Balance shaft assembly

Patent metadata

Field	Value
Publication number	US-11754145-B2
Application number	US-201917293366-A
Country	US
Kind code	B2
Filing date	Nov 12, 2019
Priority date	Nov 16, 2018
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A balance shaft includes an unbalanced shaft ( 3 ) comprising a bearing journal ( 8, 9 ), the periphery of which is merely partially cylindrical. The cylindrical partial periphery ( 10 ) of the bearing journal is oriented toward the shaft imbalance. The balance shaft also includes a needle roller cage assembly ( 15 ); and a bearing ring ( 13 ), which extends around the bearing journal, lies against the cylindrical partial periphery and forms the inner raceway of the needle roller cage assembly. The cage ( 27 ) of the needle roller cage assembly is designed to run on the end faces of the bearing ring axially on both sides by means of radially inwardly extending projections.

First claim

What is claimed is:

1. A balance shaft assembly comprising:
an unbalanced shaft comprising a bearing journal, a periphery of the bearing journal including a cylindrical partial periphery oriented toward a shaft imbalance;
a needle roller cage assembly; and
a bearing ring extending around the bearing journal, the bearing ring lying against the cylindrical partial periphery and forming an inner raceway of the needle roller cage assembly,
a cage of the needle roller cage assembly being configured to run on end faces of the bearing ring axially on both sides by radially inwardly extending projections.

2. The balance shaft assembly as recited in claim 1 , wherein an axial start-up of the cage on the bearing ring is fully circumferential, wherein the cage is supported on at least three contact points on each side on the bearing ring and a circumferential distance between two adjacent contact points of the at least three contact points is always less than 180°.

3. The balance shaft assembly as recited in claim 1 , wherein the radially inwardly extending projections of the cage are full circumferential rims and the end faces of the bearing ring are formed by full circumferential rims extending radially inwardly opposite an inner circumferential surface of the bearing ring, the bearing journal having circumferential undercuts axially on both sides of the cylindrical partial periphery, in which the full circumferential rims of the bearing ring are received without contact.

4. The balance shaft assembly as recited in claim 1 , wherein the bearing journal has a bearing journal back lying radially opposite the cylindrical partial periphery and, together with the bearing ring delimits a free space, the balance shaft assembly further comprising a clamping element clamped in the free space, the clamping element clamping the bearing ring radially against the cylindrical partial periphery.

5. The balance shaft assembly as recited in claim 4 , wherein the clamping element is configured for securing the bearing ring against axial sliding on both sides on the bearing journal, such that the clamping element is connected in an axially form-fitting manner both to the unbalanced shaft and to the bearing ring.

6. The balance shaft assembly as recited in claim 5 , wherein the axially form-fitting manner between the clamping element and the unbalanced shaft is formed by a groove in the bearing journal back, groove walls of the groove axially enclosing axial end faces of the clamping element with either no or low play.

7. The balance shaft assembly as recited in claim 5 , wherein the axially form-fitting manner between the clamping element and the bearing ring is formed such that the radially inwardly extending projections of the cage axially enclose axial end faces of the clamping element with either no or low play.

8. A method of forming a balance shaft assembly comprising:
providing an unbalanced shaft comprising unbalanced sections adjoined by bearing journals, a periphery of each of the bearing journals being partially cylindrical and including a partially cylindrical periphery and a non-cylindrical bearing journal back; and
installing a bearing ring and a needle roller cage assembly on each of the bearing journals, the bearing rings each lying against the respective partially cylindrical periphery and forming an inner raceway of the respective needle roller cage assembly, each of the needle roller cage assemblies including a cage having radially inwardly extending projections contacting axial end faces of the respective bearing ring axially on both sides.

9. The method as recited in claim 8 further comprising clamping a respective clamping element on each of the bearing journals radially between the non-cylindrical bearing journal back and an inner circumferential surface of the respective bearing ring.

10. A balance shaft assembly comprising:
an unbalanced shaft comprising unbalanced sections adjoined by a bearing journal, a periphery of the bearing journal being partially cylindrical and including a partially cylindrical periphery and a non-cylindrical bearing journal back;
a bearing ring extending around the bearing journal, the bearing ring contacting the cylindrical partial periphery; and
a needle roller cage assembly, the bearing ring forming an inner raceway of the needle roller cage assembly, the needle roller cage assembly including a cage having radially inwardly extending projections contacting axial end faces of the bearing ring axially on both sides.

11. The balance shaft assembly as recited in claim 10 further comprising a clamping element on the bearing journal configured for being positioned radially between the non-cylindrical bearing journal back and an inner circumferential surface of the bearing ring.

12. The balance shaft assembly as recited in claim 11 wherein the clamping element is a metal clip that configured for being clamped radially under elastic deformation in a free space between the non-cylindrical bearing journal back and the inner circumferential surface of the bearing ring.

13. The balance shaft assembly as recited in claim 12 wherein the elastic deformation forces the inner circumferential surface of the bearing ring against the partially cylindrical periphery.

14. The balance shaft assembly as recited in claim 10 wherein radially inwardly extending projections of the cage are formed by circumferential rims of the cage and the axial end faces of the bearing ring are formed by circumferential rims of the bearing ring.

15. The balance shaft assembly as recited in claim 14 wherein the bearing journal includes undercuts on both axial sides of the partially cylindrical periphery, the circumferential rims of the bearing ring being received in the undercuts.

16. The balance shaft assembly as recited in claim 15 wherein the circumferential rims of the bearing ring are axially spaced from the periphery of the bearing journal at the undercuts.

17. The balance shaft assembly as recited in claim 15 wherein the circumferential rims of the cage are radially spaced from the periphery of the bearing journal at the undercuts.

18. The balance shaft assembly as recited in claim 14 further comprising a clamping element on the bearing journal configured for being positioned radially between the non-cylindrical bearing journal back and an inner circumferential surface of the bearing ring, the circumferential rims of the bearing ring axially enclosing a partially cylindrical section of the clamping element.

Assignees

• Schaeffler Technologies Ag

Inventors

• Schreyer Hannes
• Dorn Stefan

Classifications

• F16F15/267 Primary

  characterised by bearing support of balancer shafts; Lubrication arrangements · CPC title

• F16C3/20

  Shape of crankshafts or eccentric-shafts having regard to balancing · CPC title

• F16C19/463

  consisting of needle rollers held in a cage, i.e. subunit without race rings · CPC title

• F16C21/00

  Combinations of sliding-contact bearings with ball or roller bearings, for exclusively rotary movement (F16C17/24, F16C19/52 take precedence) · CPC title

• F16C2360/22

  Internal combustion engines · CPC title