A gear pump

Abstract

The application discloses a gear pump, which comprises a driving gear, a driven gear, a front end fixed bearing and a rear end fixed bearing, the driving gear and the driven gear are engaged, both ends of the driving gear and both ends of the driven bearing are respectively supported by the front end fixed bearing and the rear end fixed bearing, at least one of the front end fixed bearing and the rear end fixed bearing is provided with a longitudinal unloading groove, and the longitudinal unloading groove is used for guiding oil in an oil trapping cavity to an axle hole when double-tooth engagement occurs. When the gear pump is used as an oil pump, oil in the oil trapping cavity is guided to the axle hole through the longitudinal unloading groove in the double-tooth engagement state, and the oil can be used as lubricating oil of the axle hole, so that the oil in the oil trapping cavity can be effectively discharged for unloading, and the oil in the axle hole is supplemented to increase lubrication, thereby achieving a double effect. Therefore, the problem that the unloading effect of trapped oil is poor when double-tooth engagement of the gear pump occurs can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of pump technology, and more specifically, to a gear pump. Background Technology

[0002] The fuel pump is the hydraulic supply system of a hydraulic regulating system, directly affecting the system's functionality and dynamic performance. In modern industry, involute gears are widely used as the transmission device for hydraulic pumps due to their simple structure and ease of machining. As the working environment of hydraulic systems becomes increasingly demanding, performance indicators such as low oil trapping, high precision, and high reliability are constantly improving. Therefore, the performance requirements for the hydraulic pumps used in these systems are also becoming increasingly stringent.

[0003] To improve the performance of hydraulic pumps, the industry has been conducting research on enhancing the performance of industrial hydraulic pumps by reducing oil trapping, increasing precision, and improving reliability, thereby improving the safety and reliability of pumps and their systems. Currently, many solutions have been proposed for addressing oil trapping in fuel pumps, and the degree of oil trapping mitigation generally meets engineering requirements.

[0004] However, with increasingly stringent requirements for fuel pump control, existing fuel trapping solutions are no longer sufficient. Simultaneously addressing both the fuel trapping problem and the gear shaft lubrication issue is crucial; therefore, proposing a gear pump unloading method is of great significance.

[0005] For example, Chinese patent application number 202010338877.7 discloses an oil trapping unloading structure and its design method for use in ultra-low viscosity media in aerospace gear micropumps. It mainly relies on strict control of the corner point positions to infinitely approach the central region, ensuring that during the midpoint of the double-tooth meshing period, the oil trapping cavity at the center begins to switch between connecting to the high-pressure unloading groove and the low-pressure unloading groove for unloading. Although the switching period is very short, it still exists. Current solutions can only achieve infinite proximity but cannot effectively solve the problem of oil trapping.

[0006] In summary, how to effectively solve the problem of poor oil trapping and unloading effect during double-tooth meshing in gear pumps is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a gear pump that can effectively solve the problem of poor oil trapping and unloading effect when the two gears mesh in the current gear pump.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A gear pump includes a driving gear, a driven gear, a front fixed bearing, and a rear fixed bearing. The driving gear and the driven gear mesh with each other. Both ends of the driving gear and both ends of the driven gear are supported by the front fixed bearing and the rear fixed bearing, respectively. At least one of the front fixed bearing and the rear fixed bearing is provided with a longitudinal unloading groove, which is used to guide the oil trapped in the oil cavity during double-tooth meshing to the shaft hole.

[0010] In this gear pump, when used as an oil pump, the oil trapped in the oil-trapping cavity is guided to the shaft hole through the longitudinal unloading groove during the double-tooth meshing state. This serves as lubricant for the shaft hole, effectively discharging the oil from the trapped cavity and periodically replenishing the shaft hole with oil to enhance lubrication, thus achieving a dual effect. In summary, this gear pump effectively solves the problem of poor oil trapping and unloading performance in current gear pumps with double-tooth meshing.

[0011] Preferably, at least one of the front fixed bearing and the rear fixed bearing is provided with a low-pressure unloading groove to discharge the oil on the low-pressure side of the meshing point during single-tooth meshing to the low-pressure side.

[0012] At least one of the front fixed bearing and the rear fixed bearing is provided with a high-pressure unloading groove to discharge the oil on the high-pressure side of the meshing point to the low-pressure side during single-tooth meshing.

[0013] Preferably, both the front fixed bearing and the rear fixed bearing are provided with bidirectional longitudinal unloading grooves, which are used to guide the oil to the drive shaft hole and the driven shaft hole respectively.

[0014] Preferably, the longitudinal unloading groove is symmetrical about the center line, and the line connecting the axis of the driving gear and the axis of the driven gear is the center line.

[0015] Preferably, both the front fixed bearing and the rear fixed bearing are provided with the high-pressure unloading groove and the low-pressure unloading groove.

[0016] Preferably, both the high-pressure unloading groove and the low-pressure unloading groove are arranged perpendicular to the center line.

[0017] Preferably, a lubricating oil groove is provided at the junction of the shaft hole and the longitudinal unloading groove. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the side structure of the fuel pump drive gear provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the fuel pump drive gear provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the gear meshing structure of a fuel pump provided in an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the inner structure of the front fixed bearing provided in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the inner structure of the rear fixed bearing provided in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the pump gear set provided in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the meshing zone during the left-side meshing period provided in an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of the meshing zone during the double-tooth meshing period provided in an embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram of the meshing zone during the right-side meshing period provided in an embodiment of the present invention;

[0028] Figure 10 A schematic diagram of the inner structure of another fixed bearing provided in an embodiment of the present invention;

[0029] Figure 11 This is a schematic diagram of the inner structure of another fixed bearing provided in an embodiment of the present invention.

[0030] The following labels are shown in the attached diagram:

[0031] 1. Driving gear; 2. Driven gear; 3. Front fixed bearing; 4. Rear fixed bearing; 5. Oil trapping cavity.

[0032] Front high pressure unloading groove 301, front low pressure unloading groove 302, front drive shaft hole 303, front driven shaft hole 304, front drive lubricating oil groove 305, front driven lubricating oil groove 306, front longitudinal unloading groove 307;

[0033] Rear high pressure unloading groove 401, rear low pressure unloading groove 402, rear drive shaft hole 403, rear driven shaft hole 404, rear drive lubricating oil groove 405, rear driven lubricating oil groove 406, rear longitudinal unloading groove 407. Detailed Implementation

[0034] This invention discloses a gear pump to effectively solve the problem of poor oil trapping and unloading effect when the two gears mesh in current gear pumps.

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figures 1-11 , Figure 1 A schematic diagram of the side structure of the fuel pump drive gear provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the fuel pump drive gear provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the gear meshing structure of a fuel pump provided in an embodiment of the present invention; Figure 4 A schematic diagram of the inner structure of the front fixed bearing provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the inner structure of the rear fixed bearing provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the pump gear set provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the meshing zone during the left-side meshing period provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the meshing zone during the double-tooth meshing period provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the meshing zone during the right-side meshing period provided in an embodiment of the present invention; Figure 10 A schematic diagram of the inner structure of another fixed bearing provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of the inner structure of another fixed bearing provided in an embodiment of the present invention.

[0037] In some embodiments, a fuel pump is provided, primarily a gear pump, specifically a fuel pump, and more specifically, an electric fuel pump. Specifically, the fuel pump mainly includes a driving gear 1, a driven gear 2, a front fixed bearing 3, and a rear fixed bearing 4.

[0038] The driving gear 1 and driven gear 2 are generally involute gears. The driving gear 1 and driven gear 2 mesh to form a meshing gear pair. Generally speaking, the driving gear 1 drives the driven gear 2 to rotate. Of course, in some operating conditions, the driven gear 2 can also drive the driving gear 1 to rotate in the opposite direction.

[0039] Both ends of the driving gear 1 and both ends of the driven gear 2 are supported by a front fixed bearing 3 and a rear fixed bearing 4, respectively. That is, both the front fixed bearing 3 and the rear fixed bearing 4 are provided with two shaft holes to support the driving gear 1 and the driven gear 2, respectively. Specifically, the front fixed bearing 3 and the rear fixed bearing 4 are provided with a driving shaft hole and a driven shaft hole. Specifically, the front fixed bearing is provided with a front driving shaft hole 303 and a front driven shaft hole 304, while the rear fixed bearing is provided with a rear driving shaft hole 403 and a rear driven shaft hole 404.

[0040] The two ends of the drive shaft that is connected to the drive gear 1 for torque transmission are inserted into the front drive shaft hole 303 and the rear drive shaft hole 304, respectively, while the two ends of the driven shaft that is connected to the driven gear 2 for torque transmission are inserted into the front driven shaft hole 403 and the rear driven shaft hole 404, respectively.

[0041] Involute gears exhibit different states at different times during transmission, generally falling into three main states, as shown in the attached diagram. Figure 7 , 8 9 represents the low-pressure unloading state, medium-pressure unloading state, and high-pressure unloading state, respectively.

[0042] To better illustrate the differences, some features are explained. The line connecting the axis of the driving gear 1 and the axis of the driven gear 2 is the center line, also known as the center symmetry line. In the cavities on either side of this center line, one cavity is a low-pressure cavity, and the other is a high-pressure cavity. Figure 7-9 For example, the right side is the low-pressure chamber and the left side is the high-pressure chamber. During gear operation, it is generally necessary to ensure that the low-pressure chamber and the high-pressure chamber are separated.

[0043] The gear meshing process is mainly divided into single-tooth meshing and double-tooth meshing. For example... Figure 7 , 9 As shown, this is a single-tooth meshing state, with one tooth of the driving gear 1 and one tooth of the driven gear 2 in contact; Figure 7 In the middle, the mating part is on the left side of the center line; for convenience, this is called the left-side meshing period. Figure 9 In this case, the mating part is on the right side of the center line; for ease of reference, this is called the right-side meshing period. For example... Figure 8As shown, this is a double-tooth meshing state. Two adjacent teeth of the driving gear 1 and two adjacent teeth of the driven gear 2 are engaged, meshing on the left and right sides of the center line respectively. This can be called the double-tooth meshing period. The double-tooth meshing period is actually a transitional period from the left-side meshing period to the right-side meshing period. (See attached diagram.) Figure 7-9 For example, the driving gear is above the driven gear, and the driving gear 1 rotates clockwise. Figure 7 In the middle, during the left meshing period, as the driving gear 1 continues to rotate, the next gear teeth of the driving gear 1 and the driven gear 2 also join the meshing state, that is, entering the double-tooth meshing period; as the driving gear 1 continues to rotate, the previously meshed gears begin to disengage and enter the right meshing period; then as the driving gear 1 continues to rotate, the meshing point transitions from the right to the left until it enters the left meshing period; then, the cycle repeats.

[0044] As mentioned above, both the left and right meshing phases involve single-tooth meshing. In single-tooth meshing, the meshing point serves as the boundary, with one side connecting to the low-pressure chamber and the other side connecting to the high-pressure chamber. (See attached diagram.) Figure 8 As shown, when the two teeth are meshing, an oil trapping cavity 5 is formed between the two meshing points, which is generally difficult to connect to the low-pressure cavity or the high-pressure cavity.

[0045] In this embodiment, at least one of the front fixed bearing 3 and the rear fixed bearing 4 is provided with a longitudinal unloading groove. The longitudinal unloading groove is used to guide the oil in the trapped oil cavity during double-tooth meshing to the shaft hole. It can be any one or more of the front driving shaft hole 303, the front driven shaft hole 304, the rear driving shaft hole 403, and the rear driven shaft hole 404, so as to discharge the oil in the trapped oil cavity 5 during double-tooth meshing and discharge it to the shaft hole. This allows for the supply of lubricating oil to the shaft hole while simultaneously discharging the lubricating oil to unload the trapped oil cavity. The specific configuration of the unloading groove can be set as needed, with the aim of forming a conductive oil passage. The width of the unloading groove should not be too large to avoid connecting the low-pressure chamber and the high-pressure chamber as much as possible.

[0046] In this gear pump, when used as an oil pump, the oil trapped in the oil-trapping cavity is guided to the shaft hole through the longitudinal unloading groove during the double-tooth meshing state. This serves as lubricant for the shaft hole, effectively discharging the oil from the trapped cavity and periodically replenishing the shaft hole with oil to enhance lubrication, thus achieving a dual effect. In summary, this gear pump effectively solves the problem of poor oil trapping and unloading performance in current gear pumps with double-tooth meshing.

[0047] In some embodiments, at least one of the front fixed bearing 3 and the rear fixed bearing 4 may be provided with a low-pressure unloading groove to discharge oil from the low-pressure side of the meshing point during single-tooth meshing. Correspondingly, at least one of the front fixed bearing 3 and the rear fixed bearing 4 may be provided with a high-pressure unloading groove to discharge oil from the high-pressure side of the meshing point during single-tooth meshing. Generally, both the front fixed bearing 3 and the rear fixed bearing 4 are provided with high-pressure unloading grooves and low-pressure unloading grooves. Specifically, the front fixed bearing 3 is provided with a front high-pressure unloading groove 301 and a front low-pressure unloading groove 302; correspondingly, the rear fixed bearing is provided with a rear high-pressure unloading groove 401 and a rear low-pressure unloading groove 402.

[0048] As attached Figure 7 As shown, during the engagement period on the left side, the oil on the low-pressure side of the engagement point mainly flows to the low-pressure chamber, while another part can flow to the shaft hole through the longitudinal unloading groove.

[0049] As attached Figure 9 As shown, during the engagement period on the right side, the oil on the high-pressure side of the engagement point mainly flows to the high-pressure side, while another part can flow to the shaft hole through the longitudinal unloading groove.

[0050] In some embodiments, both the front fixed bearing 3 and the rear fixed bearing 5 may be provided with bidirectionally extending longitudinal unloading grooves, which are used to guide the oil to the drive shaft hole and the driven shaft hole, respectively. That is, on the front fixed bearing 3, the bidirectionally extending front longitudinal unloading groove 307 extends to the front drive shaft hole 303 and the front driven shaft hole 304 at both ends, respectively; while on the rear fixed bearing 4, the bidirectionally extending rear longitudinal unloading groove 407 extends to the rear drive shaft hole 403 and the rear driven shaft hole 404 at both ends, respectively.

[0051] In some embodiments, both the front fixed bearing 3 and the rear fixed bearing 4 may be provided with two separate and oppositely extending longitudinal unloading grooves: one longitudinal unloading groove is a main longitudinal unloading groove for extending to the drive shaft hole; the other longitudinal unloading groove is a driven longitudinal unloading groove for extending to the driven shaft hole. On the same fixed bearing, the main longitudinal unloading groove and the driven longitudinal unloading groove are separately provided and spaced apart.

[0052] In some embodiments, the longitudinal unloading grooves are symmetrical about the centerline, wherein the line connecting the axes of the driving gear 1 and the driven gear 2 is the centerline. Alternatively, they can be inclined. If two longitudinal unloading grooves are provided, they can be located on either side of the centerline, but should be situated between the high-pressure unloading groove and the low-pressure unloading groove. Both the high-pressure and low-pressure unloading grooves can be perpendicular to the centerline and can be located at the center.

[0053] In some embodiments, to facilitate the guidance of lubricating oil, a lubricating oil groove is generally provided at the junction of the shaft hole and the longitudinal unloading groove. Correspondingly, for example, the front drive shaft hole 303 is provided with a front drive lubricating oil groove 305, the front driven shaft hole 304 is provided with a front driven lubricating oil groove 306, the rear drive shaft hole 403 is provided with a rear drive lubricating oil groove 405, and the rear driven shaft hole 404 is provided with a rear driven lubricating oil groove 406.

[0054] In some embodiments, the front fixed bearing 3 and / or the rear fixed bearing 3 may be provided with an active longitudinal unloading groove and a driven longitudinal unloading groove, wherein the active longitudinal unloading groove extends to the active shaft hole, and the driven longitudinal unloading groove extends to the driven shaft hole. With the intersection of the centerline and the meshing circle as the dividing point, the active longitudinal unloading groove and the driven longitudinal unloading groove are located on both sides of the dividing point, as shown in the attached figure. Figure 10 , 11 As shown, all of them are spaced apart from the dividing point. (See attached diagram) Figure 10 As shown, both the active and passive longitudinal unloading grooves are symmetrical about the center line. (See attached diagram.) Figure 11 As shown, the active longitudinal unloading groove is located on the low-pressure side of the centerline, while the driven longitudinal unloading groove is located on the high-pressure side of the centerline, and they are set separately from each other.

[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gear pump, comprising a driving gear, a driven gear, a front fixed bearing, and a rear fixed bearing, wherein the driving gear and the driven gear mesh, and both ends of the driving gear and both ends of the driven gear are respectively supported by the front fixed bearing and the rear fixed bearing, characterized in that, At least one of the front fixed bearing and the rear fixed bearing is provided with a longitudinal unloading groove, which is used to guide the oil in the trapped oil cavity during double tooth meshing to the shaft hole. At least one of the front fixed bearing and the rear fixed bearing is provided with a high-pressure unloading groove to discharge the oil on the high-pressure side of the meshing point to the low-pressure side when the single tooth meshes. Both the front fixed bearing and the rear fixed bearing are provided with bidirectional longitudinal unloading grooves, which are used to guide the oil to the drive shaft hole and the driven shaft hole respectively. The front fixed bearing and / or the rear fixed bearing are provided with an active longitudinal unloading groove and a driven longitudinal unloading groove. The active longitudinal unloading groove extends to the active shaft hole, and the driven longitudinal unloading groove extends to the driven shaft hole. With the intersection of the center line and the meshing circle as the dividing point, the active longitudinal unloading groove and the driven longitudinal unloading groove are located on both sides of the dividing point and are spaced apart from the dividing point. The active longitudinal unloading groove and the driven longitudinal unloading groove are symmetrical about the center line. The active longitudinal unloading groove is located on the low-pressure side of the center line, and the driven longitudinal unloading groove is located on the high-pressure side of the center line and are set separately from each other.

2. The gear pump according to claim 1, characterized in that, The longitudinal unloading groove is symmetrical about the center line, and the line connecting the axis of the driving gear and the axis of the driven gear is the center line.

3. The gear pump according to claim 2, characterized in that, Both the front fixed bearing and the rear fixed bearing are provided with the high-pressure unloading groove and the low-pressure unloading groove.

4. The gear pump according to claim 3, characterized in that, Both the high-pressure unloading groove and the low-pressure unloading groove are set perpendicular to the center line.

5. The gear pump according to claim 2, characterized in that, A lubricating oil groove is provided at the connection between the shaft hole and the longitudinal unloading groove.

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