Counterweight, and crankshaft with the counterweight

Patent metadata

Field	Value
Publication number	US-10605328-B2
Application number	US-201816048623-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Aug 1, 2017
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A counterweight forms a crankshaft of an engine, and includes: an arm connecting a crank journal and crank pin of the crankshaft; a neck extending from a first connection face of the arm in a direction opposite to the crank pin; and a substantially fan-shaped weight continuous with a portion of the neck opposite to the crank journal. The weight has left and right shoulders continuous with the neck, and each of the shoulders is tilted to be away from the neck at an angle with respect to a horizontal line orthogonal to a crankshaft center when viewed along the crankshaft center, the angle being 15° or more and 22.5° or less.

First claim

What is claimed is:

1. A counterweight forming a crankshaft of an engine, the counterweight comprising:
an arm connecting a crank journal and crank pin of the crankshaft;
a neck extending from a junction between the arm and the crank journal in a direction opposite to the crank pin with respect to a crankshaft center, and having a width smaller than a horizontal width of the junction when viewed along the crankshaft; and
a weight continuous with a portion of the neck opposite to the arm, the weight being substantially fan-shaped when viewed along the crankshaft, wherein
the weight has left and right shoulders continuous with the neck, each of the shoulders being tilted to be away from the neck at an angle with respect to a horizontal direction orthogonal to the crankshaft center when viewed along the crankshaft, the angle being 15° or more and 22.5° or less; and
the crankshaft is forged into a single piece.

2. The counterweight of claim 1 , wherein
when viewed along the crankshaft, a ratio h/R of a width h of the neck to a radius R of the counterweight from the crankshaft center is 0.44 or more and 0.49 or less.

3. A crankshaft comprising the counterweight of claim 2 .

4. A crankshaft comprising the counterweight of claim 1 .

Assignees

• Mazda Motor

Inventors

• Imano Yasuyuki
• Fukuma Masaki
• Imamura Satoshi
• Kajikawa Hisashi
• Yoneya Toshinobu
• Motohiro Ryoko
• Someno Yuichi
• Iwai Takahiro

Classifications

• F16F15/24

  of crankshaft systems by particular disposition of cranks, pistons, or the like {(shape of crankshafts or eccentric-shafts having regard to balancing F16C3/20)} · CPC title

• Y10T74/2183

  Counterbalanced · CPC title

• F16C3/08 Primary

  made in one piece (features relating to lubrication F16C3/14, to cooling F16C3/16) · CPC title

• F02B2075/1816

  four · CPC title

• F16C3/10 Primary

  assembled of several parts, e.g. by welding {by crimping} · CPC title