Rotational body and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2016273545-A1
Application number	US-201315032726-A
Country	US
Kind code	A1
Filing date	Dec 11, 2013
Priority date	Dec 11, 2013
Publication date	Sep 22, 2016
Grant date	—

Abstract

An object is to provide a rotational body in which a gap is not formed between a rotational shaft and an impeller even during rotation at high speed in the interference fit portion between the rotational shaft and the impeller, and in which misalignment between the center positions of the rotational shaft and the impeller does not arise, and a manufacturing method thereof. A rotational body 1 includes a rotational shaft 2, an impeller 3, and a nut 6. The impeller includes a hub portion 4 having a peripheral surface 4 s inclined to the axial direction of the rotational shaft and having an insert hole 4 h in which the rotational shaft is inserted, and a blade portion 5. At least one of the rotational shaft or the insert hole of the hub portion has an interference fit portion 10 for fit between the rotational shaft and the impeller, where the outside diameter of the rotational shaft is larger than the inside diameter of the insert hole of the hub portion. The interference fit portion is formed in a region which does not include the largest outside diameter portion 4 B where the hub portion has a largest outside diameter, with the rotational shaft and the impeller mating with each other.

First claim

1 . A rotational body comprising:
a rotational shaft; an impeller mating with the rotational shaft on an end side of the rotational shaft; and a nut screwed on the rotational shaft on an end side of the rotational shaft to fasten the rotational shaft and the impeller together, wherein the impeller includes a hub portion having a peripheral surface inclined to an axial direction of the rotational shaft and having an insert hole in which the rotational shaft is inserted, and a blade portion provided so as to protrude from the circumferential surface of the hub portion toward a radial direction, wherein at least one of the rotational shaft or the insert hole of the hub portion has formed an interference fit portion for fit between the impeller and the rotational shaft where an outside diameter of the rotational shaft is larger than an inside diameter of the insert hole of the hub portion, and wherein the interference fit portion is, in the axial direction of the rotational shaft, in a region which does not include a largest outside diameter portion where the hub portion has a largest outside diameter, with the rotational shaft and the impeller mating with each other.

2 . The rotational body according to claim 1 , wherein the interference fit portion includes a smaller-diameter hole portion of the insert hole of the hub portion, the smaller-diameter hole portion having a smaller diameter than the rest of the insert hole.

3 . The rotational body according to claim 1 , wherein the interference fit portion includes a larger-diameter portion of the rotational shaft, the larger-diameter portion having a larger diameter than the rest of the rotational shaft.

4 . The rotational body according to claim 1 , wherein the interference fit portion includes a smaller-diameter hole portion of the insert hole of the hub portion, the smaller-diameter hole portion having a smaller diameter than the rest of the insert hole, and a larger-diameter portion of the rotational shaft, the larger-diameter portion having a larger diameter than the rest of the rotational shaft.

5 . The rotational body according to claim 2 , wherein the smaller-diameter hole portion includes a burr of an impression formed on an inner circumferential surface of the insert hole of the hub portion.

6 . The rotational body according to claim 3 , wherein the larger-diameter portion includes a burr of an impression formed on an outer circumferential surface of the rotational shaft.

7 . The rotational body according to claim 2 , wherein the smaller-diameter hole portion has a larger surface roughness than the rest of the insert hole.

8 . The rotational body according to claim 3 , wherein the larger-diameter portion has a larger surface roughness than the rest of the rotational shaft.

9 . The rotational body according to claim 1 , wherein the interference fit portion is apart from the nut in the axial direction of the rotational shaft, with the rotational shaft and the impeller mating with each other.

10 . The rotational body according to claim 1 , wherein the interference fit portion is, in the axial direction of the rotational shaft, in a region which includes an axial middle position of the hub portion, with the rotational shaft and the impeller mating with each other.

11 . The rotational body according to claim 1 , wherein the insert hole of the hub portion is press-fitted on the rotational shaft so that the impeller mates with the rotational shaft in the interference fit portion.

12 . A method for manufacturing a rotational body including:
a rotational shaft; an impeller mating with the rotational shaft on an end side of the rotational shaft; and a nut screwed on the rotational shaft on an end side of the rotational shaft to fasten the rotational shaft and the impeller together, wherein the impeller includes a hub portion having a peripheral surface inclined to an axial direction of the rotational shaft and having an insert hole into which the rotational shaft is inserted, and a blade portion provided so as to protrude from the circumferential surface of the hub portion toward a radial direction, wherein at least one of the rotational shaft or the insert hole of the hub portion has formed an interference fit portion for fit between the impeller and the rotational shaft where an outside diameter of the rotational shaft is larger than an inside diameter of the insert hole of the hub portion, the manufacturing method comprising a fitting step of inserting the rotational shaft into the insert hole of the hub portion and mating the rotational shaft and the impeller with each other in the interference fit portion so that the interference fit portion is formed in a region which does not include a largest outside diameter portion where the hub portion has a largest outside diameter.

13 . The method for manufacturing a rotational body according to claim 12 , further comprising a fastening step of screwing the nut on the rotational shaft from an end side of the rotational shaft to fasten the rotational shaft and the impeller together.

14 . The method for manufacturing a rotational body according to claim 13 , wherein the fitting step includes a press-fitting step of press-fitting the insert hole of the hub portion onto the rotational shaft so that the rotational shaft and the impeller mate with each other in the interference fit portion.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Hayashi Noriyuki
• Ozaki Makoto
• Seike Nariaki
• Kanki Hiroshi
• Suzuki Hiroshi

Classifications

• F05D2220/40

  in turbochargers · CPC title

• F04D29/624

  especially adapted for elastic fluid pumps · CPC title

• F04D29/284

  for compressors · CPC title

• F04D29/053

  Shafts · CPC title

• F04D29/266 Primary

  mounting compressor rotors on shafts · CPC title