| abstract |
A gear pump and the like that can effectively prevent excessive heat generation between a gear shaft and a journal bearing. Lubricating gear shafts (14, 15) on which gears (12, 13) are mounted and journal bearings (62, 63) rotatably supporting the gear shafts (14, 15) with ultraviolet curable ink to be fed. The gear pump 1 has a width-diameter ratio, which is a ratio of the bearing length of the journal bearings 62 and 63 to the shaft diameter of the gear shafts 14 and 15, and is 0.5 to 2.0. The clearance ratio that is the ratio of the radial clearance between the gear shafts 14 and 15 and the journal bearings 62 and 63 to the shaft radius is 0.0009 to 0.01. [Selection] Figure 4 |