| 摘要 |
PROBLEM TO BE SOLVED: To adopt in particular a ball bearing for supporting an on-off valve of an intake manifold, prevent occurrence of rattle of the on-off valve caused by an inner clearance of the bearing by applying preload, and suppress increase in the number of installation manhours and deterioration of installation performance due to addition of preload application means.SOLUTION: When journal portions 21, 22 of an on-off valve 9 are bearing supported by a bearing block 10A, one journal portion 21 is bearing supported via a ball bearing 23, and the other journal portion 22 is directly bearing supported in a form of a slide bearing. Preload application means is formed by: a pressing element 25, a helical compression spring 26 and a retainer 27 that are housed in the bearing block 10A; and the bearing block 10A. Radial preload is applied to the ball bearing 23. The bearing block 10A is sandwiched between an upper case and a lower case for fixation. |
