Continuously variable power-split transmission

Patent metadata

Field	Value
Publication number	US-11047460-B2
Application number	US-201816771724-A
Country	US
Kind code	B2
Filing date	Nov 16, 2018
Priority date	Dec 13, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A continuously variable power-split transmission having a planetary gear mechanism arrangement. The planetary gear mechanism arrangement has three planetary gear sets, an input shaft and three output shafts. Furthermore, the transmission has a change-speed gearbox connected to the output shafts, a reverse gear mechanism and a variator. Each of the three planetary gear sets is assigned a respective output shaft. The input shaft is operatively connected in each of the three planetary gear sets via a respective gearwheel pairing to a respective output shaft. The transmission can be shifted by the change-speed gearbox and the reverse gear mechanism into at least eight driving ranges. The variator varies a transmission ratio of the transmission within the driving ranges in a continuously variable manner. The variator is continuously operatively connected to a single one of the three planetary gear sets.

First claim

The invention claimed is:

1. A continuously variable power-split transmission comprising a planetary gear mechanism arrangement having first, second and third planetary gear sets, an input shaft and first second and third output shafts, a change-speed gearbox which is connected to the first, the second and the third output shafts,
a reverse gear mechanism, and
a variator,
each of the first, the second and the third planetary gear sets being assigned, in each case, one of the first, the second and the third output shafts and the input shaft being operatively connected in each of the first, the second and the third planetary gear sets via, in each case, one gearwheel pairing to, in each case, one of the first, the second and the third output shafts,
the transmission being shiftable, by the change-speed gearbox and the reverse gear mechanism, into at least eight driving ranges, and
the variator is set up to vary a transmission ratio of the transmission within the at least eight driving ranges, in each case, in a continuously variable manner and the variator being continuously operatively connected to a single planetary gear set of the first, the second and the third planetary gear sets.

2. The continuously variable power-split transmission according to claim 1 , wherein the variator has two energy converters which are connected together and which, in each case, have one output shaft, which are continuously connected to the single planetary gear set via one or more spur gear stages.

3. The continuously variable power-split transmission according to claim 2 , wherein the two energy converters are electric machines with a power electronics unit.

4. The continuously variable power-split transmission according to claim 2 , wherein the two energy converters provide electric power, via an intermediate circuit, for a consumer.

5. The continuously variable power-split transmission according to claim 1 , wherein in the first planetary gear set, the input shaft is connected to a first planetary arrangement, the first output shaft is connected to a first ring gear, and a connecting shaft is connected to a first sun gear;
in the second planetary gear set, the input shaft is connected to a second ring gear, the second output shaft is connected to a second planetary arrangement and the connecting shaft is connected to a second sun gear, and
in the third planetary gear set, the input shaft is connected to a third planetary arrangement, the connecting shaft is connected to a third ring gear and the third output shaft is connected to a third sun gear.

6. The continuously variable power-split transmission according to claim 5 , wherein at least one of:
the third ring gear and the third output shaft are continuously operatively connected to the variator, and
the first, the second and the third planetary gear sets are arranged, in an input shaft direction, in a sequence of the first planetary gear set, the second planetary gear set and the third planetary gear set.

7. The continuously variable power-split transmission according to claim 6 , wherein the third ring gear is in engagement with a fixed gear on an output shaft of a first energy converter of the variator, via an external toothing provided on the third ring gear, and the third output shaft is operatively connected to an output shaft of a second energy converter of the variator via two spur gear stages.

8. The continuously variable power-split transmission according to claim 1 , wherein the first, the second and the third planetary gear sets have identical gear ratios.

9. The continuously variable power-split transmission according to claim 1 , wherein the change-speed gearbox is a spur gear mechanism which, for producing the at least eight driving ranges (FB 1 to FB 10 ), is able to bring three gears, which are continuously operatively connected to the first, the second and the third output shafts of the planetary gear mechanism arrangement, selectively into an operative connection with an output shaft of the change-speed gearbox via gearwheel pairings which may be engaged and disengaged.

10. The continuously variable power-split transmission according to claim 9 , wherein the change-speed gearbox has a first input shaft with a fixed gear and an idler gear which is fixedly connectable, in terms of rotation, to the first input shaft of the change-speed gearbox via a shifting element, a second input shaft of the change-speed gearbox which is coaxial to the first input shaft of the change-speed gearbox with four idler gears which are fixedly connectable, in terms of rotation, to the second input shaft of the change-speed gearbox via shifting elements, and the output shaft of the change-speed gearbox has three fixed gears, one of the three fixed gears are in engagement with the idler gear of the first input shaft and two of the three fixed gears are in engagement with idler gears of the second input shaft.

11. The continuously variable power-split transmission according to claim 10 , wherein a first idler gear of the four idler gears of the second input shaft is in engagement with a fixed gear of the second output shaft and a second idler gear of the second input shaft is in engagement with a fixed gear of the third output shaft.

12. The continuously variable power-split transmission according to claim 10 , wherein the first input shaft of the change-speed gearbox has a further idler gear which is fixedly connectable, in terms of rotation, to the first input shaft of the change-speed gearbox via a shifting element, and the output shaft of the change-speed gearbox has a further fixed gear which is in engagement with the idler gear of the first input shaft of the change-speed gearbox.

13. The continuously variable power-split transmission according to claim 9 , wherein the output shaft of the change-speed gearbox is a hollow shaft which is coaxial to the input shaft of the planetary gear mechanism arrangement.

14. The continuously variable power-split transmission ( 1 ; 2 ; 3 ; 4 ) according to claim 1 , wherein for implementing different rotational directions of the transmission output shaft, the input shaft of the planetary gear mechanism arrangement is operatively connectable with the transmission input shaft via the reverse gear mechanism, or
for implementing different rotational directions of the transmission output shaft, the output shaft of the change-speed gearbox may be brought into an operative connection with the transmission output shaft via a reverse gear mechanism.

15. The continuously variable power-split transmission according to claim 1 , wherein a power take-off shaft which is fixedly connected, in terms of rotation, to the transmission input shaft, and at least one of:
the transmission input shaft is arranged coaxially to the power take-off shaft, and/or
the transmission output shaft is arranged offset in parallel to the transmission input shaft and the input shaft of the planetary gear mechanism.

16. A continuously variable power-split transmission comprising:
a planetary gear mechanism arrangement having first, second and third planetary gear sets, an input shaft and first second and third output shafts;
a change-speed gearbox which is connected to the first, the second and the third output shafts of the planetary gear mechanism arrangement;
a reverse gear mechanism; and
a variator;
the first planetary gear set being assigned to the first output shaft, the second planetary gear set being assigned to the second output shaft, and the third planetary gear set being assigned to the third output shaft, and the input shaft of the planetary g

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Reick Benedikt
• Beck Stefan
• Rechenbach Philipp
• Himmelsbach Raphael

Classifications

• F16H2037/0866

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

• F16H3/60

  Gearings for reversal only · CPC title

• Y02T10/62

  Hybrid vehicles · CPC title

• F16H3/728

  with means to change ratio in the mechanical gearing · CPC title

• B60K6/445

  Differential gearing distribution type · CPC title