Thermistor flow path

Abstract

A fluid pump includes a pump element in communication with an inlet and an outlet. Rotation of the pump element generates a suction at the inlet and pressure at the outlet. The suction and pressure cooperate to move a fluid through a fluid path. An accessory fluid path is in communication with the inlet and outlet. The accessory fluid path includes a thermistor in communication with the accessory fluid path. The thermistor monitors a temperature of the fluid within the accessory fluid path.

Claims

1. A fluid pump comprising: a pump element in communication with an inlet and an outlet, wherein rotation of the pump element generates an inward suction at the inlet and outward pressure at the outlet that cooperatively moves a fluid through a fluid path, the pump element having a stator and a rotor within a housing; an accessory fluid path in communication with the inlet and the outlet, wherein an orifice directs a portion of the fluid through the accessory fluid path, the accessory fluid path having a low-restriction return path that generates a continuous flow of the fluid through the accessory fluid path during operation of the pump element; and a circuit board housing having a contoured portion that aligns with one side of an outer wall and the orifice, the circuit board housing having a printed circuit board with a thermistor in communication with the accessory fluid path, wherein: the continuous flow is directed between the orifice and the contoured portion and along the one side of the outer wall between the rotor and the outer wall; the low-restriction return path and the aligned orifice and contoured portion are configured to maintain a temperature of the continuous flow of the fluid in the accessory fluid path to be similar to a temperature of the fluid in the fluid path; and the thermistor is positioned in communication with the contoured portion to simultaneously monitor, in real time, the temperature of the continuous flow of the fluid in the accessory fluid path and the temperature of the fluid in the fluid path.

2. The fluid pump of claim 1, wherein operation of the pump element moves the fluid through a plurality of flow paths.

3. The fluid pump of claim 2, wherein the plurality of flow paths include the fluid path and the accessory fluid path.

4. The fluid pump of claim 2, wherein the plurality of flow paths each move the fluid to the outlet.

5. The fluid pump of claim 1, wherein the thermistor is disposed within the accessory fluid path.

6. The fluid pump of claim 1, wherein the orifice is positioned proximate the pump element, and wherein the orifice regulates a flow of the fluid into the fluid path and regulates the flow of the fluid into the accessory fluid path.

7. The fluid pump of claim 1, wherein the accessory fluid path extends through a central channel of a drive shaft of the pump element.

8. The fluid pump of claim 7, wherein the central channel of the drive shaft extends through a portion of the pump element.

9. The fluid pump of claim 1, wherein the pump element is a positive displacement pump.

10. The fluid pump of claim 6, wherein the pump element includes a regulating portion of the orifice that regulates a flow of the fluid toward the outlet and toward the accessory fluid path.

11. The fluid pump of claim 10, wherein the regulating portion of the orifice is positioned proximate the outlet.

12. A fluid pump comprising: a pump element in communication with a fluid path, the pump element including a rotor and a stator within a housing; and an orifice in communication with the pump element, wherein the pump element and the orifice generate a primary flow of a fluid that is directed to an outlet and an excess flow of the fluid that is directed through an accessory fluid path that extends between the rotor and one side of an outer wall of the housing, and a circuit board housing having a contoured portion that aligns with the one side of the outer wall and the orifice to define a portion of the accessory fluid path; wherein the accessory fluid path includes a low-restriction return path that moves the excess flow of the fluid as a continuous flow through the accessory fluid path and toward the outlet; the low-restriction return path is configured to maintain a temperature of the excess flow of the fluid in the accessory fluid path to be similar to a temperature of the primary flow of the fluid; and a thermistor is positioned in communication with the contoured portion to simultaneously monitor, in real time, the temperature of the excess flow of the fluid in the accessory fluid path and the temperature of the primary flow of the fluid in the fluid path.

13. The fluid pump of claim 12, wherein the thermistor is disposed within the accessory fluid path.

14. The fluid pump of claim 12, wherein the thermistor directly engages the excess flow of the fluid within the accessory fluid path.

15. The fluid pump of claim 12, wherein the pump element generates an inward pressure at an inlet of the fluid path and generates an outward pressure at the outlet of the fluid path.

16. The fluid pump of claim 12, wherein a regulating portion of the orifice is positioned at the pump element and divides the fluid into the primary flow of the fluid and the excess flow of the fluid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a first perspective view of a fluid pump incorporating an aspect of the thermistor fluid path;

(3) FIG. 2 is a second perspective view of the fluid pump of FIG. 1;

(4) FIG. 3 is a cross-sectional view of the fluid pump of FIG. 1 taken along line III-Ill;

(5) FIG. 4 is a cross-sectional view of the fluid pump of FIG. 3 illustrating a flow of a fluid through the thermistor flow path;

(6) FIG. 5 is a perspective view of a printed circuit board (PCB) housing assembly for a fluid pump that incorporates an aspect of the thermistor;

(7) FIG. 6 is a cross-sectional perspective view of the PCB housing assembly of FIG. 5, taken along line VI-VI; and

(8) FIG. 7 is a schematic flow diagram illustrating a method for operating a fluid pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(9) For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

(10) As shown in FIGS. 1-6, reference numeral 10 generally refers to a printed circuit board (PCB) housing assembly for a fluid pump 12 that incorporates a thermistor 14 for measuring the temperature of fluid 16 being passed through the fluid pump 12. The fluid pump 12 includes a pump element, such as a generated rotor or gerotor 18, or other similar positive displacement pump, in communication with an inlet 20 and an outlet 22 of the fluid pump 12. Activating rotation of the gerotor 18 generates a suction 24, or inward pressure, at the inlet 20 that draws fluid 16 into the fluid path 26 and outward pressure 28 at the outlet 22 that pushes fluid 16 out of the fluid path 26. The suction 24 and outward pressure 28 generated through operation of the gerotor 18 cooperate to move the fluid 16 through the fluid path 26. An accessory fluid path 30, which defines a portion of the fluid path 26, is disposed in communication with the inlet 20 and outlet 22. The accessory fluid path 30 includes the thermistor 14 that is placed in communication with fluid 16 flowing through the accessory fluid path 30. The thermistor 14 is adapted to monitor a temperature of the fluid 16 moving through the accessory fluid path 30 of the fluid pump 12.

(11) Referring again to FIGS. 1-6, a fluid pump 12, such as an electric oil pump, generally provides lubrication and cooling to various mechanisms, such as a gear box, differential unit, or other similar mechanism. The fluid pump 12, typically in the form of a gerotor 18, brushless DC (BLDC) electric motor, and a controller can be fully integrated into a housing assembly that manages the sealing, thermal transfer and part assembly for the electric fluid pump 12. The fluid pump 12 can include a rotor 40 and stator 42 that make up the motor 44 for the fluid pump 12. A drive shaft 46 is driven by rotation of the rotor 40 and serves to rotate the gerotor 18 for generating the suction 24 and outward pressure 28 for moving fluid 16 through the fluid path 26 and, in turn, the accessory fluid path 30.

(12) Referring again to FIGS. 1-6, the accessory fluid path 30, in the form of a thermistor flow path 50, serves to provide a fluid pump 12 with a temperature sensing functionality for providing real time measurements regarding fluid temperature during operation of the fluid pump 12. The temperature sensor can be a thermistor-style leaded component that is installed in the same cavity as the rotor assembly 52 that serves to drive the gerotor 18. Typically, this cavity is “wet” as the rotor 40 is submerged in fluid 16, such as oil. Within the fluid pump 12, the fluid 16 moving through the gerotor 18 flows through an outlet shadow port 60 having an orifice 62 that helps to regulate and divide the flow of fluid 16 through the fluid path 30 of the fluid pump 12, as will be described more fully below.

(13) The fluid 16 is divided between a regulated primary flow 54 of the fluid 16 and the remaining fluid 16 that defines an excess flow 56 of the fluid 16. In regulating the flow of fluid 16 from the outlet shadow port 60 and orifice 62, the primary flow 54 is a predetermined amount of the fluid 16 that is directed to the outlet 22. By dividing the fluid 16, the excess flow 56 of fluid 16 that is not part of the regulated primary flow 54 of the fluid 16 is directed through the orifice 62 and into the accessory fluid path 30. In this manner, the gerotor 18 pushes the primary flow 54 of the fluid 16 through the outlet 22 and simultaneously pushes the excess flow 56 of the fluid 16 through the orifice 62 and into the accessory fluid path 30. Directing the movement of the excess flow 56 of fluid 16 helps to ensure that there is a continuous or substantially continuous flow of fluid 16 across the thermistor 14. Additionally, this configuration of the accessory fluid path 30 in relation to the outlet shadow port 60 and orifice 62 also helps to ensure that the temperature of the excess flow 56 of the fluid 16 is at least substantially similar to the primary flow 54 of fluid 16 that is directed through the outlet 22. This configuration helps to provide real time or substantially real time temperature measurements of the fluid 16.

(14) In this disclosed device, the accessory fluid path 30 is placed in communication with the outlet shadow port 60 through the orifice 62 that controls the excess flow 56 of the fluid 16 from the outlet shadow port 60 and into the accessory fluid path 30. From the orifice 62 at the outlet shadow port 60, the excess flow 56 of fluid 16 flows around at least a portion of the rotor assembly 52, but within the housing 64 of the fluid pump 12. After passing along the side 66 of the rotor assembly 52, the excess flow 56 of fluid 16 is directed along an inner surface 68 of the PCB housing assembly 10 where the thermistor 14 is located. The inner surface 68 of the PCB housing assembly 10 includes contours 70 that are configured to direct the excess flow 56 of fluid 16 from the sides 66 of the rotor assembly 52 along the contours 70, into engagement with the thermistor 14, and to a central portion 72 of the PCB housing assembly 10. In this manner, the contours 70 and central portion 72 of the inner surface 68 of the PCB housing assembly 10 at least partially defines the thermistor flow path 50 and the accessory fluid path 30. The central portion 72 of the PCB housing assembly 10 is in communication with a channel 80 of the drive shaft 46. This channel 80 of the drive shaft 46 extends through the center of the drive shaft 46 and the rotor assembly 52 and up through the gerotor 18 and to a recirculation path 82 that recombines the excess flow 56 of the fluid 16 with fluid 16 entering the inlet 20. In this manner, the excess flow 56 of the fluid 16 is draw back into the inlet 20 by the suction 24 generated by the gerotor 18. The recombined fluid 16 is then delivered via the gerotor 18 and is divided into the primary and excess flows 54, 56 of fluid 16 as described above. In this configuration, a portion of the excess flow 56 upon leaving the recirculation path 82 may be divided again as part of the excess flow 56. It is contemplated that the excess flow 56 from the recirculation path 82 will be sufficiently mixed with the fluid 16 entering the inlet 20. Accordingly, the amount of the excess flow 56 that is divided again into a portion of the excess flow 56 is substantially minimal. The effects of a portion of the excess flow 56 being directly recirculated again through the accessory fluid path 30 as part of the excess flow 56 will have minimal effects on the temperature measurements of the thermistor 14.

(15) In various embodiments, the recirculation path 82 may direct the excess flow 56 of fluid 16 from the accessory fluid path 30 to the outlet 22 of the fluid pump 12. In this manner, the excess flow 56 can be at least partially re-combined with the primary flow 54 of fluid 16 that is moved through the outlet 22.

(16) Referring again to FIGS. 1-6, the return path of the fluid 16 within the accessory fluid path 30 and through the central channel 80 of the drive shaft 46 forces the excess flow 56 of the fluid 16 to flow directly over the thermistor 14. Accordingly, temperature measurements of the excess flow 56 of the fluid 16 moving through the thermistor flow path 50 can be taken by the thermistor 14 in real time or substantially in real time. The amount of fluid 16 moving through the accessory fluid path 30 is controlled by the size of the orifice 62 on the high pressure side of the fluid path 26. Additionally, the return path of the accessory fluid path 30 is at a lower restriction to prevent a pressure build-up within the motor cavity. In order to deliver the signal from the thermistor 14 within the PCB housing assembly 10, terminals 90 are used to connect the thermistor 14 to the PCB housing assembly 10. These terminals 90 are sealed to prevent leaking into the PCB cavity 92 on the opposite side 66 of the thermistor 14.

(17) Within conventional fluid pumps 12, very little fluid 16 is moved in and around the motor cavity. As such, placing a thermostat or other temperature sensing device within this area provides little, if any, temperature-related information.

(18) Referring again to FIGS. 1-6, the accessory fluid path 30 that provides the thermistor flow path 50 provides a convenient and accurate mechanism for measuring the temperature of the fluid 16 flowing through the fluid pump 12 while not diminishing the performance of the fluid pump 12.

(19) It is contemplated that the fluid pump 12 described herein can be used in various applications that can include, but are not limited to, fuel pumps, oil pumps, water pumps, combinations thereof, and other fluid pumps 12 that may be submerged or non-submerged.

(20) It is contemplated that the PCB housing assembly 10 and terminals 90 can be incorporated within new pumps or can be manufactured for installation with after-market pumps.

(21) Having described various aspects of the device, a method 400 is disclosed for operating the fluid pump 12. This method 400 includes step 402 of activating a pump element to draw a fluid 16 into a fluid path 26. The pump element operates to direct a fluid 16 to a position that defines a shadow port 60 (step 404). The fluid 16 is divided into a primary flow 54 of the fluid 16 toward an outlet 22 of the fluid path 26 and an excess flow 56 of the fluid 16 through an orifice of the shadow port 60 and into an accessory fluid path 30 (step 406). The excess flow 56 of the fluid 16 is directed to a thermistor 14 (step 408). A fluid temperature of the excess flow 56 of the fluid 16 in the accessory fluid path 30 is measured (step 410). The excess flow 56 of the fluid 16 is directed toward the inlet 20 of the fluid path 26 (step 412).

(22) It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.