Transmission structure and method of fuel injection pump and electronic unit pump system

Abstract

The invention discloses a transmission structure and method of an oil injection pump and an electronic unit pump system, belongs to the technical field of engines, and solves the problems that a rotating shaft of an oil injection part is too large in torsional force and easy to damage. A transmission shaft sleeve used for being connected with an engine body is arranged at the end, close to a fuel injection pump cam shaft, of the fuel injection pump, a transmission shaft is rotationally arranged in the transmission shaft sleeve, an inner spline is arranged at one end of the transmission shaft, and a transmission outer spline sleeve is arranged on the inner spline. The transmission outer spline sleeve is sleeved on a fuel injection pump cam shaft of the fuel injection pump, a gear is arranged at the other end of the transmission shaft, a plurality of mounting grooves are arranged on the fuel injection pump on the outer side of the fuel injection pump cam shaft, and supporting bushes used for supporting the fuel injection pump cam shaft are arranged in the mounting grooves. According to the transmission structure and method of the fuel injection pump and the electronic unit pump system, the structure is compact, arrangement is convenient, camshaft faults are reduced, and the stability of the fuel injection pump is improved.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a transmission structure, method, and electronically controlled unit pump system for a fuel injection pump. Background Technology

[0002] The reliability of a diesel engine largely depends on the reliability of its electronically controlled unit pump system. The electronically controlled high-pressure common rail system pressurizes fuel and delivers it to the corresponding injectors in each cylinder via an injection pump. Because the injection pump in an electronically controlled unit pump system has a high peak torque, this places high demands on the structural performance of the diesel engine's injection pump. Among these, the stability of the injection pump's transmission mechanism is particularly important.

[0003] A search revealed a fuel injection pump transmission structure, a high-pressure common rail system, and an engine with publication number CN112443438A. The disclosed design includes a fuel injection pump with a connecting seat for connecting to the engine body. The connecting seat contains a drive shaft and mounting holes. One end of the drive shaft is sleeved onto a rotating shaft, and the other end has a gear. The connecting seat has a first oil inlet passage, the rotating shaft has a third oil inlet passage, and the drive shaft has a second oil inlet passage. The end of the fuel injection pump near the rotating shaft has a first oil return passage connecting to the inside of the fuel injection pump. This design improves the stability of the fuel injection pump by increasing lubrication. However, in actual use, due to the excessive length of the drive shaft, installation in confined spaces becomes difficult due to the insufficiently compact structure, failing to meet installation requirements. Furthermore, the direct drive between the drive shaft and the rotating shaft results in excessive torsional force on the rotating shaft of the fuel injection unit, making it prone to damage and malfunctions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art by providing a transmission structure, method and electronically controlled unit pump system for a fuel injection pump. The system has a compact structure, is easy to arrange, reduces the occurrence of camshaft failures, improves the stability of the fuel injection pump, and has the characteristics of wide applicability and strong practicality.

[0005] The technical solution adopted in this invention is: a transmission structure for a fuel injection pump, including a fuel injection pump, wherein a transmission shaft sleeve for connecting the engine body is provided at one end of the fuel injection pump near its fuel injection pump camshaft, a transmission shaft is rotatably provided inside the transmission shaft sleeve, one end of the transmission shaft is provided with an internal spline, a transmission external spline sleeve is provided on the internal spline, the transmission external spline sleeve is sleeved on the fuel injection pump camshaft of the fuel injection pump, a gear is provided at the other end of the transmission shaft, and multiple mounting slots are opened on the fuel injection pump outside the fuel injection pump camshaft, and a support bushing for supporting the fuel injection pump camshaft is provided in the mounting slot.

[0006] As a further improvement, a first bushing is provided between the drive shaft sleeve and the drive shaft, the inner ring of the first bushing is rotatably connected to the drive shaft, and the outer ring of the first bushing is interference-fitted with the drive shaft sleeve.

[0007] Furthermore, the drive shaft sleeve is provided with a lubricating oil passage, the first bushing is provided with a lubrication hole corresponding to the oil outlet of the lubricating oil passage, and the drive shaft is provided with a lubrication groove corresponding to the lubrication hole.

[0008] Furthermore, a thrust washer is fitted on the outer side of the drive shaft, and a flange is provided on the outer side of the drive shaft. The thrust washer is arranged between the flange and the gear, and the gear is fixed to the engine body by locking bolts.

[0009] Furthermore, one end of the fuel injection pump camshaft is provided with a tapered portion, and the transmission external spline sleeve is mounted on the tapered portion.

[0010] Furthermore, the bottom of the fuel injection pump is provided with a fuel pump bracket for installation.

[0011] A transmission method for a fuel injection pump, applied to the aforementioned transmission structure, involves setting an external spline sleeve between the fuel injection pump camshaft and the drive shaft. An internal spline, adapted to the external spline sleeve, is formed on the drive shaft as a support point for the fuel injection pump camshaft. Two support bushings are installed inside the fuel injection pump as support points for the camshaft, forming a multi-point support shaft with bearings at both ends, thus protecting the camshaft. During transmission, the engine power drives the gear, which in turn drives the drive shaft. The drive shaft then uses a spline transmission method to drive the external spline sleeve, which in turn drives the fuel injection pump camshaft, thereby achieving efficient transmission.

[0012] Furthermore, the mating parts between the drive shaft and the drive shaft sleeve are lubricated by a lubrication channel independently provided on the drive shaft sleeve, and this lubrication system is separate from the internal lubrication system of the fuel injection pump.

[0013] Furthermore, the axial displacement of the drive shaft during operation is limited by the cooperation between the flange provided on the drive shaft and the thrust plate.

[0014] An electronically controlled unit pump system includes the transmission structure of the fuel injection pump.

[0015] Beneficial effects

[0016] Compared with the prior art, the present invention has the following advantages: 1. Using the external spline sleeve as an intermediary for spline transmission allows for a shorter drive shaft design, solving the installation problem in confined spaces. The overall structure is more compact, and the connection between the external spline sleeve and the fuel injection pump camshaft is tighter, with a larger force-bearing area. The addition of the transmission bushing and spline transmission is equivalent to adding a point support, resulting in almost no bending moment and effectively protecting the fuel injection pump camshaft.

[0017] 2. A multi-point support system consisting of an external spline sleeve for the transmission and two pump body support bushings was formed, significantly improving the support stiffness and stability of the fuel injection pump camshaft. The spline connection increases the force-bearing area, making torque transmission smoother and greatly reducing the bending moment and torsional vibration acting on the camshaft, effectively reducing the camshaft failure rate.

[0018] 3. The spline drive offers reliable connection and high transmission efficiency. An independent lubrication system is isolated from the internal lubrication of the fuel injection pump, preventing interference and improving the reliability of each system. The thrust washer structure effectively controls the axial movement of the drive shaft. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main structure of the invention. Figure 2 This is a cross-sectional structural diagram of the present invention.

[0020] Among them: 1-injection pump, 2-injection pump camshaft, 3-drive shaft sleeve, 4-drive shaft, 5-flange, 6-drive external spline sleeve, 7-first bushing, 8-thrust plate, 9-gear, 10-conical part, 11-engine body, 12-lubricating oil passage, 13-lubricating groove, 14-support bushing, 15-oil pump bracket, 16-mounting groove. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0022] See Figure 1-2 As shown, a transmission structure for a fuel injection pump according to the present invention includes a fuel injection pump 1. One end of the fuel injection pump 1 near its fuel injection pump camshaft 2 is provided with a transmission shaft sleeve 3 for connecting to the engine body 11. A transmission shaft 4 is rotatably provided inside the transmission shaft sleeve 3. One end of the transmission shaft 4 is provided with an internal spline, and a transmission external spline sleeve 6 is provided on the internal spline. The transmission external spline sleeve 6 is sleeved on the fuel injection pump camshaft 2 of the fuel injection pump 1. The other end of the transmission shaft 4 is provided with a gear 9. Multiple mounting grooves 16 are opened on the fuel injection pump 1 outside the fuel injection pump camshaft 2. A support bushing 14 for supporting the fuel injection pump camshaft 2 is provided in the mounting groove 16.

[0023] In this embodiment, by setting a transmission external spline sleeve 6, during the transmission process, the transmission shaft 4 first drives the transmission external spline sleeve 6, and then the transmission external spline sleeve 6 drives the fuel injection pump camshaft 2 to rotate. Using a spline transmission method, the connection between the transmission external spline sleeve 6 and the fuel injection pump camshaft 2 is tighter, and the force-bearing area is larger, effectively adding a support point to the fuel injection pump camshaft 2. Simultaneously, a support bushing 14 is provided inside the fuel injection pump 1 to support the fuel injection pump camshaft 2. Through the combined action of the transmission external spline sleeve 6 and the support bushing 14, the fuel injection pump camshaft 2 experiences almost no bending moment, effectively protecting the fuel injection pump camshaft 2, reducing the occurrence of fuel injection pump camshaft 2 failures, and effectively improving the stability of the fuel injection pump 1. This structure can effectively shorten the transmission shaft 4, making the overall structure more compact, and requiring only one transmission shaft sleeve 3 for installation, effectively reducing production costs. The transmission shaft sleeve 3 has an independent lubrication system, separate from the lubrication oil circuit inside the fuel injection pump 1, so they do not interfere with each other, improving overall reliability. The tight fit between the external spline sleeve 6 and the tapered portion 10 of the fuel injection pump camshaft 2 forms the first radial support point for the fuel injection pump camshaft 2. The spline connection provides a large torque transmission contact area, making the transmission smoother. Each mounting slot 16 is press-fitted with a support bushing 14. These two support bushings 14 constitute multi-point support for the fuel injection pump camshaft 2, greatly optimizing the stress state of the fuel injection pump camshaft 2. It effectively decomposes the huge bending moment that might originally act on the root of the camshaft, allowing the camshaft to mainly bear the torsional moment, significantly reducing bending stress and vibration, thereby greatly reducing the risk of camshaft breakage or damage due to fatigue and improving the overall reliability of the fuel injection pump.

[0024] Specifically, a first bushing 7 is provided between the transmission shaft sleeve 3 and the transmission shaft 4. The inner ring of the first bushing 7 is rotatably connected to the transmission shaft 4, and the outer ring of the first bushing 7 is interference-fitted with the transmission shaft sleeve 3. The first bushing 7 acts as a sliding bearing, bearing the radial force of the transmission shaft 4 and reducing its rotational friction.

[0025] Preferably, the drive shaft sleeve 3 has a lubrication channel 12, the first bushing 7 has a lubrication hole corresponding to the oil outlet of the lubrication channel 12, and the drive shaft 4 has a lubrication groove 13 corresponding to the lubrication hole. External lubricating oil is delivered through the lubrication channel 12, sprayed out from the oil outlet, enters the gap between the first bushing 7 and the drive shaft 4 through the lubrication hole on the first bushing 7, and fills the lubrication groove 13 to form a stable oil film. This lubrication system is completely independent of the fuel lubrication or lubrication system inside the fuel injection pump 1. Physical isolation is achieved, avoiding possible mixing and contamination of two different oils, and ensuring the reliability and stability of the transmission mechanism lubrication.

[0026] Furthermore, a thrust washer 8 is fitted onto the outer side of the drive shaft 4, and a flange 5 is provided on the outer side of the drive shaft 4. The thrust washer 8 is arranged between the flange 5 and the gear 9. The gear 9 is fixed to the engine body 11 by locking bolts, and the gear 9 is pressed and fixed to the mounting surface of the engine body 11 by the locking bolts. When the gear 9 is tightened, it presses the thrust washer 8 against the flange 5 of the drive shaft 4. This structure can effectively limit the axial movement that the drive shaft 4 may produce during operation.

[0027] Furthermore, the fuel injection pump camshaft 2 has a tapered portion 10 at one end, and the transmission external spline sleeve 6 is installed on the tapered portion 10. The transmission external spline sleeve 6 is firmly installed by interfering with or locking with the tapered portion 10 through its inner hole.

[0028] Furthermore, the bottom of the fuel injection pump 1 is provided with a fuel pump bracket 15 for installation. The fuel pump bracket 15 is provided with mounting holes, and the entire fuel injection pump assembly can be securely installed on the engine block or bracket by bolts, which enhances the overall rigidity and vibration resistance of the assembly.

[0029] A transmission method for a fuel injection pump, applied to a transmission structure, involves setting an external spline sleeve 6 between the fuel injection pump camshaft 2 and the drive shaft 4. An internal spline, adapted to the external spline sleeve 6, is formed on the drive shaft 4 as a support point for the fuel injection pump camshaft 2. Two support bushings 14 are installed inside the fuel injection pump as support points for the camshaft 2, forming a multi-point support shaft with bearings at both ends, thus protecting the camshaft 2. During transmission, the engine power drives a gear 9, which in turn drives the drive shaft 4. The drive shaft 4 then drives the external spline sleeve 6 via a spline transmission method, which in turn drives the fuel injection pump camshaft 2, thereby achieving efficient transmission.

[0030] Furthermore, the lubrication system is separated from the internal lubrication system of the fuel injection pump by a lubrication channel 12 independently provided on the transmission shaft sleeve 3 to lubricate the mating parts between the transmission shaft 4 and the transmission shaft sleeve 3.

[0031] Furthermore, the axial displacement of the transmission shaft 4 is restricted by the cooperation between the flange 5 and the thrust plate 8 provided on the transmission shaft 4.

[0032] In this embodiment, the engine power drives the gear 9 to rotate, and the gear 9 drives the transmission shaft 4 connected to it to rotate. The transmission shaft 4 engages with the outer spline of the transmission outer spline sleeve 6 through its internal spline, efficiently transmitting torque to the transmission outer spline sleeve 6 in a spline transmission manner. The transmission outer spline sleeve 6 drives the fuel injection pump camshaft 2, which is tightly fitted with it, to rotate. During the entire transmission process, the fuel injection pump camshaft 2 is stably supported by a multi-point support system consisting of the transmission outer spline sleeve 6, two support bushings 14 and bearings. The rotation of the transmission shaft 4 is forcibly lubricated by an independent lubrication oil circuit. This system is separate from the internal lubrication system of the fuel injection pump. The axial position of the transmission shaft 4 is limited by the tight fit of the flange 5, the thrust plate 8 and the gear 9.

[0033] An electronically controlled unit pump system includes a transmission structure for a fuel injection pump. Due to the adoption of this compact, stable, and highly reliable transmission scheme, the electronically controlled unit pump system can be more flexibly adapted to various diesel engines, especially in the design of modern compact engines with limited installation space, exhibiting higher stability and longer service life.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A transmission structure for a fuel injection pump, characterized in that, The system includes an injection pump (1), which has a drive shaft sleeve (3) for connecting the engine body (11) at one end near its injection pump camshaft (2). A drive shaft (4) is rotatably provided inside the drive shaft sleeve (3). One end of the drive shaft (4) is provided with an internal spline. An external spline sleeve (6) is provided on the internal spline. The external spline sleeve (6) is fitted on the injection pump camshaft (2) of the injection pump (1). A gear (9) is provided at the other end of the drive shaft (4). Multiple mounting slots (16) are provided on the injection pump (1) outside the injection pump camshaft (2). A support bushing (14) for supporting the injection pump camshaft (2) is provided in the mounting slot (16).

2. The transmission structure of a fuel injection pump according to claim 1, characterized in that, A first bushing (7) is provided between the drive shaft sleeve (3) and the drive shaft (4). The inner ring of the first bushing (7) is rotatably connected to the drive shaft (4), and the outer ring of the first bushing (7) is interference-fitted with the drive shaft sleeve (3).

3. The transmission structure of a fuel injection pump according to claim 2, characterized in that, The transmission shaft sleeve (3) is provided with a lubricating oil passage (12), the first bushing (7) is provided with a lubricating hole corresponding to the oil outlet of the lubricating oil passage (12), and the transmission shaft (4) is provided with a lubricating groove (13) corresponding to the lubricating hole.

4. The transmission structure of a fuel injection pump according to claim 1, characterized in that, A thrust plate (8) is sleeved on the outside of the drive shaft (4), and a flange (5) is provided on the outside of the drive shaft (4). The thrust plate (8) is arranged between the flange (5) and the gear (9). The gear (9) is fixed to the engine body (11) by locking bolts.

5. The transmission structure of an injection pump according to claim 1, characterized in that, The fuel injection pump camshaft (2) has a tapered part (10) at one end, and the transmission external spline sleeve (6) is installed on the tapered part (10).

6. The transmission structure of a fuel injection pump according to claim 1, characterized in that, The fuel injection pump (1) is provided with a fuel pump bracket (15) at the bottom for installation.

7. A method for driving a fuel injection pump, applied to the transmission structure described in any one of claims 1-6, characterized in that, By setting a transmission external spline sleeve (6) between the fuel injection pump camshaft (2) and the transmission shaft (4), and opening an internal spline on the transmission shaft (4) that is compatible with the transmission external spline sleeve (6), the fuel injection pump camshaft (2) is supported. By setting two support bushings (14) inside the fuel injection pump, the fuel injection pump camshaft (2) is supported. It forms a multi-point support shaft with the bearings at both ends, which protects the fuel injection pump camshaft (2). During the transmission process, the engine power drives the gear (9), and the gear (9) drives the transmission shaft (4). The transmission shaft (4) drives the transmission external spline sleeve (6) through the spline transmission method, and drives the fuel injection pump camshaft (2) through the transmission external spline sleeve (6), thereby achieving efficient transmission.

8. The transmission method of a fuel injection pump according to claim 7, characterized in that, The lubrication system between the drive shaft (4) and the drive shaft sleeve (3) is lubricated by a lubrication channel (12) independently set on the drive shaft sleeve (3). This lubrication system is separate from the internal lubrication system of the fuel injection pump.

9. The transmission method of a fuel injection pump according to claim 7, characterized in that, The axial displacement of the transmission shaft (4) is limited by the cooperation between the flange (5) and the thrust plate (8) on the transmission shaft (4) during operation.

10. An electrically controlled unit pump system, characterized in that, The transmission structure includes the fuel injection pump as described in any one of claims 1-6.

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