Power-split continuously variable transmission apparatus having a summing planetary transmission

Patent metadata

Field	Value
Publication number	US-9810300-B2
Application number	US-201415035394-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Nov 14, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A power-split, continuously variable transmission includes a summing planetary transmission, at least one additional planetary gear set and a variator, which are in operative connection with each other a plurality of shafts, the shafts of the plurality of shafts are couplable to each other with a plurality of shift elements in order to provide at least three transmission ratio ranges. The variator is a mechanical friction wheel variator with at least three shafts. The summing planetary transmission, the at least one additional planetary gear and the variator are arranged coaxial to one another. In one of the transmission ratio ranges of the at least three transmission ratio ranges, a total power is guidable between a transmission input shaft and a transmission output shaft by the variator. A friction wheel of the variator is approximately cone-shaped, at least in sections.

First claim

The invention claimed is:

1. A power-split, continuously variable transmission device, comprising:
an input shaft;
an output shaft;
a summing planetary transmission, the summing planetary transmission comprising a sun gear, a carrier and a ring gear;
at least one planetary gear set;
a variator, the variator being a mechanical friction wheel variator having at least three shafts, a friction wheel of the variator being approximately cone-shaped, at least in sections, the at least three shafts of the variator comprising a first shaft, a second shaft and a third shaft;
a first plurality of shafts, the summing planetary transmission, the at least one planetary gear set and the variator in operative connection with one another by the shafts of the first plurality of shafts;
a second plurality of shafts;
a plurality of shift elements, the shafts of the second plurality of shafts couplable with the plurality of shift elements for presentation of at least three transmission ratio ranges; and
an additional planetary gear set allocated to the variator, one shaft of the additional planetary gear set coupled with the third shaft of the variator, at least one additional shaft of the additional planetary gear set coupled with the first shaft of the variator or is connectable with the first shaft of the variator with one of the shift elements of the plurality of shift elements that is in operative connection with the input shaft,
wherein a continuously variable transmission ratio of the at least three transmission ratio ranges is provided by the variator,
wherein the summing planetary transmission, the at least one planetary gear set and the variator are arranged coaxial to one another, and
wherein, in one of the at least three transmission ratio ranges, a total power is guidable between the input shaft and the output shaft by the variator.

2. The power-split, continuously variable transmission of claim 1 , wherein the first shaft of the variator is operatively connected to the input shaft, the second shaft of the variator is operatively connected to the output shaft, and the third shaft of the variator is rotationally fixed.

3. The power-split, continuously variable transmission of claim 2 , wherein one shaft of the at least one planetary gear set is coupleable with the input shaft with one of the shift elements of the plurality of shift elements.

4. The power-split, continuously variable transmission of claim 2 , wherein the first shaft of the variator is in operative connection to the input shaft through the additional planetary gear set.

5. The power-split, continuously variable transmission of claim 2 , wherein the first shaft of the variator is connectable by one of the shift elements of the plurality of shift elements to a shaft of the at least one planetary gear set designed as a sun gear, the first shaft of the variator also connectable by an additional shift element of the plurality of shift elements to another shaft of the at least one planetary gear set designed as a carrier.

6. The power-split, continuously variable transmission of claim 2 , wherein the second shaft of the variator is coupled to the output shaft with a shaft formed as a sun gear of the summing planetary transmission and with a shaft formed as a ring gear of the summing planetary transmission.

7. The power-split, continuously variable transmission of claim 6 , wherein a carrier of the at least one planetary gear set is connected to a shaft of the summing planetary transmission formed as the carrier.

8. The power-split, continuously variable transmission of claim 1 , wherein the summing planetary transmission is blocked by one of the plurality of shift elements during presentation of one of the at least three transmission ratio ranges in which an overall power flow between the input shaft and the output shaft is guidable by the variator.

9. The power-split, continuously variable transmission of claim 1 , wherein the variator, the summing planetary transmission and the at least one planetary gear set are matched with one another such that a change between the transmission ratio ranges of the at least three transmission ratio ranges is approximately synchronous.

10. The power-split, continuously variable transmission of claim 1 , wherein the at least three transmission ratio ranges are presentable with exactly three shift elements of the plurality of shift elements, each shift element of the plurality of shift elements being closed in a respective one of the at least three transmission ratio ranges and the others of the plurality of shift elements being open, each closed shift element opening during a transmission ratio range change.

11. The power-split, continuously variable transmission of claim 1 , wherein the variator comprises a ring gear having friction surfaces and a sun gear also having friction surfaces, the friction wheel formed as a planetary gear, the planetary gear formed at least in sections with cone shape areas, the cone-shape areas in frictional-locking operative connection with the friction surfaces of the ring gear and the friction surfaces of the sun gear.

12. The power-split, continuously variable transmission of claim 11 , wherein the planetary gear is formed as a double truncated cone, a radius of the double truncated cone of the planetary gear steadily increasing or steadily decreasing from areas of the truncated cone turned towards each other, the ring gear and the sun gear formed to be split, a first part of the ring gear and of the sun gear contacting a first truncated cone area of the planetary gear with conical friction surfaces, a second part of the ring gear and of the sun gear contacting a second truncated cone area of the planetary gear with the conical friction surfaces.

13. The power-split, continuously variable transmission of claim 12 , wherein, the first and second parts of the ring gear and the sun gear are movable to and from each other in order to vary the transmission ratio of the variator, the planetary gear radially adjustable relative to the ring gear and the sun gear and relative to a planetary carrier, in which the planetary gear is rotatably mounted.

14. The power-split, continuously variable transmission of claim 1 , wherein the ring gear of the summing planetary transmission is in operative connection with the output shaft.

15. A power-split, continuously variable transmission device, comprising:
an input shaft;
an output shaft;
a summing planetary transmission, the summing planetary transmission comprising a sun gear, a carrier and a ring gear;
at least one planetary gear set;
a variator, the variator being a mechanical friction wheel variator having at least three shafts, a friction wheel of the variator being approximately cone-shaped, at least in sections;
a first plurality of shafts, the summing planetary transmission, the at least one planetary gear set and the variator in operative connection with one another by the shafts of the first plurality of shafts;
a second plurality of shafts; and
a first plurality of shift elements, the shafts of the second plurality of shafts couplable with the plurality of shift elements for presentation of at least three transmission ratio ranges,
wherein a continuously variable transmission ratio of the at least three transmission ratio ranges is provided by the variator,
wherein the summing planetary transmission, the at least one planetary gear set and the variator are arranged coaxial to one another,
wherein, in one of the at least three transmission ratio ranges, a total power is guidable between the input shaft and the output shaft by the variator, an

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Warth Viktor
• Reisch Matthias
• Sich Bernhard

Classifications

• F16H2037/0893

  characterised in that the ratio of the continuously variable transmission is different from zero when the output shaft speed is zero · CPC title

• F16H15/52

  in which a member of uniform effective diameter mounted on a shaft may co-operate with different parts of another member · CPC title

• F16H2037/0886

  with switching means, e.g. to change ranges · CPC title

• F16H37/0853 Primary

  CVT using friction between rotary members having a first member of uniform effective diameter cooperating with different parts of a second member · CPC title