Straightening device

1. A straightening device, including:

a plurality of rolling members, defining a first channel which is configured for a tubular member to pass therethrough, the tubular member being abuttable against the plurality of rolling members when passing through the first channel, an extending direction of the first channel being transverse to at least one axial direction of at least one of the rolling members;

at least three shells, each of the at least three shells including two arm portions which are transversely connected with each other, each of the arm portions of one of the at least three shells corresponding to one of the arm portions of another of the at least three shells, the plurality of rolling members being rotatably disposed between the arm portions of the at least three shells, at least one side of each of the arm portions having a protruding wall which is a separate element relative to and disposed adjacent to another one of the arm portions and extends toward the another one of the arm portions, the protruding wall extending along the at least one axial direction of the at least one of the rolling members and being at least partially overlapped with at least one of the plurality of rolling members as viewed in a radial direction of the at least one of the rolling members.

2. The straightening device of claim 1 , wherein the plurality of rolling members include a plurality of rolling groups, each of the rolling groups is disposed between two adjacent ones of the arm portions, and at least two of the plurality of rolling groups are arranged with their pivots of the rolling members transverse to each other.

3. The straightening device of claim 1 , wherein each of the two arm portions of each of the at least three shells has one said protruding wall.

4. The straightening device of claim 3 , wherein respective extents of the protruding walls of two adjacent ones of the at least three shells are equal.

5. The straightening device of claim 1 , wherein each of the at least three shells is L-shaped, each of the at least three shells has two inner assembling surfaces and an arcuate concave surface connected between the two inner assembling surfaces, and each of the inner assembling surfaces is connected with a plurality of the rolling members.

6. The straightening device of claim 5 , wherein each of the rolling members is a roller which defines an axial direction, each of the rollers has an arcuate abutting concave surface disposed around the axial direction, and the arcuate abutting concave surface is configured to be abutted against the tubular member.

7. The straightening device of claim 1 , wherein a plurality of the rolling members which are disposed between two adjacent ones of the arm portions include two first rolling members and a plurality of second rolling members disposed between the two first rolling members, and a distance between one of the two first rolling members and one of the second rolling members adjacent thereto is larger than a distance between two adjacent ones of the plurality of second rolling members.

8. The straightening device of claim 1 , wherein each of the at least three shells has a convex portion protruding in a thickness direction thereof and at least one recession disposed on an end thereof which are disposed in the extending direction of the first channel, the plurality of rolling members are disposed on respective convex portions of the at least three shells, and at least one of the plurality of rolling members and one of the recession define a gap therebetween.

9. The straightening device of claim 6 , wherein the plurality of rolling members includes a plurality of rolling groups, each of the rolling groups is disposed between two adjacent ones of the arm portions, and at least two of the plurality of rolling groups are arranged with their pivots of the rolling members transverse to each other; each of the arm portions has one of the protruding wall; respective extents of the protruding walls of two adjacent ones of the at least three shells are equal; a plurality of rolling members which are disposed between two adjacent ones of the arm portions include two first rolling members and a plurality of second rolling members disposed between the two first rolling members, a distance between one of the two first rolling members and one of the second rolling members adjacent thereto is larger than a distance between two adjacent ones of the plurality of second rolling members; each of the at least three shells has a convex portion protruding in a thickness direction thereof and at least one recession disposed on an end thereof which are disposed in the extending direction of the first channel, the plurality of rolling members are disposed on respective convex portions of the at least three shells, and at least one of the plurality of rolling members and one of the recession define a gap therebetween; each of the convex portions near at least one opening of the first channel has an arcuate convex which extends around the axial direction of the at least one of the rolling members and is located at one side of one of the rolling members; each of the protruding walls has an outer surface which is wavy; each of the rollers includes a bearing, a ring body sleeved on the bearing and a connecting rod which is penetrated through the bearing and two adjacent ones of the arm portions.

10. The straightening device of claim 1 , further including a plurality of pins, each of the pins is penetrated through two adjacent ones of the arm portions and non-coaxial with each of the rolling members.