| 摘要 |
A drilling apparatus having progressive cavity drive train which includes a progressive cavity device and a coupling for converting the complex motion of the rotor into simple rotation. The coupling includes a sealed universal joint assembly coupling yokes formed on a first stub shaft to yokes formed on the second stub shaft. The sealed universal joint assembly includes a cross member assembly having a cross member and a sealing cup. The cross member has a central body and two sets of pin portions extending from the body. Each set of pin portions includes two pin portions having coincident axes. The pin portions of one set are transverse to the pin portions of the other set. The sealing cup is fixed to each of the pin portions of the cross member. The sealing cup includes connecting sleeve portion fixed to the pin portion of the cross member, a flexible elastomeric section secured to the sleeve portion and a hollow upon portion enclosing the end of the pin portion. Each hollow cup portion has an interior surface and an exterior surface. A portion of the interior surface is in sliding contact with the pin portion enclosed by the sealing cup. The exterior of the cup portion being fixed to a yoke member by bonding or the like. Preferably, there are two such cross members in each joint assembly. The two cross members are coupled to one another by an intermediate shaft such that the entire assembly pivots like a double Hooke's joint. The elastomeric section of the sealing cup is sufficiently flexible to allow pivoting of the pin portion and sleeve portion with respect to the cup portion. The yoke member and the sleeve portion are sealingly connected to the pin portion such that the interior of the cup portion is hermetically sealed. |
