GEAR, GEAR TRAIN, ENGINE, USE THEREOF AND METHOD FOR MATING SUCH GEAR WITH AT LEAST ONE FURTHER GEAR WITH A PREDETERMINED BACKLASH

Abstract

A gear and methods for mating the gear to at least on further gear. The gear, for example an idler gear, comprises a gear ring rotationally mounted around a gear hub, the gear hub comprising an axial gear hub opening, wherein the gear comprises a further inner hub rotationally engaging the gear hub, the further inner hub being provided in the gear hub opening, the further inner hub being provided for predeterminedly translating the center of rotation of the gear ring by moving the gear ring and the gear hub with respect to the center of rotation of at least one further gear from a first predetermined position in which the gear mates with the at least one further gear with substantially no backlash to a second predetermined position in which the gear mates with the at least one further gear with a predetermined backlash.

Claims

1. A method for mating a gear with at least one further gear with a predetermined backlash, wherein the gear ring rotationally mounted around the gear hub is mated with the at least one further gear in the first predetermined position with substantially no backlash after which the displacement means translate the centre of rotation of the gear ring predeterminedly by moving the gear ring and the gear hub with respect to the centre of rotation of the at least one further gear from the first predetermined position to the second predetermined position in which the gear mates with the at least one further gear with the predetermined backlash.

2. The method according to claim 1 for mating a gear, wherein the gear hub opening is substantially circular, wherein the displacement means comprise a further inner hub rotationally engaging the gear hub such that upon rotation of the gear hub around the inner hub, the centre of rotation of the gear ring is predeterminedly translated such as to create the predetermined backlash, with at least one further gear with a predetermined backlash, wherein the centre of rotation of the gear ring is translated from the first predetermined position to the second predetermined position by rotating the gear hub around the inner hub.

3. The method according to claim 2 for mating a gear, wherein the gear comprises at least one bolting hole for fixing the gear hub by bolting, with at least one further gear with a predetermined backlash, wherein after the centre of rotation of the gear ring has reached the second predetermined position, the gear hub is fixed with respect to the at least one further gear, preferably by bolting.

4. The method according to claim 3 for mating a gear, wherein the inner hub comprises at least one bolting hole for fixing the position of the centre of rotation of the gear ring in the second predetermined position by bolting, with at least one further gear with a predetermined backlash, wherein the inner hub is fixed with respect to the at least one further gear, preferably by bolting.

5. The method according to claim 1, for making a gear train preferably an idler gear, mating with at least one further gear, preferably at least two further gears.

6. The method according to claim 5, wherein the gear ring rotationally mounted around the gear hub is mated with the at least two further gears in the first predetermined position with substantially no backlash.

7. The method according to claim 5, for making an engine comprising the gear train.

8. Use of the gear according to claim 1, the gear train with a gear, preferably an idler gear mating with at least one further gear, preferably at least two further gears and/or an engine comprising the gear train.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows an overview of a gear train with a gear according to the present invention.

[0034] FIG. 2 shows a sectional view of the gear shown in FIG. 1.

[0035] FIG. 3 shows an alternative embodiment of the gear shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0036] The gear 1 shown in FIG. 1 mates with a first 7 and a second 18 further gear and thus forms a gear train 17. The gear 1 shown in FIG. 1 more specifically is an idler gear 2, although this is not critical for the present invention. The gear train 17 can be part of an engine, for example a car engine, although not shown in the figures.

[0037] The gear 1 comprises a gear ring 3 which is rotationally mounted around a gear hub 4. The gear ring 3 is shown schematically in FIG. 1 and no details, such as for example gear teeth applied circumferentially along the circumference of the gear ring 3, are shown. Usually the gear ring 3 is made of metal, although not critical for the present invention, and the gear ring 3 can also be made of, for example, a polymer material depending on the desired characteristics of the gear ring 3 on its turn depending on the desired application of the gear 1.

[0038] The gear hub 4 provides a rotational mount for the gear ring 3 and thereto is for example provided with a rotational bearing, for example a ball bearing, a bearing bush, etc. The bearing for reasons of clarity of the figures is not shown in the figures.

[0039] Usually the gear hub 4 is made of metal, although not critical for the present invention, and the gear hub 4 can also be made of, for example, a polymer material depending on the desired characteristics of the gear hub 4 on its turn depending on the desired application of the gear 1.

[0040] The gear hub 4 comprises an axial gear hub opening 5. In the embodiment shown in the figures, the gear hub opening 5 is substantially circular. This is however not critical for the invention and the hub opening 5 could have other shapes as deemed appropriate by the person skilled in the art.

[0041] As shown in FIGS. 1 and 2, the gear hub opening 5 is eccentric with respect to the gear ring 3. However, as shown in FIG. 3, the opening can also be concentric with respect to the gear ring 3 and the gear hub 4.

[0042] The gear 1 further comprises displacement means 6 in the gear hub opening 5. The displacement means 6 are provided for predeterminedly translating the centre of rotation of the gear ring 3 by moving the gear ring 3 and the gear hub 4 with respect to the centre of rotation of at least one further gear 7 from a first predetermined position in which the gear mates with the at least one further gear with substantially no backlash to a second predetermined position in which the gear mates with the at least one further gear with a predetermined backlash.

[0043] As shown in FIGS. 1-3, the displacement means 6 further preferably comprise an inner hub 8 rotationally engaging the gear hub 4 such that upon rotation of the gear hub 4 around the inner hub 8, the centre of rotation of the gear ring 3 is predeterminedly translated such as to create the predetermined backlash. The inner hub 8 thereto is positioned eccentric with respect to the gear ring 3 and the gear hub 4.

[0044] As shown in FIG. 2, the inner circumference of the hub opening 5 rotationally engages the inner hub 8, more in particular the outer surface of the inner hub 8. Thereto, the inner circumference could comprise a pair of sealing rings or alternative spacing elements 19 as shown in the embodiments shown in FIG. 3 but not shown in FIG. 2. The pair of sealing rings or alternative spacing elements 19, if present, may be concentric with respect to the gear hub 4, as would be the case in the embodiment according to FIG. 2, or may be eccentric with respect to the gear hub 4, as shown in FIG. 3.

[0045] The eccentric position of the inner hub 8 in the gear hub 3 may for example be provided for by the eccentric positioning of the rotational bearing 19 inside the gear hub opening 5, as shown in FIG. 3, or may for example be provided for by the eccentric positioning of the gear hub opening 5 itself, as shown in FIG. 2, or even a combination of the two, not shown.

[0046] The rotational bearing can be any type of rotational bearing deemed appropriate by the person skilled in the art, for example a ball bearing, etc.

[0047] As shown in the figures, the gear 1 preferably comprises at least one bolting hole 16 for fixing the gear hub 4 by bolting. As shown in FIG. 2, the bolting hole 16 can be provided in the gear hub 4 or can for example be provided in the inner hub 8.

[0048] In case the inner hub 8 comprises the at least one bolting hole 16 for fixing the position of the centre of rotation of the gear ring 3 in the second predetermined position by bolting, as for example shown in FIG. 2, the rolling resistance of the gear ring 3 when rotating around the gear hub 4 preferably is smaller, preferably substantially smaller, than the rolling resistance of the gear hub 4 when rotating around the inner hub 8. In FIG. 3, for example, the at least one bolting hole 16 is provided in the gear hub 4, allowing the inner hub 8 to be mounted inside the gear hub opening 5 with for example a pair of sealing rings or alternative spacing elements 19.

[0049] As shown in the figures, the inner hub 8 and the gear hub 4 preferably comprise at least one marking 9 indicating the rotation to be followed by the gear hub 4 around the inner hub 8 such as to create the predetermined backlash. As shown in the figures, the marking 9 preferably comprises a first pair 10 of marks 12, 11 respectively on the inner hub 8 and the gear hub 4 indicating a first predetermined rotational position of the inner hub 8 with respect to the gear hub 4 in the first predetermined position in which the gear 1 mates with the at least one further gear 7 and a second pair 13 of marks 15, 14 respectively on the inner hub 8 and the gear hub 4 indicating a second predetermined rotational position of the inner hub 8 with respect top the gear hub 4 in the second predetermined position in which the gear 1 mates with the at least one further gear 7 with the predetermined backlash.

[0050] As especially shown in for example FIG. 1, the inner hub 8 comprises a triangular indicator 12 with the indication TOP to indicate that the triangle 12 should be situated at the mark 11 marked on the ring hub 4 when putting the gear 1 in the first predetermined position with respect to the further gear 7. When the gear hub 4 is then rotated clockwise with respect to the inner hub 8 till the mark 12 coincides with the mark 14 on the gear hub 4 of the pair 13, the centre of rotation of the gear ring 3 is translated by moving the gear ring 3 and the gear hub 4 with respect to the centre of rotation of at least one further gear 7 from the first predetermined position in which the gear mates with the at least one further gear with substantially no backlash to the second predetermined position in which the gear mates with the at least one further gear with a predetermined backlash. In such an embodiment, at least one of the marks of the second pair of marks is one of the marks of the first pair of marks. In the case shown in FIG. 1, the inner hub has one mark whereas the gear hub has at least two marks such that in the first predetermined position the mark of the inner hub coincides with a first of the marks on the gear hub and in the second predetermined position the mark of the inner hub coincides with the a second of the marks on the gear hub, different from the first of the marks on the gear hub.

[0051] As can be seen in the figures additional marks can be added to the gear 1, for example to further increase the accuracy with which the inner hub 8 can be positioned inside the gear hub 4.

[0052] To mount the gear 1 according to FIG. 2 in a gear train with a predetermined backlash, the gear 1 shown in FIG. 2 will first be positioned with the centre of rotation of the gear ring 3 in the first predetermined position after which it will be fastened in the gear train by using the bolting holes 16. Then, the inner hub 8 will be rotated such as to bring the centre of rotation of the gear ring 3 to the second predetermined position, using the preferred transition fit between the inner hub 8 and the gear hub 4. While in use, the gear ring 3 will rotate around the gear hub 4, whereas due to the relative larger resistance to rolling, the gear hub 4 will substantially retain its position with respect to the inner hub 8.

[0053] To mount the gear 1 according to FIG. 3 in a gear train with a predetermined backlash, the gear 1 shown in FIG. 3 will first be positioned with the centre of rotation of the gear ring 3 in the first predetermined position after which it will be fastened in the gear train by using the at least one additional bolting hole 26 in the inner hub 8. Then, the gear hub 4 will be rotated with respect to the inner hub 8 such as to bring the centre of rotation of the gear ring 3 to the second predetermined position, using the preferred sealing rings or alternative spacing elements 19 as shown in FIG. 3. When the centre of rotation of the gear ring 3 reaches the second predetermined position, the gear 1 is bolted in this location using the at least one bolting hole 16. The bolt fixing the gear 1 using the additional bolting hole in the inner hub 8 using the bolting hole 26 can then be removed or can remain. The means for fixing the gear 1 using the bolting hole 16 are preferably provided to accommodate the movement of the centre of rotation of the gear ring 3 from the first to the second predetermined position. For example, the bolting hole 16 can have a diameter and/or shape allowing a bolt provided through it with some leeway during movement of the centre of rotation of the gear ring 3. On the other hand, the hole in the piece to which the gear 1 is attached can be provided with holes providing the necessary leeway for the bolt extending through the bolting hole 16. While in use, the gear ring 3 will rotate around the gear hub 4, whereas due to the relative larger resistance to rolling, the gear hub 4 will substantially retain its position with respect to the inner hub 8.