Multiple pump hydraulic power system

• US 5,789,879 A
• Filed: 11/03/1995
• Issued: 08/04/1998
• Est. Priority Date: 11/03/1995
• Status: Expired due to Term

• Current Assignee: Noel R. Cook
• Original Assignee: Noel R. Cook
• Inventors: Cook, Noel R.
• Primary Examiner(s): Sircus, Brian
• Application Number:
  US08/552,375
• Time in Patent Office: 1,005 Days
• Field of Search: 318/49.5, 318/67, 318/98, 318/99, 318/101-103, 318/4, 318/5, 318/8, 417/1-8, 417/14, 417/20, 417/21, 417/32, 417/29-31, 417/44.1-44.4, 417/321, 417/366, 417/367, 340/606, 340/607, 340/611, 340/622
• US Class Current: 318/101
• CPC Class Codes: F04B 2207/043 of time
• CPC Class Codes: F04B 2207/703 Stopping
• CPC Class Codes: F15B 1/26 Supply reservoir or sump assemblies

Abstract

A multiple electric motor hydraulic oil pump power system including a programmable controller having electric motor starting and stopping circuitry for hydraulic oil flow control. The circuitry having means to compare each electric motor running hours and select the motor with the least running hours to adjust oil flow to the desired amount. The system monitors oil pressure and flow, comparing such pressure and flow with the desired value and automatically adjusting the system to accomplish the correction. The controller also maintains safety sensing devices for high and low oil reservoir levels, oil filter condition limits, oil temperature limits, and means to maintain a constant oil pressure under load with load flow rates varying from very low to very high.

Claims

1. A method for maintaining constant, load demand pressure with varying oil flow rates in a hydraulic power system having a plurality of electric synchronous speed motor/pump sets started and stopped by a programmable controller, the method comprising the steps of said controller starting said motor/pump sets, monitoring said oil flow rates by means of a single flow meter sensing said flow rate comparing said oil flow rate with flow load demand pressure, and stopping or starting said motor/pump sets to maintain load demand pressure.

2. The method of claim 1 comprising cooling said motor/pump sets by said hydraulic oil flow drawn through the motor/pump set cooling said motor reducing noise, vibration, and size of said system.