System and method for camshaft vibration control

Patent metadata

Field	Value
Publication number	US-2017101902-A1
Application number	US-201514882198-A
Country	US
Kind code	A1
Filing date	Oct 13, 2015
Priority date	Oct 13, 2015
Publication date	Apr 13, 2017
Grant date	—

Abstract

A system includes a camshaft disposed along an axis from a drive end to a opposite end, and the camshaft includes a plurality of journals configured to support the camshaft and is spaced along the axis. The camshaft includes a plurality of cams spaced along the axis, and is disposed along the camshaft in sets, where each set is disposed between a respective pair of journals of the plurality of journals. The camshaft includes a plurality of mass portions, where each mass portion is disposed between a set of cams and a respective journal. The plurality of mass portions is disposed along the camshaft such that a center of mass of the plurality of mass portions is nearer to the drive end than to the opposite end, and the plurality of mass portions is configured to increase a natural frequency of the shaft.

First claim

1 . A system comprising:
a camshaft disposed along an axis from a drive end to a opposite end, wherein the camshaft comprises:
a plurality of journals configured to support the camshaft, wherein each journal of the plurality of journals is spaced along the axis;
a plurality of cams spaced along the axis, wherein the plurality of cams is disposed along the camshaft in sets, wherein each set is disposed between a respective pair of journals of the plurality of journals; and
a plurality of mass portions, wherein each mass portion of the plurality of mass portions is disposed between a set of cams of the plurality of cams and a respective journal of the plurality of journals, the plurality of mass portions is disposed along the camshaft such that a center of mass of the plurality of mass portions is nearer to the drive end than to the opposite end, and the plurality of mass portions is configured to increase a natural frequency of the camshaft.

2 . The system of claim 1 , wherein one or more mass portions of the plurality of mass portions is an extension of the respective journal of the plurality of journals.

3 . The system of claim 1 , wherein one or more mass portions of the plurality of mass portions is separate from the respective journal of the plurality of journals.

4 . The system of claim 1 , wherein the camshaft comprises a body having a body diameter, each journal of the plurality of journals comprises a journal diameter greater than the body diameter, and each mass portion of the plurality of mass portions comprises a mass diameter less than or equal to the journal diameter.

5 . The system of claim 1 , wherein each mass portion of the plurality of mass portions is offset an axial distance from the respective set of cams.

6 . The system of claim 1 , wherein the camshaft comprises a plurality sections coupled along the axis, wherein each section of the plurality of sections comprises:
a pair of journals of the plurality of journals; and a set of cams of the plurality of cams.

7 . The system of claim 6 , wherein one or more sections of the plurality of sections comprises a bore along the axis.

8 . The system of claim 6 , wherein the plurality of mass portions is only disposed on a first group of sections of the plurality of sections, wherein the first group of sections is proximate to the drive end, and a remainder second group of sections of the plurality of sections is proximate to the opposite end.

9 . The system of claim 1 , comprising a reciprocating engine, wherein the reciprocating engine comprises the camshaft.

10 . A system comprising:
a camshaft disposed along an axis from a drive end to an opposite end, wherein the camshaft comprises a first section coupled to a second section, the first section is nearer the drive end, and the second section is nearer the opposite end, wherein the first section comprises:
a first plurality of journals configured to support the camshaft, wherein each journal of the plurality of journals is spaced along the axis;
a first plurality of cams spaced along the axis, wherein the plurality of cams is disposed along the camshaft in sets, wherein each set is disposed between a respective pair of journals of the plurality of journals; and
a first plurality of mass portions, wherein each mass portion of the plurality of mass portions is disposed between a set of cams of the plurality of cams and a respective journal of the plurality of journals; and
wherein the second section comprises:
a plurality of journal configured to support the camshaft, wherein each journal of the plurality of journals is spaced along the axis;
a plurality of cams spaced along the axis, wherein the plurality of cams is disposed along the camshaft in sets, wherein each set is disposed between a respective pair of journals of the plurality of journals; and
wherein the first plurality of mass portions is disposed along the camshaft such that a center of mass of the plurality of mass portions is nearer to the drive end than to the opposite end, and the plurality of mass portions is configured to increase a natural frequency of the shaft.

11 . The system of claim 10 , wherein a first mass portion of the plurality of the mass portions is disposed between the first section and the second section.

12 . The system of claim 10 , wherein the first and second sets of cams each comprise a first diameter, and the first and second pairs of journals each comprise a second diameter, wherein the second diameter is greater than the first diameter.

13 . The system of claim 12 , wherein the mass portions each comprise a third diameter, wherein the third diameter equals the second diameter.

14 . The system of claim 12 , wherein the third diameter is greater than the second diameter.

15 . The system of claim 10 , wherein the first section comprises a majority of the sections.

16 . The system of claim 10 , wherein at least one of the mass portions is coupled to at least one of the journal portions.

17 . The system of claim 10 , comprising a reciprocating engine, wherein the reciprocating engine comprises the camshaft.

18 . The system of claim 10 , wherein at least one of the mass portions is separate from at least one of the journal portions.

19 . A method of assembling a camshaft comprising:
coupling a first end of a first camshaft segment to a second drive end of a second camshaft segment along a camshaft axis, wherein the first camshaft segment comprises:
a first plurality of journals spaced along the camshaft axis;
a first plurality of cams spaced along the camshaft axis, wherein the first plurality of cams is disposed along the camshaft axis in first sets, and each first set is disposed between a respective pair of journals of the first plurality of journals; and
a first plurality of mass portions, wherein each mass portion of the first plurality of mass portions is disposed between a first set of cams of the first plurality of cams and a respective journal of the plurality of journals;
wherein the second camshaft segment comprises:
a second plurality of journals spaced along the camshaft axis;
a second plurality of cams spaced along the camshaft axis, wherein the second plurality of cams is disposed along the camshaft axis in second sets, and each second set is disposed between a respective pair of journals of the second plurality of journals;
wherein the first plurality of mass portions is disposed along the camshaft such that a center of mass of the first plurality of mass portions is nearer to a first drive end of the first camshaft segment than to a second end of the second camshaft segment, the first plurality of mass portions is configured to increase a natural frequency of the camshaft, the first drive end of the first camshaft segment is opposite the first end, and the second drive end of the second camshaft segment is opposite the second end.

20 . The method of claim 19 , comprising coupling first drive end of the first camshaft segment to a drive train of an engine.

Assignees

• Gen Electric

Inventors

• Martyn James Hugo
• Rauch Christian
• Rivellini Sandro

Classifications

• F01L1/08 Primary

  Shape of cams · CPC title

• F01L1/047 Primary

  Camshafts · CPC title

• F16F15/20

  Suppression of vibrations of rotating systems by favourable grouping or relative arrangements of the moving members of the system or systems {(F16F15/24 takes precedence)} · CPC title

• F01L2820/01

  Absolute values · CPC title

• F01L2810/03

  Reducing vibration · CPC title