Connection system for connecting a component such as a shaft, hub, bushing or the like to a gear wheel, the gear wheel comprising helical gearing

Abstract

A connection system for connecting a component to a gear wheel, wherein the gear wheel comprises helical gearing having a tooth helix angle and a first connecting section, and the component comprises a second connecting section by way of which the component can be connected or is connected to the first connecting section, wherein the component, in the second connecting section, comprises at least one depression or elevation that is operatively connected to the first connecting section when the component is connected to the first connecting section, wherein the depression has a connection helix angle, and the connection helix angle is defined as follows: 0. The disclosure furthermore relates to a device for transmitting a rotational movement, comprising a rotatable component and a gear wheel, wherein the gear wheel and the component are connected by way of such a connection system.

Claims

1. A connection system, comprising: a gear wheel that comprises: helical gearing having a tooth helix angle (); and a first connecting section; and a rotatable component connected to the gear wheel, the rotatable component comprising: a second connecting section connecting the component to the first connecting section, wherein the second connecting section comprises a depression or elevation that is operatively connected to the first connecting section when the component is connected to the first connecting section, wherein the depression or the elevation has a connection helix angle () defined as 0<; and wherein the connection helix angle () and the tooth helix angle () have the same sense of rotation.

2. The connection system according to claim 1, wherein the rotatable component, in the second connecting section, comprises a plurality of depressions or elevations, and the helical gearing of the gear wheel comprises a same number of teeth.

3. The connection system according to claim 1, wherein the first connecting section comprises protrusions corresponding to one or more depressions.

4. The connection system according to claim 1, wherein the gear wheel is made of a gear wheel material and the rotatable component is made of a rotatable component material and the gear wheel material is relatively softer than the rotatable component material.

5. The connection system according to claim 1, wherein the gear wheel comprises: a toothed ring made of a toothed ring material and in which the helical gearing is disposed, and a connecting part made of a connecting part material and which comprises the first connecting section, and wherein the toothed ring material is softer than the connecting part material.

6. The connection system according to claim 5, wherein the component comprises a hub part made of a hub part material and which comprises the second connecting section, wherein the connecting part is disposed between the toothed ring and the hub part, and wherein the connecting part material is softer than the hub part material.

7. A connection system, comprising: a gear wheel that comprises: a toothed ring with a helical gearing having a tooth helix angle (); a first connecting part that forms a first connecting section; wherein the first connecting part is made of a first material; wherein the toothed ring is made of a second material, wherein the first material is relatively softer than the second material; and a rotatable component connected to the gear wheel, the rotatable component comprising: a hub part made of a third material, wherein the second material is softer than the third material; a second connecting section disposed between the toothed ring and the hub part, the second connecting section connecting the component to the first connecting section, wherein the second connecting section comprises a depression or elevation that is operatively connected to the first connecting section when the component is connected to the first connecting section, wherein the depression or the elevation has a connection helix angle () defined as 0<; and wherein the connection helix angle () and the tooth helix angle () have the same sense of rotation.

8. The connection system of claim 7, wherein the rotatable component is selected from the group consisting of a shaft, hub, or bushing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the disclosure will be described in more detail hereafter with reference to the accompanying drawings. In the drawings:

(2) FIG. 1 shows a first exemplary embodiment of a device according to the disclosure for transmitting a rotational movement, comprising a component and a gear wheel;

(3) FIG. 2a) shows a developed view of a second connecting section of the component shown in FIG. 1;

(4) FIG. 2b) shows a developed view of the gear wheel shown in FIG. 1;

(5) FIG. 3 shows a second exemplary embodiment of a device according to the disclosure for transmitting a rotational movement, comprising a component and a gear wheel;

(6) FIG. 4 shows a third exemplary embodiment of a device according to the disclosure for transmitting a rotational movement, comprising a component and a gear wheel;

(7) FIG. 5 shows a fourth exemplary embodiment of a device according to the disclosure for transmitting a rotational movement, comprising a component and a gear wheel;

(8) FIG. 6a) shows a developed view of the second connecting section of the component shown in FIG. 5; and

(9) FIG. 6b) shows a developed view of the gear wheel shown in FIG. 5.

DETAILED DESCRIPTION

(10) FIG. 1 shows a first exemplary embodiment of a device 10.sub.1 for transmitting a rotational movement based on a schematic sectional illustration. The device 10.sub.1 comprises a component 12, for example a shaft, a hub or a bushing, which can be rotated about a rotational axis T. In the illustrated example, the component 12 shall be a shaft. Furthermore, the device 10.sub.1 comprises a gear wheel 14, which is non-rotatably connected to the component 12 by way of a connection system 16, so that torque can be transmitted from the component 12 to the gear wheel 14. In the illustrated embodiment, the connection system 16 is designed as a shaft/hub connection.

(11) So as to form the connection system 16, the gear wheel 14 comprises a first connecting section 18, and the component 12 comprises a second connecting section 20. The second connecting section 20 has a smaller diameter than the remaining component 12, whereby a projection 22 is created by way of which the first connecting section 18, and consequently the gear wheel 14, is axially positioned with respect to the component 12. The gear wheel 14 comprises a number of teeth 24, which form helical gearing 26. For the sake of illustration, the teeth 24 and the helical gearing 26 are symbolically identified by a hatched area.

(12) FIG. 2a) shows a developed view of the second connecting section 20 of the component 12 shown in FIG. 1, and FIG. 2b) shows a developed view of the gear wheel 14. In both instances, the view is onto the outer circumference of the second connecting section 20 of the component 12 or of the gear wheel 14. The teeth 24 of the helical gearing 26 of the gear wheel 14 form a tooth helix angle with the rotational axis T. A number of depressions 28 or elevations 28 are disposed on the second connecting section 20 of the component 12, which form a connection helix angle with the rotational axis T. In the illustrated example, the connection helix angle and the tooth helix angle have the same size. According to the disclosure, the connection helix angle is either equally as large as the tooth helix angle or smaller than the tooth helix angle , but larger than 0. Both the tooth helix angle and the connection helix angle have the same sense of rotation R with respect to the rotational axis T.

(13) Not shown is one embodiment in which the depressions 28 are designed so as to form a stop for the component 12, whereby the projection 22 is not required.

(14) The gear wheel 14 shown in FIG. 1 is made completely of one material, for example steel or plastic. Regardless of whether the gear wheel 14 is made of steel or plastic, the first connecting section 18 can comprise protrusions 30 corresponding to the depressions 28, whereby the connection system 16 can have a form-locked and releasable design. The depressions 28 and the protrusions 30 corresponding thereto are identified by way of a hatched area for illustration purposes. In the case where the second connecting section 20 comprises a number of elevations 28, the first connecting section 18 can comprise a number of recesses 30 corresponding thereto. In this way, a releasable form-locked connection can be provided between the gear wheel 14 and the component 12. In the case where the gear wheel 14 is made of plastic material, the gear wheel 14 can be molded around the component 12 already during production. In this case, no connection system 16 that can be non-destructively released is created between the gear wheel 14 and the component 12.

(15) FIG. 3 shows a second exemplary embodiment of the device 10.sub.2 according to the disclosure for transmitting a rotational movement, likewise based on a schematic sectional illustration. The essential composition of the device 10.sub.2 according to the second exemplary embodiment of corresponds to that of the first exemplary embodiment 10.sub.1. In this exemplary embodiment, however, the gear wheel 14 comprises a separate toothed ring 32, in which the helical gearing 26 is disposed. Furthermore, the gear wheel 14 comprises a connecting part 34, which forms the first connecting section 18. The toothed ring 32 is made of a softer material than the connecting part 34.

(16) FIG. 4 shows a third exemplary embodiment of the device 10.sub.3 according to the disclosure, again based on a schematic sectional illustration. Once again, the essential composition of the device 10.sub.1 is similar to that of the above-shown exemplary embodiments. As in the second exemplary embodiment, the gear wheel 14 comprises the toothed ring 32 and the connecting part 34. In addition to the shaft, the component 12 also comprises a hub part 36, which forms the second connecting section 20. The toothed ring 32 is made of a soft material, while the connecting part 34 is made of a harder material in relation to the material of the toothed ring 32, and the hub part 36 is made of the hardest material. In the exemplary embodiment shown in FIG. 4, the hub part 36 is made of steel and connected to the shaft 12 by way of a known press fit connection. The hub part 36 can serve as an adapter between the gear wheel 14 and the shaft of the component 12, for example so as to compensate for differences in diameter.

(17) Both in the second and in the third exemplary embodiment, it is an obvious choice to produce the gear wheel 14 from plastic material, wherein the differing materials are selected such that the functions of the toothed ring 32 of the connecting part 34 and of the hub part 36 can be optimally satisfied. The component 12, which is implemented in particular as a shaft, hub or bushing, is usually made of steel, but may also be made of plastic material. It may be an obvious choice to produce the hub part 36 and the shaft or other elements of the component 12 from the same material, making joining the same simpler. If the shaft and the hub part 36 are made of the same steel, they may be welded to one another or joined to one another by way of a press fit.

(18) In the developed view, the second connecting sections 20 correspond to the component 12 shown in FIG. 3, or the hub part 36 shown in FIG. 4, and the gear wheels 14 shown in FIGS. 3 and 4 correspond to FIGS. 2a) and 2b). In particular, both the connection helix angle and the tooth helix angle have the same sense of rotation R with respect to the rotational axis T.

(19) FIG. 5 shows a fourth exemplary embodiment of the device 10.sub.4 according to the disclosure, again based on a schematic sectional illustration. The fourth exemplary embodiment essentially corresponds to the third exemplary embodiment shown in FIG. 4, however the tooth helix angle and the connection helix angle have a different, opposite sense of rotation with respect to the rotational axis T, which is also symbolized by the hatched areas used for the helical gearing 26 and depressions 28 or elevations 28, which do not run parallel, but perpendicularly to one another.

(20) FIG. 6a) shows a developed view of the second connecting section 20 of the hub part 36 shown in FIG. 5, and FIG. 5b) shows a developed view of the gear wheel 14 shown in FIG. 5, each being shown in accordance with the fourth exemplary embodiment of the device 10.sub.4 according to the disclosure. The selected representation corresponds to that from FIGS. 2a) and 2b). In contrast to the exemplary embodiments, which relate to FIGS. 2a) and 2b), the tooth helix angle and the connection helix angle according to the fourth exemplary embodiment 10.sub.4 have a different, opposite sense of rotation R with respect to the rotational axis T.

(21) Hereafter, it is deduced why the connection helix angle is to be selected smaller than, or at most equal to, the tooth helix angle . The helical gearing 26 allows not only tangentially, but also axially acting forces and torque to be transmitted. The resulting axial forces F.sub.aS acting on the helical gearing 26 (running gear teeth) act counter to the axial forces F.sub.aV (synchronization teeth) acting between the two connecting sections 18, 20. It is to be achieved that the axial forces acting on the helical gearing, in terms of magnitude, are not greater than the forces acting between the two connecting sections 18, 20. The relationship of the axial forces F.sub.aS and F.sub.aV can be expressed by the following formula:
F.sub.aV=F.sub.tV tan F.sub.aS

(22) F.sub.aV: axial force acting between the connecting sections 18, 20

(23) F.sub.tV: tangential force acting between the connecting sections 18, 20

(24) F.sub.aS: axial force acting on the helical gearing 26

(25) The tangential force F.sub.tV is calculated from the torque to be transmitted and the diameter on which the force engages:
F.sub.tv=2M.sub.z/D.sub.v

(26) M.sub.z: moment acting on the gear wheel

(27) D.sub.v: diameter or pitch circle of the connecting sections 18, 20

(28) D.sub.s: diameter or pitch circle of the helical gearing 26

(29) This reduces deformation and increases the performance capability of the gear wheel 14. Ideally,
F.sub.aV=F.sub.aS

(30) Since the moment acting on the helical gearing 26 is identical to the supporting torque in the connecting sections 18, 20, the ideal tooth helix angle b is derived as follows:
tan =tan Dv/Ds

(31) Since D.sub.v/D.sub.s is always <1, the connection helix angle is to be selected smaller than the tooth helix angle or at most approximately the same.

(32) TABLE-US-00001 List of Reference Numerals 10, 10.sub.1, 10.sub.3 device 12 component 14 gear wheel 16 connection system 18 first connecting section 20 second connecting section 22 projection 24 tooth 26 helical gearing 28 depression, elevation 30 protrusion, recess 32 toothed ring 34 connecting part 36 hub part R sense of rotation T rotational axis connection helix angle tooth helix angle