Abstract: An impeller that rotates about a central axis extending vertically includes a base portion and blades. The base portion spreads perpendicularly to the central axis. The blades are on an upper surface of the base portion at intervals in a circumferential direction. The base portion includes an irregular portion that is radially outward and in which irregularities are repeated in the circumferential direction. The irregular portion includes one or more first irregular regions and a second irregular region. The first irregular regions include first recesses with a same shape and first projections with a same shape, the first recesses and projections being alternately arranged one by one. The second irregular region is positioned between the first irregular regions and includes at least one among a second recess with a different shape from the first recesses and a second projection with a different shape from the first projections.

Abstract: An impeller that rotates about a central axis extending vertically includes a base portion and blades. The base portion spreads perpendicularly to the central axis. The blades are on an upper surface of the base portion at intervals in a circumferential direction. The base portion includes an irregular portion that is radially outward and in which irregularities are repeated in the circumferential direction. The irregular portion includes one or more first irregular regions and a second irregular region. The first irregular regions include first recesses with a same shape and first projections with same shape, the first recesses and projections being alternately arranged one by one. The second irregular region is positioned between the first irregular regions and includes at least one among a second recess with a different shape from the first recesses and a second projection with a different shape from the first projections.

Abstract: There is provided a production line having a plurality of mounting apparatus of electronic components in which the overall production efficiency is sustained by an alternation scheme when a mounting apparatus has a long cycle time due to a high malfunction rate. At a predetermined timing, the rate of unsuccessful pick-up procedure for an electronic component is compared to a predetermined value. If the rate is higher than the value, CPU finds out if the mounting apparatus 2, or 3 is available as an alternate. When the alternate is the apparatus 2, CPU 10 changes the command parameter of the particular mounting procedure, stored in RAM 12, from “M” to “S”, and stops mounting the same component. In the mean time, the mounting apparatus 2 accepts the alternate request from the apparatus 1, changes the command parameter as required, and mounts the same component on a print circuit board.

Abstract: There is provided a production line having a plurality of mounting apparatus of electronic components in which the overall production efficiency is sustained by an alternation scheme when a mounting apparatus has a long cycle time due to a high malfunction rate. At a predetermined timing, the rate of unsuccessful pick-up procedure for an electronic component is compared to a predetermined value. If the rate is higher than the value, CPU finds out if the mounting apparatus 2, or 3 is available as an alternate. When the alternate is the apparatus 2, CPU 10 changes the command parameter of the particular mounting procedure, stored in RAM 12, from “M” to “S”, and stops mounting the same component. In the mean time, the mounting apparatus 2 accepts the alternate request from the apparatus 1, changes the command parameter as required, and mounts the same component on a print circuit board.