Power split continuously variable transmission with at least four travel ranges

Patent metadata

Field	Value
Publication number	US-11077746-B2
Application number	US-201816761279-A
Country	US
Kind code	B2
Filing date	Oct 11, 2018
Priority date	Nov 10, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A continuously variable power-split transmission with at least four driving ranges, within which the gear ratio of the power-split transmission can be continuously varied by a variator. A first planetary gearset with a plurality of shafts can be connected via shifting elements with another planetary gearset that also has a plurality of shafts and can be connected with a transmission output shaft. The first planetary gearset comprises four shafts and can be connected, via a first shaft, with a transmission input shaft and a first shaft of the variator. Furthermore, the first planetary gearset is connected, via a second shaft, to a second shaft of the variator, and the first planetary gearset is coupled, via a third shaft, to halves of two shifting elements and, via a fourth shaft, the first planetary gearset is coupled to a shifting element half of a further shifting element.

First claim

The invention claimed is:

1. A continuously variable power-split transmission with at least four driving ranges, within which a gear ratio is continuously variable in an area of a variator,
a first planetary gearset comprising first, second, third and fourth shafts being functionally connectable, via a plurality of shifting elements, with a second planetary gearset that comprises a plurality of shafts,
the second planetary gearset being functionally connectable with a transmission output shaft,
the first planetary gearset comprising the first, the second, the third and the fourth shafts and being functionally connectable, by way of the first shaft, with a transmission input shaft and a first shaft of the variator and by, way of the second shaft, being functionally connected to a second shaft of the variator,
the first planetary gearset being coupled, by way of the third shaft, to shifting element halves of two shifting elements and, by way of the fourth shaft, being coupled to a shifting element half of a further shifting element,
first and second driving-direction clutches being engagable in and disengagable from a force flow, and
gearwheel pairs associated with the first and the second driving-direction clutches, such that a rotational direction of the transmission output shaft corresponds to a rotational direction of the transmission input shaft when the first driving-direction clutch is engaged and is different therefrom when the second driving-direction clutch is engaged, and the transmission input shaft being functionally connectable with the first shaft of the first planetary gearset, via the first and the second driving-direction clutches, or the transmission output shaft being functionally connectable with the second planetary gearset, via the first and the second driving-direction clutches.

2. The continuously variable power-split transmission according to claim 1 , wherein the third shaft of the first planetary gearset is functionally connectable, via a first shifting element, with whose shifting element half the third shaft is coupled, with a first shaft of the second planetary gearset, and by a second shifting element, with whose shifting element half the third shaft of the first planetary gearset is also coupled, with a second shaft of the second planetary gearset.

3. The continuously variable power-split transmission according to claim 1 , wherein the fourth shaft of the first planetary gearset is couplable by the further shifting element with a first shaft of the second planetary gearset and a shifting element half of an additional shifting element, so that by the additional shifting element the fourth shaft of the first planetary gearset is functionally connectable with a second shaft or with a third shaft of the second planetary gearset.

4. The continuously variable power-split transmission according to claim 1 , wherein the fourth shaft of the first planetary gearset is couplable by the further shifting element to a first shaft of the second planetary gearset, while by an additional shifting element a second shaft of the second planetary gearset is functionally connectable with a third shaft of the second planetary gearset.

5. The continuously variable power-split transmission according to claim 1 , wherein a second shaft of the second planetary gearset is connectable by a shifting element, in a rotationally fixed manner, to a component fixed to a housing.

6. The continuously variable power-split transmission according to claim 1 , wherein in an area of the transmission input shaft a shifting element is provided, by which a drive machine of a vehicle drive-train made with the power-split transmission, that is couplable to the transmission input shaft, is functionally connectable with the first shaft of the first planetary gearset or is decouplable therefrom.

7. The continuously variable power-split transmission according to claim 1 , wherein the transmission input shaft is functionally connected to an electric machine.

8. The continuously variable power-split transmission according to claim 7 , wherein the first and the second driving-direction clutches are arranged in an area of the functional connection between the transmission input shaft and the first planetary gearset or in an area of the functional connection between the second planetary gearset and the transmission output shaft.

9. The continuously variable power-split transmission according to claim 1 , wherein the variator is in a form of a hydraulic variator with two hydraulic machines such that a displacement volume of at least one of the hydraulic machines is variable.

10. The continuously variable power-split transmission according to claim 1 , wherein the variator is an electric variator with two electric machines.

11. The continuously variable power-split transmission according to claim 1 , wherein the variator is functionally connected by way of the first shaft, directly, or via spur gears and/or via a first planetary gearset, to the first shaft of the first planetary gearset, and by way of the second shaft, directly, or via spur gears and/or via a first planetary gearset, to the second shaft of the first planetary gearset.

12. The continuously variable power-split transmission according to claim 1 , wherein at least two of the first planetary gearset, the second planetary gearset, the first and the second driving-direction clutches, the shifting elements and the variator are arranged coaxially with one another.

13. The continuously variable power-split transmission according to claim 1 , wherein at least two of the first planetary gearset, the second planetary gearset, the first and the second driving-direction clutches, the shifting elements and the variator are arranged offset from one another and on countershafts spaced apart from one another.

14. The continuously variable power-split transmission according to claim 1 , wherein the variator is arranged, in an axial direction, between the transmission input shaft and the first planetary gearset, coaxially with the first planetary gearset or, in a radial direction, offset relative to the first planetary gearset.

15. The continuously variable power-split transmission according to claim 1 , wherein the second shaft of the first planetary gearset, in an axial direction, is connected to the second shaft of the variator between the transmission input and the first planetary gearset, while the first shaft of the variator is functionally connected to the first shaft of the first planetary gearset, in the axial direction between the second planetary gearset and the transmission output.

16. The continuously variable power-split transmission according to claim 8 , wherein the first and the second driving-direction clutches are arranged radially offset relative to one another and, in an axial direction, in a common plane.

17. The continuously variable power-split transmission according to claim 15 , wherein the transmission input and the transmission output are arranged on a same side or in the axial direction on different sides.

18. The continuously variable power-split transmission according to claim 1 , wherein the first planetary gearset comprises a stepped planetary gearset and the first shaft of the first planetary gearset is connected to a sun gear of the stepped planetary gearset, the second shaft of the first planetary gearset is connected to a ring gear of the stepped planetary gearset, the third shaft of the first planetary gearset is connected to a planetary carrier of the stepped planetary gearset and the fourth shaft of the first pl

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Rechenbach Philipp
• Reick Benedikt

Classifications

• B60K6/543 Primary

  the transmission being a continuously variable transmission · CPC title

• F16H37/084

  at least one power path being a continuously variable transmission, i.e. CVT · CPC title

• F16H2037/0866

  Power-split transmissions with distributing differentials, with the output of the CVT connected or connectable to the output shaft · CPC title

• B60K2006/4825

  Electric machine connected or connectable to gearbox input shaft · CPC title

• B60K6/445

  Differential gearing distribution type · CPC title