US 11,852,071 B2
Crankshaft, power unit, two stroke piston engine, and hand-held power tool
Patrik Sigurdh, Huskvarna (SE); Anders Hansson, Huskvarna (SE); Per-Arne Järnland, Huskvarna (SE); Johan Lönn, Jönköping (SE); and Mikael Evergren, Ulricehamn (SE)
Assigned to HUSQVARNA AB, Huskvarna (SE)
Appl. No. 17/908,749
Filed by HUSQVARNA AB, Huskvarna (SE)
PCT Filed Mar. 16, 2021, PCT No. PCT/SE2021/050227
§ 371(c)(1), (2) Date Sep. 1, 2022,
PCT Pub. No. WO2021/201740, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2050349-6 (SE), filed on Mar. 30, 2020.
Prior Publication US 2023/0128697 A1, Apr. 27, 2023
Int. Cl. F02B 33/04 (2006.01); F02F 3/24 (2006.01); F16C 3/20 (2006.01)
CPC F02B 33/04 (2013.01) [F02F 3/24 (2013.01); F16C 3/20 (2013.01); F16C 2322/50 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A crankshaft for a crankcase scavenged two stroke piston engine,
wherein the crankshaft is configured to rotate around a rotation axis during operation,
and wherein the crankshaft comprises:
a crankpin configured to move in a crank plane upon rotation of the crankshaft, and
a first and a second counterweight arranged on either side of the crank plane,
wherein the first counterweight has a first outer radius measured from the rotation axis and the second counterweight has a second outer radius measured from the rotation axis,
wherein the first outer radius is smaller than the second outer radius, and
wherein the second counterweight comprises a recess at a radially outer portion thereof, and wherein the recess extends in a first angular sector of the second counterweight measured from the rotation axis, wherein the first angular sector is smaller than a total angular sector occupied by the second counterweight measured from the rotation axis.