Integrated liquid level sensor for lubricant pump assembly

Abstract

The lubricant pump assembly includes a fill tube and a sensor tube located within the fill tube. The sensor tube has a plurality of sensors disposed within the sensor tube, and the sensors are configured to generate a signal indicative of a fill level of lubricant within the lubricant pump assembly when triggered by a magnetic indicator. A follower within the lubricant pump assembly moves up and down over the lubricant within the lubricant pump assembly. A fill tube is disposed between the sensor tube and the magnetic indicator.

Description

Technical Field

[0001] The present invention generally relates to lubrication systems. More specifically, the present invention relates to lubricant level sensing for a lubricant reservoir. Background Art

[0002] Machines generally require lubrication to operate. Seals, pistons, bearings, and other parts may need to be lubricated with small, measured amounts of grease or oil at short and frequent intervals to prevent wear, corrosion, over-lubrication, or under-lubrication. Lubricant is injected at specific locations where lubrication is required by a lubricant metering device. A local lubricant reservoir can store a certain volume of lubricant until the lubricant is to be applied. The lubricant reservoir holds a limited volume of lubricant, and when the volume of lubricant in the reservoir is small, it must be refilled from a larger lubricant source. Lubricant is drawn out of the lubricant reservoir and pumped through a lubrication line to the lubricant metering device. The lubricant metering device is configured to inject a set of small amounts of lubricant into a specific location within the machine once the pressure within the lubrication line reaches a predetermined threshold level. Summary of the Invention

[0003] According to one aspect of the present invention, a lubricant pump assembly includes: a base, a reservoir housing supported by the base, and a lubricant chamber at least partially disposed within the reservoir housing. The lubricant pump assembly further includes a follower disposed within the reservoir housing and a fill tube extending downward from the top of the reservoir housing. The follower is configured to rise and fall with the lubricant fill level within the lubricant chamber. The fill tube has a first tube end and a second tube end, wherein the fill tube extends through the follower and is configured to output lubricant into the lubricant chamber. Additionally, the lubricant pump includes a sensor assembly that includes a sensor tube and a magnetic indicator. The sensor tube has a plurality of sensors disposed within the sensor tube, and the sensor tube is at least partially disposed within the fill tube. The magnetic indicator is supported by the follower such that the magnetic indicator moves relative to the sensor tube and the fill tube together with the follower, wherein the magnetic indicator is configured to trigger the plurality of sensors to cause the plurality of sensors to output signals indicative of the lubricant fill level.

[0004] According to another or alternative aspect of the present invention, a lubricant pump assembly includes: a base having an outlet port, an outlet pump disposed within the base, wherein the outlet pump is configured to discharge lubricant through the outlet port. The lubricant pump assembly further includes a reservoir housing supported by the base, a fill tube defining a fill tube inlet and a fill tube outlet, the fill tube disposed within the reservoir housing, a follower plate disposed within the reservoir housing, wherein the fill tube is configured to receive lubricant at the fill tube inlet, and the follower plate includes: an outer seal engaging a sidewall of the reservoir housing, a guide hole through which the fill tube extends, and a vent valve configured to allow air to flow between a region above the follower plate and a region below the follower plate. Additionally, the lubricant pump assembly includes a magnetic indicator supported by the follower plate. Further still, the lubricant pump assembly includes an auto-fill cut-off assembly including an AFSO housing and a valve, the AFSO housing including an AFSO side, the valve at least partially disposed within the AFSO housing, the valve including a valve stem and a valve seat, wherein the valve stem is configured to engage the valve seat when the valve is in a closed state and disengage from the valve seat when the valve is in an open state. Further, there is an AFSO air inlet disposed on the AFSO side, an AFSO hole extending from the bottom of the AFSO housing into the AFSO housing, wherein the AFSO hole is configured to receive the fill tube, and wherein the valve seat is disposed between the AFSA air inlet and the AFSO hole. Additionally, the lubricant pump assembly further includes a sensor assembly having a sensor tube surrounding a plurality of sensors, the sensor tube at least partially disposed within the fill tube, wherein the magnetic indicator is configured to trigger the plurality of sensors to cause the plurality of sensors to output signals indicative of the lubricant fill level, wherein the plurality of sensors are fluidly isolated from the lubricant by the sensor tube, the fill tube outlet is configured to output lubricant below the follower plate, and the follower plate is configured to be located at the top of the lubricant when the lubricant is disposed within the reservoir housing.

[0005] According to another additional or alternative aspect of the present disclosure, a method of determining a lubricant pump assembly includes flowing lubricant into the lubricant pump assembly, flowing the lubricant downwardly along a space between the interior of the fill tube and the exterior of the sensor tube. Additionally, the method includes releasing the lubricant from the fill tube and into a lubricant chamber, and raising a follower plate disposed within a reservoir housing of the lubricant pump assembly via the lubricant below the follower plate, sensing a lubricant fill level within the reservoir housing by signals received from a plurality of sensors disposed within the sensor tube, wherein a magnetic indicator supported by the follower plate triggers a plurality of sub-sensors disposed within the sensor tube to output signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a block diagram of a lubricant pump assembly.

[0007] Figure 2 is an isometric view of a lubricant pump assembly.

[0008] Figure 3A is a cross-sectional view of a lubricant pump assembly taken along line A-A Figure 2 of

[0009] Figure 3B is a cross-sectional view of a lubricant pump assembly taken along line B-B Figure 2 of

[0010] Figure 4 is a plan view of a magnetic indicator that can be used within a lubricant pump assembly. DETAILED DESCRIPTION

[0011] Generally speaking, the present invention relates to the use of a level sensor and an automatic fill shut-off assembly (AFSO) in a lubricant pump assembly configured to dispense a lubricant, such as grease or oil. The AFSO is disposed at the top of a reservoir housing of the lubricant pump and is configured to receive the lubricant through a lubricant inlet, and the lubricant flows to a fill tube that outputs the lubricant into the reservoir housing. The level sensor includes a plurality of sensors disposed within a sensor tube that extends downwardly from the AFSO. The sensor tube is at least partially disposed within the fill tube and can be coaxial with the fill tube in some examples. This placement of the sensor tube within the fill tube provides a simplification of the overall design, reducing leak points and / or pinch points. When the fill tube releases the lubricant, such as at the bottom of the reservoir, the rising lubricant level causes a follower within the housing to shift upward. The follower supports a magnetic indicator that triggers the sensors within the sensor tube as the follower shifts within the reservoir. The signals provided by the sensors indicate the lubricant level within the reservoir. In some examples, when the lubricant reaches a full level within the reservoir, the follower is configured to actuate a valve within the AFSO to a closed state to stop the flow of lubricant to the fill tube and the reservoir. When the lubricant is withdrawn from the lubricant pump to lubricate mechanical components within the system, the level sensor can provide lubricant level information based on the decreasing lubricant level. Information regarding the decreasing lubricant level can be used to determine when to refill the lubricant reservoir, thus providing a more efficient use of resources, allowing for advance scheduling, and preventing the lubricant pump from running dry.

[0012] Figure 1 is a block diagram of a lubricant system 1. The lubricant system 1 includes a lubricant pump assembly 10, an input pump 12, an input hose 14, an automatic fill cut-off assembly 16 (AFSO16), an AFSO passage 18 (which can also be referred to as a lubricant path), a valve 20, a sensor assembly 22, a fill tube 28, a fill tube axis FA, a reservoir housing 30, a body 31, a base 32, a lubricant chamber 34, a follower 36, a magnetic indicator 38, a controller 42, an output pump 44, an output hose 46, and a lubricated component 48. The sensor assembly 22 includes a sensor tube 24, sensors 26, and a sensor relay 40.

[0013] The lubricant system 1 is configured to store and dispense lubricants, such as greases or oils, among other options. The lubricant pump assembly 10 is configured to receive lubricant from an input pump 12, which is configured to draw lubricant from a lubricant source and convey the lubricant to the lubricant pump assembly 10 via an input hose 14. The input pump 12 is connected to the input hose 14, and the input hose 14 is fluidly connected to the AFSO 16. An AFSO passage 18 is provided within the AFSO 16. The AFSO passage 18 can have an inlet connected to the input hose 14. A valve 20 is at least partially disposed within the AFSO passage 18, downstream along the flow direction from the inlet, which is configured to receive lubricant. The valve 20 can be in a closed state or an open state. When the valve 20 is in the closed state, the valve 20 is configured to stop the flow of lubricant from the inlet to the fill tube 28.

[0014] The sensor assembly 22 is at least partially disposed within the AFSO 16. It should be understood that in various examples, the sensor assembly 22 can include a plurality of sensors 26 disposed within a sensor tube 24. The sensor assembly 22 is at least partially disposed within the fill tube 28. The sensor assembly 22 can be supported by the AFSO 16. In various examples, the sensor assembly 22 can extend upwardly through the AFSO 16. The sensor assembly 22 extends into the reservoir housing 30 and can extend into the lubricant chamber 34. In some examples, the sensor tube 24 of the sensor assembly 22 and the fill tube 28 can be coaxially disposed. In these examples, the sensor tube 24 can also be coaxial with the follower 36, where the fill tube 28 is also coaxial with the follower 36. The fill tube 28 and the sensor assembly 22 can both be centered about a fill tube axis FA. In other examples, the sensor tube 24 can be at least partially disposed within the fill tube 28 but not coaxial with the fill tube 28.

[0015] The fill tube 28 is configured to receive lubricant from the AFSO passage 18. The fill tube 28 is disposed below the AFSO 16. The AFSO 16 is disposed at the top of the reservoir housing 30. The fill tube 28 extends into the reservoir housing 30. The fill tube 28 is configured to release lubricant into the lubricant chamber 34. The lubricant chamber 34 defines an available volume that the lubricant can occupy. The lubricant chamber 34 is at least partially defined by the reservoir housing 30. The lubricant chamber 34 can be at least partially defined by the base 32. The reservoir housing 30 is disposed on top of the base 32. The base 32 can support the reservoir housing 30. The body 31 includes the reservoir housing 30 and the base 32.

[0016] The follower 36 is disposed within the reservoir housing 30 and is configured to rise and fall as the lubricant fill level within the reservoir housing 30 changes. The follower 36 at least partially surrounds the fill tube 28 and supports the magnetic indicator 38. In some examples, the follower 36 can be a follower plate. In other examples, the follower 36 can be a follower plate that extends to engage the inner surface of the reservoir housing 30. For example, the follower 36 can include one or more seals that engage and seal the inner surface of the reservoir housing 30. The follower 36 can be configured to float on top of the lubricant such that an increase in the lubricant level causes the follower 36 to rise within the lubricant chamber 34 and a decrease in the lubricant level causes the follower 36 to fall within the lubricant chamber 34. In an example where the follower 36 extends fully to the sidewall of the reservoir housing, as the lubricant fills the lubricant chamber 34, the volume of the lubricant chamber 34 increases as the follower 36 rises with the rising lubricant level. In an example where the follower 36 does not extend outwardly to the sidewall of the reservoir housing, the available volume for the lubricant to occupy can include the entire reservoir housing 30 and the wet portion of the base 32.

[0017] The follower 36 can be disposed entirely annularly around the fill tube 28. The follower 36 is configured to be in sliding communication with the fill tube 28. The follower 36 can be guided by the fill tube 28 such that the follower 36 can be considered to ride on the fill tube 28 as the lubricant fill level rises and falls. The follower 36 does not directly contact the sensor tube 24. The follower 36 is radially outwardly spaced from the sensor tube 24 by a distance with respect to the fill tube axis FA. The follower 36 can support the magnetic indicator 38.

[0018] The magnetic indicator 38 includes one or more permanent magnets. The sensor 26 is disposed within the sensor tube 24. The magnetic indicator 38 is configured to trigger the sensor 26 disposed within the sensor tube 24 of the sensor assembly 22. The magnetic indicator 38 outputs a magnetic field sensed by the sensor 26. The magnetic indicator 38 is configured to rise and fall as the lubricant level within the lubricant chamber 34 changes by being supported by the follower 36. The change in the position of the magnetic indicator 38 changes the position of the magnetic force on the sensor 26, and the sensor 26 outputs a signal based on the sensed magnetic field. The signal output by the sensor 26 provides information about the lubricant level within the lubricant chamber 34. In the example shown, the magnetic indicator 38 is supported by the follower 36 such that the magnetic indicator 38 travels with the follower 36. The magnetic indicator 38 does not directly contact the sensor tube 24. Instead, the magnetic indicator 38 is disposed outside the fill tube 28 such that the magnetic indicator 38 is spaced from the sensor tube 24 by the flow gap between the outside of the sensor tube 24 within the fill tube 28 and the inside of the fill tube 28 and the thickness of the fill tube 28.

[0019] The sensor tube 24 can be closed so that the interior of the sensor tube 24 is isolated from the lubricant fluid within the reservoir housing 30. The sensor relay 40 extends from a portion of the sensor tube 24 that is disposed outside of the reservoir housing 30. In the illustrated example, the sensor relay 40 is connected to the sensor tube 24 at a location outside of the housing of the AFSO 16. The sensor relay 40 is operatively electrically connected and / or communicatively connected to the sensor 26 to receive a sensor signal from the sensor 26.

[0020] The sensor relay 40 is configured to transmit the sensor signal to the controller 42. The sensor relay 40 is connected to the sensor tube 24 and is configured to transmit a signal from the sensor 26 disposed within the sensor tube 24 to the controller 42. The sensor assembly 22 is configured to output a level signal indicative of the level of lubricant within the lubricant chamber 34. The sensor assembly 22 is operatively electrically connected and / or communicatively connected to the controller 42 to provide the level signal to the controller 42. In the illustrated example, the sensor assembly 22 is operatively connected to the controller 42 via the sensor relay 40, and the sensor relay 40 can be formed as a wired or wireless connection between the sensor assembly 22 and the controller 42.

[0021] The controller 42 can be, for example, a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other equivalent discrete or integrated logic circuit configured to implement functional and / or procedural instructions. In some examples, the controller 42 can include an on-board computer-readable memory. The computer-readable memory of the controller 42 can be configured to store information during operation of the lubricant pump assembly 10. In some examples, the computer-readable memory can include a non-transitory medium. The term “non-transitory” can indicate that the storage medium is not included in a carrier wave or propagated signal. In certain examples, the non-transitory storage medium can store data that varies over time (e.g., in RAM or a cache). In some examples, the computer-readable memory can include a temporary storage element, which means that the primary purpose of such a computer-readable storage element is not long-term storage. In certain examples, the temporary storage element can be described as volatile memory, which means that when the power to the controller 42 is turned off, the temporary storage element does not retain stored content. Examples of volatile memory can include random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), and other forms of volatile memory.

[0022] In some examples, the computer-readable memory of the controller 42 is used to store program instructions executed by the controller 42. For example, during operation of the lubricant pump 10, the computer-readable memory of the controller 42 can be used by software, firmware, or applications executed by the controller 42. In some examples, the computer-readable memory of the controller 42 can also include non-volatile storage elements configured to retain stored content when the power to the lubricant pump 10 is turned off. Examples of such non-volatile storage elements can include flash memory, electrically programmable read-only memory (EPROM), electrically erasable and programmable (EEPROM) memory, or other forms of non-volatile storage elements.

[0023] The controller 42 can be configured to provide a lubricant level indication regarding the sensed lubricant level within the lubricant chamber 34. In some examples, the controller 42 includes a user interface, which can be any graphical and / or mechanical interface that enables a user to interact with the controller 42, such as scheduling a refill time for the lubricant chamber 34 or removing lubricant from the lubricant chamber 34.

[0024] The output pump 44 is configured to draw lubricant out of the lubricant chamber 34. The output pump 44 can be disposed entirely or partially within the base 32, entirely or partially within the reservoir housing 30, and / or entirely or partially external to the base 32 and the reservoir housing 30. The output pump 44 can be connected to an output hose 46 to provide lubricant downstream through the output hose 46. The output hose 46 can be fluidly connected to the output pump 44 and is configured to distribute the lubricant to the lubricated component 48.

[0025] During the filling operation, the input hose 14 is connected to the AFSO 16 of the lubricant pump assembly 10 to fluidly connect the input pump 12 with the lubricant pump assembly 10. The lubricant is first received through the AFSO 16. The lubricant flows through the open valve 20 and into the filling tube 28. Then, the lubricant flows downward along the filling tube 28 from the AFSO 16 at the first tube end, and as the lubricant flows downward along the filling tube 8, the lubricant surrounds the sensor tube 24, which is at least partially disposed within the filling tube 28. Thus, both the outer surface of the sensor tube 24 and the inner surface of the filling tube 28 are in direct contact with the lubricant flowing within the filling tube 28. As the lubricant flows downward to fill the lubricant chamber 34, the lubricant and the sensor tube 24 are disposed within the filling tube 28. The lubricant flows out of the filling tube 28 through the filling tube outlet at the second tube end and into the lubricant chamber 34 to fill the lubricant chamber 34. The filling tube outlet can be formed as the open end of the filling tube 28 opposite the end that receives the lubricant from the AFSO 16, and additionally or alternatively can be formed as one or more ports extending through the filling tube 28 among other options. As the lubricant flows downward along the filling tube 28, around the sensor tube 24, and out of the filling tube outlet, the lubricant fills the lubricant chamber 34, and the lubricant filling level within the lubricant chamber 34 begins to rise. Thus, during the filling operation, the lubricant contacting the sensor tube 24 travels in a direction (downward) opposite to the direction (upward) of the lubricant filling within the lubricant chamber 34.

[0026] During the lubricating operation, the output pump 44 withdraws lubricant from the lubricant chamber 34 and drives the lubricant through the output hose 46 to a downstream lubricating component 48. The output pump 44 that sucks the lubricant from the lubricant chamber 34 causes the lubricant filling level within the lubricant chamber 34 to drop.

[0027] The magnetic indicator 38 is configured to rise as the lubricant level within the lubricant chamber 34 rises and is configured to drop as the lubricant level within the lubricant chamber 34 drops. The magnetic indicator 38 is configured to axially shift along the filling tube axis FA with the variable lubricant filling level. Thus, the magnetic indicator 38 is configured to shift relative to the filling tube 28, the sensor tube 24, and the sensor 26. Depending on how much of the lubricant chamber 34 is occupied by the lubricant, the magnetic indicator 38 will trigger different sensors 26 disposed inside the sensor tube 24 through the magnetic field output from the magnetic indicator 38. The sensors 26 send signals to the controller 42 through the sensor relay 40. These signals indicate the lubricant level of the lubricant within the lubricant pump assembly 10.

[0028] Figure 2is an isometric view of the lubricant pump assembly 10. The lubricant pump assembly 10 includes an AFSO 16, a valve 20 (not shown), a signal indicator 21, a sensor assembly 22, a reservoir housing 30, and a base 32. The outlet port 45 of the base 32 is shown. A portion of the sensor assembly 22 is shown. The sensor relay 40 of the sensor assembly 22 is shown. The sensor assembly 22 extends through the reservoir housing 30 and the AFSO 16. The signal indicator 21 extends from the valve 20 and is located on top of the AFSO 16. The valve 20 is disposed within the AFSO 16. The AFSO 16 is disposed on top of the reservoir housing 30. The reservoir housing 30 is supported by the base 32. The reservoir housing 30 receives lubricant through the AFSO 16, and the lubricant can be withdrawn from the reservoir housing 30 through the base 32 for use on or within separate components, which, in one example, can be gears, bearings, shafts, cylinders, joints, pistons, elastomeric seals such as O-rings, and other options. The fill level of the lubricant within the lubricant pump assembly 10 can be determined by a signal transmitted through the sensor relay 40. The fill level can also be referred to as the lubricant fill level or the lubricant level.

[0029] Figure 3A is a cross-sectional view of the lubricant pump assembly 10 taken along Figure 2 line A-A. Figure 3B is a cross-sectional view of the lubricant pump assembly 10 taken along Figure 2 line B-B in Figure 3A and 3B are discussed together and continue to refer to Figure 1 and Figure 2 .

[0030] The lubricant pump assembly 10 includes an AFSO 16, a valve 20, a signal indicator 21, a sensor assembly 22, a fill tube 28, a reservoir housing 30, a base 32, a lubricant chamber 34, a follower 36, a magnetic indicator 38, an outlet pump 44, a pressure plate 50, a motor 52, a drive shaft 54, bearings 56, a stirring assembly 58, an inner seal 60, a spring 62, a static seal 64, fasteners 70, and a locator 124. The AFSO 16 includes an AFSO passage 18, a valve 20, an AFSO housing 72, an AFSO top 74, an AFSO side 76, an AFSO inlet 78, an AFSO hole 80, and a lubricant port 82. The valve 20 includes a valve stem 84, a valve seat 86, and a pin 88. The sensor assembly 22 includes a sensor tube 24, a sensor 26, a sensor relay 40, a mounting plate 68, a sensor tube end 90, and a sensor tube surface 92. The fill tube 28 includes a fill tube inlet 94, a first tube end 95, a fill tube outlet 96, a second tube end 97, a fill tube inner surface 98, and a fill tube outer surface 100. The reservoir housing 30 includes a reservoir housing top 102, a reservoir housing side wall 104, a drain hole 106, a dry part of the housing 108, and a wet part of the housing 110. The follower 36 includes a guide hole 112, an outer seal 114, and an exhaust valve 116. The base includes a wet part of the base 118, a dry part of the base 120, and an outlet port 45.

[0031] In the lubricant pump assembly 10, the AFSO 16 is disposed on the reservoir housing top 102, and the reservoir housing 30 is supported by the base 32. The valve 20 is at least partially disposed within the AFSO 16. The valve seat 86 can be formed by the AFSO housing 72 and other options. In some examples, the valve 20 includes a valve stem 84, a valve seat 86, and a pin 88. In some examples, the valve stem 84 can extend outwardly from the AFSO top 74 into the signal indicator 21. In these examples, the signal indicator 21 can be disposed on the AFSO top 74. When the lubricant pump assembly 10 is in the full state, the valve stem 84 extending into the signal indicator 21 visually indicates that the lubricant pump assembly 100 is full. In the case where the valve 20 is in the closed state, the valve stem 84 extends into the signal indicator 21. In the closed state, the enlarged portion of the valve stem 84 engages the valve seat 86, and the valve 20 cuts off the flow of lubricant into the lubricant pump assembly 10. In the illustrated example, the valve 20 is switched to the closed state by engaging with the follower 36 through the pin 88 and being driven upward by the follower 36. The pin 88 projects out of the bottom of the AFSO housing 72 and into the reservoir housing 30. In some examples, the pin 88 and the valve stem 84 can be integrally formed as a single unit.

[0032] The valve 20 is configured to transition between an open state and a closed state within the AFSO 16. When the valve 20 is in the open state, the AFSO passage 18 has free fluid communication within the AFSO housing 72 between the AFSO inlet 78, the AFSO bore 80, and the lubricant port 82. The AFSO passage 18 is disposed within the AFSO housing 72 and is downstream of the AFSO inlet 78 with respect to the flow direction. The AFSO passage 18 is disposed within the AFSO housing 72 and is configured to direct the flow of lubricant. The AFSO inlet 78 is disposed at the upstream end of the AFSO passage 18 (with respect to the flow direction), and the AFSO inlet 78 is disposed on the AFSO side 76. In some examples, the AFSO inlet 78 is disposed on the AFSO top 74. The AFSO inlet 78 is configured to be connected to a line, such as a hose, to receive lubricant from an upstream lubricant source. The lubricant port 82 is also disposed on the AFSO side 76. The lubricant port 82 may connect the AFSO inlet 78 and the AFSO bore 80. When the valve 20 is in the open state, the lubricant port 82 is in fluid communication with the AFSO inlet 78 and the AFSO bore 80. The valve 20 is disposed downstream of the AFSO inlet 78 along the flow direction through the AFSO 16. Additionally, when the valve 20 is in the open state, the AFSO inlet 78 is in fluid communication with the AFSO bore 80.

[0033] The AFSO bore 80 is disposed within the AFSO housing 72 at the downstream end of the AFSO passage 18. The AFSO bore 80 extends from the bottom of the AFSO 16 into the AFSO housing 72. The AFSO bore 80 is downstream of both the valve 20 and the AFSO inlet 78 along the flow direction through the AFSO passage 18. The AFSO bore 80 is configured to interface with the fill tube 28.

[0034] The fill tube 28 is connected to the AFSO 16 at the AFSO bore 80. For example, the fill tube 28 may be connected to the AFSO 16 by interface threads and other options (e.g., fasteners, bayonet connections, press fits, etc.). The fill tube 28 may be at least partially disposed within the AFSO 16 at the interface with the AFSO bore 80. The fill tube 28 may be supported by the AFSO housing 72. In some examples, the fill tube 28 is supported within the reservoir housing 30 from the reservoir housing top 102. The fill tube 28 extends into the reservoir housing 30. The fill tube 28 is configured to transport lubricant from the AFSO 16 to a location within the reservoir housing 30 that is on the side of the follower 36 opposite the AFSO 16 along the fill tube axis FA. The fill tube inlet 94 is configured to receive lubricant from the AFSO passage 18 into the fill tube 28 at the AFSO bore 80. The fill tube inlet 94 is disposed at the first tube end 95 of the fill tube 28.

[0035] The sensor assembly 22 is at least partially disposed within the fill tube 28. The sensor assembly 22 includes a sensor tube 24, a sensor 26 disposed within the sensor tube 24, a mounting plate 68, a sensor tube end 90 disposed at an end of the sensor tube 24, a sensor tube surface 92, and a sensor relay 40 disposed at the top of the sensor assembly 22. Although the sensor tube 24 is at least partially disposed within the AFSO 16, in some examples, the sensor tube 24 may only contact a static seal 64 within the AFSO housing 72 and not directly contact the AFSO housing 72. The static seal 64 is disposed within and supported by the AFSO housing 72. The static seal 64 prevents leakage of lubricant between the AFSO housing 72 and the sensor tube 24.

[0036] In the example shown, the sensor tube 24 only contacts a static seal member and does not contact a dynamic seal member configured to slide along and seal the sensor tube surface 92. The sensor tube surface 92 is the outer surface of the sensor tube 24. In the example shown, the sensor tube surface 92 may include a 32 micro-inch surface finish that is suitable for static sealing with the static seal 64 and does not require the more stringent or finer surface finish required for sealing at a dynamic seal interface. For example, a surface finish may require a 16 micro-inch surface finish to be sealed with a dynamic seal. Sealing the sensor tube 24 only with a static seal member (such as the static seal 64) reduces cost and manufacturing time by allowing the use of a less fine surface finish. In some examples, only a single static seal (such as the static seal 64) is required to contact the sensor tube 24. Additionally, in the example shown, the sensor tube 24 does not contact a dynamic seal. As Figures 3A to 3B shown, the sensor tube end 90 is enclosed to prevent contact between the lubricant and the sensor 26. The sensor tube 24 is sealed relative to the lubricant such that the lubricant does not enter the sensor tube 24.

[0037] In some examples, the sensor assembly 22 can extend out of the AFSO top 74. Thus, the sensor assembly 22 can extend completely through the AFSO 16 through the top and bottom ends of the AFSO housing 72. The AFSO top 74 can abut against the bottom of the mounting plate 68. The mounting plate 68 projects outwardly from the sensor tube 24. The sensor assembly 22 can be attached to the AFSO housing 72 by fasteners 70 that are fixed to and attached to the AFSO 4 housing 72 through the mounting plate 68. It should be understood that while the examples shown include multiple fasteners 70, not all examples are so limited. Additionally, the fasteners 70 can include any type of fastener known to those of ordinary skill in the art, including but not limited to screws, nails, bolts, rivets, threaded rods, etc. The sensor relay 40 extends from the top of the sensor tube 24. In some examples, the sensor relay 40 can be a wired connector for data communication. In other examples, the sensor relay 40 can be an antenna configured to communicate with the controller 42 (such as Figure 1 as shown). The data transmitted through the sensor relay 40 is received from the sensors 26 disposed within the sensor tube 24.

[0038] The sensors 26 are disposed within the sensor tube 24 and are arranged along the length of the sensor tube 24. It should be understood that the sensors 26 disposed within the sensor tube 24 can include multiple sensors 26. The sensors 26 are configured to generate a signal (or stop generating a signal) in response to the magnetic field generated by the magnetic indicator 38. For example, the sensors 26 can include one or more of a reed switch, a Hall effect sensor, a coil sensor, a magnetoresistive element, and other options. As Figures 3A-3B shown, while the sensor tube 24 is at least partially disposed within the fill tube 28, the sensor tube 24 does not contact or interface with the fill tube 28. However, in some examples, the sensor tube 24 can contact the fill tube 28, such as where a section of the sensor tube surface 92 contacts a section of the fill tube inner surface 98 on one side, in order to place the sensors 26 closer to a particular portion of the magnetic indicator 38 and / or create a wider gap at different locations between the sensor tube 24 and the fill tube 28 to allow lubricant to flow through. Both the fill tube 28 and the sensor tube 24 extend through the AFSO bore 80 and downward into the reservoir housing 30. In the example shown, the sensor tube 24 extends completely through the fill tube 28 such that the sensor tube 24 projects from a first tube end 95 connected to the AFSO housing 72 and a second tube end 97 disposed within the reservoir housing 30.

[0039] The reservoir housing 30 includes a reservoir housing top 102, a reservoir housing sidewall 104, a drain hole 106 disposed through the reservoir housing sidewall 104, a dry housing portion 108, and a wet housing portion 110. The reservoir housing 30 supports the AFSO 16. The lubricant chamber 34 is at least partially disposed within the reservoir housing 30. The fill tube 28 and the sensor assembly 22 both extend downwardly into the reservoir housing 30 and may at least partially extend into the lubricant chamber 34. The lubricant chamber 34 defines an available volume that the lubricant can occupy. In the example shown, the volume of the lubricant chamber 34 can be considered to change as the follower 36 moves with the lubricant. The follower 36 is disposed within the reservoir housing 30. The fill tube outlet 96 is disposed at the second tube end 97 of the fill tube 28 and is configured to output lubricant into the lubricant chamber 34.

[0040] The lubricant entering the lubricant chamber 34 will lift the follower 36 within the reservoir housing 30. The follower 36 is disposed around the fill tube 28 and is configured to rest on top of the lubricant filling the lubricant chamber 34. The follower 36 generally divides the reservoir housing into a dry housing portion 108 and a wet housing portion 110, where the dry housing portion 08 is disposed above the follower 36 and the wet housing portion 100 is disposed below the follower 36.

[0041] The follower 36 is configured to be in sliding communication with the fill tube 28 and to rise and fall with the lubricant fill level. The follower 36 supports the inner seal 60. The inner seal 60 interfaces with the outer surface 100 of the fill tube. In the example shown, as the follower 36 moves relative to the fill tube 28, the inner seal 60 slides along the outer surface 100 of the fill tube, and the inner seal 60 thus forms a dynamic seal. In Figures 3A-3B the example shown, the follower 36 extends to the reservoir housing sidewall 104. In these examples, the follower 36 supports the outer seal 114, and the outer seal 114 interfaces with the reservoir housing sidewall 104 and is configured to be in sliding communication with the reservoir housing sidewall 114. It should be understood that the outer seal 114 may include multiple outer seals 114 or a single outer seal 114. Compared to a single and very thick outer seal 114, multiple outer seals 114 can maintain greater flexibility and the ability to adapt to different environments, while also providing greater traction at the interface between the reservoir housing sidewalls 104 than a single and thin outer seal 114. The multiple outer seals 114 can provide a first outer seal to prevent lubricant leakage between the follower 36 and the reservoir housing 30, and a backup outer seal in the event that some lubricant leaks through the first seal.

[0042] The exhaust valve 116 is at least partially disposed within the follower 36. As the follower 36 rises and falls with the fill level of the lubricant, a vacuum can potentially develop in the wet portion 110 of the housing disposed below the follower 36. The exhaust valve 116 is configured to allow air to flow above or below the follower 36, while not allowing the lubricant to travel through the follower 36. When (the exhaust valve 116) is open and as the lubricant level continues to drop below the lowest stroke level of the follower 36, the exhaust valve 116 allows air to flow from the dry portion 108 of the housing to the wet portion 110 of the housing. The exhaust valve 116 is configured to switch to a closed state by the rising lubricant, and the air within the wet portion 110 of the housing can be discharged through the exhaust valve 116 to the dry portion 108 of the housing. In the example shown, the lubricant pump assembly 10 includes a drain hole 106 disposed through the sidewall 104 of the reservoir housing. The drain hole 106 is configured to allow air to enter or leave the reservoir housing 30. In the event of failure or overflow of the AFSO 16, the drain hole 106 can act as a pressure relief to prevent damage to the reservoir housing 30. In examples that do not include the AFSO 16, the drain hole 106 also allows lubricant to leak from the reservoir housing 30 to provide a visual indication that the lubricant chamber 34 is full, such as when filling through the lubricant port 82.

[0043] In addition, the follower 36 has only a single opening or single guide hole 112, which is configured to allow a solid object, column, pipe, tube, or columnar structure to extend therethrough. The guide hole 112 is disposed to extend completely through the follower 36. Both the sensor tube 24 and the fill tube 28 extend through the single hole or guide hole 112 in the follower 36. The inner seal 60 is supported by the follower 36 and is disposed within the guide hole 112 in contact with the outer surface 100 of the fill tube to be in sliding communication with the follower 36. The inner seal 60 forms a dynamic seal interface with the fill tube 28. In the example shown, no direct seal interface is formed between the follower 36 and the sensor tube 24.

[0044] Extending downward from the top 102 of the reservoir housing is a spring 62, which is configured to bias the follower 36 downward. The spring biasing helps extract lubricant from the lubricant pump assembly 10. For example, the grease may be very viscous and not flow easily. The spring 62 can push the follower 36 such that the follower 36 can help discharge the grease from the lubricant pump assembly 10. Additionally, if the follower 36 were to become stuck at the interface between the reservoir housing sidewall 104 and the outer seal 114, including the spring 62 can help prevent the follower 36 from becoming stagnant.

[0045] Supported by the follower 36 is a magnetic indicator 38 surrounding the fill tube 28. Since the sensor tube 24 is disposed within the fill tube 28, the magnetic indicator 38 will send a magnetic field through the fill tube 28 to reach the sensor 26 disposed within the sensor tube 24. The fill tube 28 is formed of a non-ferrous material (e.g., aluminum, etc.) such that the material of the fill tube 28 does not interfere with the magnetic field, thereby allowing the signal generated by the sensor 26 to have higher accuracy. The sensor 26 is configured to be triggered by the magnetic field from the magnetic indicator 38, and the triggered sensors in the sensor 26 are configured to send information about the fill level of the lubricant chamber 34 to the controller 42 (as Figure 1 shown).

[0046] The lubricant chamber 34 may be at least partially defined by or partially disposed within the base 32. The reservoir housing 30 is supported by the base 32. The base 32 defines a base wet portion 118 and a base dry portion 120. The base wet portion 118 includes the lubricant chamber 34 into which lubricant can enter and occupy. The intersection between the reservoir housing 30 and the base 32 is a pressure plate 50. The pressure plate 50 may be configured to separate or dilute the lubricant before the lubricant reaches one or more outlet pumps 44. The pressure plate 50 may be disposed at a lower portion of the lubricant chamber 34 to dilute the lubricant just before it is pumped out by the outlet pumps 44. A stirring assembly 58 is disposed above the pressure plate 50 and at the bottom of the reservoir housing 30. The stirring assembly 58 is configured to assist the lubricant in flowing downward and out of the lubricant pump assembly 10.

[0047] The stirring assembly 58 is connected to a drive shaft 54. The drive shaft 54 is disposed within the base dry portion 120 and may be partially disposed within the base wet portion 118 and / or the housing wet portion 110. The drive shaft 54 interfaces with a bearing 56 and extends through the pressure plate 50. At the bottom end of the drive shaft 54, the drive shaft 54 interfaces with a motor 52. The motor 52 is disposed within the base dry portion 120 and is configured to interact with the drive shaft 54 to rotate the stirring assembly 58. The drive shaft 54 is also configured to provide power for pumping through one or more outlet pumps 44. For example, a cam on the drive shaft 54 may provide power for pumping. It should be understood that some examples do not include the stirring assembly 58 such that the drive shaft 54 provides power for pumping but does not drive the stirring assembly 58.

[0048] In Figures 3A-3B the example shown, the outlet pumps 44 are disposed within the base wet portion 118. It should be understood that the base may include a plurality of outlet ports 45 and is not limited to a single outlet port 45. Further, it can be understood that the outlet pumps 44 do not need to be disposed within the base wet portion 118. The outlet pumps 44 are configured to drive the lubricant out of the lubricant pump assembly 10 and disperse the lubricant to the lubricated component 48 (as Figure 1As shown). It should be understood that the lubricant pump assembly 10 may include multiple outlet pumps 44. For example, separate outlet pumps 44 may be configured to pump lubricant to different lubricated components 48. The example shown includes three outlet ports 45 and may have three outlet pumps 44, but it should be understood that other numbers of ports and pumps are possible.

[0049] The locator 124 interfaces with the fill tube 28 and the sensor tube 24. The locator 124 interfaces with the second tube end 97 and the sensor tube end 90 and is configured to align the fill tube 28. The locator 124 aligns the fill tube 28 and holds the second tube end 97 opposite the first tube end 95 connected to the AFSO housing 72. In the example shown, a portion of the locator 124 extends into the fill tube 28 such that a portion of the fill tube 28 is disposed directly radially outside the locator 124. The locator 124 also positions the sensor tube 24 relative to the fill tube 28. The locator 124 may maintain the concentricity of the sensor tube 24 relative to the fill tube 28. In the example shown, the sensor tube 24 extends into the locator 124 such that the sensor tube end 90 is disposed within the locator 124. In some examples, the locator 124 may be configured to ride on the agitation assembly 58 but not rotate with the agitation assembly 58.

[0050] To use the lubricant pump assembly 10, lubricant is pumped through the AFSO inlet 78. Then, the lubricant flows through the ASFO passage 18 to the AFSO bore 80 within the AFSO housing 72. Then, the lubricant will contact the sensor tube surface 92 of the sensor tube 24 and flow downward along the fill tube 28 starting from the fill tube inlet 94 while surrounding the sensor tube 24 disposed within the fill tube 28. Since the pump does not draw lubricant from the fill tube 28, the enclosed space within the fill tube 28 will not have as high a pressure due to the absence of a pump. This allows for flexibility in placing a more delicate / vulnerable type of sensor tube 24 within the fill tube 28 without fear of damaging the sensor tube 24. Additionally, positioning the AFSO 16 at the inlet of the fill tube inlet 94 provides additional security for the sensor tube 24 placed within the fill tube 28 because once the lubricant pump assembly 10 reaches a full state, the AFSO 16 will enter a closed state and the lubricant will stop flowing to the area around the sensor tube 24.

[0051] The lubricant will leave the fill tube 28 at the fill tube outlet 96 and enter the lubricant chamber 34 below the follower 36. When the lubricant chamber 34 is filled with lubricant, the lubricant will begin to raise the follower 36 within the reservoir housing 30. As the height of the follower 36 increases or decreases as lubricant is withdrawn from the lubricant chamber 34, the magnetic indicator 38 will trigger the sensor 26 disposed within the sensor tube 24, and in accordance with the variable output of the sensor 26, such as the respective voltage levels when in contact with a magnetic field, signal through the sensor relay 40 to convey the lubricant fill level within the reservoir housing 30. Then, the lubricant can be withdrawn from the lubricant chamber 34 by activating one or more outlet pumps 44 to withdraw the lubricant through the outlet port 45 to be provided to and used on the lubrication component 48. The descending magnetic indicator 38 triggers the sensor 26, and the sensor 26 provides a signal indicating a decrease in the lubricant level.

[0052] When the lubricant chamber 34 is filled with lubricant and the follower 36 reaches maximum capacity within the reservoir housing 30, the follower 36 will engage the pin 88, causing the valve stem 84 to engage the valve seat 86, thereby placing the valve 20 in a closed state to stop the intake of lubricant. When the valve 20 is in the closed state, as opposed to the open state where lubricant can freely flow into the lubricant pump assembly 10 and the lubricant chamber 34, the valve stem 84 also rises into the signal indicator 21 to provide a visual indication that the lubricant pump assembly 100 is full.

[0053] The lubricant pump assembly 10 provides significant advantages. Having the sensor tube 24 within the fill tube 28 provides fewer contact points or pinch points to cause leakage at the dynamic interface with the follower 36. In the example shown, there is only a single hole or single guide hole 112 for the sensor tube 24 and the fill tube 28 to extend through, and only one dynamic interface between the follower 36 and the fill tube 8. When the follower 36 moves up and down within the reservoir housing (30) in the case of a changing lubricant level, each tube, column, strut, or duct extending through the follower 36 needs to be aligned with the follower 36, otherwise the follower 136 may become stuck and bond or be pushed through, thereby causing damage to the entire tube or system. Since the present invention has the sensor tube 24 within the fill tube 28, this eliminates the need to align the sensor tube 24 and the fill tube 28 at different guide holes within the follower 36 and reduces potential damage, thereby reducing costs and simplifying operation. In the example shown, the follower 36 does not include multiple guide holes. With a single through-hole (e.g., guide hole 112) in the follower 36, it is easier to seal because only an inner seal 60 is required at the single junction between the follower 36 and the potential tube, column, strut, or duct passing through it, which means fewer seals will fail and the likelihood of leakage is reduced, thereby increasing the life of the lubricant pump assembly 10 and reducing costs.

[0054] The sensor tube 24 is disposed within the fill tube 28 such that there are fewer objects traveling through the follower 36. In an example of a follower plate that houses multiple tubes at different through-holes in these follower plates, unless each tube is perfectly perpendicular and aligned with these follower plates, it is easy to have bonding points and pinch points where these follower plates will get stuck and stop performing their normal function, or barely pass through due to damage to the tubes or these follower plates and cause leakage.

[0055] Furthermore, disposing the sensor tube 24 within the fill tube 28 and having only a single through-hole or a single guide hole 112 within the follower plate 36 means that the follower 36 does not need to be as thick as a follower plate that houses multiple tubes passing through it at multiple openings. A very thick follower plate is configured to force-align or straighten each of the multiple tubes extending through the respective through-holes in these follower plates to prevent bonding. Having a single through-hole for the fill tube 28 and the sensor tube 24 to pass through not only reduces the likelihood of bonding or damage, but also allows for a thinner follower plate 36, which minimizes the volume of the design, makes the lubricant pump assembly 10 less bulky, results in a lower overall cost of the lubricant pump assembly 10 due to less material, and also allows the lubricant pump assembly 10 to take up less space on the machine where the user can store the lubricant pump assembly 10.

[0056] Since the lubricant may be a viscous fluid, due to flow restrictions, it may be difficult for the lubricant to flow between the sensor tube 24 and the fill tube 28. Providing a ratio of at least 10:7 for the diameter of the inner surface of the fill tube 28 (fill tube inner surface 98) to the outer surface of the sensor tube 24 (sensor tube surface 92) allows for flow without impeding the operation of the lubricant pump assembly 10, which includes filling and removing lubricant. A ratio of at least 10:7 allows for sufficient space around the sensor tube 24 without flow restrictions, backpressure, or resistance.

[0057] Figure 4Is a plan view of an example of the magnetic indicator 38. In this example, the magnetic indicator 38 includes an indicator body 120, which can be formed as a ring configured to extend around the fill tube 28 and the sensor tube 24. The indicator body 120 can be formed of a non-ferrous material. A plurality of magnets 122 are supported by the indicator body 120. In the example shown, the magnetic indicator 38 includes a plurality of discrete permanent magnets 122. The permanent magnets 122 can be mounted to the indicator body 120 and, in some examples, are at least partially disposed within the indicator body 120. To improve the accuracy of the fill level reading, it is helpful to adjust the magnetic strength of the magnetic field of the magnetic indicator 38 by including more or fewer magnets 122. This is because the magnetic field needs to travel through the thickness of the fill tube 28, the lubricant occupying the flow gap between the inner surface 98 of the fill tube and the surface 92 of the sensor tube, and through the thickness of the sensor tube 24 until it reaches the sensor 26. The magnetic indicator 38 is disposed radially outside the fill tube 28 relative to the fill tube axis FA and is spaced from the sensor tube 24 by a gap that includes the thickness of the fill tube 28 and the flow gap.

[0058] An annular array of permanent magnets 122 can provide the required magnetic strength for triggering the sensor 26. It should be understood that in various other examples, the magnetic indicator 38 can include an annular permanent magnet (e.g., a single permanent magnet) or a plurality of magnets 122. If the magnetic field generated by the magnetic indicator 38 is too strong, it may cause the sensor 26 to give an inaccurate reading. At the same time, the magnetic field generated by the magnetic indicator 38 needs to be strong enough to travel through the fill tube 28 and through the gap between the fill tube 28 and the sensor tube 24 to reach and trigger the sensor 26.

[0059] Although the present invention has been described with reference to (one or more) exemplary embodiments, those skilled in the art will understand that various changes can be made and elements thereof can be replaced with equivalents without departing from the scope of the present invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from the basic scope thereof. Therefore, the present invention is not intended to be limited to the (one or more) particular embodiments disclosed, but the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A lubricant pump assembly, comprising: Pedestal; a reservoir housing supported by the base; a lubricant chamber disposed at least partially within the reservoir housing; a follower disposed within the reservoir housing, the follower being configured to rise and fall with a lubricant fill level within the lubricant chamber; a fill tube extending downwardly from a top of the reservoir housing, the fill tube having a first tube end and a second tube end, wherein the fill tube extends through the follower, and the fill tube is configured to output the lubricant into the lubricant chamber; a sensor assembly including a sensor tube having a plurality of sensors disposed within the sensor tube, the sensor tube being at least partially disposed within the fill tube; and A magnetic indicator is supported by the follower so that the magnetic indicator moves with the follower relative to the sensor tube and the fill tube, wherein the magnetic indicator is configured to trigger the plurality of sensors to cause the plurality of sensors to output signals indicative of the lubricant fill level.

2. The lubricant pump assembly of claim 1 further comprising a spring disposed within the reservoir housing, the spring being coupled to the follower to bias the follower downwardly within the reservoir.

3. The lubricant pump assembly of any one of claims 1 to 2, wherein the follower has a single guide bore through which both the fill tube and the sensor tube extend.

4. The lubricant pump assembly of claim 3, wherein the follower does not include a plurality of guide holes.

5. The lubricant pump assembly according to any one of claims 1 to 4, further comprising an automatic filling and shut-off assembly disposed on top of the reservoir housing, the automatic filling and shut-off assembly comprising: an AFSO housing, wherein the AFSO housing defines a lubricant path, the lubricant path including an AFSO inlet and an AFSO bore; and A valve is disposed within the AFSO housing.

6. The lubricant pump assembly of claim 5, wherein the follower is a follower plate engaged with a side wall of a reservoir housing via an outer seal, the follower plate separating the lubricant chamber from a dry portion within the reservoir housing. 7 . The lubricant pump assembly of claim 6 , wherein the follower plate is configured to actuate the valve to a closed state when the lubricant fill level is in a full state.

8. A lubricant pump assembly according to any one of claims 5 to 7, wherein the fill tube is mounted to the AFSO housing.

9. The lubricant pump assembly of claim 8, wherein the sensor tube extends into the AFSO housing.

10. The lubricant pump assembly of any one of claims 5 to 9, wherein the sensor tube extends from the first tube end of the fill tube and passes completely through the AFSO housing.

11. The lubricant pump assembly of any preceding claim, wherein the sensor tube surface comprises a 32 micro-inch surface finish.

12. A lubricant pump assembly according to any preceding claim, wherein the sensor tube does not interface with a dynamic seal.

13. The lubricant pump assembly of any one of claims 5 to 12, wherein the sensor tube interfaces with a single static seal disposed within and supported by the AFSO housing.

14. A lubricant pump assembly according to any preceding claim, wherein the sensor tube and the fill tube are arranged coaxially.

15. The lubricant pump of claim 14, wherein the sensor tube and the fill tube are coaxial with the driven plate.

16. A lubricant pump assembly according to any preceding claim, wherein the fill tube is formed from a non-ferrous material.

17. A lubricant pump assembly according to any preceding claim, wherein the magnetic indicator comprises a plurality of magnets disposed within a non-ferrous ring.

18. A lubricant pump assembly according to any preceding claim, wherein the sensor tube is closed at the sensor tube end within the lubricant chamber.

19. A lubricant pump assembly according to any preceding claim, wherein the ratio of the diameter of the inner surface of the fill tube to the diameter of the outer surface of the sensor tube is at least 10:

7.

20. The lubricant pump assembly of claim 19, wherein the magnetic indicator is disposed radially outside the fill tube and is separated from the sensor tube by a gap, the gap comprising a thickness of the fill tube and a flow gap defined by a distance between an outer surface of the sensor tube and an inner surface of the fill tube.

21. A lubricant pump assembly according to any preceding claim, wherein the sensor tube is exposed to lubricant within the fill tube.

22. The lubricant pump assembly of any preceding claim, further comprising a pump disposed within the base and fluidly connected to the lubricant chamber to remove lubricant from the lubricant chamber.

23. The lubricant pump assembly of any one of the preceding claims, further comprising a locator disposed at the second tube end, the locator interfacing with the fill tube and the sensor tube to concentrically align the sensor tube and the fill tube.

24. The lubricant pump assembly of claim 1, wherein the follower is a follower plate engaged with a side wall of the reservoir housing via an outer seal, the follower plate separating a wet portion and a dry portion within the reservoir housing.

25. A lubricant pump assembly, the lubricant pump assembly comprising: a base including an outlet port; an outlet pump disposed within the base, wherein the outlet pump is configured to discharge lubricant through the outlet port; a reservoir housing supported by the base; a fill tube including a fill tube inlet and a fill tube outlet, the fill tube being disposed within the reservoir housing, wherein the fill tube is configured to receive the lubricant at the fill tube inlet; A follower plate is disposed in the reservoir housing, the follower plate comprising: an outer seal engaged with a sidewall of the reservoir housing; a guide hole through which the fill tube extends; and an exhaust valve configured to allow air to flow between an area above the follower plate and an area below the follower plate; a magnetic indicator supported by the follower plate; Automatic filling and cutting assembly, including: an AFSO housing, the AFSO housing comprising an AFSO side; a valve disposed at least partially within the AFSO housing, the valve comprising a valve stem and a valve seat, wherein the valve stem is configured to engage the valve seat when the valve is in a closed state and to disengage from the valve seat when the valve is in an open state; an AFSO air inlet, the AFSO air inlet being arranged on the AFSO side; and an AFSO bore extending from a bottom of the AFSO housing into the AFSO housing, wherein the AFSO bore is configured to receive the fill tube, wherein the valve seat is disposed between the AFSO inlet and the AFSO bore; and a sensor assembly having a sensor tube surrounding a plurality of sensors, the sensor tube being at least partially disposed within the fill tube, wherein the magnetic indicator is configured to trigger the plurality of sensors so that the plurality of sensors output signals indicative of a lubricant fill level, wherein the plurality of sensors are fluidly isolated from the lubricant by the sensor tube, the fill tube outlet is configured to output the lubricant below the follower plate, and the follower plate is configured to be located on top of the lubricant when the lubricant is disposed within the reservoir housing.

26. The lubricant pump assembly of claim 25, wherein a ratio of a diameter of an inner surface of the fill tube to a diameter of an outer surface of the sensor tube is at least 10:

7.

27. A method of determining a lubricant fill level within a lubricant pump assembly, the method comprising: allowing lubricant to flow into the lubricant pump assembly; allowing the lubricant to flow downwardly along a space between an interior of the fill tube and an exterior of the sensor tube; releasing the lubricant from the fill tube and into a lubricant chamber; raising a follower plate disposed within a reservoir housing of the lubricant pump assembly via lubricant beneath the follower plate; and A lubricant fill level within the reservoir housing is sensed by signals received from a plurality of sensors disposed within the sensor tube, wherein a magnetic indicator supported by the follower plate triggers the plurality of sensors disposed within the sensor tube to output signals.

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