IP Library Granted Patent US 12,533,786
Granted Patent B2
US 12,533,786 · App. 18/835,736 · Granted Jan 27, 2026

Work machine

Inventors: Hiroyuki Tagami (Ibaraki, JP); Naoto Ichihashi (Ibaraki, JP)
Assignee: Koki Holdings Co., Ltd.
B25D17/20B25D2217/0061B25D2217/0065B25D2250/095
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Quick Facts
Patent No.
US 12,533,786
App. No.
18/835,736
Granted
Jan 27, 2026
Kind
B2
Abstract

A work machine includes: a motor; an output shaft, rotated by driving of the motor; a first fan, fixed to and rotating integrally with the output shaft; a second fan, located on one side of the first fan in an axial direction of the output shaft, fixed to and rotating integrally with the output shaft; and a rectification member, accommodating the first and second fans, and, when the output shaft rotates to one side in a rotation direction, causing a first airflow blown out from the first fan and a second airflow blown out from the second fan to join together and flow out toward one side in the axial direction. The rectification member includes a rectification section in which the second airflow is rectified to flow to the one side in the axial direction and is prevented from flowing to the other side in the axial direction.

Claims (54)

1 . A work machine, comprising:

a motor;

an output shaft, rotated by driving of the motor;

a first fan, fixed to the output shaft and rotating integrally with the output shaft;

a second fan, located on one side of the first fan in an axial direction of the output shaft, fixed to the output shaft, and rotating integrally with the output shaft; and

a rectification member, accommodating the first fan and the second fan therein, and, in response to the output shaft rotating to one side in a rotation direction, causing a first airflow blown out from the first fan and a second airflow blown out from the second fan to join together and flow out toward one side in the axial direction, wherein

the rectification member comprises:

a guide wall, which is arranged radially outside the output shaft with respect to the first fan and the second fan, and extends in the rotation direction, and

a rectification section, which extends radially inward of the output shaft from the guide wall, and rectifies the second airflow so as to flow to the one side in the axial direction and is suppressed from flowing to the other side in the axial direction.

2 . The work machine according to claim 1 , wherein

the first fan and the second fan are centrifugal fans.

3 . The work machine according to claim 1 , wherein

the rectification section is formed in a rib shape extending along a direction that is inclined to the one side in the axial direction as going toward the one side in the rotation direction as viewed in a radial direction of the output shaft.

4 . The work machine according to claim 3 , wherein

a rectification extension section extending to the one side in the axial direction is provided at one end in the axial direction of the rectification section; and

the rectification extension section comprises an extension surface connected to the other side surface in the rotation direction of the rectification section and arranged along a plane orthogonal to the rotation direction.

5 . The work machine according to claim 1 , comprising:

a housing, comprising a first housing section that accommodates the motor and the rectification member and has an air intake port and a dust collection port formed therein, and a second housing section that has an exhaust port formed therein;

the rectification member comprises a partition wall, the partition wall partitioning out, as a second airflow passage, a portion of space on the one side in the axial direction with respect to the second fan; and

the second airflow passage communicates with the dust collection port, and is arranged at a position where the rectification section and the second airflow passage do not overlap as viewed in the axial direction.

6 . The work machine according to claim 5 , wherein

a dust collector is attached to the housing; and

the dust collector is configured to comprise:

a suction section, suctioning air around a tip tool and causing the air to flow into the dust collector; and

a discharge section, connected to the dust collection port, and causing the dust collection air inside the dust collector to flow out into the first housing section.

7 . The work machine according to claim 5 , wherein

a transmission mechanism that transmits a driving force of the motor to a tip tool is accommodated in the second housing section.

8 . The work machine according to claim 1 , wherein

an air volume of the first airflow blown out from the first fan is larger than an air volume of the second airflow blown out from the second fan.

9 . The work machine according to claim 1 , wherein

the rectification member includes a plurality of the rectification sections,

the plurality of the rectification sections are arranged at intervals in the rotation direction on the guide wall; and

the first airflow passes between the plurality of rectification sections and flows toward one side in the axial direction, and merges with the second airflow in a region between the guide wall and the second fan in a radial direction of the output shaft.

10 . A work machine, comprising:

a motor;

an output shaft, rotated by driving of the motor;

a first fan, being a centrifugal fan fixed to the output shaft and rotating integrally with the output shaft;

a second fan, being a centrifugal fan located on one side of the first fan in an axial direction of the output shaft, fixed to the output shaft, and rotating integrally with the output shaft; and

a rectification member, accommodating the first fan and the second fan therein, and, in response to the output shaft rotating to one side in a rotation direction, causing a first airflow blown out from the first fan and a second airflow blown out from the second fan to join together and flow out toward one side in the axial direction, wherein

the rectification member comprises a rectification section in which the second airflow is rectified so as to flow to the one side in the axial direction and is suppressed from flowing to the other side in the axial direction, wherein

the rectification section is arranged radially outside the output shaft with respect to at least the second fan, and changes a direction of the second airflow into toward the one side in the axial direction; and

a sub rectification section is provided radially outside the first fan; and

the sub rectification section is arranged on the other side in the rotation direction with respect to the rectification section, and is formed in a rib shape extending along a direction that is inclined to the one side in the axial direction as going toward the one side in the rotation direction as viewed in a radial direction of the output shaft.

11 . The work machine according to claim 10 , wherein

an inclination angle of one end in the rotation direction of the rectification section with respect to the rotation direction is set larger than an inclination angle of one end in the rotation direction of the sub rectification section with respect to the rotation direction as viewed in the radial direction of the output shaft.

12 . The work machine according to claim 10 , wherein

a length of the rectification section in the axial direction is set larger than a length of the sub rectification section in the axial direction.

13 . A work machine, comprising:

a motor;

an output shaft, rotated by driving of the motor;

a first fan, being a centrifugal fan fixed to the output shaft and rotating integrally with the output shaft;

a second fan, being a centrifugal fan located on one side of the first fan in an axial direction of the output shaft, fixed to the output shaft, and rotating integrally with the output shaft; and

a rectification member, accommodating the first fan and the second fan therein, and, in response to the output shaft rotating to one side in a rotation direction, causing a first airflow blown out from the first fan and a second airflow blown out from the second fan to join together and flow out toward one side in the axial direction, wherein

the rectification member comprises a rectification section arranged radially outside the output shaft with respect to at least the second fan and formed in a rib shape extending along a direction that is inclined to the one side in the axial direction as going toward the one side in the rotation direction as viewed in a radial direction of the output shaft.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 7, 2024
From: TAGAMI, HIROYUKI; ICHIHASHI, NAOTO
To: KOKI HOLDINGS CO., LTD.
Reel/Frame 068202/0395 →
Priority Claims (1)
JP 2022-061289 · Mar 31, 2022 · national
Continuity (1)
Related Publication 20250135620A1 · May 1, 2025
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