Engine power take-off pilot pump

Abstract

An engine power take-off pilot pump comprises a pump body, a cavity is formed in the pump body, a driving gear and a driven gear which are matched with each other are arranged in the cavity, the driving gear and the driven gear divide the cavity into an oil suction cavity and an oil pressing cavity which are not communicated with each other, and teeth are arranged on the upper portion of the driving gear and the upper portion of the driven gear. A pressure relief assembly is arranged in the middle of teeth on the driving gear; the guide grooves are arranged to balance the oil pressure of the closed oil cavity and the oil suction cavity or the oil pressing cavity, the oil trapping phenomenon caused by the fact that the volume of the closed oil cavity is increased or decreased is prevented, meanwhile, abrasion between gears or between the gears and the cover plate and the shaft sleeve is not increased, the service life of the pilot pump can be effectively prolonged, and noise and vibration are reduced. The oil pressure loss of the pilot valve is lower than that of a pressure relief groove, and the effect is good.

Description

Technical Field

[0001] The utility model relates to the technical field of excavators, and more specifically to an engine power take-off pilot pump. Background Art

[0002] The pilot pump pushes the main control valve block via a pilot PPC valve, directing the main pump's high-pressure oil to the designated cylinder or motor. The pilot pump provides low-pressure oil to the control system, including handles, foot pedals, and control valves attached to the travel and swing motors. It primarily consists of a housing and two gears. As the gears rotate, hydraulic oil flows from the suction chamber into the pressure chamber, essentially flowing from the low-pressure area to the high-pressure area before being squeezed out. This can cause oil entrapment during operation. This occurs when the enclosed volume at the intersection of the gears changes over time during the operation of the involute gear pump, often trapping some of the hydraulic oil between the teeth. Because hydraulic oil is incompressible, this can cause significant vibration and noise in the external gears, impacting the proper functioning of the system.

[0003] At present, the oil trapped phenomenon is usually overcome by setting a pressure relief groove. However, no matter whether it is a symmetrical pressure relief groove or an asymmetrical pressure relief groove, in order to prevent the high-pressure area and the low-pressure area from being connected, there are many restrictions on the size of the area set, resulting in an unsatisfactory solution to the oil trapped phenomenon. At the same time, since the pressure relief groove is set on the cover, if the end face spacing is kept very small, the wear between the gear and the cover will increase. If the end face spacing is expanded, internal leakage will occur, that is, the hydraulic oil will flow from the high-pressure area to the low-pressure area, thereby causing the pressure in the pilot pump to decrease and the efficiency will also decrease. Therefore, it is very important to find a new structure to make up for the shortcomings of the pressure relief groove. Utility Model Content

[0004] One advantage of the present invention is that it provides an engine power take-off pilot pump, which balances the oil pressure between the closed oil chamber and the oil suction chamber or the oil pressure chamber by setting a guide groove, thereby preventing oil trapping caused by the increase or decrease in the volume of the closed oil chamber, and at the same time will not increase the wear between the gears or between the gears and the cover plate or the shaft sleeve. It can effectively improve the service life of the pilot pump and reduce noise and vibration. At the same time, experiments have shown that the oil pressure loss of the pilot valve is lower than that of using a pressure relief groove, which has a good effect.

[0005] In order to achieve at least one of the above advantages of the present invention, the present invention provides an engine power take-off pilot pump, including a pump body, a chamber is provided inside the pump body, and a driving gear and a driven gear matching each other are provided inside the chamber. The driving gear and the driven gear divide the chamber into a non-connected oil suction chamber and an oil pressure chamber. The upper parts of the driving gear and the driven gear are both provided with teeth, and a pressure relief assembly is provided in the middle of the teeth on the driving gear.

[0006] According to an embodiment of the present utility model, an oil inlet and an oil outlet are provided on the pump body. The oil inlet is communicated with the oil suction chamber, and the oil outlet is communicated with the oil pressure chamber.

[0007] According to an embodiment of the present invention, teeth on the driving gear and the driven gear that are in contact with each other form a closed oil chamber.

[0008] According to one embodiment of the present invention, the pressure relief assembly includes a pressure relief groove arranged on the end face of the tooth and a guide groove arranged on both side faces of the tooth. The pressure relief groove and the guide groove are connected, and the closed oil chamber and the oil suction chamber are connected through the pressure relief groove and the guide groove.

[0009] According to an embodiment of the present invention, the guide groove extends from the end of the tooth to the root to the middle of the tooth, and the inner side surface of the guide groove is a curved surface structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the external structure of the utility model;

[0011] Figure 2 This is a schematic diagram of the operating state of the utility model;

[0012] Figure 3 This is a schematic diagram of the active gear structure of the utility model;

[0013] In the attached figure: 1. pump body, 2. oil inlet, 3. driven gear, 4. driving gear, 5. teeth, 6. pressure relief groove, 7. guide groove. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following will be combined with the appendix of the present invention. Figure 1 ~Attachment Figure 3 , the utility model is described in more detail.

[0015] The following description is intended to disclose the present invention and enable those skilled in the art to implement the present invention. The preferred embodiments described below are provided for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention as defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0016] Those skilled in the art should understand that, in the disclosure of the specification, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms cannot be understood as limiting the present invention.

[0017] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0018] The utility model provides an engine power take-off pilot pump, including a pump body 1, a chamber is provided inside the pump body 1, a driving gear 4 and a driven gear 3 are provided inside the chamber to match each other, the driving gear 4 and the driven gear 3 divide the chamber into an oil suction chamber and an oil pressure chamber that are not connected, the driving gear 4 and the driven gear 3 are both provided with teeth 5 on the upper part, and a pressure relief component is provided in the middle of the teeth 5 on the driving gear 4; an oil inlet 2 and an oil outlet are provided on the pump body 1, and an oil inlet 2 and an oil outlet are provided. The oil port 2 is connected to the oil suction chamber, and the oil outlet is connected to the oil pressure chamber; the teeth 5 on the driving gear 4 and the driven gear 3 that contact each other form a closed oil chamber; the pressure relief component includes a pressure relief groove 6 arranged on the end face of the tooth 5 and a guide groove 7 arranged on both sides of the tooth 5. The pressure relief groove 6 and the guide groove 7 are connected, and the closed oil chamber and the oil suction chamber are connected through the pressure relief groove 6 and the guide groove 7; the guide groove 7 extends from the end of the tooth 5 to the root to the middle position of the tooth 5, and the inner side of the guide groove 7 is a curved surface structure.

[0019] The first embodiment of the present utility model is as follows:

[0020] An engine power take-off pilot pump includes a pump body 1. A chamber is provided inside the pump body 1. Two matching gears are provided inside the chamber. The gears divide the chamber into a low-pressure oil suction chamber and a high-pressure oil pressure chamber. An oil inlet 2 and an oil outlet are provided on the pump body 1. The oil inlet 2 is connected to the oil suction chamber, and the oil outlet is connected to the oil pressure chamber. The rotation of the gears causes the volume of the oil suction chamber to circulate from small to large, generating low pressure, sucking in the hydraulic oil in the pipeline. At the same time, the volume of the oil pressure chamber circulates from large to small, generating high pressure, and pressing out the hydraulic oil.

[0021] The gears include a driving gear 4 and a driven gear 3 that match each other. The teeth 5 on the driving gear 4 and the driven gear 3 that contact each other form a closed oil chamber. As the gears rotate, the volume of the closed oil chamber will first change from large to small, and after reaching the minimum volume, it will change from small to large until the teeth 5 are separated and the closed oil chamber is connected to the oil suction chamber. A transmission shaft is provided in the middle of the driving gear 4. The transmission shaft passes through one end of the pump body 1 and is connected to the power take-off of the engine. The power take-off is installed on the engine housing, directly taking power from the engine and transmitting it directly to the driving gear 4 through the transmission shaft. The force transmission is direct and powerful.

[0022] Teeth 5 are provided on the upper part of the gear, and a pressure relief assembly is provided in the middle of the teeth 5 of the driving gear 4. The pressure relief assembly includes a pressure relief groove 6 provided at the end of the tooth 5 and a guide groove 7 provided on both sides of the tooth 5. The pressure relief groove 6 and the guide groove 7 are connected, and the closed oil chamber and the oil suction chamber are connected through the pressure relief groove 6 and the guide groove 7. The guide groove 7 extends from the end of the tooth 5 to the root to the middle position of the tooth 5. The inner side surface of the guide groove 7 is an arc-shaped structure. When the closed oil chamber is formed, due to the presence of the pressure relief groove 6 and the guide groove 7, the closed oil chamber and the oil suction chamber will be connected. During the volume change of the closed oil chamber, there will be no oil trapped or cavitation due to high pressure or low pressure inside it, thereby reducing vibration and noise.

[0023] This solution creatively changes the traditional thinking and keeps the closed oil chamber connected to the oil suction chamber. Since the volume of the closed oil chamber is very small, the impact on the pressure of the pilot pump is very small. Even if it is connected to the oil suction chamber, no unnecessary pressure loss will be generated. On the contrary, there is no need to set a traditional pressure relief groove 6 on the cover, which can effectively improve the end face sealing effect, greatly reduce the internal leakage caused by the setting of the pressure relief groove 6, and at the same time reduce the noise and vibration caused by the oil trapped phenomenon. Whether compared with the traditional pilot pump or compared with the pilot pump with the pressure relief groove 6, it has considerable advantages in both aspects.

[0024] It should be noted that the terms "first, second and third" in the present invention are only used for descriptive purposes and do not indicate any order. They cannot be understood as indicating or implying relative importance. These terms can be interpreted as names.

[0025] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended only as examples and do not limit the present invention. The advantages of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles herein.

Claims

1. An engine power take-off pilot pump, characterized in that: It includes a pump body, a chamber is provided inside the pump body, a driving gear and a driven gear matching each other are provided inside the chamber, the driving gear and the driven gear divide the chamber into an unconnected oil suction chamber and an oil pressure chamber, the upper parts of the driving gear and the driven gear are both provided with teeth, and a pressure relief component is provided in the middle of the teeth on the driving gear.

2. The engine power take-off pilot pump according to claim 1, characterized in that: The pump body is provided with an oil inlet and an oil outlet, the oil inlet is communicated with the oil suction chamber, and the oil outlet is communicated with the oil pressure chamber.

3. The engine power take-off pilot pump according to claim 2, characterized in that: The teeth on the driving gear and the driven gear that contact each other form a closed oil chamber.

4. The engine power take-off pilot pump according to claim 3, characterized in that: The pressure relief assembly includes a pressure relief groove arranged on the end face of the tooth and a guide groove arranged on both side faces of the tooth. The pressure relief groove and the guide groove are connected, and the closed oil chamber and the oil suction chamber are connected through the pressure relief groove and the guide groove.

5. The engine power take-off pilot pump according to claim 4, characterized in that: The guide groove extends from the end of the tooth to the root to the middle of the tooth, and the inner side surface of the guide groove is a curved surface structure.

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