Engine crankshaft including a planetary gear balance unit

Patent metadata

Field	Value
Publication number	US-2016298722-A1
Application number	US-201615093100-A
Country	US
Kind code	A1
Filing date	Apr 7, 2016
Priority date	Apr 8, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

Methods and systems are provided for an engine crankshaft including an un-balanced mass coupled to a planetary gear set driven by the engine crankshaft. In one example, a system may include an engine crankshaft as a sun gear for a planetary gear set, with a single un-balanced mass coupled to an outer ring of the planetary gear set. In another example, a method may include driving an engine crankshaft in a first direction and driving an un-balanced mass coupled to an outer ring of a planetary gear set in a second direction opposite to the first direction, with rotation of the outer ring being driven by the engine crankshaft.

First claim

1 . A crankshaft, comprising:
a shaft formed about a rotation axis, and at least one connecting rod bearing coupled to the shaft, wherein the crankshaft has at least one balance unit formed from a planetary gear set arranged concentrically to the shaft and at least one un-balanced mass attached to the planetary gear set, wherein the planetary gear set comprises a first stage and a second stage, wherein the first stage has a plurality of first planet gears, a first planet carrier and a first ring gear, and the second stage has a plurality of second planet gears, a second planet carrier and a second ring gear; wherein the shaft is configured as a sun gear of the planetary gear set, and wherein the first ring gear and the second planet carrier are connected together rotationally fixedly, and the at least one un-balanced mass is attached to the second ring gear.

2 . The crankshaft of claim 1 , wherein the first planet gears each have a radius half of a radius of the sun gear of the planetary gear set, wherein the first ring gear has a radius twice the radius of the sun gear of the planetary gear set, wherein the second planet gears each have a same radius as the radius of the sun gear of the planetary gear set, and wherein the second ring gear has a radius three times the radius of the sun gear of the planetary gear set.

3 . The crankshaft of claim 1 , wherein the crankshaft has at least one function unit and the at least one balance unit is integrated in the at least one function unit.

4 . The crankshaft of claim 1 , wherein the crankshaft has three connecting rod bearings and wherein an angle between two connecting rod bearings is 120°.

5 . The crankshaft of claim 1 , wherein the first planet carrier is arranged rotationally fixedly to a housing of an internal combustion engine.

6 . A system comprising:
an engine crankshaft; and a first planetary gear set directly coupled to and driven by the engine crankshaft, wherein the first planetary gear set includes a first outer ring, and wherein the first outer ring rotates in a direction opposite to rotation of the engine crankshaft.

7 . The system of claim 6 , wherein the system includes exactly two planetary gear sets directly coupled to the crankshaft, the gear sets including the first planetary gear set and a second planetary gear set directly coupled to and driven by the engine crankshaft, wherein the second planetary gear set includes a second outer ring, and wherein the second outer ring rotates in a direction opposite to rotation of the engine crankshaft.

8 . The system of claim 7 , wherein the first outer ring and the second outer ring rotate at a same speed as the crankshaft.

9 . The system of claim 8 , wherein rotation of the first outer ring and the second outer ring is driven by the engine crankshaft.

10 . The system of claim 9 , wherein the crankshaft forms a sun gear of the first planetary gear set and the second planetary gear set.

11 . The system of claim 10 , wherein the sun gear of the first and second planetary gear sets rotates in an opposite direction to the first and second outer rings.

12 . The system of claim 11 , wherein the first and second planetary gear sets are rotationally symmetric planetary gear sets.

13 . The system of claim 12 , wherein the first outer ring includes exactly one first un-balanced mass, and the second outer ring includes exactly one second un-balanced mass.

14 . The system of claim 13 , wherein the exactly one first un-balanced mass is directly coupled to an outer circumferential surface of the first outer ring of the first planetary gear set, and wherein the exactly one second un-balanced mass is directly coupled to an outer circumferential surface of the second outer ring of the second planetary gear set.

15 . The system of claim 14 , wherein a sun gear of the first and second planetary gear sets does not have any un-balanced masses.

16 . The system of claim 15 , wherein the system includes a one-way clutch and a brake directly coupled to the first and second planetary gear sets.

17 . A method comprising:
driving a planetary gear set directly attached to an engine crankshaft via rotation of the engine crankshaft, with an outer ring of the planetary gear set rotating in a direction opposite to a direction of rotation of the engine crankshaft.

18 . The method of claim 17 , wherein the method further comprises driving an un-balanced mass directly coupled to the outer ring of the planetary gear set, which includes driving the engine crankshaft in a first direction and driving the outer ring of the planetary gear set in a second direction opposite to the first direction.

19 . The method of claim 18 , further comprising driving the outer ring of the planetary gear set at a rate asynchronous to the rotation of the engine crankshaft by disengaging a one-way clutch directly coupled to the planetary gear set.

20 . The method of claim 19 , further comprising decelerating the rotation of the outer ring of the planetary gear set by actuating a brake directly coupled to the planetary gear set.

Assignees

• Ford Global Tech Llc

Inventors

• Khosravi Maziar
• Quiring Stefan
• Lutz Martin

Classifications

• F16H1/46

  Systems consisting of a plurality of gear trains each with orbital gears, {i.e. systems having three or more central gears} · CPC title

• F16F15/26 Primary

  of crankshaft systems using solid masses, other than the ordinary pistons, moving with the system {, i.e. masses connected through a kinematic mechanism or gear system (F16F15/226 takes precedence)} · CPC title

• F02B75/32

  Engines characterised by connections between pistons and main shafts and not specific to preceding main groups · CPC title

• F16H1/28

  with gears having orbital motion · CPC title