Torsionally compliant sprocket system for balance shaft drive

• US 6,109,227 A
• Filed: 09/17/1998
• Issued: 08/29/2000
• Est. Priority Date: 09/17/1998
• Status: Expired due to Term

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Mott, Philip J.
• Primary Examiner(s): Lo, Weilun
• Application Number:
  US09/154,814
• Time in Patent Office: 712 Days
• Field of Search: 123/90.31, 123/192.2, 74/574, 74/573 R, 74/443, 74/440, 74/411, 474/94, 474/903, 464/180
• US Class Current: 123/90.31
• CPC Class Codes: F16F 15/264 Rotating balancer shafts F16F15/262 takes precedence
• CPC Class Codes: F16H 2055/306 with means providing resilience or vibration damping in chain sprocket wheels
• CPC Class Codes: F16H 2055/366 with means providing resilience or vibration damping
• CPC Class Codes: F16H 55/30 Chain-wheels
• CPC Class Codes: F16H 55/36 Pulleys with features essential for adjustment F16H55/52
• CPC Class Codes: F16H 7/06 with chains
• CPC Class Codes: Y10T 74/19633 Yieldability in gear trains
• CPC Class Codes: Y10T 74/2131 Damping by absorbing vibration force [via rubber, elastomeric material, etc.]

Abstract

The present invention relates to a torsionally compliant sprocket assembly which reduces the transfer of the crankshaft torsional oscillations to other components in the engine such as the balance shaft drives. The assembly comprises a first sprocket, second sprocket and a planar torsion spring located between the two sprockets and the shaft.

Claims

1. An engine timing system comprising:

a crankshaft having a crankshaft drive sprocket and a balance shaft drive sprocket mounted thereon;

at least one camshaft having a camshaft sprocket thereon;

a first timing chain connecting the crankshaft sprocket with the camshaft sprocket;

a balance shaft having at least one driven sprocket thereon;

a second timing chain drivingly connecting said balance shaft drive sprocket and said balance shaft driven sprocket;

planar torsion spring positioned between said crankshaft drive sprocket and said balance shaft drive sprocket, said torsion spring permitting limited relative movement between said balance shaft drive sprocket and said crankshaft.

2. An engine timing system as claimed in claim 1 wherein said planar torsion spring is concentrically disposed about said crankshaft.

3. An engine timing system as claimed in claim 1, wherein said planar torsion spring is attached to said balance shaft drive sprocket.

4. An engine timing system as claimed in claim 3 wherein said planar torsion spring is attached to said crankshaft.