| 摘要 |
A main bearing cap (A') made of powder metal has a body portion (Y) made fro m one powder metal material (Q), and a bearing arch portion (H), foot joint fa ce portions (S) and/or wings (W) made of a different powder metal material (P). The material (Q) of the body portion (Y) is harder than the material (P) of the other portions (H, S, W), and the material (P) of the other portions (H, S, W) is relatively machinable. For the bearing arch portion (H), the machinability of the material (P) approximately matches the machinability of the bearing support structure (B) to which the bearing cap (A') is assembled to produce a good quality bore and longer tool life during line boring. The bearing arch material (P) may be a bearing material. |
