Counterbalance gear with shot damper

Patent metadata

Field	Value
Publication number	US-10473185-B2
Application number	US-201715643627-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 7, 2017
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

An engine system has a crankshaft gear coupled to an engine crankshaft and a balance gear coupled to a balance shaft. The balance gear is formed by a disc having first and second opposite sides and a series of teeth. A first sector of the disc has at least one aperture therethrough, and a second opposite sector of the disc defines a recess intersecting the first side. The balance gear has a damper formed by a cover plate connected to the first side to enclose the recess and contain a plurality of particles therein. A gear and a method of forming a gear is also provided, with the gear having a first sector defining at least one aperture therethrough and a second sector defining a recess intersecting the first side. A plurality of particles are positioned in the recess, and a cover plate encloses the recess to form a damper.

First claim

What is claimed is:

1. An engine system comprising:
a crankshaft gear coupled to a crankshaft of an engine for rotation therewith; and
a balance gear coupled to a balance shaft for rotation therewith, the balance gear formed by a disc having first and second opposite sides extending radially outwardly to a circumferential edge, the circumferential edge defining a series of teeth extending between the first and second sides, the series of teeth of the disc of the balance gear in meshed engagement with the crankshaft gear, a first sector of the disc having at least one aperture therethrough, the at least one aperture intersecting the first and second sides of the disc, and a second opposite sector of the disc defining a recess intersecting the first side, the balance gear having a damper comprising a cover plate connected to the first side of the disc to enclose the recess and contain a plurality of particles therein, wherein the at least one aperture is empty such that the balance gear is eccentrically weighted by the damper and the at least one aperture.

2. The engine system of claim 1 wherein the balance shaft has an eccentric weight connected thereto for rotation therewith; and
wherein the damper of the balance gear is radially opposite to the eccentric weight.

3. The engine system of claim 1 further comprising a sealing member positioned between the cover plate and the disc to seal the recess.

4. The engine system of claim 1 wherein the cover plate and recess cooperate to define a volume for the damper; and
wherein the plurality of particles fills between eighty and ninety percent of the volume.

5. The engine system of claim 1 wherein the plurality of particles comprises steel shot.

6. A balance gear for a vehicle shaft comprising:
a disc having first and second opposite sides extending radially outwardly to an edge defining a series of teeth, the disc having a first sector defining at least one aperture therethrough and a second sector defining a recess intersecting the first side;
a plurality of particles positioned in the recess; and
a cover plate connected to the first side of the disc to enclose the recess, wherein the cover plate, the recess, and the plurality of particles cooperate to form a damper for the balance clear;
wherein the at least one aperture intersects the first and second opposite sides of the disc and remains empty such that the balance clear is eccentrically weighted by the damper and the at least one aperture.

7. The balance gear of claim 6 wherein the first sector and the second sector are opposed to one another such that the balance gear is counterweighted.

8. The balance gear of claim 6 wherein the first sector provides a first half disc, and the second sector provides a second half disc.

9. The balance gear of claim 6 wherein the recess and the cover plate cooperate to define a volume therebetween.

10. The balance gear of claim 9 wherein the volume is in a range of 10-40 percent of the volume of the second sector.

11. The balance gear of claim 10 wherein each particle in the plurality of particles has a diameter 1000 orders of magnitude smaller than the volume.

12. The balance gear of claim 9 wherein the plurality of particles is provided to fill between seventy and ninety percent of the volume.

13. The balance gear of claim 6 wherein an outer surface of the cover plate and the first side of the disc are coplanar with one another.

14. The balance gear of claim 6 wherein the disc defines the recess with an end wall and a side wall, the end wall spaced apart from the second side of the disc, the side wall intersecting the first side of the disc.

15. The balance gear of claim 14 wherein the end wall extends parallel to the second side of the disc.

16. The balance gear of claim 6 wherein the recess is the sole recess in the disc receiving particles and enclosed by the cover plate.

17. A method of forming a balance gear for a vehicle balance shaft comprising:
forming a disc having first and second opposite sides extending radially outwardly to a circumferential edge;
forming a series of teeth on the circumferential edge;
forming a single recess into the disc, the recess intersecting the first side of the disc and extending to a blind depth therein, the recess extending adjacent to the circumferential edge;
forming at least one aperture in the disc, the at least one aperture intersecting the first and second sides of the disc such that the at least one aperture extends through the disc, and the at least one aperture being radially opposed to the recess;
providing a plurality of shot particles into the recess to a specified fill fraction; and
attaching a cover plate to the first side of the disc to enclose the recess, retain the plurality of shot particles therein, and form an internal damper in the balance gear;
wherein a volume of the internal damper, the specified fill fraction, and a diameter of shot particles are sized to damp whine caused by at least second orders of distortion of the balance gear; and
wherein the at least one aperture is empty such that the balance gear is eccentrically weighted by the internal damper and the at least one aperture.

18. The method of claim 17 further comprising positioning a sealing member between the cover plate and the disc to seal the recess.

19. The engine system of claim 1 wherein the recess is the sole recess in the disc receiving particles and enclosed by the cover plate.

Assignees

• Ford Global Tech Llc

Inventors

• Zouani Abdelkrim

Classifications

• F16H55/17

  Toothed wheels (worm wheels F16H55/22; chain wheels F16H55/30) · 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

• B23P15/14

  gear parts, e.g. gear wheels · CPC title

• F16F15/262 Primary

  Masses attached to pinions, camshafts or driving shafts for auxiliary equipment, e.g. for an oil pump · CPC title

• B23F17/00

  Special methods or machines for making gear teeth, not covered by the preceding groups · CPC title