CN209943967U - Rotor type oil pump, engine comprising same and working machine - Google Patents

Abstract

The utility model relates to a rotor type oil pump reaches engine and operation machinery including it. The oil pump comprises a shell, a shaft, a gear, an inner rotor and an outer rotor; the shaft is fixed in the housing; the gear is meshed with a driving wheel to receive power transmitted to the oil pump; the inner rotor is sleeved on the shaft and can rotate relative to the shaft; the outer rotor is arranged on the radial outer side of the inner rotor so as to form a pump oil cavity with variable volume between the inner rotor and the outer rotor; the outer rotor and the inner rotor are accommodated in a hub of the gear, a concave part is formed on the outer peripheral surface of the outer rotor, and a protruding part which is complementarily matched with the concave part is correspondingly formed on the inner peripheral surface of the hub, so that the gear drives the outer rotor to synchronously rotate.

Description

Rotor type oil pump, engine comprising same and working machine

Technical Field

The present invention relates to a rotor type oil pump used in an engine of, for example, a working machine.

Background

An oil pump is often used as a key component of an engine lubrication system in an engine of a working machine such as a loader, a bulldozer, an excavator, etc., and functions to lift oil to a certain pressure and forcibly press and feed the oil to the surface of an engine part for lubrication.

The oil pump can be divided into a gear type oil pump and a rotor type oil pump according to the structure. The rotor type oil pump comprises an inner rotor and an outer rotor, and the inner rotor and the outer rotor rotate in the same direction and asynchronously. During the rotation of the inner rotor and the outer rotor, the volume of the pump oil cavity between the inner rotor and the outer rotor is changed along with the rotation, low pressure is formed to generate suction force, and engine oil is sucked into the pump oil cavity and is sent to a lubricating oil channel of an engine through an oil return hole of the engine oil pump in a pressing mode.

A rotation mode of an inner rotor and an outer rotor is as follows: the inner rotor is arranged on the central shaft, and the central shaft rotates to drive the inner rotor and further drive the outer rotor to rotate in the same direction. With the development of the technology, a technical scheme that a drive gear on an engine camshaft drives a drive gear of an oil pump, the drive gear drives an outer rotor contained in the drive gear to synchronously rotate, and then the outer rotor drives an inner rotor to rotate so as to achieve an oil pumping effect is also provided.

For the structure that the outer rotor is driven by the gear of the oil pump to rotate synchronously with the gear, and then the outer rotor drives the inner rotor to rotate, in order to ensure the synchronous rotation of the outer rotor and the gear, the scheme that the outer rotor is fixed in the gear through the positioning pin is adopted in the prior art, and meanwhile, in order to prevent the play of the positioning pin from coming off, the annular spring is sleeved on the outer peripheral surface of the hub of the gear and the outer side of the positioning pin hole.

However, the technical scheme has the risks that the spring is easy to fall off, so that the positioning pin is easy to shift and fall off, the oil pump is damaged, and the engine cannot normally work, so that serious consequences are caused, and the structure is complex and difficult to maintain.

The present invention is directed to solving the above problems and/or other problems in the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model provides a rotor type oil pump, which comprises a shell, a shaft, a gear, an inner rotor and an outer rotor; the shaft is fixed in the housing; the gear is mounted around the housing and engaged with a drive wheel to receive power transmitted to the oil pump; the inner rotor is sleeved on the shaft and can rotate relative to the shaft; the outer rotor is arranged on the radial outer side of the inner rotor so as to form a pump oil cavity with variable volume between the inner rotor and the outer rotor; the outer rotor and the inner rotor are accommodated in a hub of the gear, a concave part is formed on the outer peripheral surface of the outer rotor, and a protruding part which is complementarily matched with the concave part is correspondingly formed on the inner peripheral surface of the hub, so that the gear drives the outer rotor to synchronously rotate.

As an example, the recessed portion in the form of a circular arc curved surface is formed on an outer peripheral surface of the outer rotor, and the protruding portion complementary in shape to the recessed portion is correspondingly formed on an inner peripheral surface of the hub of the gear.

As an example, the outer rotor includes a plurality of concave teeth formed on an inner circumferential surface thereof, wherein each concave tooth is defined by two adjacent curved profile surfaces protruding radially inward; wherein the recess in the form of a circular arc curved surface corresponds in radial direction to the curved profile surface.

As an example, the recessed portion is plural and is uniformly distributed on the outer peripheral surface of the outer rotor in the circumferential direction.

As an example, the recesses and the protrusions are configured as mating splines.

As an example, the housing is at least partially inserted into the hub, an oil inlet hole and an oil outlet hole that communicate with oil passages of an engine, respectively, are provided in a portion of the housing exposed outside the hub, and a chamber that communicates the oil inlet hole and the oil outlet hole is formed in the housing, and the housing, the outer rotor, and the inner rotor are adjacently arranged in the hub such that the chamber communicates with the pump oil chamber.

The utility model also provides an engine, it includes as above rotor formula oil pump.

The utility model also provides an operation machine, it includes as above the engine.

The utility model discloses following beneficial effect has at least: the outer peripheral surface of the outer rotor and the inner peripheral surface of the gear hub are directly provided with the matched concave part and the matched convex part to realize power (torque) transmission therebetween, so that the number of parts of the pump (such as a plurality of positioning pins and springs for fixing the positioning pins in the prior art) is reduced, the complexity of the structure (such as pin holes and grooves for the springs) and the maintenance difficulty are reduced, and a more reliable and stable joint mode is formed; furthermore, the concave part and the protruding part with the surfaces in the form of the arc curved surfaces are jointed, and the joint surface in the form of the arc curved surfaces enables the angle of force transmission to be larger during transmission, so that the power transmission between the gear and the outer rotor is more convenient; moreover, the recessed portion on the outer rotor is formed to correspond to the curved profile surface in the radial direction, so that the reduction of the strength of the outer rotor due to the formation of the recessed portion can be minimized, and more design space is left for the depth of the recessed portion, further, the problem that the design of the joint portion is limited by the size of the outer rotor is eliminated; the spline joint mode ensures stable synchronous rotation between the outer rotor and the gear. Moreover, the arrangement in which at least a portion of the housing of the oil pump is disposed within the hub also reduces the likelihood of oil leakage.

Drawings

Fig. 1 shows a perspective view of an exemplary working machine to which a rotor-type oil pump according to the present invention is applied.

Fig. 2 shows a perspective exploded schematic view of a rotor type oil pump according to a first exemplary embodiment of the present invention;

FIG. 3 is a perspective exploded view of the rotor oil pump of FIG. 2 from another angle;

FIG. 4 shows a cross-sectional schematic view of the rotor oil pump of FIG. 2 in an assembled state;

fig. 5 shows a plan view of the rotor type oil pump shown in fig. 2 showing only a gear and an outer rotor; and

fig. 6 shows a perspective exploded view of a rotor oil pump according to a second exemplary embodiment of the present invention, wherein only the gear, the outer rotor and the inner rotor are shown for simplicity.

Detailed Description

Fig. 1 illustrates an exemplary work machine 100. Work machine 100 may be any type of machine that performs operations associated with a particular industry (e.g., construction, mining, farming, transportation, etc.) and operates in a variety of work environments, such as a wheel loader, a motor grader, a hydraulic excavator, a wheel dozer, a track-type excavator, and so forth.

The work machine 100 may include a main frame 101, an operator accommodating space (e.g., a cab 102), and a work implement 103. As an example, the work implement 103 may be a bucket applied to a loader. A traveling device is disposed at a lower portion of the work machine 100 to support and move the work machine 100. As an example, the running gear comprises wheels 104.

The work machine 100 shown in fig. 1 includes an engine (not shown) to drive operation of the work machine. Lubrication of the components of the engine is performed by a rotor type oil pump (not shown in fig. 1) to be described later.

Fig. 2 and 3 show exploded perspective views of a rotor type oil pump according to a first exemplary embodiment of the present invention. The rotor type oil pump comprises a shell 5, when the assembled oil pump 10 is integrally put into an oil pump hole (not shown) in an engine body, an oil inlet of the oil pump is communicated with, for example, a vertical oil passage of the engine body, an oil outlet is communicated with, for example, a main oil passage of the engine body, and the shell 5 is in interference fit with the oil pump hole so as to be positioned in the oil pump hole. The oil pump also comprises a shaft 1 which is fixed in the housing 5, for example by means of a nut 6, i.e. the shaft 1 is fixed. The inner rotor 2 is sleeved on the shaft 1 and can rotate relative to the shaft 1. The oil pump further comprises a gear 4, which gear 4 is mounted around the housing 5 to mesh with a drive wheel in a drive gear train on the engine camshaft to receive power transmitted to the oil pump and rotate. The oil pump comprises an outer rotor 3 which is sleeved on the radial outer side of the inner rotor 2 so as to form a pump oil cavity with variable volume between the inner rotor 2 and the outer rotor 3 when the two rotate. In fig. 2 to 6, it is shown that the number of concave teeth on the inner peripheral surface of the outer rotor 3 is five and the number of convex teeth of the inner rotor 2 is 4, as an example. However, it will be appreciated by those skilled in the art that the engagement surfaces and engagement means of the inner and outer rotors may be other profiles and corresponding engagement means.

Wherein the outer rotor 3 and the inner rotor 2 are accommodated in a hub of the gear 4, and a recess 32 is formed on an outer circumferential surface of the outer rotor 3, and a protrusion 42 complementarily fitting the recess 32 is correspondingly formed on an inner circumferential surface of the hub, so that the gear 4 drives the outer rotor 3 to rotate synchronously, and the inner rotor 2 is further driven to rotate relative to the shaft 1 by the rotation of the outer rotor 3.

By adopting the mode that the concave part and the convex part which are matched with each other are directly and respectively arranged on the outer peripheral surface of the outer rotor and the inner peripheral surface of the gear hub to prevent the relative rotation between the outer rotor and the gear hub so as to realize the force transmission and the motion transmission between the outer rotor and the gear hub, compared with the prior art, the number of parts of the pump (such as a plurality of positioning pins and springs for fixing the positioning pins) is reduced, the structural complexity (such as no pin holes and grooves where the springs are arranged) and the maintenance difficulty are reduced, a more reliable and stable joint mode is formed, and the synchronous rotation between the gear and the outer rotor is ensured.

As an example, the rotor type oil pump further includes a pump cover 7, as shown in fig. 2 to 4, the pump cover 7 is mounted on the axially outer side of the outer rotor 3, and one side of the pump cover 7 is provided with an adjusting shim 8, one end of the adjusting shim 8 is provided with a spring 9, the spring 9 is disposed on a spring seat 12, and one end of the spring seat 12 is mounted with a split washer 11. One end of the shaft 1 is provided with a retainer groove into which the split retainer 11 can be pressed, and the other end is provided with a thread into which the nut 6 is screwed, thereby positioning the components of the oil pump on the shaft 1. Since the pump cover 7 is pressed on the surfaces of the inner rotor and the outer rotor by the spring 9 in the example, the pressing force of the spring is adjusted by adjusting the thickness of the gasket 8, so that the oil pump is ensured not to generate excessive heat generated by friction between the inner rotor and the outer rotor during movement due to excessive pressing force, but not to generate large oil leakage due to too small pressing force. Those skilled in the art will appreciate that the rotor type oil pump may include other components besides those described above.

As an example, a first embodiment of the engagement of the outer rotor and the gear is shown in fig. 2-5. It is shown that a plurality of said recesses 32 in the form of circular curved surfaces are formed on the outer peripheral surface of said outer rotor 3 (see in particular fig. 5), whereas a plurality of protrusions 42 complementary to the shape of said recesses 32 are correspondingly formed on the inner peripheral surface of said hub of the gear.

It will be understood by those skilled in the art that the term "arcuate surface" is used herein to mean that, as shown in particular in fig. 5, the recess 32 and the corresponding projection 42 each project as an arc of a circle in a cross-section perpendicular to the axial direction.

In the structure of adopting recess 32 that has the form of circular arc curved surface, the composition surface of circular arc curved surface form makes the angle of power transmission bigger during the transmission, and the moment of torsion of transmission is bigger, the transmission of power of being more convenient for to reach better synchronous rotation effect between gear 4 and outer rotor 3.

It should be noted that the manner of engagement of the outer rotor and the gear is not limited to the structure and manner shown in fig. 2 to 5, and for example, an exploded perspective view of a rotor type oil pump according to a second exemplary embodiment of the present invention is shown in fig. 6, in which only the gear, the outer rotor, and the inner rotor are shown for simplicity. The recessed portion 32 of the outer rotor 3 and the protruding portion 42 of the gear 4 are configured as mating splines, teeth of the splines on the inner peripheral surface of the gear 4 are used as the protruding portion 42, and tooth grooves of the splines on the outer rotor 3 are used as the recessed portion 32, which are engaged with each other to ensure that the gear 4 and the outer rotor 3 rotate synchronously. The engagement with the spline having a plurality of teeth ensures stable synchronous rotation between the gear 4 and the outer rotor 3.

As an example, as shown in fig. 5, the outer rotor 3 includes a plurality of recessed teeth 33 formed on an inner circumferential surface thereof, wherein each recessed tooth 33 is defined by two adjacent curved profile surfaces 34 protruding radially inward; wherein the recess 32 corresponds in radial direction to said curved profile surface 34. Since the material thickness of the curved profile surface 34 in the radial direction is thick due to its radially inwardly protruding shape as clearly shown in fig. 5, forming the recessed portion 32 at a position in the radial direction corresponding to the curved profile surface 34 can minimize the reduction in strength of the outer rotor 3 due to the formation of the recessed portion 32 and leave more design space for the depth of the recessed portion 32.

Further, for example, with the second exemplary embodiment shown in fig. 6, when this structure is applied to an oil pump of a smaller size, since the size of the outer rotor 3 is correspondingly smaller, the radial distance between the bottom of the concave teeth 33 of the outer rotor 3 and the outer circumferential surface of the outer rotor is smaller, if the spline is further machined on the outer surface of the outer rotor, there may be encountered a problem that the strength of the outer rotor is reduced due to the thinner wall of the outer rotor after the spline is machined on the outer surface. There may even be a case where it is difficult to machine splines on the outer surface thereof due to the small size of the outer rotor.

This drawback is avoided by the solution shown in fig. 2-5, in which the recess 32 corresponds in the radial direction to said curved profile surface 34, without the problem of the size limitation of the outer rotor.

As an example, the number of the concave portions 32 is the same as the number of the curved surface profile surfaces 34, and corresponds one-to-one with the curved surface profile surfaces 34 in the radial direction. With this structure, the number of the recessed portions 32 can be increased to the maximum while ensuring the strength of the outer rotor. As an example, a plurality of the recessed portions 32 are evenly distributed in the circumferential direction on the outer circumferential surface of the outer rotor 3. As an example, in a cross-section perpendicular to the axial direction, the arc length projected by the recess 32 is smaller than the arc length projected by the curved profile surface 34. This arrangement avoids causing an excessively close distance between the recessed portion 32 and the recessed teeth 33 and a resultant reduction in thickness and strength of the outer rotor.

However, it will be appreciated by those skilled in the art that although the above is given as a preferred solution, the recessed portion 32 may be provided at a position other than the curved profile surface, for example, at the tooth bottom of the concave tooth 33, as long as the depth of the recessed portion is set to ensure the required strength of the outer rotor 3. It is also reasonable that the arc length and/or the number of the recessed portions 32 can be set as needed while securing the strength of the outer rotor 3.

It should be noted that although in the embodiments of fig. 2 to 5, only the recessed portion 32 is formed on the outer peripheral surface of the outer rotor 3, it is understood by those skilled in the art that a protruding portion or only a protruding portion may be provided on the outer peripheral surface at the same time, and correspondingly, a recessed portion may be provided on the inner peripheral surface of the hub at the same time or only in cooperation therewith.

As shown in fig. 4, the hubs of the gear 4 of this oil pump include a first hub 43 and a second hub 44 extending in opposite directions, wherein the outer rotor 3 and the inner rotor 2 are accommodated in the first hub 43, and a part of the housing 5 is accommodated in the second hub 44. The case 5 is at least partially inserted into the hub, an oil inlet hole 52 and an oil outlet hole (not shown) that communicate with oil passages of the engine, respectively, are provided in a portion of the case 5 exposed outside the hub, and a chamber 51 that communicates the oil inlet hole and the oil outlet hole is formed in the case 5. The housing 5, the outer rotor 3 and the inner rotor 2 are arranged adjacent in the hub so that the chamber 51 communicates with the pump oil chamber. In this structure, since a part of the housing 5 is accommodated in the second hub 44 and the chamber 51 is in direct communication with the pump oil chamber formed between the inner and outer rotors, the possibility of oil leakage is reduced relative to the prior art in which a flange connection is employed between the housing and the hub.

Fig. 6 shows a perspective exploded view of a rotor oil pump according to a second exemplary embodiment of the present invention, in which only the gear 4, the outer rotor 3 and the inner rotor 2 are shown for simplicity. The difference from the first embodiment is only the engagement manner between the gear 4 and the outer rotor 3, and the operation principle and advantages of the second embodiment are described above and will not be described again.

The utility model discloses still provide an engine including the rotor formula oil pump that any one above-mentioned technical scheme described. The engine has the advantages of the rotor type oil pump, good lubricating performance and stable and reliable quality. The utility model discloses still provide an operating machine including above-mentioned engine, this operating machine has possessed the various advantages of above-mentioned rotor formula oil pump and engine from this.

Industrial applicability

The rotor type oil pump according to the present invention can be used particularly in an engine, for example, an engine of a working machine (such as a bulldozer, a loader, an excavator, etc.). But is not limited thereto and it will be apparent that it can be used in a variety of systems where a pumped liquid is required.

The working principle and the using flow of the rotor type oil pump 10 of the present invention are described below by taking the embodiments shown in fig. 2 to 5 as examples: when the oil pump is mounted in, for example, a water-cooled diesel engine, the components of the oil pump are first assembled onto the shaft 1 and then placed into an oil pump hole for the oil pump in the engine body. The position of the oil pump is placed in such a way that an oil inlet 52 of the oil pump is communicated with, for example, a vertical oil passage of an engine body, an oil outlet is communicated with, for example, a transverse oil passage of the engine body, the shell 5 and the oil pump hole are in interference fit, when the engine runs, a crankshaft gear of the engine drives an oil pump gear 4 to run, as a protruding part 42 arranged on the inner circumferential surface of a hub of the gear 4 is mutually jointed with a recessed part 32 arranged on the outer circumferential surface of an outer rotor 3, the oil pump gear 4 drives the outer rotor 3 to integrally rotate, the outer rotor 3 drives an inner rotor 2 to rotate through the joint with the outer contour of the inner rotor, and the volume of a pump oil cavity between the inner rotor 2 and the outer rotor 3.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments disclosed above without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples disclosed herein be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

Claims (8)

1. A rotor-type oil pump, characterized in that the oil pump (10) comprises:

a housing (5);

a shaft (1) fixed in the housing (5);

a gear (4) mounted around the housing, the gear (4) being configured to receive power transmitted to the oil pump for rotation;

the inner rotor (2) is sleeved on the shaft (1) and can rotate relative to the shaft (1);

an outer rotor (3) disposed radially outside the inner rotor (2) to form a pump oil chamber of varying volume between the inner rotor (2) and the outer rotor (3);

wherein the outer rotor (3) and the inner rotor (2) are accommodated in a hub of the gear (4), and a recess (32) is formed on the outer peripheral surface of the outer rotor (3), and a protrusion (42) complementarily fitting the recess (32) is correspondingly formed on the inner peripheral surface of the hub, so that the gear (4) drives the outer rotor (3) to synchronously rotate.

2. The rotor type oil pump according to claim 1,

the recessed portion (32) in the form of a circular arc curved surface is formed on the outer peripheral surface of the outer rotor (3), and

the protruding portion (42) complementary in shape to the recessed portion (32) is formed on the inner peripheral surface of the hub of the gear, respectively.

3. The rotor type oil pump according to claim 2,

the outer rotor (3) comprises a plurality of concave teeth (33) formed on the inner peripheral surface thereof, wherein each concave tooth is defined by two adjacent curved profile surfaces (34) protruding radially inwards;

wherein the recess (32) in the form of a circular arc curve corresponds in the radial direction to the curved profile surface (34).

4. The rotor type oil pump according to claim 1,

the recessed portions (32) are plural and are uniformly distributed on the outer peripheral surface of the outer rotor (3) in the circumferential direction.

5. The rotor type oil pump according to claim 1,

the recesses (32) and the projections (42) are configured as mating splines.

6. A rotor type oil pump according to any one of claims 1 to 5,

the shell (5) at least partially extends into the hub, an oil inlet and an oil outlet which are respectively communicated with an oil passage of an engine are arranged in the part of the shell (5) exposed out of the hub, and a cavity communicated with the oil inlet and the oil outlet is formed in the shell (5);

wherein the housing (5), the outer rotor (3) and the inner rotor (2) are arranged adjacent in the hub such that the chamber is in communication with the pump oil chamber.

7. An engine, characterized by comprising a rotor type oil pump according to any one of claims 1 to 6.

8. A work machine, characterized by comprising an engine according to claim 7.

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