MXPA99003338A - Piston pump and method of reducing vapor lock - Google Patents

Abstract

A pump includes a housing defining a cavity, at least one bore, a bore inlet, and a bore outlet. The bore extends from the cavity to the outlet and the inlet communicates with the bore at a position between the cavity and the outlet. A crankshaft is mounted in supports and has an eccentric portion disposed in the cavity. The eccentric portion is coupled to a piston so that rotation of the crankshaft reciprocates the piston in the bore between a discharge position and an intake position. The bore may be offset from an axis of rotation to reduce bending of the piston during crankshaft rotation. During assembly of the pump, separate parts of the housing can be connected together to facilitate installation of internal pumping components.

Description

PISTON PUMP AND METHOD FOR REDUCING VAPOR CLOSURE BACKGROUND OF THE INVENTION Field of the Invention This invention is generally concerned with piston pumps and methods for reducing steam shutdown during pumping. In particular, the present invention is concerned with magnetically driven piston pumps capable of being used with thermal pump systems for absorption and air conditioning.

Description of the Related Art Recent attention has been given to the commercial viability of the thermal pump systems of absorption and air conditioning and in particular to its use in residential and commercial heating and cooling applications. This increased attention has required developments in the reduction of the physical size of such systems, the increase in the heating or cooling efficiencies of such systems, and the increase in the service life of such systems. As improvements are made to the overall system, the individual components also receive increased attention and refinement as they contribute to additional gains associated with the thermal pump system. REF. 30048 A component of the thermal pump systems, the solution pump of the absorption system has such a large number of operating requirements and design restrictions, especially in the lower tonnage systems that use ammonia / water, that few improvements have been made. performed to them by the previous technique. Such pumps for solutions must be relatively small in size; resistant to corrosion, in particular to a solution of ammonia and water; hermetic; capable of providing a pressure rise of at least 21.09 Kg / cm2 (300 pounds / square inch), capable of pumping liquid, vapor or both (and thus have a net positive suction hydrostatic pressure (NPSH) of zero); wear-free even if exposed to abrasive particles; and ideally they should have a relatively long service life of approximately 60,000 to 80,000 hours, when using non-normal lubricants. Although pumping devices are known that provide one or more of these characteristics or capabilities, none are known to provide the full combination of these features. Service life is a factor that contributes to the commercial success of a thermal pump. Service time means the period of time that a pump must operate without maintenance or failure. When pumping devices are incorporated into larger packaged systems, such as thermal absorption pump systems, the pumping device must have a service life at least as long as the packaged system, since the replacement of the pumping device it frequently requires the disassembly of the system. It is expected that competitive thermal pump systems will be up to 20 years or 60,000 hours in operation without significant maintenance. Thus, there is a need for a pumping device that has a service life of at least 60,000 to 80,000 hours. In addition, the fluid pumps used in thermal absorption pump systems that employ a solution of ammonia and water are particularly susceptible to internal corrosion (or other chemical reactions) from prolonged exposure to the solution. In addition, corrosion problems may arise when certain salts or other additives are placed in the ammonia and water systems to increase or decrease the operating temperature range of the system or to operate the pumps at temperatures higher or lower than the normal range of 26.7-54.4 ° C (80-130 ° F). Thus, there is a need for a pumping device that is relatively resistant to corrosion or other chemical reactions with ammonia and water solutions and potential additives. In thermal pump systems that use a solution of ammonia and water, the pumping device must have a head (or hydrostatic pressure) of net positive suction (NPSH) equal to zero because the pump will commonly be exposed to an incoming solution that is at or near its boiling temperature. boiling. If the pressure of a liquid at the inlet of the pump is less than the NPSH of a normal pump, the solution will vaporize at least partially, to cause destructive cavitation of the inside of the pump. In addition, in ammonia-water pumps, a zero NPSH is necessary because the pump will be required to pump steam along with the liquid for most of its operating life. The pump must also be free of the possibility of leaks and must also have high efficiency. Piston pumps, such as the pump described in U.S. Patent No. 3,584,975, have been considered for use in absorption cooling systems, but most of these pumps have one or more disadvantages when used in pump systems. thermal Many existing piston pumps are not durable enough to provide the continuous and frequent operation required in a thermal pump system. For example, piston pumps are susceptible to wear and / or have parts that must be replaced or repaired periodically. Complex manufacturing processes increase the cost of many piston pumps and make them too expensive to be used in the permissible thermal pump systems. In addition, many existing piston pumps suffer from a condition known as vapor closure (interruption of a liquid flow by the formation of vapor bubbles or gas in the conduit) when used to pump liquids that are close to their boiling point. during admission or that contain significant amounts of steam.

Brief description of the invention Thus, the present invention is directed to pumps and pumping methods that substantially eliminate one or more of the limitations of the related art. In particular, the present invention provides a relatively low-cost, corrosion-resistant, substantially maintenance-free, hermetic pump capable of being used in thermal pump absorption systems, preferably, the pump is small in size, provides a Pressure rise of more than 21.09 Kg / cm2 (300 pounds / square inch), pumped liquid and steam and has a long service life. To obtain these and other advantages and in accordance with the purposes of the invention, as widely implemented and described herein, the invention includes a pump comprising a crankshaft having opposite end portions and an eccentric portion between the portions of the end and a box defining a cavity, an outlet, at least one perforation extending between the cavity and the outlet and at least one entrance communicating with the perforation. The eccentric portion of the crankshaft is located in the cavity and the end portions of the crankshaft are rotatably coupled to the box, the bore is offset (or offset) in such a way that the axis of the bore does not intersect the axis of rotation of the crankshaft . The pump also includes a piston having a base disposed in the cavity, and a head disposed in the bore. The base of the piston is coupled to the eccentric portion of the crankshaft in such a way that the rotation of the eccentric portion in the cavity alternately causes the piston head to move in the bore to provide discharge of the bore through the outlet and the intake to piercing through the entrance. A valve structure is arranged to open and close the outlet in response to movement of the piston head during discharge and intake. In another aspect, the invention includes a pump having a box defining a cavity, an outlet, at least one bore extending between the cavity and the I exit, and at least one entrance that communicates with the intermediate perforation to the cavity and the exit. A first support is in a portion of the end of the box and a second support is in another portion of the box end. It will be understood that the foregoing general description, and the following detailed description are exemplary and are intended to provide additional explanation of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. In the drawings, Figure 1 is a partial cross-sectional view of a first embodiment of the pump of the invention; Figure 2 is a side view of a box shown in Figure 1 and includes dashed lines that - represent the internal structure of the box; Figure 3 is a cross-sectional view of the box taken along line 3-3 of Figure 2 and includes lines showing off-center bore axes and radial lines extending from a rotation axis of a crankshaft shown in figure 1; Figure 4 is a side view of a first support shown in Figure 1 and includes broken lines representing the internal structure of the first support; Figure 5 is an end view of the first support shown in Figure 4; Figure 6 is a side view of a second support shown in Figure 1 and includes broken lines representing the internal structure of the second support; Figure 7 is an end view of the second support shown in Figure 6; Figure 8 is a side view of the crankshaft shown in Figure 1; Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8; Figure 10 is a side view of the pistons coupled to a coupling structure shown in Figure 1; Figure 11 is a side view of one of the pistons shown in Figures 1 and 10; Figure 12 is a top view of the piston shown in Figure 11; Figure 13 is a side view of the coupling structure shown in Figures 1 and 10; Figure 14 is a cross-sectional view taken along line 14-14 of Figure 13; Figure 15 is a partial cross-sectional view of a second embodiment of the pump; Figure 16 is a partial cross-sectional view showing how liquid and vapor enter an inlet tube shown in Figure 1; Figure 17 is a partial cross-sectional view of a third embodiment of the pump; Figure 18 is a partial cross-sectional view of a crankshaft, eccentric portion, coupling structure and integral pistons shown in Figure 17; and Figure 18a is a partial cross-sectional view of a crankshaft, eccentric portion, coupling structure, and integral positions for use with the pump shown in Figure 17, the bores of the pump are off-center; and Figure 19 is a partial cross-sectional view of a fourth embodiment of the pump.

Description of the preferred embodiments Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. ever possible, the same reference numbers are used in the drawings and description to refer to the same or similar parts. According to the invention, there is provided a pump that includes a box defining a cavity, an outlet, at least one bore extending between the cavity and the outlet and at least one inlet communicating with the bore. As implemented herein and illustrated in Figure 1, a pump 10 includes an inner box 20 defining a cavity 22. Preferably, the box 20 is formed of a material resistant to solutions of ammonia and water or other substances pumped by the pump 10. For example, the box 20 is preferably manufactured from a steel or cast iron. As shown in Figures 2 and 3, the box 20 includes perforations 24a, 24b, 24c and 24d extending from the cavity 22 and terminating in respective outlets 26a, 26b, 26c and 26c. Each of the perforations 24a, 24b, 24c and 24d preferably includes at least one respective inlet 28a, 28b, 28c and 28d formed in the box 20 and spaced between the cavity 22 and the respective outlets 26a, 26b, 26c and 26d . The inputs 28a, 28b, 28c and 28d and outputs 26a, 26b, 26c and 26d respectively communicate with the perforations 24a, 24b, 24c and 24d to allow the pumped substance to enter and exit the perforations 24a, 24b, 24c and 24d .

As partially shown in Figure 1, the inlet tubes, such as the inlet tubes 23a and 23b, extend from each of the inlets 28a, 28b, 28c and 28d. The inlet tubes 23a and 23b include a respective open end 25a and 25b with the front facing away from the box 20 and an opening 27a and 27b spaced between the open end 25a and 25b and the box 20. The opening 27a, 27b near the bottom of the inlet pipes 23a and 23b provides the maximum head or hydrostatic pressure of liquid stored in the pump 10 before flowing to the inlet orifices 28a, 28b, 28c and 28d. Although the inlet tubes 27a and 27b are shown with only one opening 27a, 27b, the inlet tubes could have a plurality of openings preferably located at the same height along the respective inlet tubes. As described in more detail later herein, the inlet tubes limit the presence of steam closure by rapidly increasing the head or hydrostatic pressure of the liquid at the inlet to the boreholes ever the inlet flow is braked, such as a steam shutdown tries to start. In addition, the inlet tubes dose the liquid flow to the perforation inlets 28a, 28b, 28c and 28d to establish a relatively constant supply of the solution to be pumped.

As partially illustrated in Figure 1, auxiliary inputs, such as auxiliary inputs 29a, and 29b are optionally formed in case 20. Auxiliary inputs communicate with respective perforations 24a, 24b, 24c and 24d and are in an opposite relationship with respect to the perforation inputs 28a, 28b, 28c and 28d. Passages or passages (not shown) are optionally formed in the box 20 adjacent the perforations and inlets to allow fluid flow to the auxiliary inlets. In addition, plugs, such as the plugs 31a and 31b shown in Figure 1 can be placed in the box 20 and used to seal the auxiliary entries of the direct communication with an inner chamber formed by a casing or casing for the pump 10. Each one of the perforations 24a, 24b, 24c and 24d has a longitudinal axis AA, BB, CC and DD shown in figure 3. The perforations 24a and 24b form a first pair of opposed perforations and the perforations 24c and 24d form a second pair of opposite perforations. As explained in more detail later herein, the perforations 24a, 24b, 24c and 24d are off-center such that the axes I A-A and B-B of the first pair of opposing perforations 24a and 24b are parallel to each other without intersecting and in such a way that the axes C-C and D-D of the second pair of opposing perforations 24c and 24d are parallel to each other without intersecting.

As illustrated in Figure 1, a first support 40 is mounted to a first end portion 30 of the box 20 and a second support 50 is mounted to a second end portion 32 of the box 20. The first support 40 is shown in more detail. detail in figures 4 and 5, the second support 50 is shown in more detail in figures 6 and 7. During the assembly of the pump 10, one or both of the first and second supports 40 and 50 are preferably attached to the box 20 by means of welding or any known connector, such as threaded bolts. Optionally, the first and second supports 40 and 50 could be formed integrally (in one piece) with the box 20. However, the joining of one or both of the first and second supports 40 and 50 to the box 20 during the assembly of the pump 10 provides certain advantages. For example, the first and second supports 40 and 50 can be attached to the box 20 after the formation of the cavity 22, the perforations 24a, 24b, 24c and 24d, the outlets 26a, 26b, 26c and 26d and the inlets 28a , 28b, 28c and 28d to simplify the manufacture of the box 20. In addition, the first and second supports 40 and 50 can be attached to the box 20 after the placement of the components of the piston pump in the cavity 22, the perforations 24a, 24b, 24c and 24d and the first and second supports 40 and 50 to facilitate assembly of the pump 10.

As shown in Figures 5 and 7, the first and second supports 40 and 50 preferably include respective alignment holes 42 and 52 to correspond with alignment holes (not shown) in the first portion of the end 30 and the second portion of the second portion. end 32 of the box 20, in such a way that the box 20 and the first and second supports 40 and 50 can be aligned with alignment pins before joining. When the first and second supports 40 and 50 are joined to the box 20, a cylindrical portion 44 of the first support 40 is preferably coaxial with a cylindrical portion 54 of the second support 50 as shown in Figure 1. The inlet tubes, such as the inlet tubes 23a and 23b shown in figure 1, fit in the rounded edge slots 55 shown in figure 7. According to the invention, a crankshaft has opposite end portions rotatably coupled to the box and a portion eccentric in the cavity. As shown in Figure 1, a crankshaft 60 shown in more detail in Figures 8 and 9, includes a first end portion 62 mounted for rotation in the cylindrical portion 44 of the first support 40 and a second end portion 64 mounted for its rotation in the cylindrical portion 54 of the second support 50. The crankshaft 60 also includes at least an eccentric portion 66 located between the end portions 62 and 64 of the crankshaft and in the cavity 22. As illustrated in Figure 1, the crankshaft 60 preferably includes a thrust / counterweight bearing 68 between the eccentric portion 66 and the second portion 64 of the end of the crankshaft. In addition, a sleeve 70 of the shaft and a main counterweight / thrust bearing 72 are preferably mounted on the first portion 62 of the end of the crankshaft. Optionally, the sleeve 70 of the shaft and the main counterweight / thrust bearing 72 can be formed unitarily with the crankshaft 60. The crankshaft 60 is preferably formed of a hardened steel having a nitrated surface, a hardened stainless steel or a ceramic. As shown in Figure 1, a first cylindrical bearing or bearing sleeve 46 is preferably positioned in the cylindrical portion 44 between the first support 40 and the sleeve 70 of the shaft. In addition, a second bushing or bearing sleeve 56 is preferably positioned in the cylindrical portion 54 between the second support 50 and the second portion 64 of the end of the crankshaft. One or both of the support sleeves 46 and 56 act as thrust bearings and / or bearings or thrust supports for the crankshaft 60. Preferably, the first and second bearing or support sleeves 46 and 56 are attached to the respective cylindrical portions 44 and 54 with a set screw or an appropriate adhesive. During the operation of the pump 10, the crankshaft 60 rotates about its axis of rotation EE shown in Figure 8. The eccentric portion 66 is off-center from the axis of rotation EE such that the eccentric portion 66 moves in a circular path of movement in the cavity 22 when the crankshaft 60 rotates. The thrust bearing / counterweight 68 and the main counterweight / thrust bearing 72 are offset from the axis of rotation EE in an opposite direction of the eccentric portion 66 to place the center of mass of the crankshaft 60 and a coupling structure 90, shown in figures 1, 10, 13 and 14, along the crankshaft of rotation EE. This minimizes vibration as the crankshaft 60 rotates. To reduce friction during rotation of the crankshaft 60, especially during the initial start-up of the pump 10, the first and second bearing sleeves 46 and 56 are preferably formed from a lubricious material. For example, the first and second bearing sleeves 46 and 56 are preferably formed of graphite, carbon, carbon graphite or an appropriate ceramic. Preferably, the friction is also reduced by transporting the liquid to be pumped along the portions of the crankshaft 60 to provide what is commonly known as a rolling or hydrodynamic bearing film. As shown in FIGS. 1 and 8, the sleeve 70 of the shaft, the second portion 64 of the end of the crankshaft and the eccentric portion 66 of the crankshaft each preferably include an external helical groove 73, 74 and 76. During the rotation of the crankshaft 60, the helical grooves 73, 74 and 76 convey the fluid stored in a shell or envelope of the pump 10 respectively between the sleeve 70 of the shaft and the first bearing sleeve 46 between the second portion 64 of the end of the crankshaft and the second bearing sleeve 56 or bearing and between the eccentric portion 66 and a piston coupling structure 90, described hereinafter. The fluid conveyed through the helical grooves 73, 74 and 76 reduces friction and provides cooling while lubricating the support surfaces. As shown in Figures 1 and 7, the second support 50 preferably includes one or more passages or passages, such as the passage 58 for directing the fluid to one end of the helical groove 74. The first support 40 may also include a passage similar to passage 58. According to the invention, a piston has a head disposed in the bore and a base coupled to the eccentric portion of the crankshaft. As partially shown in Figure 1, the pistons 80a, 80b, 80c and 80d, shown in Figures 10-12, have heads 82a, 82b, 82c and 82d disposed in respective perforations 24a, 24b, 24c and 24d and bases 84a , 84b, 84c and 84d disposed in the cavity 22. The coupling structure 90 shown in Figures 1, 10, 13 and 14 couples the piston bases 84a, 84b, 84c and 84d to the eccentric portion 66 of the crankshaft in such a manner that the rotation of the crankshaft 60 reciprocates the piston heads 82a, 82b, 82b and 82d in the respective bores 24a, 4b, 24c and 24d between an intake position (see piston 80b in FIG. 1), wherein the inlets 28a, 28b, 28c and 28d are opened to allow the flow of substances to the perforations 24a, 24b, 24c and 24d and a discharge position (see piston 80a in Figure 1), where the inlets 28a, 28b, 28c and 28d are closed by piston heads 82a, 82b, 82c and 82d and the substances are discharged of the outputs 26a, 26b, 26c and 26d. When the piston heads 82a, 82b, 82c and 82d reach the unloading position, they have traveled preferably completely or until the end of the outlets 26a, 26b, 26c and 26d to discharge all or substantially all of the liquid from the perforations 24a, 24b, 24c and 24d. This substantially decreases the probability of having liquid in the perforations 24a, 24b, 24c and 24d that could be vaporized and create a vapor closure.

Preferably, the pistons 80a, 80b, 80c and 80d are formed of a relatively lightweight plastic material having low friction, low wear and compatibility with the pumped substances, such as mixtures of ammonia and water. Preferred materials for the pistons 80a, 80b, 80c and 80d are RULON or Teflon filled with molybdenum disulfide. To absorb the sudden changes in pressure that may occur in the perforations 24a, 24b, 24c and 24d during movement to the unloading position, the pistons 80a, 80b, 80c and 80d are preferably manufactured from a plastic having a capacity of a light elastic compression. As shown in Figure 12, the piston heads 82a, 82b, 82c and 82d include an annular groove 86 in an upper surface thereof. The annular groove 86 allows an outer annular portion 88 of the piston heads 82a, 82b, 82c and 82d to expand and expand in the respective bores 24a, 24b, 24c and 24d in response to the pressure experienced during pumping. This expansion improves the sealing between the heads 82a, 82b, 82c and 82d of the piston and the respective perforations 24a, 24b, 24c and 24d as long as the substances are pumped. The seal provided by the expansion of the outer annular portion 88 preferably eliminates the need for o-rings or piston rings.

As shown in Figures 1, 10, 13 and 14, the coupling structure 90 preferably includes a sliding block 92 and a retractor or retainer 94. In the preferred embodiment, the sliding block 92 and the detent 94 are separate components attached together by thermal contraction of the detent 94 on the sliding block 92 - heating the detent 94 in such a way that it expands, placing it around a portion of the sliding block 92 and then allowing it to cool and contract in such a way as to hold the sliding block 92. However, the sliding block 92 and the retainer 94 could be formed unitarily from materials such as ceramics, steel alloys or plastics. The sliding block 92 is preferably formed of a lubricious material, such as carbon graphite or ceramic, such as silicon nitride or silicon carbide. Optionally, the sliding block 92 can be coated with a lubricious material and / or have an external surface of hardened carbide such as Purabide or pure carbon. To minimize friction and wear, the material selected for the sliding block 92 is preferably compatible with the material selected for the pistons 80a, 80b, 80c and 80d. As shown in Figure 1, the eccentric portion 66 of the crankshaft passes through a bore 96 of the crankshaft formed in the sliding block 92 and is rotatable in the bore 96 of the crankshaft. Preferably, the sliding block 92 is mounted on the crankshaft 60 before the axle sleeve 70 and the main counterweight / thrust bearing 72 are attached to the crankshaft 60. To reduce friction and provide cooling when the crankshaft 60 rotates, the Helical groove 76 in the eccentric portion 66 conveys fluid to the bore 96 of the crankshaft between the sliding block 92 and the eccentric portion 66. The detent 94 is preferably formed of stainless steel and includes flanges 98a, 98b, 98c and 98d, spaced from the outer surface of the sliding block 92. As shown in FIGS. 1 and 10, the portions of the bases 84a, 84b, 84c and 84d of the piston are slidably fitted in the grooves or slits formed between the flanges 98a, 98b, 98c and 98d and the outer surfaces of the sliding block 92. When the crankshaft 60 rotates about its longitudinal axis EE, the eccentric portion 66 of the crankshaft rotates in the borehole. 96 of the crankshaft and the coupling structure 90 moves in a circular path in the cavity 22 without rotating. As the coupling structure 90 moves in its circular path, the pistons 80a, 80b, 80c and 80d move alternately in the perforations 24a, 24b, 24c and 24d between an intake stroke and a discharge stroke. During the intake stroke, the detent flanges 98a, 98b, 98c and 98d pull the bases 84a, 84b, 84c and 84d of the pistons and their piston heads away from the outlets of the perforations 26a, 26b, 26c and 26d. During the unloading stroke, the sliding block 92 urges the piston bases 84a, 84b, 84c and 84d and the piston heads towards the outlets 26a, 26b, 26c and 26d of the bore. When the pistons 80a, 80b, 80c and 80d move alternately, the outer surfaces of the sliding block 92 slide in relation to the respective piston bases 84a, 84b, 84c and 84d, while the respective portions of the bases 84a, 84b 84c and 84d are retained in the slots formed between the flanges 98a, 98b, 98c and 98d and the external surfaces of the sliding block 92. This sliding is carried out in a direction perpendicular to the respective axes AA, BB, CC and drilling DD. To reduce friction as the piston bases 84a, 84b, 84c and 84d slide, the outer surfaces of the sliding block 92 and the internal surfaces of the flanges 98a, 98b, 98c and 98d are preferably lubricious. As shown in Figure 12, the bases 84a, 84b, 84c and 84d of the pistons are preferably circular. This shape allows the bases 84a, 84b, 84c and 84d of the pistons to rotate on the sliding block 92 during sliding and thereby reduces the likelihood that the piston bases 84a, 84b, 84c and 84d will wear unevenly. Furthermore, the round shape for the piston bases 84a, 84b, 84c and 84d makes them less expensive than the square-shaped bases and easier to mount in the coupling structure 90. Although FIG. 3 does not show the crankshaft 60, it shows the position of the longitudinal axis EE of the crankshaft in the case 20 when the crankshaft 60 is rotatably mounted in the first and second supports 40 and 50. As shown in this figure, the perforations 24a, 24b, 24c and 24d are off-center, so that the drilling axes AA, BB, CC and DD have no intersection with the axis of rotation EE of the crankshaft. More specifically, the perforations 24a, 24b, 24c and 24d are off-center such that each of the drilling axes AA, BB, CC and DD are generally parallel to (and lack of intersection with) a respective radial line Rl, R2, R3 and R4 extending from the axis of rotation EE of the crankshaft in a plane parallel to the axis of rotation EE of the crankshaft (in the plane taken along line 3-3 of Figure 2). This off-center spacing of the perforations 24a, 24b, 24c and 24d reduces the likelihood that the pistons 80a, 80b, 80c and 80d will suffer excessive stress and deform after a long period of use of the pump 10.

In Figure 3, each of the drilling axes AA, BB, CC and DD are shown spaced from the respective radial lines Rl, R2, R3 and R4 in a counter-clockwise direction and the crankshaft 60 rotates in the clockwise direction. When the pistons 80a, 80b, 80c and 80d are in their discharge strokes, this displacement or decentration causes the eccentric portion 66 of the crankshaft and the coupling structure 90 to be closer to the axes AA, BB, CC and DD of the piston. perforation than what would be if perforations 24a, 24b, 24c and 24d were not offset. Consequently, the moments or amount of bending movement acting on the pistons 80a, 80b, 80c and 80d are reduced. In addition, the piston heads 82a, 82b, 82c and 82d are moved in the bores 24a, 24b, 24c and 24d closest to the bore outlets 26a, 26b, 26c and 26d before increased sliding friction forces are applied to the piston bases 84a, 84b, 84c and 84d during the rotation of the crankshaft 60. It has been found that when the solution pumps have bore axes coaxial with the respective ones I radial lines, similar to the radial lines Rl, R2, R3 and R4, the pistons can be flexed during the operation under certain conditions.

In Figure 3, as the crankshaft 60 and the coupling structure 90 rotate clockwise about the axis of rotation of the crankshaft EE, the circular movement of the coupling structure 90 causes the pistons 80a to move, 80b, 80c and 80d in and out of their respective perforations 24a, 24b, 24c and 24d. When the eccentric portion 66 and the coupling structure 90 are in the twelve o'clock position in Figure 3, the head 82a of the piston in the bore 24a is in the bore outlet 26a, while the piston 80b in the perforation 24b is fully retracted to open the intake hole 28b (see figure 1). Because each piston 80a, 80b, 80c and 80d is moved linearly by the rotational movement of the coupling structure 90, its speed of reciprocating motion is essentially sinusoidal. When the coupling structure 90 passes through the twelve o'clock position (shown in Figure 1), the pistons 80a and 80b in the perforations 24a and 24b have zero velocity and the pistons 80c and 80d in the perforations 24c and 24c are at their maximum speeds. As the crankshaft 60 continues to rotate clockwise from the twelve o'clock position, the piston 80b in the bore 24b begins its pumping stroke. If the perforation 24b has been filled with liquid during the preceding intake stroke, the pressure in the perforation 24b will rise to a discharge pressure when the piston 80b in the perforation 24b closes the intake damper 28b. Then, a discharge valve structure 100b shown in Fig. 1 will open and because the piston 80b will still be at a low speed, no large pressure pulse will be present. If the fluid that is pumped is a mixture of two liquid phases and its vapor, the piston 80b compresses the mixture and the liquid portion absorbs the vapor portion with only a slight pressure rise in the perforation. When the last steam bubble is absorbed, the eccentric portion 66 of the crankshaft may have rotated to approximately the three o'clock position in Figure 3. At this time, the piston 80b may be at its maximum speed while the liquid it has remained static because the valve 100b has been closed by the discharge pressure. The resulting sudden impact on vapor absorption can cause a pressure rise of more than 70.3 Kg / cm2 (1000 pounds / square inch). The force of the impact tends to move the piston 80b backwards in the perforation 24b along the axis B-B of the perforation, while the moment of the eccentric portion 66 of the crankshaft and the coupling structure 90 cause an opposite force which is out of alignment with the axis B-B of the bore. These two forces tend to flex or bend (or bend) the portion of the piston 80b that does not extend into the bore 24b. The decentering of the portions places them closer to the alignment with the average direction of force exerted by the eccentric portion 66 of the crankshaft and the coupling structure 90 and limits the probability that the piston will bend or bend by reducing the bending moments that act on the pistons. According to the invention, a valve structure is arranged to open and close the outlet of the bore in response to movement of the piston to the unloading position. As implemented herein and shown in Figure 1, the valve structures 100a and 100b are secured to the box 20 on the outlets 26a and 26b of the perforations 24a and 24b. (Valve structures (not shown) similar in structure and function to the valve structures 100a and 100b are also secured on the outlets 26c and 26d of the perforations 24c and 24d). Preferably, the valve structures 100a and 100b are flexible resilient hinge valves or reed valves formed from thin strips of Swedish steel, stainless steel or carbon steel, such as those used in refrigeration and air conditioning compressors that They operate at similar speeds. To substantially prevent backflow of the pumped liquids, the valve structures 100a and 100b are urged or predisposed to close the outlets 26a and 26b during the intake strokes of the pistons 80a and 80b. The pressure of the fluid generated during the movement of the heads 82a and 82b of the piston to its unloading position moves the valve structures 100a and 100b away from the outlets 26a and 26b to allow the unidirectional liquid discharge of the outlets 26a and 26b. Preferably, the pump 10 is capable of operating at crankshaft speeds of approximately 3600 revolutions per minute. This speed requires that the valve structures 100a and 100b be capable of flexing from the outlets 26a and 26b sixty times per second. This relatively high bending speed subjects them to potential fatigue failures. Accordingly, the valve structures 100a and 100b should be constructed of appropriate materials and designed with the proper dimensions to operate at stresses below the strength limit. Preferably, the valve structures 100a and 100b have a relatively small mass and fast opening and closing times to help alleviate any pressure rise that occurs in the perforations 24a, 24b, 24c and 24d and to prevent backflow at the beginning of the admission race.

The valve structures 100a and 100b are preferably fixed to the box 20 with rivets or threaded bolts to the fastener holes 102, shown in Figure 2. The fastener holes 102 are formed in the box 22 and positioned to orient the structures of valve at any preferred angle relative to the case 20. Preferably, the outer surface portions 104a, 104b, 104c and 104d shown in Figure 3 around the periphery of the perforation outlets 26a, 26b, 26c and 26d are machined and ground such that they are flat and smooth, not curved like the rest of the outer surface of the case 20. As shown in Figure 2, the portion 104d of the outer surface includes a circular groove 105 formed around the outlet 26d and a straight slot 106 formed between the holes 102 for the fasteners and the outlet 26d. The circular slit 104 and slot 106 combined with the movement of the valves serves to produce turbulence of the liquid and trajectories to disperse the particulate material that would otherwise obstruct the settlement of the valve structure on the outlet. The valve structures may also include valve detents to limit the distances that the valve structures flex from the housing 22. For example, the valve retainers may be the same as the valve retainers described in the original application mentioned above ( Serial No. 08 / 195,193). According to the invention, a magnetic element is coupled to the crankshaft to couple the crankshaft magnetically with an external magnetic field capable of rotating the crankshaft. As shown in Figure 1, the magnetic element 110 is preferably coupled to the second end portion 64 of the crankshaft 60 in such a way that an external magnetic field can be magnetically coupled with the magnetic element 110 and rotate the crankshaft 60. When the pump 10 is used to pump certain substances, a magnetic drive coupling is preferred with respect to a direct coupling, in such a way that the motor or other drive source for rotating the crank 60 can be hermetically isolated from the inside of the pump 10. For example, ammonia solutions in water, especially those that include inhibitors, quickly corrode many materials, such as copper, aluminum, brass, etc., which are commonly used in hermetic compressor engines in electric thermal pumps, conditioners of air, etc., for its operation with refrigerants of I chlorofluorocarbon, hydrochlorofluorocarbon and hydrofluorocarbon. The pump 10 is preferably manufactured from carbon steels and other materials that are not affected by ammonia / water and inhibitors. In addition, the magnetic element 110 is made of materials such as ceramic, ferrite or metals which are not affected by ammonia, water or inhibitors. Preferably, the pump 10 is constructed in such a way that it is airtight in locating at least a portion of the case 20 and all the internal components, in which the crankshaft 60 and the magnetic element 110 are included, in a shell or envelope sealed weldment including a first cover 120, a second cover 122 and a third cover 124. As shown in Figure 1, the first cover 120 is welded circumferentially to the first end portion 30 of the box 22 to enclose a lower portion of the pump 10. The first cover 120 preferably includes one or more brackets or mounting brackets 126 for mounting the pump 10 such that the first portion of the crankshaft end 62 is below the second end portion 64 of the crankshaft . The second cover 122 is welded circumferentially to the first end portion 30 of the box and the second end portion 32 of the box to form an annular discharge chamber 128 surrounding the exit holes 26a, 26b, 26c and 26d of the perforation. The discharge chamber 128 communicates with a discharge tube 130 attached to an opening in the second cover 122 in such a manner that the pumped substances can be removed from the discharge chamber 128 and directed towards the high pressure section of a heat pump when the pump 10 is used in a thermal pump system. The third cover 124 is welded circumferentially to the second portion 32 of the end of the box to enclose the magnetic element 110 and the second portion of the end 64 of the crankshaft. As shown in Figure 1, an intake pipe 132 is attached to an opening in the third cover 124 in such a way that the substances can enter an interior portion of the pump 10 and be temporarily stored in a chamber formed by the first cover 120, third cover 124 and cavity 22 of the box before being pumped. Preferably, the third cover 124 is made of a non-magnetic material, such as stainless steel, which has minimal effects on the magnetic coupling with the magnetic element 110. As shown in the embodiment of FIG. 1, a motor 134 having a shaft or shaft 136 of rotary drive is mounted to the outside of the third cover 124. The motor 134 is preferably a two-pole motor to allow high-speed operation. A driving or driving magnet 138 is coupled directly to the drive shaft or shaft 136 and magnetically coupled to the magnetic element 110 with a slip-free coupling. Preferably, the drive magnet 138 and the magnetic element 110 have three pairs of north and south poles magnetically coupled together. When the motor 134 is energized to rotate the drive shaft 136, the magnetic coupling between the drive magnet 138 and the magnetic element 110 transmits rotation to the crankshaft 60. Although an axial magnetic coupling is shown in the embodiment of FIG. 1 , radial magnetic couplings can also be used. In addition, the pump 10 may include a decoupling detector (not shown) for detecting whether the drive magnet 138 or the magnetic element 110 is rotating out of synchrony or not rotating. Fig. 15 shows a second embodiment of the invention including a pump 10 'similar to the pump 10 shown in Fig. 1. The pump 10 includes a magnetic element 110' arranged radially and a third cover 124 covering the magnetic element 110 ' , the crankshaft 60 'and other internal components of the pump 10'. To rotate the magnetic element 110 'and the crankshaft 60', the pump 10 'includes an electromagnetic stator 140 pressurized or mounted rigidly on the third cover 124'. The electromagnetic stator 140 includes windings capable of generating rotating magnetic fields when energized. The drive system for the electromagnetic stator 140 can be of a Hall effect type or another three-phase type and the magnetic coupling can be radial, as shown in Figure 15 or axial. The electromagnetic stator 140 eliminates the need for a drive magnet, motor rotor and motor shaft, costs less than an external motor system and reduces the likelihood of decoupling. Vapor closure is a common consequence when attempting to pump any boiling liquid or such as a liquid and its vapor. When the steam shutdown occurs in normal pumps, it is usually necessary to turn off the pump, allow it to cool, fill it with liquid and then restart it. The controls in a thermal pump system will do this if necessary. However, it is preferable to stop the steam shutdown before it reaches this state. In accordance with this invention, a method for reducing vapor closure is also provided. This method is explained later in the present by explaining the operation of the modalities described above. Nevertheless, it should be understood that the method of the invention is not limited to the structure described herein. In Figure 1, a substance having at least one liquid component is supplied through the intake pipe 132 to a chamber formed by the first cover 120, the third cover 124 and the cavity 22 of the box. Preferably, the pump 10 is oriented such that the first portion of the crankshaft end 62 is located below the second end portion 64 of the crankshaft. When a substance having a liquid phase and a vapor phase, such as ammonia and water, enters the pump 10, this orientation of the pump 10 allows the liquid portion to accumulate in a lower portion of the pump 10 and the portion of steam accumulates in an upper portion of the pump 10. Preferably, the magnetic element 110 is located above the level of the liquid which accumulates in the pump 10 to reduce the losses by entrainment associated with the rotation of the magnetic element 110. in the liquid. As partially shown in Figure 16, the liquid preferably accumulates around each intake tube 23a, 23b and rises to a level of preference above the openings 27a and 27b and below the open ends 25a, 25b. This allows steam to enter the inlet pipes 23a, 23b through the open ends 25a, 25b, while the liquid enters the inlet pipes 23a, 23b through the openings 27a, 27b. The openings 27a, 27b are holes that establish the height of the liquid stored in a chamber formed by the third cover 124, shown in figure 1. By restricting the flow of liquid to the perforations, the openings in the intake pipes cause the Liquid flowing from a source, such as an absorber, accumulates in the pump chamber until it rises to a level where it flows at a normal speed to the boreholes. The hydrostatic head of pressure and the volume of the stored liquid serve to prevent the closing of steam. If the inlet tubes were not present, the vapor closure could prevent a low hydrostatic pressure from the liquid from driving the liquid into the perforations. The inlet tubes allow a relatively continuous flow from the pump chamber to the boreholes. The level of the liquid in the inlet tubes quickly accumulates to produce a hydrostatic head of the liquid at each inlet 28a, 28b, 28c and 28d of the bore which is much larger than normal to drive the liquid to the boreholes. This allows even a small stream of liquid to enter the perforations, thereby reversing any vapor closing effect and to restore normal pumping. The openings 27a, 27b dose the liquid flow to the inlet tubes 23a, 23b to maintain a relatively constant flow of liquid to the perforations 24a, 24b if the flow of liquid to the pump 10 is interrupted, such as when the flow of liquid is interrupted. an absorber is retarded 1 temporarily. In addition, the liquid entering the inlet pipes 23a, 23b via the openings 27a, 27b is mixed with the steam entering the inlet pipes 23a, 23b via the open ends 25a, 25b to ensure that a liquid-vapor mixture instead of alternating streams of pure steam and liquid-vapor between the perforations 24a, 24b through the inlets 28a, 28b. The provision of a supply of a liquid around the inlet tubes and the mixing of the liquid and vapor reduces the likelihood of vapor closure and also allows pumping at various speeds and pumping of substances that have a wide range of ammonia concentrations and various proportions or ratios of vapor to liquid. In addition, the mixing of the liquid and the vapor creates many small vapor bubbles of various sizes, which enter the perforations 24a, 24b, 24c and 24d with the liquid. During compression, the many sizes of the bubbles in the perforation are crushed at different times, instead of all together or as a bubble. This makes uniform the pressure elevations that could cause cylinder erosion. The pumping is initiated by energizing the motor 134, shown in Fig. 1 or the electromagnetic stator 140 shown in Fig. 15. The magnetic coupling between the drive magnet 138 and the magnetic element 110 or between the electromagnetic stator 140 and the magnetic element 110 'rotate the magnetic element 110, 110' and cause the corresponding crankshaft 60, 60 'to rotate about its axis of rotation EE and thereby alternately move the pistons 80a, 80b, 80c and 80d in the perforations 24a, 24b , 24c and 24d. When the crankshaft 60 rotates, the coupling structure 90 moves in the cavity 22 in a circular path about the axis of rotation E-E of the crankshaft without rotating. The mobile coupling structure 90 causes each piston 80a, 80b, 80c and 80d to move alternately in their respective bore 24a, 24b, 24c and 24d. The distally opposite pistons 80a, 80b or 80c and 80d move alternately in phase with each other since as a piston reaches the upper dead point near an outlet, the opposite piston reaches a fully retracted position in the cavity 22. A As the pistons 80a, 80b, 80c and 80d move alternately within their perforations 24a, 24b, 24c and 24d, each travels during an intake stroke towards the cavity 22 such that the heads 82a, 82b, 82c and 82d of the piston open the inlets 28a, 28b, 28c and 28d and allow the solution to enter the perforations 24a, 24b, 24c and 24d via the inlet pipes, the inlets 28a, 28b, 28c and 28d and optional auxiliary entries such as the entries 29a and 29b. When the pistons 80a, 80b, 80c and 80d move in their discharge strokes, they travel towards the outlets 26a, 26b, 26c and 26d to seal the perforations 24a, 24b, 24c 24d of the fluid communication with the inlets 28a, 28b, 28c and 28d and the auxiliary inputs 29a, 29b. The increased pressure of the fluid generated in the perforations 24a, 24b, 24c and 24d causes the valve structures, such as the valve structures 100a and 100b to flex and separate from the box 20 and allow the solution in the perforations 24a, 24b, 24c and 24d is ejected through the outlets 26a, 26b, 26c and 26d when the pressure in each perforation slightly exceeds the discharge pressure in the discharge chamber 128 shown in Figure 1. The expelled solution travels to the chamber of discharge 128 and is pumped through the discharge tube 130. When the pistons 80a, 80b, 80c and 80d terminate their discharge stroke and the intake stroke begins, the valve structures close the outlets 26a, 26b, 26c and 26d to prevent significant counterflow to the perforations 24a, 24b, 24c and 24d. Preferably, the piston heads 82a, 82b, 82c and 82d are virtually flush with the outer surface of the case 20 when in their fully extended position. This ensures that the perforations 24a, 24b, 24c and 24d are essentially emptied of any remaining liquid. Otherwise, such a liquid, if allowed to remain in the perforations 24a, 24b, 24c and 24d, could evaporate excessively as the pistons 80a, 80b, 80c and 80d retract and the vapor decrease the pumping volume at move the incoming solution and thus tend to cause the steam to close. Preferably, the piston heads 82a, 82b, 82c and 82d do not extend beyond the outer surface of the casing 20 since such would increase the tendency of the pistons 80a, 80b, 80c and 80d to impact with the structures of the piston. valve. As the solution continues to enter the pump 10, 10 'through the intake pipe 132, the solution enters the passage 58 shown in Figs. 1 and 7 and flows directly into the helical groove 74 shown in Fig. 1. In addition , some solution enters the cavity 22 and the area enclosed by the first cover 120. When the crankshaft 60 rotates, the helical grooves 73, 74 and 76 convey solution towards the second portion 64 of the end of the crankshaft to lubricate and cool the surfaces of the crankshaft. support or bearing between the sleeve 70 of the shaft and the first bearing sleeve 46, between the second portion 64 of the end of the crankshaft and the second bearing sleeve 56 and between the eccentric portion 66 and the sliding block 92. The use of multiple pistons also reduces the likelihood of steam closing, because it is unlikely that all pistons will experience vapor closures at the same time. If one or two of the pistons experience steam shutdown, the others continue to pump. Since the total flow of the liquid is less than the maximum design flow under most operating conditions, the pistons that do not undergo vapor closure pump most or perhaps all of the incoming liquid flowing from such a source. as an absorber. This liquid flows through the pump and helps prevent overheating of cylinders that experience steam shutdown. Other embodiments of the invention are shown in Figures 17-19. As shown in Figure 17, a pump 210 includes a box 220 having a pair of generally parallel body elements 221 and 223 spaced apart to define a cavity 222 therebetween. The case 220 also includes a first support 240 coupled to the body members 221 and 223 in an end portion of the case 220 and a second support 250 coupled to the body elements 221 and 223 in another end portion of the case 220 Preferably the body members 221 and 223, the first support 240 and the second support 250 each have a generally parallelepiped shape and rectangular shaped faces which make each of these parts relatively simple to manufacture with a reduced machining . As shown in Figure 17, the body members 221 and 223, the first support 240 and the second support 250 form a framework of generally rectangular shape. Although the body elements 221 and 223 are preferably joined to the first and second supports 240 and 250 by means of welding, threaded bolts or other connecting structures, the body elements 221, 223 and the first and second supports 240 and 250 they can be formed integrally. The joining of some or all of the parts, of the box 220 after the mounting of the pumping components in the cavity 222 facilitates a quick and inexpensive assembly of the pump 210. The body member 221 defines a pair of perforations 224a and 224b extending from cavity 222 and ending at exits 226a and 226b. Similarly, the body member 223 defines a pair of perforations 224c and 224d extending from the cavity 222 and ending at the outlets 226c and 226d. As shown in Figure 17, the perforations 224a and 224c and the perforations 224b and 224d are preferably opposite each other in a coaxial manner, however, in another embodiment using the pistons 280a 'and 280c' shown in Figure 18, the perforations 224a and the perforations 224d are offset from each other to reduce the probability of bending or curvature of the piston. The inputs 228a and 228b and the inputs 228c and 228d respectively formed in the body elements 221 and 223 communicate with the perforations 224a, 224b, 224c and 224d at a position located between the cavity 222 and the outlets 226a, 226b, 226c, 226d. Preferably, auxiliary inputs (not shown) are also formed in the body members 221 and 223 and communicate with the perforations 224a, 224b, 224c and 224d in positions opposite the inlets 228a, 228b, 228c and 228d. The pump 210 also includes a crankshaft 260 between the body members 221 and 223. The crankshaft 260 has a first end portion rotatably mounted on the first support 240 and a second end portion rotatably mounted on the second support 250. To support the crankshaft 260 and reduce friction during rotation, a first bearing sleeve 247 and first bearing sleeve 246 are preferably positioned between the first end portion of the crankshaft and the first support 240 and a second bearing sleeve or bearing 257 and a second thrust sleeve 256 are preferably positioned between the second end portion of the crankshaft and the second support 250. The bearing or support sleeves 247 and 257 are preferably manufactured from the same types of lubricious materials as the bearing sleeves. or support 46 and 56 described in relation to the embodiment shown in figure 1. As shown in FIG. Fig. 17, the crankshaft 260 preferably has a first eccentric portion 266a and a second eccentric portion 266b disposed in the cavity 222 and facing in opposite directions a rotational axis of the crankshaft 260. The eccentric portions 266a and 266b are either joined together to the crankshaft 260 or integrally formed with the crankshaft 260. Because the eccentric portions 266a and 266b face the opposite directions of the axis of rotation of the crankshaft, they help to balance the crankshaft 260 and reduce the need for counterweights. As shown in figures 17 and 18, the pump 210 includes a first coupling structure 290a, having a bore receiving the first eccentric portion 266a, and a second coupling structure 290b having a bore receiving the second eccentric portion 266b. The pump 210 also includes pistons 280a, 280b, 280c and 280d having respective bases disposed in the cavity 222 and heads disposed in the perforations 224a, 224b, 224c and 224d. The bases of the pistons 280a and 280c are coupled to the first coupling structure 290a and the bases of the pistons 280b and 280d are coupled to the second coupling structure 290b. As shown in Figure 18, the bases of the pistons 280a and 280c are joined together and form a cavity for the first coupling structure 290a. Similarly, the bases of the pistons 280b and 280d are joined together and form a cavity for the second coupling structure 290b. Preferably, the pistons 280a and 280c and pistons 280b and 280d are integrally formed of a flexible plastic material, such as the materials used to form the pistons 80a-80d described above. The integral formation of the pistons 280a and 280c and the pistons 280b and 280d facilitates the orientation of the pistons in the perforations 224a, 224b, 224c and 224d during assembly. In the embodiments of Figures 17-19, the coupling structures 290a and 290b are preferably sliding blocks capable of sliding within the cavities formed by the pistons as the crankshaft 260 rotates. In an alternative embodiment (not shown), the bases of the pistons 280a and 280c are individually formed and fastened to the coupling structure 290a and the bases of the pistons 280b and 280d are individually formed and fastened to the coupling structure 290b. Integral pistons 280a and 280c and integral pistons 280b and 280d shown in Figure 18 are preferred, however, because they do not require a holding structure. As shown in Figure 18, opposed pistons 280a 'and 280c' have piston heads offset from each other. The pistons 280a 'and 280c' are used in a mode where the opposite perforations in the pump 210 are offset from each other. As shown in Fig. 18, the heads of the pistons 280a 'and 280'c are off-center in the counterclockwise direction of radial lines extending from a rotation axis of the crankshaft 260 and the crankshaft 260 rotates preferably in a clockwise direction. Off-center perforations in the pump 210 reduce the likelihood of bending or bending the piston. The rotation of the crankshaft 260 reciprocates the heads of the pistons 280a, 280b, 280c and 280d in the respective bores 224a, 224b, 224c and 224d. During the intake strokes, the piston heads move respectively towards the cavity 222 and allow flow to the perforations 224a, 224b, 224c and 224d via the inlets 228a, 228b, 228c and 228d. During a discharge stroke, the piston heads respectively seal the inlets 228a, 228b, 228c and 228d and pump substances from the bores 224a, 224b, 224c and 224d via the outlets 226a, 226b, 226c and 226d. The piston heads travel respectively to the end of the outlets 226a, 226b, 226c and 226d to empty the liquid from the perforations 224a, 224b, 224c and 224d. Valve structures 300a and 300b and valve structures 300c and 300d are respectively mounted to body members 221 and 223. Valve structures 300a, 300b, 300c and 300d are preferably flexible hinge valves or reed valves that they open in response to the increased pressure in perforations 224a, 224b, 224c and 224d. The valve structures 300a, 300b, 300c and 300d are urged to close the outlets 226a, 226b, 226c and 226d of the bore during the intake stroke. The discharge boxes 322a and 322b are respectively joined to the external surfaces of the body elements 221 and 223 and are spaced apart from the valve structures 300a, 300b, 300c and 300d to provide separate discharge chambers for the pumped substances passing from the outlets 226a, 226b, 226c and 226d of the bore. As shown in Figure 17, the discharge pipe 330 communicates with the chambers formed by the discharge boxes 322a and 322b to separate the pumped substances. The pump 210 further includes a magnetic element 310 mounted to the second end portion of the crankshaft 260. The magnetic element 310 allows the crankshaft 260 to be rotated via a magnetic coupling. A wrapping hermetically insulates the pump 210. The wrapping includes a first cover 331, the bracket or bracket 332 and the second cover 334. The first cover 331 partially surrounds the box 220 and includes an intake pipe 340 to allow the flow of substances to the container. the envelope or envelope. The intake tube may instead be attached to the second cover 334. The discharge tube 330 coupled to the discharge boxes 322a and 322b passes in a sealed manner through the first cover 331.

The bracket or bracket 332 is attached to the box 220 and welded to the first cover 331 to support the box 220 in the wrapping. The second cover 334 is welded to the first cover 331. The second cover 334 partially encloses a portion of the box 222 and the magnetic element 310. The first cover 331 and the second cover 334 are preferably sealed hermetically to form a chamber for accumulating substances flowing to the pump 210 via the intake pipe 340. In the embodiment of Figure 17, an electromagnetic stator 350 is press-fitted or mounted on the second cover 334. The electromagnetic stator 350 acts in response to an electrical input for generating a magnetic field capable of rotating the magnetic element 310 and the crankshaft 260. Preferably, the magnetic coupling is radial, as shown in Figure 17. However, other magnetic couplings are also possible. For example, the magnetic coupling can be axial by mounting an electromagnetic stator 350 ', shown in FIG. 19 on an end portion of a second cover 334' and ac magnetic stipulation of the electromagnetic stator with a magnetic element 310 '. In addition, a motor and drive magnet (not shown) could be used to rotate the crankshaft 260.

Although the embodiments shown in Figures 1-19 include one or two eccentric portions of the crankshaft and four pistons, the present invention could be practiced, with any number of eccentric portions or pistons, which include, a single piston or eight pistons. Each of the embodiments described above are particularly suitable for pumping mixtures of ammonia and water. However, the invention could be implemented to pump many different types of substances. In addition, the invention could be implemented without a magnetic coupling to rotate the crankshaft. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure and methodology of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is proposed that the present invention cover the modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. It is noted that, in relation to this date, the best method known to the applicant, to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Claims (26)

1. Claims Having described the invention as above, the content of the following claims is claimed as property: 1. A pump, characterized in that it comprises: a crankshaft having opposite end portions and an eccentric portion between the end portions; a box defining a cavity, an outlet, at least one bore extending between the cavity and the outlet and at least one inlet communicating with the bore, the eccentric portion of the crankshaft being in the cavity and the portions from the end of the crankshaft are rotatably coupled to the box, the perforation is off-center in such a way that an axis of the perforation, lacks intersection with an axis of rotation of the crankshaft; a piston having a base disposed in the cavity and a head disposed in the bore, the base of the piston is coupled to the eccentric portion of the crankshaft in such a way that rotation of the eccentric portion in the cavity causes the piston head to reciprocate in the perforation to provide the discharge of the perforation through the outlet and the admission of the perforation through the inlet; and a valve structure arranged to open and close the outlet in response to movement of the piston head during discharge and intake.
2. 2. The pump according to claim 1, characterized in that the bore is offset, such that the axis of the bore is generally parallel to a line extending from the axis of rotation of the crankshaft in a plane perpendicular to the axis. of rotation.
3. 3. The pump according to claim 1, characterized in that the inlet communicates with the perforation in an intermediate position to the cavity and the outlet. The pump according to claim 1, characterized in that it further comprises a magnetic element coupled to one of the portions of the crankshaft end to magnetically couple the crankshaft with an external magnetic field capable of rotating the crankshaft. The pump according to claim 4, characterized in that it also comprises at least one cover enclosing the magnetic element and an electromagnetic stator mounted to the cover, the electromagnetic stator is magnetically coupled to the magnetic element for rotating the magnetic element and the crankshaft The pump according to claim 1, characterized in that the box defines an auxiliary bore and at least one inlet and one outlet communicating with the auxiliary bore, the auxiliary bore has an axis parallel to the axis of the at least one a perforation and lacks intersection with the rotational axis of the shaft or crankshaft and wherein the pump further comprises: an additional piston having a head disposed in the auxiliary bore and a base coupled to the eccentric portion of the crankshaft in such a way that the rotation of the eccentric portion in the cavity alternately causes the auxiliary piston head to move in the auxiliary perforation to provide the discharge of the auxiliary perforation and the admission to the auxiliary perforation. The pump according to claim 6, characterized in that the box defines two opposite entrances for each of the perforations. The pump according to claim 1, characterized in that the box defines first and second pairs of perforations and entrances and exits communicating with the perforations, the first pair of perforations having parallel axes lacking intersection with the rotational axis of the perforation. The crankshaft and the second pair of perforations have parallel axes that lack intersection with the rotational axis of the crankshaft and wherein the pump further comprises: pistons having each, a head disposed in one of the perforations and a base coupled to the eccentric portion of the crankshaft. 9. The pump according to claim 1, characterized in that it also comprises an inlet tube that extends from the perforation that communicates with the inlet, the inlet tube has at least one hole positioned along the length of the same, the hole allows the liquid to flow to the inlet tube and mix with the steam in the inlet tube. The pump according to claim 1, characterized in that it further comprises: a first support attached to one end of the box, a second support attached to the other end of the box, a first bearing sleeve or bearing arranged in the first support , and a second bearing sleeve or bearing arranged in the second support, the end portions of the crankshaft are rotatably mounted in the first and second bearing sleeves. The pump according to claim 1, characterized in that it further comprises a coupling structure having a bore of the crankshaft which rotatably receives the eccentric portion of the crankshaft and is coupled to the base of the piston. The pump according to claim 11, characterized in that the coupling structure includes a sliding block and a flange extending above a surface of the sliding block, the perforation of the crankshaft passes through the sliding block and the base of the The piston is slidably positioned between the flange and the surface of the sliding block. 13. The pump in accordance with the claim 11, characterized in that the coupling structure has a thermally contracted retainer on the sliding block, the flange is a portion of the retainer. A pump characterized in that it comprises: a box defining a cavity, an outlet, at least one perforation extending between the cavity and the outlet and at least one entrance communicating with the intermediate perforation to the cavity and the departure; a first support attached to a portion of the end of the box; a second support attached to another end portion I from the box; a crankshaft having a first end portion rotatably mounted on the first support, a second end portion rotatably mounted on the second support and at least one eccentric portion disposed in the cavity; a piston having a base disposed in the cavity, and a head disposed in the bore to reciprocate between a discharge position near the outlet and an intake position allowing flow to the bore through the inlet; a coupling structure having a crankshaft bore which rotatably receives the eccentric portion of the crankshaft, the coupling structure is coupled to the base of the piston in such a way that rotation of the eccentric portion in the cavity causes the head to move alternately of the piston in the perforation of the box; a valve structure arranged to open and close the outlet in response to movement of the piston head from the unloading position to the intake position; and a magnetic element coupled to the crankshaft to magnetically couple the crankshaft with an external magnetic field, capable of rotating the crankshaft. 15. The pump in accordance with the claim 14, characterized in that it also comprises at least one cover enclosing the magnetic element and an electromagnetic stator mounted to the cover, the electromagnetic stator is magnetically coupled to the magnetic element to rotate the magnetic element and the crankshaft. The pump according to claim 14, characterized in that the coupling structure includes a sliding block and a flange extending above a surface of the sliding block, the perforation of the crankshaft passes through the sliding block and the base of the sliding block. The piston is slidably positioned between the flange and the surface of the sliding block. 17. The pump according to claim 16, characterized in that the coupling structure has a retainer thermally contracted on the sliding block, the flange consists of a portion of the retainer. 18. The pump in accordance with the claim 14, characterized in that the box includes a first body element and a second body element spaced from the first body element, in such a way that the first and second body elements form the cavity between them, the first support is attached to the first and second body elements in the end portion of the box and the second holder is joined to the first and second body members in the other end portion of the box. The pump according to claim 18, characterized in that the first and second body elements and the first and second supports form a framework of generally rectangular shape. 20. The pump according to claim 18, characterized in that the first and second body elements are formed integrally with the first and second supports. The pump according to claim 18, characterized in that the first and second body elements each define at least one bore, and at least one inlet and one outlet that communicate with the bore, and wherein the pump further comprises a first piston having a head disposed in the bore of the first body member and a second piston having a head disposed in the bore of the second body member, the first and second pistons have a base coupled to the coupling structure . 22. The pump in accordance with the claim 21, characterized in that the first piston is formed integrally with the second piston. 23. The pump in accordance with the claim 22, characterized in that the coupling structure includes a sliding block having the perforation of the crankshaft passing therethrough, the sliding block being movable in a cavity formed by the first and second piston bases. 24. The pump according to claim 14, characterized in that the box defines first and second perforations and at least one inlet and one outlet for each of the perforations, the crankshaft includes a first eccentric portion and a second eccentric portion and wherein the The pump further comprises: a first piston having a base disposed in the cavity and a head disposed in the first bore, a second piston having a base disposed in the cavity and a head disposed in the second bore, a first coupling structure that it has a crankshaft bore which rotatably receives the first eccentric portion of the crankshaft, the first coupling structure is coupled to the base of the first piston, and a second coupling structure having a crankshaft bore which rotatably receives the second eccentric portion. of the crankshaft, the second coupling structure is coupled gives the base of the second piston. 25. The pump according to claim 24, characterized in that the box defines third and fourth perforations and wherein the pump further comprises: a third piston having a base coupled to the first coupling structure and a head disposed in the third piercing , and a fourth piston having a base coupled to the second coupling structure and a head disposed in the fourth bore. 26. The pump according to claim 14, characterized in that it further comprises a first bearing sleeve or support between the first support and the first portion of the end of the crankshaft and a second bearing or bearing sleeve between the second support and the second support. end portion of the crankshaft.