Chain tensioner and chain transmission device

Patent metadata

Field	Value
Publication number	US-9587720-B2
Application number	US-201214370807-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Jan 10, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A chain guide is provided which reduces moving resistance of a camshaft-driving, torque-transmitting timing chain. The chain guide includes a guide base provided on one side of the timing chain to face the timing chain and having an opposed pair of side plates. The side plates support respective ends of roller shafts each rotatably supporting a chain-guiding needle roller bearing. Each needle roller bearing includes a retainer guided by needle roller elements.

First claim

What is claimed is:

1. A chain guide configured to be arranged along a portion of an outer periphery of a timing chain, and comprising:
a guide base elongated in a moving direction of the timing chain and including side plates;
a plurality of roller shafts spaced apart from each other in a length direction of the side plates and each having two ends supported by the respective side plates; and
rollers rotatably mounted on the respective roller shafts and configured to guide the timing chain, wherein each of the rollers is a roller bearing comprising:
an outer race formed with flanges extending radially inwardly from respective axial ends of the outer race;
a retainer mounted in the outer race and formed with pockets spaced apart from each other in a circumferential direction of the retainer; and
roller elements received in the respective pockets and capable of rolling on a roller element rolling surface formed on an inner periphery of the outer race and on a cylindrical outer peripheral surface of a corresponding one of the roller shafts,
wherein in each of the roller bearings, the retainer has a radially outer surface kept out of contact with the roller element rolling surface of the outer race, and a radially inner surface kept out of contact with the cylindrical outer peripheral surface, and wherein the roller elements are guided by the retainer, and
wherein in each of the roller bearings, the flanges of the outer race have an inner diameter larger than a diameter of circular contact portions between the retainer and the roller elements, and smaller than an outer diameter of the retainer at outer ends of the retainer.

2. The chain guide of claim 1 , wherein in each of the roller bearings, the retainer is formed by pressing or forming a steel plate, crossbars are defined between respective adjacent pairs of the pockets, and each of the crossbars comprises an inner crossbar portion located radially inwardly of a pitch circle of the roller elements and having two axial ends, inclined crossbar portions integrally connected to the respective axial ends of the inner crossbar portion and each having an outer axial end, and outer crossbar portions integrally connected to the outer axial ends of the respective inclined crossbar portions and located radially outwardly of the pitch circle of the roller elements, whereby the retainer has a V-shaped section.

3. The chain guide of claim 2 , wherein in each of the roller bearings, each of the pockets has a circumferentially opposed pair of side surfaces which are inclined inwardly in opposite directions to each other such that an opening of the pocket on the radially outer surface of the retainer has a width in the circumferential direction of the retainer which is larger than a diameter of the roller elements, and such that an opening of the pocket on the radially inner surface of the retainer has a width in the circumferential direction of the retainer which is smaller than the diameter of the roller elements.

4. The chain guide of claim 2 , wherein the crossbars have guide surfaces guided by the roller elements, wherein the guide surfaces are shear surfaces.

5. The chain guide of claim 1 , wherein in each of the roller bearings, the flanges of the outer race have radially inner surfaces tapered such that diameters of the radially inner surfaces of the respective flanges increase toward outer side surfaces of the respective flanges.

6. The chain guide of claim 5 , wherein in each of the roller bearings, the outer side surfaces of the flanges of the outer race are convex curved surfaces.

7. A chain transmission device comprising a driving sprocket, a driven sprocket, a timing chain trained around the driving sprocket and the driven sprocket, a pivotable chain guide provided on one side of a slack side of the timing chain so as to guide a movement of the timing chain, and having a first end about which the chain guide is pivotable, and a second end remote from the first end, and a chain tensioner configured to apply an adjusting force to the second end of the chain guide, thereby pressing the second end of the chain guide against the timing chain,
wherein the pivotable chain guide is the chain guide of claim 1 .

8. A chain transmission device comprising a driving sprocket, a driven sprocket, a timing chain trained around the driving sprocket and the driven sprocket, a pivotable chain guide provided on one side of a slack side of the timing chain so as to guide a movement of the timing chain, and having a first end about which the chain guide is pivotable, and a second end remote from the first end, a chain tensioner configured to apply an adjusting force to the second end of the chain guide, thereby pressing the second end of the chain guide against the timing chain, and a stationary chain guide fixedly mounted in position on one side of a tension side of the timing chain so as to guide the movement of the timing chain,
wherein one of the pivotable chain guide and the stationary chain guide is the chain guide of claim 1 .

Assignees

• Kato Akio
• Oishi Shinji
• Ntn Toyo Bearing Co Ltd

Inventors

• Kato Akio
• Oishi Shinji

Classifications

• F16C2361/63

  Gears with belts and pulleys · CPC title

• F16C33/583

  Details of specific parts of races · CPC title

• F16H2007/0865

  Pulleys · CPC title

• F16C19/466

  comprising needle rollers and an outer ring, i.e. subunit without inner ring · CPC title

• F16H2007/0893

  Circular path · CPC title