Combination pump and excavator

Abstract

The utility model provides a combination pump and an excavator. The combination pump comprises a pump shell. The utility model relates to a hydraulic pump, which comprises a pump shell, a front pump output shaft, a rear pump output shaft, a front pump cylinder body, a rear pump cylinder body, a front pump plunger, a rear pump plunger, a front pump oil distribution disc and a rear pump oil distribution disc, the front pump output shaft and the rear pump output shaft are respectively in transmission connection with the front pump cylinder body and the rear pump cylinder body, and the front pump oil distribution disc and the rear pump oil distribution disc are both fixed on the pump shell. The front pump oil distribution disc and the rear pump oil distribution disc are positioned between the front pump cylinder body and the rear pump cylinder body; the front pump cylinder body and the rear pump cylinder body are provided with a front pump plunger hole and a rear pump plunger hole respectively, the front pump plunger and the rear pump plunger are connected to the front pump plunger hole and the rear pump plunger hole respectively in a telescopic mode, and the front pump oil distribution disc and the rear pump oil distribution disc are provided with a front pump oil hole and a rear pump oil hole respectively. The orthographic projection coincidence area of the front pump plunger hole and the front pump oil hole is different from the orthographic projection coincidence area of the rear pump plunger hole and the rear pump oil hole, so that synchronous flow output of the two pumps is avoided, and the pressure fluctuation amplitude of the combination pump is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic systems, in particular to a composite pump and excavator. BACKGROUND

[0002] In the hydraulic system of a large excavator, a composite pump group usually adopts double axial piston pumps to meet the flow demand of the actuator.

[0003] In the related art, when the double pumps are combined through a rubber pipe, the cylinder body and the distribution disc of the two pumps are in synchronous phase, resulting in the superposition of the flow fluctuations of the two pumps. When the double pumps are in the maximum or minimum flow state at the same time, the change in the superimposed flow will cause a high pressure peak or a low pressure valley, significantly increasing the amplitude of the system pressure fluctuation. This problem not only affects the stability of the hydraulic system, but also exacerbates the fatigue loss of the components, affecting the service life of the equipment. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a composite pump and excavator, which.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0006] The first aspect of the present application provides a composite pump, which comprises:

[0007] a pump housing;

[0008] a front pump assembly comprising a front pump output shaft, a front pump cylinder body, a front pump plunger and a front pump oil distribution disc, the front pump output shaft being in transmission connection with the front pump cylinder body, and the front pump oil distribution disc being fixed to the inner wall of the pump housing;

[0009] a rear pump assembly comprising a rear pump output shaft, a rear pump cylinder body, a rear pump plunger and a rear pump oil distribution disc, the rear pump output shaft being in transmission connection with the rear pump cylinder body, the rear pump oil distribution disc being fixed to the inner wall of the pump housing, the rear pump output shaft being in transmission connection with the front pump output shaft, the front pump oil distribution disc and the rear pump oil distribution disc being located between the front pump cylinder body and the rear pump cylinder body, and the front pump oil distribution disc being arranged close to the front pump cylinder body and the rear pump oil distribution disc being arranged close to the rear pump cylinder body;

[0010] The front pump cylinder body is provided with a front pump plunger hole, the front pump plunger is telescopically connected to the front pump plunger hole, the rear pump cylinder body is provided with a rear pump plunger hole, the rear pump plunger is telescopically connected to the rear pump plunger hole, the front pump oil distribution disc and the rear pump oil distribution disc are respectively provided with a front pump oil hole and a rear pump oil hole, and along the axial direction of the front pump output shaft, the overlapping area of the front pump plunger hole and the front pump oil hole is different from the overlapping area of the rear pump plunger hole and the rear pump oil hole.

[0011] In a possible implementation, the front pump plunger hole and the front pump oil hole have a larger overlapping area of the projection than the rear pump plunger hole and the rear pump oil hole.

[0012] Alternatively, the front pump plunger hole and the front pump oil hole have a smaller overlapping area of the projection than the rear pump plunger hole and the rear pump oil hole.

[0013] In a possible implementation, the front pump distribution plate and the front pump cylinder body are provided with a first identification group, the rear pump distribution plate and the rear pump cylinder body are provided with a second identification group, the first identification group includes two first sub-identifications, and the two first sub-identifications are arranged on the front pump distribution plate and the front pump cylinder body respectively; the second identification group includes two second sub-identifications, and the two second sub-identifications are arranged on the rear pump distribution plate and the rear pump cylinder body respectively; along the axial direction of the front pump output shaft, the two first sub-identifications are aligned, and the two second sub-identifications are aligned.

[0014] In a possible implementation, the first sub-identification and / or the second sub-identification is a recess or a protrusion.

[0015] In a possible implementation, the front pump output shaft and the rear pump output shaft are drivingly connected through a coupling.

[0016] In a possible implementation, the front pump cylinder body is drivingly connected to the front pump output shaft through a spline, and / or the rear pump cylinder body is drivingly connected to the rear pump output shaft through a spline.

[0017] In a possible implementation, the front pump plunger hole and the rear pump plunger hole are both multiple, the multiple front pump plunger holes are circumferentially arranged on the front pump cylinder body along the axial direction of the front pump output shaft, the multiple rear pump plunger holes are circumferentially arranged on the rear pump cylinder body along the axial direction of the rear pump output shaft, and the front pump plunger hole and the rear pump plunger hole are through holes.

[0018] In a possible implementation, the front pump plunger hole and the rear pump plunger hole are both odd in number.

[0019] In a possible implementation, the front pump output shaft or the rear pump output shaft is driven by the motor to rotate the front pump output shaft, the front pump cylinder body, the rear pump output shaft, and the rear pump cylinder body coaxially.

[0020] The composite pump provided in the first aspect of the present application adjusts the relative positions of the cylinder bodies of the front pump and the rear pump to make the overlapping areas of the front pump and the rear pump different, so as to realize staggered peak output. For example, when the front pump is in the maximum flow state, the rear pump is in the minimum flow state, or when the front pump is in the minimum flow state, the rear pump is in the maximum flow state, at this time, the output flow difference of the double pump is about 70%, or the output flow difference of the front and rear pumps is 25% or 50%, which can avoid the peak superposition when the flow of the double pump is the same, and significantly reduce the pressure fluctuation amplitude of the composite pump.

[0021] The second aspect of the present application provides an excavator comprising the composite pump provided in any one of the technical solutions.

[0022] The excavator provided in the second aspect of the present application has all the beneficial effects of the composite pump provided in the first aspect of the present application, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0024] Figure 1 The structure schematic diagram of the composite pump provided in the embodiment of the present application in the plunger extension state;

[0025] Figure 2 The structure schematic diagram of the composite pump provided in the embodiment of the present application in the plunger retraction state;

[0026] Figure 3 For Figure 2 The structure diagram along the I direction;

[0027] Figure 4 For Figure 2 The structure diagram along the II direction;

[0028] Figure 5 The pressure curve when the oil passing areas of the front pump assembly and the rear pump assembly of the composite pump provided in the embodiment of the present application are the same;

[0029] Figure 6 The pressure curve when the oil passing areas of the front pump assembly and the rear pump assembly of the composite pump provided in the embodiment of the present application are different.

[0030] Explanation of reference signs:

[0031] 100, front pump assembly;

[0032] 110, front pump output shaft; 120, front pump cylinder block; 121, front pump plunger hole;

[0033] 130, front pump plunger; 140, front pump oil distribution plate; 141, front pump oil hole; 150, first identification group;

[0034] 200, rear pump assembly;

[0035] 210, rear pump output shaft; 220, rear pump cylinder block; 221, rear pump plunger hole;

[0036] 230, rear pump plunger; 240, rear pump oil distribution plate; 241, rear pump oil hole; 250, second identification group;

[0037] 300, coupling;

[0038] 400, first communication area;

[0039] 500, second communication area.

[0040] The specific embodiments of the present application have been shown in the above drawings, and will be described in more detail hereinafter. These drawings and the written description are not intended to restrict the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0041] As described in the background, in the hydraulic system of a large excavator, a composite pump group usually adopts two axial piston pumps to meet the flow demand of the actuator. In the related art, when the two pumps are combined through a rubber pipe, the cylinder blocks and the oil distribution plates of the two pumps are in a synchronous phase, resulting in the superposition of the flow fluctuations of the two pumps. When the two pumps are in the maximum or minimum flow state at the same time, the superimposed flow change will cause a high pressure peak or a low pressure valley, resulting in a significant increase in the amplitude of the system pressure fluctuation. This problem not only affects the stability of the hydraulic system, but also aggravates the fatigue loss of the actuator, affecting the service life of the equipment.

[0042] To solve the above technical problems, the embodiments of the present application provide a composite pump and an excavator. By adjusting the relative position of the cylinder blocks of the front pump and the rear pump, the overlapping areas of the projections of the plunger holes and the oil holes of the two pumps are different, the peak output is staggered, for example, when the front pump is in the maximum flow state, the rear pump is in the minimum flow state, and vice versa, so as to avoid the superposition of the flow peaks of the two pumps, and the amplitude of the pressure fluctuation is significantly reduced.

[0043] In order to make the above objectives, characteristics and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0044] Reference Figures 1 to 6 In a first aspect, the composite pump provided by the embodiments of the present application comprises: a pump shell (not shown in the figure); a front pump assembly 100 comprising a front pump output shaft 110, a front pump cylinder body 120, a front pump plunger 130 and a front pump oil distribution disc 140, the front pump output shaft 110 being in transmission connection with the front pump cylinder body 120, and the front pump oil distribution disc 140 being fixed to the inner wall of the pump shell; a rear pump assembly 200 comprising a rear pump output shaft 210, a rear pump cylinder body 220, a rear pump plunger 230 and a rear pump oil distribution disc 240, the rear pump output shaft 210 being in transmission connection with the rear pump cylinder body 220, the rear pump oil distribution disc 240 being fixed to the inner wall of the pump shell, the rear pump output shaft 210 being in transmission connection with the front pump output shaft 110, for example, the two can transmit power through mechanical structures such as splines and shaft couplings 300, the front pump oil distribution disc 140 and the rear pump oil distribution disc 240 being located between the front pump cylinder body 120 and the rear pump cylinder body 220, and the front pump oil distribution disc 140 being arranged close to the front pump cylinder body 120, and the rear pump oil distribution disc 240 being arranged close to the rear pump cylinder body 220.

[0045] The front pump cylinder body 120 is provided with a front pump plunger hole 121, the front pump plunger 130 is telescopically connected to the front pump plunger hole 121, the rear pump cylinder body 220 is provided with a rear pump plunger hole 221, the rear pump plunger 230 is telescopically connected to the rear pump plunger hole 221, the front pump oil distribution disc 140 and the rear pump oil distribution disc 240 are respectively provided with a front pump oil hole 141 and a rear pump oil hole 241, and along the axial direction of the front pump output shaft 110, the overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 is different from the overlapping area of the rear pump plunger hole 221 and the rear pump oil hole 241.

[0046] The overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 can be understood as the area of the overlapping region of the plunger hole and the oil hole when projected along the axial direction of the front pump output shaft 110, which determines the instantaneous flow rate.

[0047] In this way, by adjusting the relative position of the cylinder installation of the front pump and the rear pump, the overlapping area of the front pump plunger hole and the oil hole is different, and the peak output is realized. For example, when the front pump is in the maximum flow state, the rear pump is in the minimum flow state, or when the front pump is in the minimum flow state, the rear pump is in the maximum flow state, at this time, the output flow difference of the double pump is about 70%, or the output flow difference of the front and rear pumps is 25% or 50%, which can avoid the peak superposition of the same flow of the double pump, and significantly reduce the pressure fluctuation amplitude of the composite pump.

[0048] In some embodiments, along the axial direction of the front pump output shaft 110, the overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 is greater than the overlapping area of the rear pump plunger hole 221 and the rear pump oil hole 241; or, the overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 is less than the overlapping area of the rear pump plunger hole 221 and the rear pump oil hole 241.

[0049] As shown in Figure 3 , the overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 is the largest, and the overlapping area of the rear pump plunger hole 221 and the rear pump oil hole 241 is the smallest, and the angle of the cylinder is adjusted during assembly.

[0050] In this way, by controlling the flow area difference between the front and rear pumps, the fluid output of the double pump is accurately adjusted, and the pressure fluctuation suppression effect is optimized.

[0051] In some embodiments, the front pump oil distribution plate 140 and the front pump cylinder 120 are provided with a first identification group 150, and the rear pump oil distribution plate 240 and the rear pump cylinder 220 are provided with a second identification group 250. The first identification group 150 includes two first sub-identifications, which are respectively arranged on the front pump oil distribution plate 140 and the front pump cylinder 120. The second identification group 250 includes two second sub-identifications, which are respectively arranged on the rear pump oil distribution plate 240 and the rear pump cylinder 220. Along the axial direction of the front pump output shaft 110, the two first sub-identifications are aligned, and the two second sub-identifications are aligned.

[0052] In some embodiments, the first sub-identification and / or the second sub-identification is a recess or a protrusion.

[0053] For example, the two first sub-identifications of the first identification group 150 are respectively arrow marks engraved on the edges of the front pump oil distribution plate 140 and the front pump cylinder 120. When the two first sub-identifications are aligned, the overlapping area of the front pump plunger hole 121 and the front pump oil hole 141 is the largest.

[0054] The two second sub-identifications of the second identification group 250 are respectively protrusions provided on the edges of the rear pump oil distribution plate 240 and the rear pump cylinder 220. When the two second sub-identifications are aligned, the overlapping area of the rear pump plunger hole 221 and the rear pump oil hole 241 is the smallest.

[0055] In this way, the assembly precision is ensured by identifying the group, the manual adjustment error is avoided, and the reliability of the phase difference control is improved.

[0056] In some embodiments, the front pump output shaft 110 and the rear pump output shaft 210 are drivingly connected through the shaft coupling 300. This arrangement ensures the rotational synchronism of the front and rear pump output shafts 210, reduces power loss, and improves the operation stability of the composite pump set.

[0057] In some embodiments, the front pump cylinder body 120 is drivingly connected with the front pump output shaft 110 through a spline, and / or the rear pump cylinder body 220 is drivingly connected with the rear pump output shaft 210 through a spline. Further, the front pump cylinder body 120 and the rear pump cylinder body 220 are each provided with an internal spline, and the front pump output shaft 110 and the rear pump output shaft 210 are each provided with an external spline. In this way, the torque is transmitted through the engagement of the internal and external splines, which has high precision and torsional resistance.

[0058] In some embodiments, the front pump plunger holes 121 and the rear pump plunger holes 221 are each a plurality of holes. Along the axial direction of the front pump output shaft 110, the plurality of front pump plunger holes 121 are circumferentially arranged on the front pump cylinder body 120, and the plurality of rear pump plunger holes 221 are circumferentially arranged on the rear pump cylinder body 220. The front pump plunger holes 121 and the rear pump plunger holes 221 are through holes.

[0059] In some embodiments, the front pump plunger holes 121 and the rear pump plunger holes 221 are each an odd number of holes. For example, the front pump cylinder body 120 and the rear pump cylinder body 220 are each provided with 11 plunger holes, which are uniformly distributed along the axial direction. The plunger holes are through holes to accommodate the reciprocating motion of the plungers. In this way, the oil distribution efficiency is relatively high.

[0060] In some embodiments, the front pump output shaft 110 or the rear pump output shaft 210 can drive the front pump output shaft 110, the front pump cylinder body 120, the rear pump output shaft 210, and the rear pump cylinder body 220 to rotate coaxially under the drive of the driving motor. In this way, single-motor driving simplifies the system structure, reduces energy consumption, and is suitable for space-limited scenarios such as excavators.

[0061] In a second aspect, the embodiments of the present application provide an excavator, which includes the composite pump provided by any one of the embodiments of the first aspect. Further, the composite pump is integrated into the hydraulic system of the excavator, and is used for double-pump combined flow control of a bucket arm excavating action.

[0062] In this way, the combined flow pressure fluctuation is significantly reduced, the hydraulic system stability is improved, and the element life is prolonged. Figure 5 、 6 The embodiments of the present application show that the fluctuation amplitude of the double-pump hydraulic staggered peak output is reduced.

[0063] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0064] In addition, the terms "first", "second", are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0065] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it can only mean that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it can only mean that the horizontal height of the first feature is less than that of the second feature.

[0067] The embodiments or implementations in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0068] It should be noted that the use of "a" or "an" or "the" or similar referents in the specification are used inclusively and in the discretion of the inventor(s) to refer to both of or one of a possible set of alternatives and / or to refer to other possibilities commonly understood by one of ordinary skill in the art, which possibilities can be covered by the application. It is also noted that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Further, the use of "primed" or "unprimed" in the specification is used to refer to the same element unless the context clearly dictates otherwise.

[0069] Finally, it should be noted that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the above-mentioned embodiments, those ordinarily skilled in the art should understand: the technical solutions recorded in the above-mentioned embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composite pump, characterized in that, include: Pump casing; The front pump assembly includes a front pump output shaft, a front pump cylinder, a front pump plunger, and a front pump distribution plate. The front pump output shaft is drivenly connected to the front pump cylinder, and the front pump distribution plate is fixed to the inner wall of the pump housing. The rear pump assembly includes a rear pump output shaft, a rear pump cylinder, a rear pump plunger, and a rear pump distributor plate. The rear pump output shaft is drivenly connected to the rear pump cylinder. The rear pump distributor plate is fixed to the inner wall of the pump housing. The rear pump output shaft is drivenly connected to the front pump output shaft. Both the front pump distributor plate and the rear pump distributor plate are located between the front pump cylinder and the rear pump cylinder, with the front pump distributor plate closer to the front pump cylinder and the rear pump distributor plate closer to the rear pump cylinder. The front pump cylinder body is provided with a front pump plunger hole, and the front pump plunger is telescopically connected to the front pump plunger hole. The rear pump cylinder body is provided with a rear pump plunger hole, and the rear pump plunger is telescopically connected to the rear pump plunger hole. The front pump distribution plate and the rear pump distribution plate are respectively provided with a front pump oil hole and a rear pump oil hole. Along the axial direction of the front pump output shaft, the overlapping area of ​​the orthographic projection of the front pump plunger hole and the front pump oil hole is different from the overlapping area of ​​the orthographic projection of the rear pump plunger hole and the rear pump oil hole.

2. The composite pump according to claim 1, characterized in that, Along the axial direction of the front pump output shaft, the overlapping area of ​​the orthographic projection of the front pump plunger hole and the front pump oil hole is greater than the overlapping area of ​​the orthographic projection of the rear pump plunger hole and the rear pump oil hole. Alternatively, the overlapping area of ​​the orthographic projection of the front pump plunger hole and the front pump oil hole is smaller than the overlapping area of ​​the orthographic projection of the rear pump plunger hole and the rear pump oil hole.

3. The composite pump according to claim 1 or 2, characterized in that, The front pump distribution plate and the front pump cylinder body are provided with a first identification group, and the rear pump distribution plate and the rear pump cylinder body are provided with a second identification group. The first identification group includes two first sub-identifiers, which are respectively disposed on the front pump distribution plate and the front pump cylinder body. The second identification group includes two second sub-identifiers, which are respectively disposed on the rear pump distribution plate and the rear pump cylinder body. Along the axial direction of the front pump output shaft, the two first sub-identifiers are aligned with each other, and the two second sub-identifiers are aligned with each other.

4. The composite pump according to claim 3, characterized in that, The first sub-identifier and / or the second sub-identifier are recessed or raised portions.

5. The composite pump according to claim 1 or 2, characterized in that, The front pump output shaft and the rear pump output shaft are connected by a coupling.

6. The composite pump according to claim 1 or 2, characterized in that, The front pump cylinder body is connected to the front pump output shaft via a spline, and / or the rear pump cylinder body is connected to the rear pump output shaft via a spline.

7. The composite pump according to claim 1 or 2, characterized in that, There are multiple front pump plunger holes and multiple rear pump plunger holes. The multiple front pump plunger holes are circumferentially disposed in the front pump cylinder along the output shaft of the front pump, and the multiple rear pump plunger holes are circumferentially disposed in the rear pump cylinder. The front pump plunger holes and the rear pump plunger holes are through holes.

8. The composite pump according to claim 7, characterized in that, Both the front pump plunger holes and the rear pump plunger holes have an odd number of holes.

9. The composite pump according to claim 1 or 2, characterized in that, Driven by a motor, the front pump output shaft, the front pump cylinder, the rear pump output shaft, and the rear pump cylinder can rotate coaxially.

10. An excavator, characterized in that, Including the composite pump as described in any one of claims 1-9.

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