DE102013208163A1 - Adapter for an output shaft of a gearbox - Google Patents

Abstract

A connection between an output shaft (7) of a transmission (1) with a round mechanical interface and a pinion (5) is proposed. The area of application of the gears (1) is expanded by the connection according to the invention without design changes being necessary. In addition, the connection according to the invention enables the use of very small pinions (5), which has an advantageous effect on the size and manufacturing costs of the transmission (1).

Description

The invention is based on a transmission which has on a shaft, preferably on its output shaft, a round mechanical interface comprising a plane surface with a plurality of fastening threads arranged concentrically to the axis of rotation of the shaft and a centering device. This round mechanical interface is for example in the Standard EN ISO 9004-1-A Are defined. If a transmission has such a standardized mechanical interface, it can be mass-produced in series and adapted to the specific conditions of use via the said interface.

An unsatisfactory problem has been solved by flanging a pinion on this interface. So far, the outer diameter of the pinion must be significantly larger than the pitch circle diameter of the fastening threads in the plane surface for the following reasons.

When the external forces acting on the pinion in the tangential direction are given, the large pinion diameter results in large torques acting on the shaft and the transmission. This is the case, for example, when the pinion drives a rack which displaces an object in the vertical direction against gravity.

Another important reason lies in manufacturing technology. Namely, if the pinion has a smaller diameter than the flat surface of the round mechanical interface, the pinion can only be made by broaching. Such produced pinion has large manufacturing inaccuracies, which greatly limits its scope.

In addition, the pinion can not be hardened because the resulting distortion during curing can not be removed by a subsequent grinding process.

From the DE 0 2007 028 873 A1 and the DE 10 2008 024 070 A1 Solutions are known which provide a frictional and / or positive connection of pinion and adapter plate.

The invention has for its object to provide an adapter for a pinion and a round mechanical interface of the type mentioned above, which is also used with pinion diameters, which is smaller than the pitch circle diameter of the mounting thread and otherwise offers manufacturing advantages.

This object is achieved in a generic adapter for a shaft flange of a transmission shaft with the features of the characterizing part.

Due to the invention claimed training a receiving bore in the adapter, the pinion with its stub shaft is positively connected to the adapter.

Since in the adapter according to the invention, the diameter of the receiving bore is not subject to any restrictions, the diameter of the receiving bore can be much smaller than the pitch circle diameter of the mounting threads of the round mechanical interface on the output shaft of the transmission. As a result, the outer diameter of the pinion can be selected smaller than the above-mentioned pitch circle diameter.

By virtue of the smaller outer diameters of the pinion, which are possible according to the invention, the torques acting on the shaft can be reduced, given otherwise identical boundary conditions. As a result, more compact, lighter, and much less expensive gears can be used to provide a given tangential force on the pinion.

Because of the constructive freedom through the use of the adapter according to the invention, the areas of application already produced in series gear can be increased.

In addition, the production of the pinion according to the invention is subject to no restrictions. It can be made for example by milling and / or grinding with the highest accuracy. Finally, the highly loaded pinion can be made of a very high quality material and cured if necessary, while for the adapter usually a cheaper material is sufficient. Also, the replacement of a damaged pinion 5 is very fast and inexpensive possible.

Moreover, the device according to the invention still offers a potential for weight saving, namely, if the adapter is made of light metal. This is especially true because the non-circular turning the torque transmission takes place on a large area, so that the specific surface load is comparatively low.

If the Unrundprofil invention is formed in several stages, then the pressing of pinion and adapter is facilitated. In addition, the diameter of the stepped receiving bore of the shaft journal the bending moment course can be adjusted accordingly and thus the performance of the pinion or the adapter can be further increased.

Alternatively, the centering means can be formed as a fitting or centering collar, so that the adapter according to the invention is compatible with various round mechanical interfaces.

In a variant of the invention it is provided that the receiving bore and the stub shaft of the pinion by a press fit, in particular a transverse press fit or an oil press fit, are non-positively connected to each other.

Alternatively, the receiving bore and the stub shaft can also be frictionally connected to each other by a shrink fit or a conical seat. Through these embodiments, the per se known advantages of these non-positive connections can also be usefully used in the adapter according to the invention, especially as a captive.

The inventive design of the shaft and the pinion and their connection can be used both on the output side of a transmission and on the drive side of a transmission if necessary.

The connection according to the invention and design of shaft and pinion can be used in a wide variety of transmission designs, but especially in coaxial transmissions.

The solution claimed according to the invention can be used to particular advantage when the pinion is engaged with a toothed rack. In this case, the smaller the diameter of the pinion, the lower the load on the transmission with torques. Since with the solution claimed according to the invention, the diameter of the pinion can be reduced compared to conventional pinion and shaft connections, the load on the transmission can be reduced very effectively in this particular application.

A particularly advantageous possibility of torque transmission between the pinion and adapter is to weld the adapter and the pinion in the region of the receiving bore and the stub shaft with each other. As a result, a clamping element is unnecessary, which reduces the size of the adapter according to the invention and often leads to cost savings.

Further advantages and advantageous embodiments of the invention are the following drawings, the description and the claims removable. All of the features disclosed in the drawing, the description and the claims can be essential to the invention both individually and in any combination with one another.

drawing

Show it:

1 a first embodiment of an adapter according to the invention,

2 a second embodiment of an adapter according to the invention,

3 : a section along the line AA 1 and 2 .

4 : an isometric of the pinion 2 .

5 to 11 : further embodiment of inventive adapter, and

12 : Examples and variations of non-circular profiles that can be used in the invention.

Description of the embodiments

1 shows a gearbox 1 in partial section at the output shaft of an inventive adapter 3 for a pinion 5 is attached.

The output shaft of the transmission 1 is with the reference numeral 7 been provided; an input shaft is not shown.

In the in 1 shown first embodiment are on the output shaft 7 a plane surface 9 and a cylindrical outer surface 11 educated. The cylindrical outer surface 11 is coaxial with a rotation axis (without reference numeral) of the output shaft 7 arranged and serves to center the adapter according to the invention 3 ,

In the plane surface 9 are fastening threads 13 formed, which is also concentric with the axis of rotation of the output shaft 7 are ordered, trained. The pitch diameter on the mounting threads 13 are arranged, has the reference D _Tk .

On the adapter according to the invention 3 is one with the plane surface 9 and the cylindrical outer surface 11 the output shaft 7 cooperative fitting 15 educated. By the pass 15 becomes the adapter 3 concentric with the cylindrical outer surface 11 positioned.

In the adapter 3 are mounting holes 17 arranged the same Pitch circle diameter D _TK like the fastening thread 13 in the plane area 9 to have. Through the mounting holes 17 can screws 19 in the fastening thread 13 the output shaft 7 be screwed and in this way the adapter 3 on the output shaft 7 be positioned and secured against rotation. On the adapter 3 is a first concentricity test surface 21 educated. With the first concentricity test surface 21 It is possible to easily and reliably determine if the concentricity of the adapter 3 meets the requirements.

With the reference number 30 is a second concentricity test surface 30 on the pinion 5 designated. The second concentricity test surface 30 allows it after the assembly of the pinion 5 to reliably check compliance with the specified concentricity and to correct it if necessary. A correction of the concentricity is often easily possible by the adapter 3 relative to the output shaft 7 is twisted and screwed in this changed position.

At the in 1 illustrated embodiment, the adapter 3 a continuous receiving bore 23 on. This mounting hole 23 However, as well as blind hole (not shown) or as a stepped bore (see 4 ) be formed. The receiving bore 23 and the pass 15 of the adapter 3 are arranged coaxially with each other. In the receiving hole 23 becomes a stub shaft 25 of the pinion 5 added.

To the torque between adapters 3 and the pinion 5 to transfer, have both the receiving bore 23 as well as the stub shaft 25 a non-circular profile. The non-circular profile may be formed as a polygonal profile, triangular profile, square profile or another polygonal profile.

Due to the non-circular profiles creates a positive connection between the output shaft 13 and the stub shaft 25 of the pinion 5 That ensures high torque safely and reliably between the pinion 5 and the output shaft 7 transfers.

The number of corners and the configuration of the cross section depends inter alia on the expected loads and the available space. In the 12 various suitable non-circular profiles are shown.

The outer diameter of the pinion 5 is in 1 denoted by the reference D _a . From the comparison of the outer diameter D _{a of} the pinion 5 and the pitch circle diameter D _TK in 1 it becomes clear that even very small sprockets 5 on the output shaft 7 of the transmission 1 can be attached. This allows the tangential force on the outer diameter D _{a of} the pinion 5 at the same output torque of the output shaft 7 increase. As a result, it is possible to use smaller gear to a predetermined tangential force on the pinion 5 to reach. This results in a significant economic advantage and also the smaller gearboxes require this gear less space, which is always a big advantage in modern designs. This is particularly advantageous when the pinion 5 a rack 37 drives.

A particular advantage of this embodiment is the fact that the positive torque transmission through the Unrundprofil 27 is very powerful and has a low notch effect. Another advantage is the fact that pinion 5 and adapter plate 3 can be made of different materials. This opens up further optimization potential and in many cases also reduces costs. In the embodiment according to 1 are the receiving hole 23 and stub shaft 25 secured or fixed by a press fit in the axial direction.

In the embodiment according to 2 the axial securing takes place via a circlip 42 that with a corresponding groove 32 in the stub shaft 25 interacts.

In this embodiment, a transition fit or a slight clearance fit between receiving bore 23 and stub shaft 25 be present, which facilitates the assembly.

By way of illustration is in 3 the non-circular connection according to the invention a section along the line AA from the two embodiments described above. In this embodiment, the non-circular profile 27 six radial projections 29 and correspondingly six slightly concave surfaces 31 on. The corner measure of this non-circular profile 27 is with the reference numeral 33 denotes while a spacing surfaces 31 With 35 is designated.

The non-circular profiles 27 of receiving bore 23 and stub shaft 25 allow a flat and almost kerbwirkungsfreie transmission of torque. It is advantageously by non-circular turning both in the receiving bore 23 as well as on the stub shaft 25 applied during normal turning. A re-tightening is usually unnecessary.

So that both components 3 and 5 can be secured captive with each other, in the area of the non-circular profile 27 a press fit are provided. For joining the components, the adapter 3 to be heated.

This is the captive of the pinion 5 non-positively, while the torque is substantially positive.

For further illustration, see 4 a pinion 5 with a non-circular profile 27 trained stub shaft 23 shown isometrically. The groove 32 in the stub shaft 23 is clearly visible in this illustration.

In 5 a second embodiment is shown. In this embodiment, the stub shaft 23 and the mounting hole 23 graduated. The steps have the reference numerals 32.1 to 32.4 , where all stages 32 are designed as non-circular profiles.

Due to the stepped configuration, the joining of the components 3 and 5 relieved without having to give up a press fit. If a press fit is not desired, a screw can also be used as a captive 34 in conjunction with a disc 36 or a circlip 42 as in 2 be used. In this case are pinions 5 and adapters 5 relatively easy to separate again.

In the 6 is a section taken along the line AA 5 shown. The 7 and 8th show the adapter plate 3 and the pinion 5 as isometries.

In the 9 another embodiment is shown. In this embodiment, the stub shaft 25 and the mounting hole 23 conical and at the same time designed as Unrundprofil (see also the 11 ).

Due to the conical design, the joining and disassembly of the components 3 and 5 relieved again. Depending on how the cone angle of stub shaft 25 and receiving bore 23 is selected, this compound is self-locking or not.

As an additional axial securing is on the stub shaft 25 an external thread 38 provided that with a mother 40 interacts.

In the 10 is a section taken along the line AA 9 shown. The 11 shows the pinion 5 as isometries. In this view are the conical out of round connection 27 clearly visible.

In the 12 There are several variations with respect to the number of corners and the degree of out-of-roundness of the non-circular profile 27 shown. On the one hand, it should show the variety of possible variations and on the other make it clear that the relevant expert can select from a large selection of non-circular profiles for a specific application. Of course, all these profiles can also be stepped or conical. The various axial securing devices of the embodiments described above can also be varied.

It goes without saying that the inventive design of the connection of a shaft with a pinion not on output shafts 13 are limited. If necessary, of course, the drive shaft of a transmission or any other shaft which is to be rotatably connected to a pinion, be configured in the inventive manner. Protection should also be claimed for these embodiments and applications.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 02007028873 A1 [0006]
• DE 102008024070 A1 [0006]

Cited non-patent literature

• Standard EN ISO 9004-1-A [0001]

Claims (17)

Adapter for a round mechanical interface of a gear shaft ( 7 ) with centering means ( 11 . 39 ), with a plane surface ( 9 ) and with several fastening bores ( 17 ), whereby the fastening bores ( 17 ) concentric with the centering means ( 11 . 39 ) are arranged, wherein the adapter has a receiving bore ( 23 ), and wherein the receiving bore ( 23 ) for receiving a stub shaft ( 25 ) of a pinion ( 5 ), characterized in that the stub shaft ( 25 ) positively with the receiving bore ( 23 ) connected is. Adapter according to claim 1, characterized in that the receiving bore ( 23 ) and the stub shaft ( 25 ) at least partially as a non-circular profile ( 27 ) are formed, and that over the Unrundprofil ( 27 ) a torque transfer between adapters ( 3 ) and pinion ( 5 ) he follows. Adapter according to claim 1 or 2, characterized in that the receiving bore ( 23 ) and the stub shaft ( 25 ) and that the out-of-round profile ( 27 ) at least at one stage ( 32.1 to 32.4 ), but preferably at several stages ( 32.1 to 32.4 ) is trained. Adapter according to one of the preceding claims, characterized in that the non-circular profile ( 27 ) is conical in the axial direction. Adapter according to one of the preceding claims 2, characterized in that the non-circular profile ( 27 ) is a polygon profile with two or more corners. Adapter according to one of the preceding claims, characterized in that the pinion ( 5 ) in the axial direction on the adapter plate ( 3 ) is secured. Adapter according to one of the preceding claims, characterized in that the axial securing a groove ( 32 ) and a retaining ring (( 30 ), a screw ( 34 ), a disk ( 36 ) and an internal thread in the stub shaft ( 25 ) and / or an external thread ( 38 ) on the stub shaft ( 25 ) and / or a mother ( 40 ). Adapter according to one of the preceding claims, characterized in that the centering means as Einpass ( 11 ) are formed. Adapter according to one of the preceding claims, characterized in that the centering means as Zentrierbund ( 39 ) are formed. Adapter according to one of the preceding claims, characterized in that an outer diameter (D _a ) of the pinion ( 5 ) smaller than a pitch circle diameter (D _TK ) of the mounting holes ( 17 ). Adapter according to one of the preceding claims, characterized in that the adapter ( 3 ) and the stub shaft ( 25 ) are non-positively connected by a shrink fit or a conical seat. Adapter according to one of the preceding claims, characterized in that the shaft as the output shaft ( 7 ) of a transmission ( 1 ) is trained. Adapter according to one of the preceding claims, characterized in that the transmission ( 1 ) is a coaxial transmission. Adapter according to one of the preceding claims, characterized in that the transmission ( 1 ) is a cycloid gear, a flex spline gear or a planetary gear. Adapter according to one of the preceding claims, characterized in that the pinion ( 5 ) with a rack ( 37 ) is engaged. Adapter according to one of the preceding claims, characterized in that a pitch circle diameter (D _Tk ) of the mounting holes 25 mm, 31.5 mm, 40 mm, 50 mm, 63 mm, 80 mm, 100 mm, 125 mm, 160 mm, 200 mm , 250 mm or 315 mm. Adapter according to one of the preceding claims, characterized in that a diameter of the centering collar ( 39 ) Is 16 mm, 20 mm, 25 mm, 31.5 mm, 40 mm, 50 mm, 63 mm, 80 mm, 100 mm, 125 mm or 160 mm.

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