2 have a serrated shape. Accordingly, the flange 13 and the housing 2 are connected via a partially positive connection when the flange 13 is pressed onto the housing 2 by means of the tension screw 16.

[0042] Alternatively, the support area 20 of the flange 13 and the support area 21 of the housing 2 can have a wave shape. In this case, too, the flange 13 and the housing 2 are connected via a partially positive connection when the flange 13 is pressed onto the housing 2 by means of the tension screw 16.

Claims

1. Crown wheel gear (1), with a housing (2), a pinion shaft (3) mounted so as to be rotatable relative to the housing (2), a pinion (4) connected to the pinion shaft (3), a crown wheel shaft (5) mounted so as to be rotatable relative to the housing (2), and a crown wheel (6) connected to the crown wheel shaft (5), wherein the pinion (4) and the crown wheel (6) are in toothed engagement (7) with one another, wherein the crown wheel shaft (5) has a crown wheel shaft axis (8) characterized in that the crown wheel (6) and the crown wheel shaft (5) are rotatable relative to the housing (2) but are fixed in position, and the pinion (4) is displaceable relative to the crown wheel (6) in order to adjust a torsional backlash between the crown wheel (6) and the pinion (4), wherein the pinion (4) is displaceable parallel to the crown wheel shaft axis (8), wherein the pinion shaft (3) is rotatably mounted in a flange (13) and the flange (13) is displaceable relative to the housing (2), wherein at least one longitudinal fit arranged parallel to the crown wheel shaft axis (8) is arranged between the housing (2) and the flange (13) in order to align the pinion shaft (3).

2. Crown wheel gear according to claim 1, wherein the pinion shaft (3) has a pinion shaft axis (18) and the pinion shaft (3) and the crown wheel shaft (5) are mounted by means of the housing (2) in such a way that the pinion shaft axis (18) is arranged perpendicular to the crown wheel shaft axis (8).

3. Crown wheel gear according to at least one of claims 1 or 2, wherein the flange (13) is connected to the housing (2) by compression screws and / or lag screws (16).

4. Crown wheel gear according to at least one of claims 1 to 3, wherein a contact area (20) of the flange (13) and a contact area (21) of the housing (2) are designed so that the flange (13) and the housing (2) are connectable via a friction-locked connection.

5. Crown wheel gear transmission according to at least one of claims 1 to 3, wherein a contact area (20) of the flange (13) and a contact area (21) of the housing (2) are designed so that the flange (13) and the housing (2) are connectable via a partially formfitting connection6. Crown wheel gear according to claim 5, wherein the contact area (20) of the flange (13) and / or the contact area (21) of the housing (2) has a jagged shape or a wavy shape.

7. Crown wheel gear according to at least one of claims 1 to 6, wherein the longitudinal fit has a groove in the housing (2), a groove in the flange (13), and a feather key arranged in both grooves.