销联接一般用来传递不大的载荷或作安全装置；另一作用是起***作用。常与带孔螺栓和六角开槽螺母配对使用，把销插入螺栓的孔与螺母的槽中，以防螺母松脱。销按形状分为圆柱销、圆锥销和异形销三类。

Pin connecti are generally used to transfer ***all loads or safety devices; the other is to play the role of . It is often paired with hole bolts and six angle slotting nuts to insert the pin into the hole of the bolt and the slot in the nut so as to prevent the loosening of the nut. The pin is divided into three types: cylindrical pin, conical pin and special pin.

型面联接：是利用非圆剖面的轴与相应形状的零件的毂孔配合而构成的联接，作为机械传动中的联接方式，型面联接相对于传统的键联接相比，具有联接强度高，没有应力集中，可以传递大扭矩且的同时也可以承受冲击载荷，并且对于一些大型机械装备来讲其拆装方便及维修便利。

is the hub hole type surface connection: the non-circular section axis and the corresponding shape parts with a connection, as the connection mode in mechanical tran***ission, compared with the traditional linkage type surface connection compared with connecting strength, no stress , can large torque and high efficiency at the same time it can withstand the impact load, and for some large mechanical equipment for its disassembly and convenient maintenance.

螺旋副的间隙大，旋转时费力，使用中稳定性差。机用虎钳开合行程大，螺旋副的运行长度较长，为保证能够快速装夹，（金属加工真不错）机用虎钳螺旋副的螺距较大。较大的螺距意味着较大的螺旋升角，转动单圈进给量较大，使用时较费力；较大的螺距需要更大的配合间隙来确保螺旋副的正常使用。

The clearance of the helix pair is large, the rotation is hard and the stability of the use is poor. The machine has large opening and closing stroke, and the operation length of the screw pair is longer. In order to ensure quick clamping, metal machining is good. Larger pitch means larger spiral angle, larger single turn feed and more laborious use. Larger pitch needs more fit clearance to ensure the normal use of screw pair.

装夹后产品靠近活动钳口附近容易上翘、抬起，多次装夹一致性差。传统机用虎钳的螺旋副间隙较大，在使用中会产生较大振幅的振动；而活动座和虎钳体之间的滑动接触面较大，采用的间隙也较大。

After the clamping, the product is easy to and lifted near the movable jaw, and the cistency of the clamping is poor many times. The spiral pair clearance of traditional machine vice is bigger, which will cause large amplitude vibration in use. The sliding contact between movable seat and jaw vice body is larger, and the gap used is bigger.