When implementing the double wedge assembly, care must be taken to account for the frictional torque moment imparted by the spinning pump swash plate. This torque component affects only the upper wedge so that maintaining the -2φ and φ angular relationship between the upper and lower wedges becomes problematic. This can be corrected by placing a thin pin-ended torque plate 35 between the top wedge and the swash plate. This should not be confused with the heavy pin-ended yoke found in typical axial pumps. In this case, the torque plate passes all axial loading through to the wedge stack in direct compression. The pin-ends 36 rest in retaining supports which need only fit loosely and carry shear loads equal to those produced by the induced frictional moment.
When a pair of reinforcing ribs are arranged centrally in the central region of the partition floor the two hollow tubular longitudinal edges lie relatively close to one another, the cable already in the cable protection pipe, if of relatively large diameter, cannot jam between the hollow tubular longitudinal edges, and in this way there is avoided a possible increase in friction. The same applies to the cable to be subsequently pulled along the partition floor.
Apparatus for controlling an axial pump having a drive shaft with an axis of rotation and a plurality of pistons parallel to and surrounding an extension of said shaft of rotation beyond said drive shaft, comprising: a base member 12 surrounding said drive shaft and rotatable with respect thereto, said base member including a circular recess with a flat surface surrounding said shaft and facing said pistons, and a first wedge member having an annular portion which is rotatably received within said circular recess and solidly mounted on said base member between said base member and said pistons, said first wedge member having first and second opposed non-parallel flat faces, said first of said opposed faces of said first wedge member engaging said flat surface of said base member and said second of said opposed faces of said first wedge member being in driving relationship to said pistons.
Cements, or adhesives, used to form PVC pipe joints must meet both a lap shear bond strength standard and a hydrostatic burst strength standard, both set forth in ASTM D 2564-88, incorporated herein by reference. A strong bond between two pieces, at least one of which is thermoplastic PVC, is obtained by softening the PVC with the solvent in the cement so that the thermoplastic resin at the interface of the pieces to be joined flow together to bond the pieces when they are pressed together.
In the description, first an analysis of typical axial pump timing error and the effects of such error on performance and noise will be presented. Particular attention will be paid to the effects on noise due to trapped oil volume caused by timing overlap at the inlet to outlet valve transition. Graphs of trapped volume/cycle versus pump stroke for this pump configuration profile will be shown. These graphs will be discussed along with their impact on pump design and noise reduction.
