Fluid pump, a fluid-transfer plate and an inductive sensor for a fluid pump

• US 20060127249A1
• Filed: 07/10/2003
• Published: 06/15/2006
• Est. Priority Date: 09/12/2002
• Status: Active Grant

• Current Assignee: Empresa Brasileira de Compressores SA (Whirlpool Corporation)
• Original Assignee: Empresa Brasileira de Compressores SA (Whirlpool Corporation)
• Inventors: Lilie, Dietmar Erich Bernhard
• Granted Patent: US 7,744,354 B2
• Time in Patent Office: Days
• US Class Current: 417/417
• CPC Class Codes: F04B 2201/0201 Position of the piston
• CPC Class Codes: F04B 35/045 using solenoids
• CPC Class Codes: F04B 39/1066 Valve plates
• CPC Class Codes: F04B 39/122 Cylinder block

Abstract

The present invention relates to a fluid pump and a fluid-transfer plate and a sensor for a fluid pump, particularly applicable to linear compressors, for detecting the position of the respective piston and preventing the latter from colliding with the fluid-transfer plate upon variations in the compressor operation conditions, or even variations in the feed voltage. The objectives of the present invention are achieved by means of a fluid pump (1) comprising a piston (2) that is axially displaceable within a cylinder (3), the cylinder (3) comprising a cylinder closing fluid-transfer plate (40), the piston (2) being displaced toward the fluid-transfer plate (40) and capturing a gas or fluid from a low-pressure environment (11), and the fluid pump (11) comprising a sensor assembly (98), which includes an inductive sensor (8) associated with the fluid-transfer plate (40). The objectives of the present invention are also achieved by means of a fluid-transfer plate (40) particularly applicable to a fluid pump (1) and that comprises a valve plate (4) provided with a though-bore (10) for associating a protector (9) that cooperates with the cavity (10), the protector (9) comprising at least one sensor cavity (8′) for associating an inductive sensor (8). An inductive sensor (8) is also foreseen, which is applicable to the fluid pump (1).

Claims

1. A fluid pump comprising:

a piston that is axially displaceable within a cylinder;

the cylinder comprising a cylinder closing fluid-transfer plate;

the piston being displaced towards the fluid-transfer plate and capturing gas or fluid from a low-pressure environment; and

the fluid pump being characterized in that it comprises a sensor assembly that includes an inductive sensor associated with the fluid-transfer plate (40), the fluid-transfer plate comprises a valve plate provided with a through-bore for association of a protector that cooperates with the bore, the sensor being positioned in contact with the low-pressure environment.

2. A fluid pump according to claim 1, characterized in that the protector comprising at least one sensor cavity for associating the inductive sensor.

3. A fluid pump according to claim 2, characterized in that the inductive sensor emits a magnetic field in the direction of the piston.

4. A fluid pump according to claim 3, characterized in that the protector comprises a fitting portion, an open portion, and a closed portion, the fitting portion being cooperatively associated with the bore, the closed portion aligning with the inner face of the cylinder, and the open portion comprising the sensor cavity.

5. A fluid pump according to claim 4, characterized in that the valve plate comprises a suction valve associated with a low-pressure environment and a discharge valve associated with a high-pressure environment, and still in that the open portion is in contact with the low-pressure environment and the closed portion is in contact with the high-pressure environment.

6. A fluid pump according to claim 5, characterized in that the protector has substantially the same shape as the cavity.

7. A fluid pump according to claim 1, characterized in that the protector is built with a material having low magnetic permeability.

8. A fluid pump according to claim 1, characterized in that the sensor is fixed to the closed portion of the protector.

9. A fluid pump according to claim 2, characterized in that the valve plate comprises recesses for fixing the protector, the protector comprising protuberant ends and being fixed to the valve plate by means of a sealing joint.

10. A fluid pump according to claim 2, characterized in that the valve plate comprises recesses for fixing a protecting disc, the protecting disc forming a cavity for installation of the sensor.

11. A fluid-transfer plate particularly applicable to a fluid pump, characterized by comprising:

a valve plate provided with a through-bore for association with a protector that cooperates with the bore, the protector comprising at least one sensor cavity for association of an inductive sensory.

12. A fluid-transfer plate according to claim 11, characterized in that the protector comprises a fitting portion, an open portion and a closed portion, the fitting portion being cooperatively associated with the bore, the closed portion aligning with an inner face of the cylinder, and the open portion comprising the sensor cavity.

13. A fluid-transfer plate according to claim 11, characterized by comprising recesses for fixing the protector, the protector comprising protuberant ends and being fixed to the valve plate by means of a sealing joint.

14. A fluid-transfer plate according to claim 11, characterized in that a valve plate comprises recesses for fixing a protecting disc, the protecting disc forming a cavity for installing the sensor.

18. A sensor according to claim 12, characterized in that the protector comprises protuberant ends associable with recesses in the valve plate, the protector being fixed to the valve plate by means of a sealing joint.

15. An inductive sensor for a fluid pump particularly applicable for detecting the position of a piston, the piston being axially displaceable in a cylinder, the fluid pump comprising a valve plate, the inductive sensor being characterized in that it is installed on a protector, the protector being fixed to a through-bore provided in the valve plate.

16. A sensor according to claim 15, characterized in that the protector comprises a cavity for positioning the sensor.

17. A sensor according to claim 15, characterized in that the protector comprising a fitting portion, an open portion and a closed portion, the fitting portion being cooperatively associated with the through-bore, the closed portion aligning with an inner face of the cylinder, and the open portion comprising the sensor cavity.

19. A sensor according to claim 15, characterized in that it is fixed to a protecting disc, the protecting disc being fixed in recesses provided on the valve plate.