The Vane Pump Mounting Requirements

1.Mounting Dimensions

Requirements

Dimensional control requirements of the customer’s mounting pad to which the pump or motor is affixed are as follows.

Pilot Diameter

Concentricity of the customer’s female pilot diameter relative to the effective axis of the female drive must be within 0,10 mm (.004 in.) total indicator reading. The clearance between the male and female pilot diameters must be +0,01 to +0,05 mm (+.0005 to +.0020 in.).

Mounting Face

The customer’s mounting face to which the pump or motor is affixed must be square to the axis of the female drive within 0,0381 mm per mm (.0015 inch per inch).

Shafts

Dimensions of keyed shaft receivers must be between +0,003 and +0,03 mm (+.0001 and +.0010 in.) of the maximum shaft diameter shown on the Vickers installation drawing.

2. Circuitry Requirements

Valves

In the event of acceleration or deceleration of the drive or driven members, overrunning loads or system bleed-off, control valves and circuitry must provide a continuous supply of oil to the pump or motor. This supply should be sufficient to prevent transient or continuous cavitation, but not so large as to result in speeds beyond the published maximum speed.

Protect against hydraulic surge pressures (inlet, outlet or drain) applied to or generated by the pump or motor. Relief valves must prevent these surges from exceeding published pressure ratings.

Never assume a relief valve setting is the maximum pressure a pump experiences. Shock conditions may exist which can exceed circuit and pump limitations.

Piping

Hydraulic lines should be as short and have as large an inside diameter as possible. Where lines are long, it is desirable to adapt to a larger capacity line than a unit’s ports specify. Inlet, outlet and drain lines should not be

smaller than the nominal port size shown on installation drawings. A “Y” shaped inlet should not be used to feed two separate pumps because one may be starved and cavitate.

There should be as few bends and fittings in lines as possible. High-pressure lines and fittings are restrictive to flow and may result in excessive pressure drop through the system. They should be used only where necessary in a pressure line.

Hose

Because steering components move during operation, their working hydraulic lines consist mainly of flexible hoses. Long lines may be partly flexible hose and partly tubing where flexibility is not required.

When installing a hose, allow enough slack to avoid kinking. A taut hose will not allow movement with pressure surges. Slack in the line compensates for surges, relieving strain. The hose should not be twisted during installation or while in operation. Twisting will weaken the hose and loosen connections.

For power steering pumps using a remote reservoir, connecting hoses should not exceed three feet in length. It is highly desirable to design the reservoir-pump relationship so that there is always a static head on the pump inlet port.

A neater installation is usually obtainable by using extra fittings to minimize unusually long loops in a line. Hoses should be clamped to prevent rubbing and entanglement with moving parts. Where hoses are subject to chafing, they should be run through protective neoprene hose or shielded metallic guards.