Abstract:
A fluid supplying device comprises a reservoir configured to store a fluid and a conveying element disposed in or in fluid communication with a lower portion of the reservoir. The conveying element includes a rotatable shaft and a device configured to convey or move a fluid, e.g., a lubricant. A radial-piston pump having at least one radial-piston unit is in fluid communication with a fluid output of the conveying element. The pump comprises a shaft part rotatably coupled with the shaft of the conveying element. A motor drives both the conveying element and the pump. The motor, the conveying element shaft and the pump are sequentially arranged one after another in the axial direction of the shaft.

Description:
CROSS-REFERENCE 
       [0001]    The present application claims priority to European patent application no. 09 005 883 filed Apr. 28, 2009, the contents of which are fully incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention generally relates to fluid supplying devices, as well as to methods of making and using the same, which may be utilized in preferred embodiments, e.g., to supply a fluid (e.g., lubricants) to an engine. 
       KNOWN ART 
       [0003]    A device for supplying motor oil to an internal combustion engine is known from DE 10 2006 016 687 A1, wherein the lubricant supplying device comprises a worm shaft driven by a chain drive. The worm shaft simultaneously drives an oil pump that suctions oil from a lower-lying space and conveys the oil into the internal combustion engine. 
         [0004]    Another lubricant supplying device is known from EP 0 009 908 B1 and its counterpart U.S. Pat. No. 4,457,670, wherein an auger moves the lubricant from a hopper to a space adjacent to a pump. The pump then pressurizes the lubricant to a desired pressure. The auger and the pump are driven by separate devices. 
         [0005]    From EP 0 642 913 A1, EP 1 352 729 A1, U.S. Pat. No. 4,642,040 and DE 103 48 985 B3 (and its counterpart U.S. Pat. No. 7,354,188), is it known to use a single drive for conveying and pressurizing a medium. However, these devices exhibit various shortcomings. 
       SUMMARY 
       [0006]    In one aspect of the present teachings, devices and methods are taught for conveying and pressurizing a lubricant or other fluid medium using a single drive, prime mover or motor. Preferably, such an embodiment is embodied in a relatively simple and compact structure. 
         [0007]    In another aspect of the present teachings, a fluid supplying device may have a modular construction, which makes it possible to install and perform maintenance on the device in a simple manner. A problem-free replacement of components is possible in certain embodiments of the present teachings. 
         [0008]    In another aspect of the present teachings, a fluid supplying device preferably includes a reservoir for the fluid, e.g., a lubricant. A fluid conveying element is preferably located in a bottom or lower-lying portion of the reservoir or is in fluid communication with the reservoir. The conveying element is preferably configured to convey the fluid to the vicinity of a pump, which then supplies the fluid at an increased pressure to a fluid conduit. The conveying element preferably comprises a shaft driven by the motor. At least one fluid conveying means is disposed on or extends around the shaft. Preferably, one axial end of the shaft is connected with a shaft part of the pump so that the shaft and shaft part rotate together. In such an embodiment, the motor is preferably designed to drive both the conveying element (e.g., the shaft) and the pump. 
         [0009]    In a further preferable embodiment, the motor, the shaft with the fluid conveying means and the pump may be sequentially arranged one after another along the axial direction of the shaft. In addition or in the alternative, the pump may comprise a radial-piston pump having at least one radial-piston unit. 
         [0010]    The conveying element is preferably embodied as or comprises one of a screw conveyor, an auger or a worm shaft. For example, the conveying means may comprise at least one screw channel that extends around the shaft. The shaft can optionally extend beyond the axial length of the at least one screw channel. 
         [0011]    In a further preferable embodiment, the shaft and shaft part of the pump may be arranged coaxially to each other and may be connected with each another via connection selected from a form-fit, a shape-fit, an interference-fit and/or an interleaved fit. In such an embodiment, it is advantageous if the form-fit, shape-fit, interference-fit or interleaved connection is the sole connection between the shaft and the shaft part of the pump. For example, the shaft of the conveying element and the shaft part of the pump are preferably connected via an interleaved structure or a mutually-interlocking structure. 
         [0012]    In a further preferable embodiment, a plurality of radial piston units may be disposed around the circumference of the shaft part of the pump. It is especially preferred to dispose between 2 and 10 radial piston units equidistantly around the circumference of the shaft part of the pump. All of the radial piston units can be driven by an eccentric cam, which is connected with the shaft part of the pump so that the shaft part and eccentric cam rotate together. Further, one or more springs or other biasing element(s) may be provided to urge the radial piston units radially inward towards a defined or predetermined position that the radial piston assumes in the absence of external application of force. In the alternative or in addition, the pistons may be positively driven towards the defined or predetermined position. 
         [0013]    The motor can be electrically-, hydraulically- or pneumatically-driven. 
         [0014]    In a further preferable embodiment, a lubricant conduit preferably comprises an annular conduit and is supplied with pressurized lubricant from the radial piston units. A one-way valve may be disposed between one radial piston unit and the annular conduit. In addition or in the alternative, the annular conduit may be connected with a pressure relief valve. In addition or in the alternative, the annular conduit may be connected with at least one directional control valve. 
         [0015]    In preferred embodiments of the present teachings, it is possible to assemble and to later disassemble the connection between the screw conveyor and the pump in a rapid and simple manner in order to service and/or replace components of the apparatus. Thus a modular construction is advantageous. 
         [0016]    In preferred embodiments of the present teachings, an overall space-saving and radially compact construction is achieved, which may also assist in reducing manufacturing costs. 
         [0017]    Further advantages, objects and features of the present teachings will be readily derivable by a skilled person from the following detailed description of the figures and from the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0018]      FIG. 1  shows a side view of a representative, non-limiting fluid supplying device. 
           [0019]      FIG. 2  shows a partially cut-away side view of the pump of the apparatus of  FIG. 1 . 
           [0020]      FIG. 3  shows a front view of the pump of  FIG. 2 . 
           [0021]      FIG. 4  shows a schematic conduit diagram of a two-line central lubrication system having two control valves, though which system the lubricant supplied by the device of  FIG. 1  is distributed. 
           [0022]      FIG. 5  shows the system of  FIG. 4  in a practical implementation. 
           [0023]      FIG. 6  shows a schematic conduit diagram of a two-line central lubrication system without control valves, though which system the lubricant supplied by the device of  FIG. 1  is distributed. 
           [0024]      FIG. 7  shows the system of  FIG. 6  in a practical implementation. 
           [0025]      FIG. 8  shows a schematic conduit diagram of a one-line central lubrication system having one control valve, though which system the lubricant supplied by the device of  FIG. 1  is distributed. 
           [0026]      FIG. 9  shows the system of  FIG. 8  in a practical implementation. 
           [0027]      FIG. 10  shows a schematic conduit diagram of a central lubrication system without control valves, though which system the lubricant supplied by the device of  FIG. 1  is distributed. 
           [0028]      FIG. 11  shows the system according to  FIG. 10  in a practical implementation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved fluid supplying devices, as well as methods for designing, constructing and using the same. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in combination, will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, combinations of features and steps disclosed in the following detail description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the present teachings. 
         [0030]    Moreover, the various features of the representative examples and the dependent claims may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. In addition, it is expressly noted that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter independent of the compositions of the features in the embodiments and/or the claims. It is also expressly noted that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter. 
         [0031]      FIG. 1  shows a preferred fluid supplying device  1  configured to convey and pressurize a fluid or liquid medium, e.g., a lubricant such as grease or oil. However, it is understood that the present teachings are applicable to any designs in which a fluid medium should be conveyed and subsequently pressurized, preferably using a single drive, prime mover or motor to perform both tasks. 
         [0032]    Furthermore, the apparatus  1  shown in  FIG. 1  is characterized by a modular structure and can be designed for various lubrication systems, such as, but not limited to, a two-line central lubrication system, a one-line central lubrication system or a progressive lubrication system. 
         [0033]    The apparatus  1  has a reservoir  2  for lubricant (e.g., oil or grease) and is preferably cylindrical, although polygonal or other curved (e.g. oval, semi-circular, etc.) base shapes for the reservoir  2  are also possible. A motor  3  drives the shaft  7  of a conveying element  4 , which is preferably a screw conveyor or auger or worm shaft, all of which are intended to be interchangeable terms for the fluid conveying structure shown in  FIG. 1 . A screw channel  8 , which functions as the fluid conveyor, helically extends around the shaft  7  in a known manner and conveys lubricant when the shaft  7  rotates. A pump  5  is disposed at one axial end (right end in  FIG. 1 ) of the shaft  7  and is preferably a radial-piston pump. The pump  5  includes a shaft part  9 , which is coupled to the shaft  7  so that they rotate together. 
         [0034]    The connection  16  of the shaft  7  and shaft part  9  (see  FIG. 1 ) is preferably configured so that torque is transmitted from the shaft  7  to the shaft part  9  exclusively by a form-fit, shape-fit, interference-fit or interleaved coupling. For example, as shown in  FIG. 3 , the connection  16  may preferably comprise a radially-extending groove  17  (e.g., in the shaft part  9 ) and a congruently-formed projection (e.g., extending from the shaft  7 —not shown in  FIG. 3 ) is engaged, disposed or interleaved in the groove  17 . It is preferable that no other connection between the parts  7  and  9  is provided, so that the connection  16  functions solely on a form-fit, shape-fit or interference-fit basis or as interlocking or interleaved structures. The nature of the connection is not particularly limited, although it is preferably that the shaft  7  can be easily disassembled or removed from the shaft part  9  to expedite repairs or maintenance of the fluid supplying device. 
         [0035]    Referring to  FIGS. 2 and 3 , the pump  5  is preferably embodied as a radial piston pump, i.e. one or more radial piston units  10  are arranged equidistantly around the circumference of the shaft part  9  of the pump  5 . The radial piston units  10  of the pump  5  are actuated or driven by an eccentric cam  11 , which is connected with the shaft part  9  of the pump  5  so that they rotate together. The eccentric cam  11  causes the respective pistons to move radially outwardly as it rotates. The piston return movement (suction phase) can be performed by providing respective compression springs to urge the pistons radially inwardly or by providing another positive or active drive coupled to the pistons for returning the pistons to a normal or idle (predetermined) position. The radial piston unit(s)  10  convey(s) the fluid medium via a one-way valve  13  into an annular conduit  12  (see  FIGS. 4 to 10 ). 
         [0036]    Four different embodiments of a lubrication conduit  6  are disclosed by  FIGS. 4 and 5 ,  6  and  7 ,  8  and  9  and  10  and  11 , respectively. The lubricant conduit  6  fluidly connects to the pump  5  and serves to supply pressurized lubricant to a device in need of lubrication, e.g., a motor. 
         [0037]    The lubricant conduit  6  of each embodiment can be protected from damage caused by excessive pressure by providing a pressure relief valve  14 . 
         [0038]    In the embodiment of  FIG. 4 , a conduit or pipe leads from the annular conduit  12  to two input ports “A” of respective 3-port/2-position valves (i.e. directional control valves)  15 . The valve ports “B” in FIGS.  4 / 5  are each in fluid communication with a reservoir T (e.g., reservoir  2  of  FIG. 1 ). Valve ports “C” are each in fluid communication with a pump outlet A/P and B/R, respectively. The other pump ports are the pressure gauge ports MA and MT, a measuring port M and a vent E. 
         [0039]    Thus, in  FIGS. 4 and 5 , a two-line central lubrication system includes two directional control valves  15  in the form of two 3-port/2-position valves  18 ,  19 , respectively, which operate as follows. If the valve  18  is switched to the first position, lubricant is supplied through outlet A/P and if valve  18  is switched to the second position, lubricant is supplied to the reservoir T (unpressurized). If the valve  19  is switched to the first position, lubricant is supplied through outlet B/R and if valve  19  is switched to the second position, lubricant is supplied to the reservoir T (unpressurized). The valves are preferably switched alternately for this application. 
         [0040]    In the embodiment of  FIGS. 6 and 7 , a two-line central lubrication system is shown that does not include 3-port/2-position valves. In place of the two valves, two deflection plates  20  and  21  are provided in this embodiment. A two-line directional control valve may be installed separately after the pump  5  in the two main conduits. The port A/P is the pressurized lubricant supply port and the port B/R is a reservoir connection for pressure discharge. 
         [0041]    In the embodiment of  FIGS. 8 and 9 , a one-line central lubrication system with one 3-port/2-position valve  15 ,  18  is shown. Similar to the embodiment of  FIGS. 4 and 5 , if the valve  18  is switched to the first position, lubricant is supplied through outlet A/P and if valve  18  is switched to the second position, lubricant is supplied to the reservoir T (unpressurized). In the embodiment of  FIG. 9 , the corresponding valve ports of the valve  19  from  FIG. 5  are sealed by a sealing plate  22 , such that the outlet B/R is sealed or closed. 
         [0042]    In the embodiment of  FIGS. 10 and 11 , a central lubrication system is shown without 3-port/2-position valves. In the embodiment according to  FIG. 11 , a deflection plate  23  is provided at the corresponding port for the valve  18  according to  FIG. 5  and a sealing plate  24  is provided at the corresponding port for the valve  19  according to  FIG. 5 . Thus, the entire supply flows through outlet A/P and the port B/R is sealed. 
         [0043]    The motor  3  is preferably a geared motor that is, e.g., electrically-, hydraulically- or pneumatically-driven. The screw conveyor  4  conveys medium to the pump  5  when the motor  3  rotates and, in preferred embodiments, the motor  3  simultaneously drives both the screw conveyer  4  and the pump  5 . 
         [0044]    The reservoir  2  is preferably designed with a reservoir size for holding 15, 30 or 60 kg of lubricant. 
         [0045]    In the preferred embodiment, the arrangement of the motor, screw conveyor and pump is constructed in a modular manner. These elements are preferably coupled only via their respective (e.g., interlocking, interleaved) shapes, i.e., they are interleaved together and are not connected or bound by frictional forces. This enables a simple disassembly and/or a simple replacement of pump and motor without disassembly of each of the other components. Due to this modular construction, pumps or motors/gears can be later replaced in a simple manner, e.g., in order to provide other capacity ranges and/or for maintenance purposes. 
         [0046]    By changing the number of the radial piston units  10 —preferably between 1 and 6 units are selected—any desired fluid supply output capacity can be realized. 
         [0047]    The pump  5  can—as embodied above—pressurize the outlet conduits or serve as a return line by using different accessories (e.g., one 3-port/2-position valve, two 3-port/2-position valves or no 3-port/2-position valve). 
       REFERENCE NUMBER LIST 
       [0000]    
       
           1  Fluid (e.g., lubricant) supplying device 
           2  Reservoir 
           3  Motor 
           4  Conveying element (e.g., screw conveyor) 
           5  Pump (e.g., radial piston pump) 
           6  Lubricant conduit 
           7  Shaft 
           8  Conveying means (e.g., screw channel) 
           9  Shaft part 
           10  Radial piston unit 
           11  Eccentric cam 
           12  Annular conduit 
           13  One-way valve 
           14  Pressure relief valve 
           15  Directional control valve 
           16  Rotatable-together connection 
           17  Groove 
           18  Directional control valve 
           19  Directional control valve 
           20  Deflection plate 
           21  Deflection plate 
           22  Sealing plate 
           23  Deflection plate 
           24  Sealing Plate