High-pressure plunger pump

Abstract

A high-pressure plunger pump (1) comprises a pump head (2), a housing (11) which is fastened to the pump head (2), at least one working plunger arrangement (3) which is arranged in the housing (11) and which has a working chamber (31) and an axially movably arranged working plunger (32) delimiting the working chamber (31), in each case a valve body (4) which is arranged between the pump head (2) and the housing (11) and adjoins the working chamber (31) and has a through-channel (41) and a suction channel (42) that is closable by a closing body (43), and at least one outlet valve (5) which is fastened to the pump head (2) and has an outlet (53) that can be blocked by a closing body (51), wherein the through-channel (41) of the valve body (4) opens into a compression chamber (22) of the pump head (2), wherein at least one additional plunger arrangement (6) is fastened to the pump head (2), wherein the at least one additional plunger arrangement (6) has a working chamber (61) fluidically connected to the working chamber (22) of the pump head (2) and has an axially movably arranged spring-loaded additional plunger (62) which delimits the working chamber (61) and by means of which the working chamber (61) of the additional plunger arrangement (6) can be set to a predefined volume.

Description

[0001] HIGH-PRESSURE PLUNGER PUMP

[0002] The present invention relates to a high-pressure plunger pump according to the preamble of claim 1.

[0003] High-pressure plunger pumps of this type are used in a wide variety of applications. They are characterized by their robustness and their design-related capabilities, particularly for generating working pressures above 2000 bar, especially for fluids. For this purpose, plungers are arranged side by side in series and driven by a motor via a connected crankshaft.

[0004] To promote a uniform flow rate and achieve "harmonious" operation, the crankshaft's crankpins are arranged offset over 360° according to their number, allowing the associated plungers to perform an oscillating movement within a working chamber (crank drive). The fluid is drawn in via a corresponding valve arrangement, compressed, and fed into a collecting channel. The displaced volume of the aligned plungers of a high-pressure pump determines the total flow rate over a unit of time.

[0005] However, the usability of high-pressure plunger pumps of this type is limited with regard to volume flow control at constant speed.

[0006] Control is only possible via the motor speed, often with a frequency converter-driven motor. However, if very fast control is required, the system's inertia determines the response time.

[0007] In addition, a lower speed of the high-pressure pump causes a structurally increased pulsation, which has a detrimental or even harmful effect on the area of ​​application or on the durability of the components.

[0008] Particularly in the field of component testing, predefined pressure build-up and pressure reduction times with rapid control are required, which must be implemented within a narrow pressure-related tolerance range. This rapid pressure control is very complex and costly to achieve with selected electric drive elements; sometimes, depending on the requirements, it is even impossible to implement. For several years now, the high-pressure plunger pumps functionally described above have also been used with stroke adjustment, for example, known from DE 20 2011 109 897 U1, to compensate for the disadvantages mentioned.

[0009] Here, the high-pressure pump is driven by a main motor with a constant speed, and the stroke adjustment within the pump is achieved by two eccentrics driven by an additional motor and pivoting relative to each other. This design is relatively expensive and complicated.

[0010] The invention is based on the object of further developing a high-pressure plunger pump of the generic type in such a way that the flow rate and / or the pressure of the high-pressure plunger pump can be adjusted in a simpler manner.

[0011] This object is achieved by a high-pressure plunger pump having the features of claim 1.

[0012] The high-pressure plunger pump according to the invention has a pump head, a housing fastened to the pump head and at least one plunger arrangement arranged in the housing with a working chamber and an axially movable working plunger delimiting the working chamber.

[0013] The high-pressure plunger pump further comprises at least one inlet valve attached to or in the pump head with an inlet that can be blocked by a closing body.

[0014] Furthermore, at least one outlet valve with an outlet that can be blocked by a closing body is attached to or in the pump head.

[0015] At least one additional plunger assembly is attached to the pump head.

[0016] This at least one additional plunger arrangement has a working chamber fluidically connected to the working chamber of the pump head and an axially movable additional plunger that delimits the working chamber and with which the working chamber of the additional plunger arrangement can be adjusted to a predetermined volume. Such a high-pressure plunger pump according to the invention enables a significantly more cost-effective design of such a high-pressure plunger pump with improved performance, in particular by enabling faster control of the volume flow and rapid pressure adjustment in the event of a sudden change in volume reduction, since many of the previously required additional components, such as the frequency converter-driven motor, are no longer necessary.

[0017] The high-pressure plunger pump according to the invention is particularly suitable for use on laboratory machines, as a test pump with special characteristics or as a sensor and injector test pump.

[0018] Advantageous embodiments of the invention are the subject of the subclaims.

[0019] According to an advantageous embodiment, the additional plunger arrangement has an actuating unit with an actuating element with which the required volume of the working space of the additional plunger arrangement for pressure generation can be adjusted by limiting a deflection of the additional plunger to a predetermined amount.

[0020] This makes it easy to set different operating pressures and flow rates.

[0021] According to an advantageous development, the actuating element is designed as a travel adjustment unit. Pneumatic, electrical, or hydraulic adjustment of the actuating element is conceivable.

[0022] In a preferred embodiment, the travel adjustment unit is designed as an adjusting screw.

[0023] The additional plunger is preferably spring-loaded by an energy accumulator accommodated in a housing of the actuating unit, preferably in the form of a compression spring.

[0024] According to an alternative design, the travel adjustment unit is designed as a linear actuator directly coupled to the additional plunger. According to another alternative design, the additional plunger can be controlled by a control unit housed in a housing of the adjustment unit.

[0025] According to a preferred development of the invention, the additional plunger is coupled to the compression spring via a pressure piston.

[0026] According to an advantageous design variant, the outlet valve can be controlled pneumatically, electrically or hydraulically.

[0027] According to one embodiment, the at least one inlet valve is integrated into a valve body arranged between the pump head and the housing. The valve body has a through-channel adjoining the working chamber and opening into the compression chamber of the pump head, as well as a suction channel that can be closed with a closing body. The suction channel, together with the closing body, forms the inlet valve.

[0028] According to a preferred alternative embodiment, the at least one inlet valve is attached to the pump head as a separate component.

[0029] The design of the inlet valve as a separate component on the pump head makes maintenance of this component of the high-pressure plunger pump particularly easy.

[0030] According to a preferred embodiment, the working plunger, the additional plunger and a respective sealing bushing receiving the latter are made of hard metal or ceramic.

[0031] According to one embodiment, the at least one inlet valve is integrated into a valve body arranged between the pump head and the housing. The valve body has a through-channel adjoining the working chamber and opening into the compression chamber of the pump head, as well as a suction channel that can be closed with a closing body. The suction channel, together with the closing body, forms the inlet valve.

[0032] According to a preferred embodiment, several working plunger assemblies are arranged on the pump head, and a number of additional plunger assemblies corresponding to the number of working plunger assemblies are attached. This enables particularly good realization of test curves without pressure deviation, especially when the high-pressure plunger pump is used as a test pump.

[0033] In addition, such a high-pressure plunger pump enables low pulsations at reduced volume flows in relation to the maximum flow rate of the high-pressure plunger pump.

[0034] Preferred embodiments are explained in more detail below with reference to the accompanying drawings. They show:

[0035] Fig. 1 and 2 are schematic isometric views of a first embodiment of a high-pressure plunger pump according to the invention,

[0036] Figure 3 is a sectional view through the high-pressure plunger pump according to Figure 1 showing a working plunger arrangement, a pump head mounted thereon with an integrated inlet valve and an outlet valve and additional plunger arrangement attached thereto,

[0037] Figure 4 is an enlarged detail of the pump head area shown in Figure 2,

[0038] Figure 5 is a representation corresponding to Figure 4 of the area of ​​the pump head with a non-controllable spring-loaded outlet valve,

[0039] Fig. 6 to 8 schematic sectional views of various embodiments of the additional plunger arrangement,

[0040] Figure 9 is a schematic isometric view of an alternative embodiment of a high-pressure plunger pump according to the invention,

[0041] Figure 10 shows an enlarged detail of the area of ​​the alternative pump head corresponding to Figure 4 in a sectional view through the high-pressure plunger pump according to Figure 9, Figure 11 shows an enlarged detail of the area of ​​a further alternative embodiment of the high-pressure plunger pump with controlled inlet and outlet valves in a sectional view through the high-pressure plunger pump according to Figure 9, and

[0042] Figure 12 is an enlarged detail corresponding to Figure 4 of the area of ​​another alternative embodiment of the high-pressure plunger pump with externally mounted spring-loaded outlet and inlet valves.

[0043] In the following description of the figures, terms such as top, bottom, left, right, front, rear, etc., refer exclusively to the exemplary representation and position of the high-pressure plunger pump, working plunger, auxiliary plunger, working chamber, valve body, outlet valve, actuating unit, and the like chosen in the respective figures. These terms are not to be understood as limiting; i.e., these references may change due to different working positions or the mirror-symmetrical design, etc.

[0044] In Figures 1 to 3 and in Figure 9, the reference numeral 1 denotes embodiments of a high-pressure plunger pump according to the invention.

[0045] In both variants, the high-pressure plunger pump 1 has a pump head 2 with a compression chamber 22 and a housing 11 fastened to the pump head 2, in which at least one working plunger arrangement 3 is arranged.

[0046] In all variants, the working plunger arrangement 3 has a pump head 2 with a compression chamber 22 and a housing 11 fastened to the pump head 2, in which at least one working plunger arrangement 3 is arranged.

[0047] In all variants, as shown in Figures 3, 4, 9, and 10, the working plunger arrangement 3 has a working chamber 31 and a working plunger 32 which delimits the working chamber 31 and is arranged to be axially movable in a plunger housing 33. The working plunger 32 is coupled to a drive shaft 13 driven by a motor, for example an electric motor, as shown in Figure 3. The drive shaft 13 is surrounded by a housing 12 of the high-pressure plunger pump 1. The axial movement of the working plunger 32 occurs axially to the longitudinal axis AAP of the working plunger 32, in Figures 1 to 3, 8, and 9 in the z-direction.

[0048] As further shown in Figures 3 and 4, between the pump head 2 and the housing 11 there is at least one valve body 4 adjoining the working chamber 31 with a through-channel designed here as a pressure channel

[0049] 41 and a suction channel 42 that can be closed by a closing body 43. The medium to be compressed is introduced into the working chamber 31 through the suction channel 42. In this first embodiment, the suction channel 42 and the closing body 43 form an inlet valve 9' for introducing the medium to be compressed into the working chamber 31.

[0050] In the embodiment shown, the closing body 43 is designed as the suction channel

[0051] 42 is designed with a conical seal at its opening into the working chamber 31 of the working plunger assembly 3. Other sealing types (plate, ball, etc.) are also conceivable. During the suction stroke of the working plunger 32, the closing body is pushed away from the opening of the suction channel by the differential pressure between the supply pressure and the suction pressure.

[0052] If the released working chamber 31 of the working plunger arrangement 3 is filled with the medium during the suction stroke and the pressure stroke is initiated, the closing body 43 is pressed against the mouth of the suction channel 42 and thus closes the suction channel 42.

[0053] The valve body 4 can be provided with one suction channel 42 or with several suction channels 42, each of which is assigned a closing body 43 together or individually. The suction channel 42, together with the closing body 43, forms the inlet valve 9', which is designed here as a suction valve.

[0054] In the embodiments of the high-pressure plunger pump 1 shown in Figures 9 to 12, the at least one inlet valve 9 is mounted as a separate component on the pump head 2, in the embodiment shown opposite the working chamber 31 of the working plunger arrangement 3.

[0055] The coupling of the working plunger arrangement 3 to the pump head 2 is effected here via a simple valve body 4 with a through-channel 41 for connecting the working chamber 31 with the compression chamber 22 of the pump head 2, but without a suction channel 42 and closing body 43.

[0056] In the embodiments shown in Figures 10 and 12, the inlet valve 9 has a closing body 91, which serves to close an inlet 93. The closing body 91 is accommodated in a housing 94 and is loaded by a compression spring on its side facing away from the inlet 93 to allow inflow during the suction stroke of the working plunger 32, but to close the inlet 93 during the pressure stroke. The housing 94 further has a passage 92 for connection to the compression chamber 22 of the pump head 2.

[0057] In the alternative embodiment according to Figure 11, the inlet valve 9 is designed as a controllable inlet valve, analogous to the outlet valve 5 described in more detail below according to Figures 3 and 4.

[0058] Furthermore, in both embodiments of the high-pressure plunger pump 1, at least one outlet valve 5 is attached to the pump head 2.

[0059] The outlet valve 5 has an outlet 53 which can be blocked by a closing body 51 and through which the high-pressure medium is discharged from the high-pressure plunger pump 1.

[0060] If several working plungers 32 are connected in series for the common fluid conveyance and the associated outlets 53 are connected to one another, the backflow of the compressed and discharged medium located in a collecting channel into the working chamber 31 is prevented by the closing bodies 43 during the suction stroke.

[0061] The outlet valve 5 can preferably be controlled pneumatically, electrically or hydraulically, as shown in Figures 3, 4 and 11.

[0062] In the embodiments according to Figures 5 and 12, the outlet valve 5 is almost identical in construction to the inlet valve 9 shown in Figures 10 and 12, with a compression spring 55' acting on the closing body 51 and a passage 52' which can be closed by the closing body 51, which is designed here as a ball, wherein the closing body 51 in the pressure stroke when the maximum pressure p ma x of the medium releases the outlet 53. Only the force of the compression spring 55' is opposite to the force of the compression spring of the inlet valve 9. The through-channel 41 of the valve body 4 opens into a compression chamber 22 of the pump head 2, which leads firstly to the outlet valve 5 and secondly to an additional plunger arrangement 6 attached to the pump head 2.

[0063] In the embodiment shown in Figure 1, a total of three outlet valves 5 and correspondingly three additional plunger arrangements 6 are fixed to the pump head 2. Depending on the capacity requirement, more or fewer outlet valves 5 and additional plunger arrangements 6 are also conceivable, which are fixed to a correspondingly designed pump head 2.

[0064] Figures 6 to 8 show different embodiments of the additional plunger arrangements 6.

[0065] Common to all variants of the additional plunger arrangements 6 is a working chamber 61 fluidically connected to the working chamber 22 of the pump head 2 and an additional plunger 62 which delimits the working chamber 61 and is arranged to be axially movable.

[0066] The variable working chamber 61 of the additional plunger 62 forms, together with the compression chamber 22 of the pump head 2, a total compression chamber to which the medium can be compressed in a pressure stroke of the working plunger 32 of the working plunger arrangement 3 and which has a maximum pressure p ma x of the medium.

[0067] While in the embodiments of the additional plunger arrangement 6 shown in Figures 6 and 8, the working chamber 61 of the additional plunger arrangement 6 can be adjusted to a predetermined maximum volume defining the maximum pressure pmax of the medium by means of a variable stop, in the embodiment of the additional plunger arrangement 6 shown in Figure 7, the maximum pressure pmax of the medium is defined exclusively by means of the spring pressure force resulting from the spring constant in conjunction with a variable, adjustable spring preload force of a force accumulator 66.

[0068] In the embodiments shown in Figures 6 and 8, the additional plunger assembly 6 has an actuating unit 63 with an actuating element 64 for setting a predetermined volume of the working chamber 61 required for pressure generation. The actuating element limits the deflection of the additional plunger 62 in the axial direction AZP to a predetermined amount. The actuating element is preferably designed as a travel actuating unit.

[0069] In the embodiment shown in Figure 7, an adjusting unit 63 with an adjusting element 64 is also present, which here serves to adjust the spring preload force of the energy accumulator 66.

[0070] In the preferred embodiment of the additional plunger assembly 6 shown in Figures 5 and 6, the adjusting element 64 is designed as an adjusting screw. Here, the adjusting screw is screwed into an internal thread of a housing 69 of the adjusting unit 63.

[0071] It is also conceivable, as shown in Figure 8, to design the travel adjustment unit, here the actuating element 64, as a linear actuator directly coupled to the additional plunger 62.

[0072] The additional plunger 62 can preferably be controlled by a control unit accommodated in a housing of the actuating unit 63.

[0073] As further shown in Figure 6, an end 642 remote from a screw head of the adjusting screw projects into a cavity 691 of the housing 69 of the adjusting unit 63. This end 642 serves as a stop for the additional plunger 62.

[0074] In the embodiment shown in Figure 6, a piston 65 movable in the axial direction AZP and a force accumulator 66 loading the piston 65 are mounted in the cavity 691 of the housing 69. The force accumulator 66 pushes the piston away from the end 642 of the adjusting screw. A first end of the additional plunger 62 is fixed to the end of the piston 65 facing away from the force accumulator 66. The force accumulator 66 is preferably designed as a compression spring, as shown in Figures 3 to 7 and 10 to 12.

[0075] The penetration depth of the adjusting screw into the cavity 691 of the housing 69, ie the position of the end 642 of the adjusting element 64 designed as an adjusting screw, viewed in the axial direction AZP, is easily adjustable by the screw head.

[0076] In the embodiment shown in Figure 6, the path-dependent spring force of the energy accumulator 66 resulting from the spring constant also causes a compression of the medium volume, increasing the pressure of the medium. The spring constant of the energy accumulator 66 is dimensioned in this embodiment such that the maximum pressure p ma x of the medium is only reached after the additional piston 62 has stopped at the end 642 of the actuating element 64.

[0077] As further shown in Figures 4 to 8 and 10 to 12, the additional plunger 62 is guided in a plunger guide 68 adjoining the actuating unit 63. The plunger guide 68 is fastened, in particular screwed, to the pump head 2 together with a guide housing 67.

[0078] Preferably, a coupling piece 8 with a passage 81 for the medium between the compression chamber 22 of the pump head 2 and the outlet 53 of the outlet valve 5 is provided between the pump head 2 and a housing 54 of the outlet valve 5.

[0079] The working plunger 32, the additional plunger 62 and a respective sealing bushing 14 receiving the latter, for example shown in Figures 3 to 5 and 10 to 12, are preferably made of hard metal or ceramic.

[0080] List of reference symbols

[0081] 1 high-pressure plunger pump

[0082] 2 pump head

[0083] 21 Valve accommodation space

[0084] 22 Compression chamber

[0085] 3 Working plunger arrangement

[0086] 31 work space

[0087] 32 working plungers

[0088] 33 Guide housing

[0089] 4 valve bodies

[0090] 41 Through channel

[0091] 42 suction channel

[0092] 43 locking bodies

[0093] 5 exhaust valve

[0094] 51 locking body

[0095] 52 pistons

[0096] 52' passage

[0097] 53 Outlet

[0098] 54 housings

[0099] 55' compression spring

[0100] 6 Additional plunger arrangement

[0101] 61 workspace

[0102] 62 additional plungers

[0103] 63 Actuator

[0104] 64 Control element

[0105] 642 End

[0106] 65 pressure pistons

[0107] 66 compression spring

[0108] 67 Guide housing

[0109] 68 Plunger guide

[0110] 69 housings

[0111] 691 Cavity 8 Coupling piece

[0112] 81 Passage

[0113] 9, 9' intake valve

[0114] 91 locking body

[0115] 92 passage

[0116] 93 Entrance

[0117] 94 housings

[0118] 11 housings

[0119] 12 housings

[0120] 13 Drive shaft

[0121] 14 socket

[0122] X direction

[0123] Y direction

[0124] Z direction

[0125] AAP movement axis working plunger

[0126] AZP movement axis additional plunger

Claims

Claims 1. High-pressure plunger pump (1 ), comprising - a pump head (2) with a compression chamber (22), - a housing (11) attached to the pump head (2), - at least one working plunger arrangement (3) arranged in the housing (11) with a working chamber (31) and an axially movable working plunger (32) delimiting the working chamber (31), - at least one inlet valve (9, 9') attached to or in the pump head (2) with an inlet (93, 42) which can be blocked by a closing body (91, 43), - at least one outlet valve (5) attached to or in the pump head (2) with an outlet (53) which can be blocked by a closing body (51), characterized in that - at least one additional plunger arrangement (6) is attached to the pump head (2), - wherein the at least one additional plunger arrangement (6) has a working chamber (61) fluidically connected to the compression chamber (22) of the pump head (2) and an additional plunger (62) which delimits the working chamber (61) and is arranged to be axially movable, with which the working chamber (61) of the additional plunger arrangement (6) can be adjusted to a predetermined volume.

2. High-pressure plunger pump (2) according to claim 1, characterized in that the additional plunger arrangement (6) has an actuating unit (63) with an actuating element (64) with which a volume of the working space (61) of the additional plunger arrangement (6) required for pressure generation can be adjusted to a predetermined amount by limiting a deflection of the additional plunger (62).

3. High-pressure plunger pump according to claim 2, characterized in that the adjusting element (64) is designed as a travel adjusting unit.

4. High-pressure plunger pump according to claim 3, characterized in that the travel adjustment unit is designed as an adjusting screw.

5. High-pressure plunger pump according to claim 2 to 4, characterized in that the additional plunger (62) is spring-loaded by a force accumulator (66) accommodated in a housing of the actuating unit (63).

6. High-pressure plunger pump according to claim 5, characterized in that the energy accumulator (66) is designed as a compression spring (66).

7. High-pressure plunger pump according to claim 3, characterized in that the travel adjustment unit is designed as a linear actuator directly coupled to the additional plunger (62).

8. High-pressure plunger pump according to claim 3, characterized in that the additional plunger (62) can be controlled by a control unit accommodated in a housing of the actuating unit (63).

9. High-pressure plunger pump according to claim 8, characterized in that the additional plunger (62) is coupled to the compression spring (66) via a pressure piston (65).

10. High-pressure plunger pump according to one of the preceding claims, characterized in that the outlet valve (5) can be controlled pneumatically, electrically or hydraulically.

11. High-pressure plunger pump according to one of the preceding claims, characterized in that a control of the outlet valve (5) is designed such that an opening of the outlet valve (5) can be controlled after one working cycle of the working plunger (32) or a plurality of working cycles of the working plunger (32).

12. High-pressure plunger pump according to one of the preceding claims, characterized in that the at least one inlet valve (9) is attached to the pump head (2) as a separate component.

13. High-pressure plunger pump according to one of the preceding claims, characterized in that the working plunger (32), the additional plunger (62) and a respective sealing bushing (14) receiving the latter are made of hard metal or ceramic.

14. High-pressure plunger pump according to one of the preceding claims, characterized in that the at least one inlet valve (9') in a valve body (4) is integrated, which is arranged between the pump head (2) and the housing (11) and has a through-channel (41) adjoining the working chamber (31) and opening into the compression chamber (22) of the pump head (2), as well as a suction channel (42) which can be closed by a closing body (43), wherein the suction channel (42) together with the closing body (43) forms the inlet valve (9').

15. High-pressure plunger pump according to one of the preceding claims, characterized in that a plurality of working plunger arrangements (3) are arranged on the pump head (2) and a number of additional plunger arrangements (6) corresponding to the number of working plunger arrangements (3) are fastened.

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