Component Mounter Head Unit R-Axis Gear Relocation

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Solution Overview

Problem

High-speed rotation of rotating heads in component mounters leads to increased moment of inertia, causing twisting and overshooting of suction nozzles, which reduces mounting accuracy and requires large vertical space due to the conventional placement of R-axis gear and motor.

Innovation Solution

The R-axis gear is relocated to the lower surface of the rotating head, reducing the distance to the rotating head and allowing the R-axis motor to be positioned lower, with the R shaft fixed to the main body frame, enabling only the rotating head to rotate, thus minimizing moment of inertia and improving accuracy while reducing the overall size of the head unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the R-axis gear is placed at the upper end of the R shaft to drive the rotating head at high speed, then the rotation speed of the rotating head is improved, but the moment of inertia increases causing twisting and overshooting that reduces positioning accuracy

Engineering Contradiction:
Improverotation speed of rotating headVSAvoidpositioning accuracy of suction nozzle
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The R-axis gear is relocated from the vertical direction (upper end of R shaft) to the horizontal dimension (lower surface of rotating head), changing the spatial arrangement to reduce the rotational moment arm and moment of inertia while maintaining driving function

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Speed

If the R-axis gear and R-axis motor are arranged at the upper end of the R shaft to enable high-speed rotation, then the rotating head can achieve high rotation speed, but the vertical size of the head unit becomes large requiring more space

Engineering Contradiction:
Improverotation speed of rotating headVSAvoidvertical size of head unit
Core Design Contradiction:
SpeedVSLength of stationary object

Solution Approach 1:

The driving mechanism is redistributed from vertical stacking to horizontal arrangement, with the R-axis gear on the lower surface of the rotating head and the R-axis motor positioned laterally, converting vertical space requirements into horizontal space usage

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3324720B1Head unit of component mounter
Publication Date: 2020.04.01 FUJI CORP
  • EP3324720B1 patent drawingFigure 1
  • EP3324720B1 patent drawingFigure 2
  • EP3324720B1 patent drawingFigure 3

AI summary

In a component mounter, an R-axis driving mechanism (46) that rotates a rotating head (14) around an R shaft (13) is configured from an R-axis gear (42) that rotates together with the rotating head around the R shaft, and an R-axis motor (48) that rotates a driving gear (47) that is engaged with the R-axis gear, with the R-axis gear being provided on a lower surface of the rotating head. The R shaft is fixed to a main body frame (12) of a head unit (11), and the rotating head is rotatably supported on the R shaft via a shaft bearing (15). A head rotation support section (41) that rotatably supports a circumferential section of the rotating head via a shaft bearing (40) is provided on the main body frame (12) of the head unit (11). The R-axis motor is arranged at a position higher than the rotating head shifted towards the R shaft side.