An assembly including: a cartridge including: a rotor having a wheel (53, 54) and a rotational shaft; and a bearing housing accommodating a bearing rotatably supporting the rotor; a wheel-side housing being to be pressed to the bearing housing in an axial direction; a vibration insulator mounted between the cartridge and the wheel-side housing, wherein the vibration insulator comprising: an annular outer ring portion having a wheel-side contact surface configured to come into contact with the wheel-side housing; an annular inner ring portion disposed inside the outer ring portion with a clearance from the outer ring portion and having a bearing-side contact surface configured to come into contact with the bearing housing; and a flexible support portion interposed between the outer ring portion and the inner ring portion and connecting the outer ring portion and the inner ring portion, the flexible support portion being elastically deformable, wherein the flexible support portion includes: an annular plate spring part having an annular shape and disposed in the clearance; an outer-ring-side joint part connecting the outer ring portion and a part of the annular plate spring part; and an inner-ring-side joint part connecting the inner ring portion and a part of the annular plate spring part at a portion different in a circumferential direction from a portion where the outer-ring-side joint part is connected to the annular plate spring part, wherein the inner-ring-side joint part is disposed on a part of the annular plate spring part and the annular inner ring portion, wherein the outer-ring-side joint part is disposed on a part of the annular plate spring part and the annular outer ring portion, and wherein the outer-ring-side joint part and the inner-ring-side joint part are located on a same first straight line passing through a central line of the inner ring portion. a cartridge including: a rotor having a wheel (53, 54) and a rotational shaft; and a bearing housing accommodating a bearing rotatably supporting the rotor; a wheel-side housing being to be pressed to the bearing housing in an axial direction; a vibration insulator mounted between the cartridge and the wheel-side housing, wherein the vibration insulator comprising: an annular outer ring portion having a wheel-side contact surface configured to come into contact with the wheel-side housing; an annular inner ring portion disposed inside the outer ring portion with a clearance from the outer ring portion and having a bearing-side contact surface configured to come into contact with the bearing housing; and a flexible support portion interposed between the outer ring portion and the inner ring portion and connecting the outer ring portion and the inner ring portion, the flexible support portion being elastically deformable, an annular outer ring portion having a wheel-side contact surface configured to come into contact with the wheel-side housing; an annular inner ring portion disposed inside the outer ring portion with a clearance from the outer ring portion and having a bearing-side contact surface configured to come into contact with the bearing housing; and a flexible support portion interposed between the outer ring portion and the inner ring portion and connecting the outer ring portion and the inner ring portion, the flexible support portion being elastically deformable, wherein the flexible support portion includes: an annular plate spring part having an annular shape and disposed in the clearance; an outer-ring-side joint part connecting the outer ring portion and a part of the annular plate spring part; and an inner-ring-side joint part connecting the inner ring portion and a part of the annular plate spring part at a portion different in a circumferential direction from a portion where the outer-ring-side joint part is connected to the annular plate spring part, an annular plate spring part having an annular shape and disposed in the clearance; an outer-ring-side joint part connecting the outer ring portion and a part of the annular plate spring part; and an inner-ring-side joint part connecting the inner ring portion and a part of the annular plate spring part at a portion different in a circumferential direction from a portion where the outer-ring-side joint part is connected to the annular plate spring part, wherein the inner-ring-side joint part is disposed on a part of the annular plate spring part and the annular inner ring portion, wherein the outer-ring-side joint part is disposed on a part of the annular plate spring part and the annular outer ring portion, and wherein the outer-ring-side joint part and the inner-ring-side joint part are located on a same first straight line passing through a central line of the inner ring portion.