Pump apparatus, system having the same, and method for operating the same

Abstract

A pump apparatus includes a housing. A rotor is eccentrically accommodated in the housing. A motor rotates the rotor in the housing. A vane is substantially radially movable relative to the rotor. The vane has a radially outer end that is slidable relative to an inner circumferential periphery of the housing as the rotor and the vane rotates for increasing or decreasing pressure of gas. A pressure sensor detects pressure of the gas. A control unit that evaluates whether an adherence abnormality, in which the vane adheres to the rotor, occurs in accordance with both a detection signal of the pressure sensor and electricity supplied to the motor when the motor rotates the rotor. When the control unit determines the adherence abnormality to be caused, the control unit operates the motor to remove the vane from the rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a schematic view showing a leak check system;

FIG. 2 is a sectional view showing a pump module of the leak check system;

FIG. 3 is a time chart showing change in pressure in a leak check operation;

FIG. 4 is a time chart showing change in pressure and a motor current in a normal condition;

FIG. 5 is a time chart showing change in pressure and a motor current in an abnormal condition;

FIG. 6 is a time chart showing change in pressure and a motor current in an abnormal condition in which dew condensation is caused; and

FIG. 7 is a flowchart showing the leak check operation.

Claims

1. A pump apparatus comprising: a housing;a rotor that is eccentrically accommodated in the housing;a motor for rotating the rotor;a vane that is substantially radially movable relative to the rotor, the vane having a radially outer end that is slidable relative to an inner circumferential periphery of the housing as both the rotor and the vane rotate for increasing or decreasing pressure of gas;a pressure sensor that detects pressure of the gas; anda control unit that evaluates whether an adherence abnormality, in which the vane adheres to the rotor, occurs, in accordance with both a detection signal of the pressure sensor and electricity supplied to the motor when the motor rotates the rotor,wherein when the control unit determines the adherence abnormality to be caused, the control unit operates the motor to remove the vane from the rotor.

2. The pump apparatus according to claim 1, wherein the control unit determines the adherence abnormality to be caused when both the following two conditions are satisfied:pressure, indicated by the detection signal of the pressure sensor, is in the vicinity of atmospheric pressure compared with pressure in a normal pressure range; andelectricity supplied to the motor is greater than a normal electricity range.

3. The pump apparatus according to claim 1, wherein when the control unit determines the adherence abnormality to be caused, the control unit increases rotation speed of the motor compared with rotation speed in a normal operating condition.

4. A leak check system for an evaporator system, which is adapted to purging fuel vapor from a fuel tank into an intake passage of an internal combustion engine, the leak check system comprising: the pump apparatus according to claim 1 for decreasing or increasing pressure in the evaporator system;a reference orifice for detecting reference pressure used for evaluating whether leakage occurs in the evaporator system; andan evaluating unit that evaluates whether leakage occurs in the evaporator system by comparing pressure detected using the pressure sensor with the reference pressure when the pump apparatus decreases or increases pressure in the evaporator system,wherein the control unit evaluates whether the adherence abnormality occurs in accordance with both a detection signal of the pressure sensor and electricity supplied to the motor when detecting the reference pressure.

5. A pump apparatus comprising: a housing;a rotor that is accommodated in the housing;a motor for rotating the rotor;a vane that is substantially radially extendable relative to the rotor as the motor rotates for increasing or decreasing pressure of gas;a pressure sensor that detects pressure of the gas; anda control unit that evaluates whether the vane adheres to the rotor in accordance with both the pressure of the gas and electricity supplied to the motor when the motor rotates the rotor,wherein when the control unit determines the vane to be adhering to the rotor, the control unit operates the motor-to remove the vane from the rotor.

6. A method for operating a pump apparatus, the method comprising: supplying electricity to a motor for rotating a rotor and radially extending a vane from the rotor by centrifugal force for increasing or decreasing pressure of gas;detecting pressure of the gas;evaluating whether the vane adheres to the rotor in accordance with both the pressure of the gas and the electricity supplied to the motor; andoperating the motor to remove the vane from the rotor when determining the vane to be adhering to the rotor.

7. A method for operating a system, which is substantially enclosed, the method comprising: operating a switching valve to communicate a pump with the system through a reference orifice;supplying electricity to a motor of a pump for rotating a rotor and radially extending a vane from the rotor by centrifugal force for increasing or decreasing pressure of gas in the system through the reference orifice;detecting pressure of the gas;evaluating whether both the pump and the switching valve are normal, in accordance with both the pressure of the gas and the electricity supplied to the motor when detecting the pressure of the gas;operating the switching valve to communicate the pump directly with the system when both the pump and the switching valve are determined to be normal; andevaluating whether leakage occurs in the system by comparing a time trend of the pressure of the gas with a predetermined time trend.

8. A method for operating a system, which is substantially enclosed, the method comprising: operating a switching valve to communicate a pump with the system through a reference orifice;supplying electricity to a motor of a pump for rotating a rotor and radially extending a vane from the rotor by centrifugal force for increasing or decreasing pressure of gas in the system through the reference orifice;detecting pressure of the gas;evaluating whether both the pump and the switching valve are normal, in accordance with both the pressure of the gas and the electricity supplied to the motor when detecting the pressure of the gas;determining the vane to be adhering to the rotor when pressure of the gas is abnormal and electricity supplied to the motor is equal to or greater than predetermined threshold; anddetermining the switching valve to be abnormal when pressure of the gas is abnormal and when electricity supplied to the motor is less than predetermined threshold.