Common rail pump drive for a diesel engine and diesel engine comprising the same

Abstract

The present application relates to a kind of common rail pump driving device for diesel engine, it includes: coupling disc, coupling disc is the axial hollow cylindrical structure as a whole, wherein, axial hollow is conical frustum, coupling disc and camshaft are fixed to circumferential direction, when coupling disc rotates, drive camshaft to rotate, realize the drive of common rail pump;Fuel injection pump gear, fuel injection pump gear is the hollow disc of concave outer drum, outer circumferential edge is set with the gear of fuel injection pump driving gear matching, coupling disc is set and fixed fuel injection pump gear;Bushing, bushing is cylindrical tube structure, one end is set on the outer circumference of coupling disc, the other end is set and connected common rail pump, for sealing the oil of transmission case, and play the role of support and sliding bearing;Wherein, timing gear, fuel injection pump driving gear and fuel injection pump gear are matched and engaged transmission power, further through coupling disc drive common rail pump camshaft rotation, drive common rail pump oil supply, realize the fuel supply of common rail pump.

Description

Technical Field

[0001] This invention relates to the field of diesel engine technology, and more specifically, to a common rail pump drive device for a diesel engine and a diesel engine including the device. Background Technology

[0002] Currently, inline six-cylinder diesel engines use an inline pump drive system, such as... Figure 1 As shown, the timing gear assembly installed in the transmission box drives the injection pump gear to rotate, which in turn drives the shaft of the injection pump connecting plate to rotate. Through the coupling, the coupling is driven to achieve synchronous rotation of the inline injection pump.

[0003] The inline pump drive uses a coupling connection, which makes the diesel engine unstable during operation, prone to oil leakage, low operating efficiency, and excessively high parameters such as fuel consumption, vibration, and noise. This outdated technology can no longer meet current market demands.

[0004] Therefore, it is urgent to improve the fuel injection system of the mechanical inline fuel injection pump of diesel engine in order to improve operating efficiency and diesel engine performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that diesel engines using mechanical inline fuel injection pumps have low operating efficiency and excessively high parameters such as fuel consumption, vibration, and noise.

[0006] To solve the above-mentioned technical problems, according to one aspect of the present invention, a common rail pump drive device for a diesel engine is provided, wherein the common rail pump drive device is disposed between the timing gear assembly of the diesel engine and the camshaft of the common rail pump of the diesel engine, for realizing that the timing gear drives the camshaft of the common rail pump to rotate, wherein the timing gear assembly includes a timing gear and an injection pump drive gear fixedly connected, wherein the timing gear meshes with the crankshaft gear of the diesel engine, and the torque is transmitted to the common rail pump drive device meshed with it through the injection pump drive gear, thereby driving the camshaft of the common rail pump to rotate. Its common rail pump drive device includes: a connecting plate, which is an integral hollow cylindrical structure, wherein the hollow part is a 1:5 tapered frustum cone shape. The connecting plate and the camshaft are fixed relative to each other in the circumferential direction. When the connecting plate rotates, it drives the camshaft to rotate, thereby driving the common rail pump; and an injection pump gear, which is a hollow disc with an inner concave and outer convex shape. The outer peripheral edge is provided with gears that match the injection pump drive gear. The end of the connecting plate away from the common rail pump has a radially narrowing step on its outer periphery for fitting and fixing. The fuel injection pump gear and bushing are cylindrical structures. One end of the bushing is fitted onto the outer circumference of the connecting plate, and the other end is fitted onto the common rail pump. The bushing is used to seal the oil in the transmission box and also serves as a support and sliding bearing. The fuel injection pump gear is fixedly connected to the connecting plate and meshes with the fuel injection pump drive gear. It is used to transmit power through the timing gear, the fuel injection pump drive gear, and the matching meshing of the fuel injection pump gear. In turn, it drives the common rail pump camshaft to rotate through the connecting plate, thereby driving the common rail pump to supply fuel.

[0007] According to an embodiment of the present invention, a groove may be provided on the inner wall of the axially hollow side of the connecting disc as a keyway. The connecting disc and the camshaft are fixed relative to each other in the circumferential direction by a semi-circular key and the keyway. When the connecting disc rotates, it drives the camshaft to rotate, thereby driving the common rail pump.

[0008] According to an embodiment of the present invention, the connecting disc step can be positioned by engaging with the inner bore of the fuel injection pump gear, wherein the surface roughness of the step is set to... The step is fitted with the inner hole of the fuel injection pump gear with a clearance range of 0.03mm to 0.09mm. The end face of the fuel injection pump gear is close to the end face of the connecting plate step, which serves a positioning function.

[0009] According to an embodiment of the present invention, the connecting disc and the fuel injection pump gear can be made of high-strength, high-toughness, and well-hardenable alloy structural steel 42CrMo-GB / T3077, which is tempered and nitrided, with a core hardness of 280-380HB and a surface hardness of 480-580HV. The surface treatment has a nitriding depth of 0.3-0.5mm. Magnetic particle testing must be performed before the fuel injection pump gear is hobbed.

[0010] According to an embodiment of the present invention, the timing gear assembly, the fuel injection pump gear, the connecting disc, the bushing, and the common rail pump camshaft can be installed in the transmission box; the fuel injection pump gear and the connecting disc can be fixedly connected by eight M8×25-10.9 screws, and the connecting disc is connected to the common rail pump camshaft by a 1:5 tapered surface and a semi-circular key, and fixedly connected by an M24×1.5 nut.

[0011] According to an embodiment of the present invention, the common rail pump drive device for a diesel engine may further include: an O-ring rubber seal, wherein the outer circle of the bushing extends into the inner hole of the transmission box, with clearance fit; wherein a concave groove is provided on the outer circle of the bushing, and an O-ring rubber seal 106×3.55 is installed to seal the engine oil, wherein the O-ring rubber seal is made of fluororubber.

[0012] According to an embodiment of the present invention, the bushing inner hole may have two sections with different inner diameters, one section being connected to the connecting disc to ensure a gap of 0.036 to 0.125 mm; the other section being connected to the common rail pump housing to provide support.

[0013] According to an embodiment of the present invention, the bushing may be made of alloy structural steel 40Cr-GB / T3078 with high strength and good comprehensive mechanical properties, quenched and tempered, with a hardness of 28-32HRC, and surface oxidized.

[0014] According to an embodiment of the present invention, the timing gear and the fuel injection pump drive gear are fastened together by six M8×30-10.9 bolts.

[0015] According to another aspect of the present invention, a diesel engine is provided, comprising: a crankshaft gear for outputting power; a timing gear assembly including a timing gear and a fuel injection pump drive gear fixedly connected, wherein the timing gear meshes with the diesel engine crankshaft gear; and a common rail pump drive device, which is the aforementioned common rail pump drive device, disposed between the diesel engine timing gear assembly and the camshaft of the diesel engine common rail pump, wherein the fuel injection pump drive gear transmits torque to the meshed common rail pump drive device, thereby driving the camshaft of the common rail pump to rotate and driving the common rail pump to supply fuel, thus realizing the fuel supply of the common rail pump.

[0016] Compared with the prior art, the technical solution provided by the embodiments of the present invention can achieve at least the following beneficial effects:

[0017] According to the common rail pump drive device for diesel engines of the present invention, the original engine coupling connection method is eliminated, and the common rail pump drive is realized by using a connecting disc for transmission. Furthermore, in order to realize the connecting disc transmission, the fuel injection pump gear is designed with improvements, and the fuel injection pump gear transmission structure and bushing are matched. The original engine fuel injection pump coupling drive method is eliminated and replaced with direct gear drive. By modifying the original six-cylinder diesel engine into an electronically controlled common rail high-pressure fuel injection system, the power of the original six-cylinder diesel engine is increased by 10% from the original 300kW, and parameters such as fuel consumption, vibration, and noise are improved, and emissions are reduced.

[0018] According to the common rail pump drive device for diesel engines of the present invention, by modifying a six-cylinder diesel engine to install a high-pressure common rail system, and after calibration, debugging, and testing of the common rail diesel engine's ECU (Electronic Control Unit), the common rail diesel engine can meet the original engine's performance. A power enhancement test was conducted on the common rail diesel engine, and the exhaust temperature and detonation pressure were normal at the rated power of 330 kW. During the test, the common rail diesel engine operated smoothly and gently, with significantly reduced noise. All performance parameters met the design requirements, with the rated detonation pressure decreasing from 17 MPa to 16.2 MPa and the exhaust temperature decreasing from 550°C to 488°C. The common rail pump drive device demonstrated stable transmission reliability and no oil leakage throughout the entire operation. This indicates that the design scheme of the common rail pump drive device is feasible, effective, and has achieved substantial success.

[0019] According to the common rail pump drive device for diesel engines of the present invention, the successful development of the common rail pump drive device design provides a practical and feasible technical reference for the installation and transmission of structurally similar functional components in the research and design of diesel engines. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0021] Figure 1 This is a schematic diagram illustrating the existing diesel engine inline fuel injection pump drive structure;

[0022] Figures 2a-2b This is a schematic diagram illustrating a common rail pump drive device for a diesel engine according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of a timing gear assembly according to an embodiment of the present invention;

[0024] Figure 4a This is a front view showing the fuel injection pump drive gear according to an embodiment of the present invention;

[0025] Figure 4b yes Figure 4a Sectional view along axis AA;

[0026] Figure 5a This is a front view of the coupling disk according to an embodiment of the present invention;

[0027] Figure 5b yes Figure 5a Sectional view along axis AA;

[0028] Figure 5c yes Figure 5a A magnified view of a portion of the image;

[0029] Figure 6a This is a schematic diagram showing an axial cross-section of a bushing according to an embodiment of the present invention;

[0030] Figure 6b yes Figure 6a A magnified view of a portion of the image. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. Based on the described 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.

[0032] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0033] Figures 2a-2b This is a schematic diagram illustrating a common rail pump drive device for a diesel engine according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a timing gear assembly according to an embodiment of the present invention; Figure 4a This is a front view showing the fuel injection pump drive gear according to an embodiment of the present invention; Figure 4b yes Figure 4a A sectional view along the AA direction.

[0034] The common rail pump drive unit is located between the diesel engine timing gear assembly 2 and the camshaft 9 of the diesel engine common rail pump. It is used to enable the timing gear to drive the common rail pump camshaft 9 to rotate. The timing gear assembly 2 includes a timing gear and an injection pump drive gear 21 that are fixedly connected. The timing gear meshes with the diesel engine crankshaft gear. The torque is transmitted to the common rail pump drive unit that meshes with it through the injection pump drive gear 21, thereby driving the camshaft 9 of the common rail pump 12 to rotate.

[0035] like Figures 2a to 4b As shown, the common rail pump drive unit for a diesel engine includes: a connecting plate 10, an injection pump gear 3, and a bushing 8.

[0036] The connecting disc 10 is an axially hollow cylindrical structure, wherein the axial hollow part is a 1:5 tapered frustum shape. The connecting disc 10 and the camshaft 9 are fixed relative to each other in the circumferential direction. When the connecting disc 10 rotates, it drives the camshaft 9 to rotate, thereby driving the common rail pump 12.

[0037] The fuel injection pump gear 3 is a hollow disc with an inner concave and outer bulge. The outer periphery is provided with a gear that matches the fuel injection pump drive gear 21. The end of the connecting disc 10 away from the common rail pump 12 is provided with a radially narrowing step on the outer periphery for fitting and fixing the fuel injection pump gear 3.

[0038] The bushing 8 is a cylindrical structure. One end is fitted on the outer circumference of the connecting plate 10, and the other end is fitted to connect the common rail pump 12. It is used to seal the oil in the transmission box 1 and to support and slide the bearing.

[0039] The fuel injection pump gear 3 is fixedly connected to the connecting plate 10 and meshes with the fuel injection pump drive gear 21. It is used to transmit power through the timing gear, the fuel injection pump drive gear 21 and the fuel injection pump gear 3, and then drive the common rail pump camshaft 99 to rotate through the connecting plate 10, thereby driving the common rail pump 12 to supply fuel and realize the fuel supply of the common rail pump 12.

[0040] According to the common rail pump drive device for diesel engines of the present invention, the original engine coupling connection method is eliminated, and the common rail pump drive is realized by using a connecting disc for transmission. Furthermore, in order to realize the connecting disc transmission, the fuel injection pump gear is designed with improvements, and the fuel injection pump gear transmission structure and bushing are matched. The original engine fuel injection pump coupling drive method is eliminated and replaced with direct gear drive. By modifying the original six-cylinder diesel engine into an electronically controlled common rail high-pressure fuel injection system, the power of the original six-cylinder diesel engine is increased by 10% from the original 300kW, and parameters such as fuel consumption, vibration, and noise are improved, and emissions are reduced.

[0041] Figure 5a This is a front view of the coupling disk according to an embodiment of the present invention;

[0042] Figure 5b yes Figure 5a Sectional view along axis AA;

[0043] Figure 5c yes Figure 5a A magnified view of a portion of the image;

[0044] According to one or more embodiments of the present invention, the connecting disc 10 has a groove on the inner wall of one side that is hollow in the axial direction, which serves as a keyway. The connecting disc 10 and the camshaft 9 are fixed relative to each other in the circumferential direction by the semi-circular key 5 and the keyway. When the connecting disc 10 rotates, it drives the camshaft 9 to rotate, thereby driving the common rail pump 12.

[0045] According to one or more embodiments of the present invention, the connecting disc 10 steps are positioned in conjunction with the inner hole of the fuel injection pump gear 3, wherein the surface roughness of the steps is set to... The step is in clearance fit with the inner hole of the fuel injection pump gear 3, with the clearance range being 0.03mm to 0.09mm. The end face of the fuel injection pump gear 3 is close to the end face of the step of the connecting plate 10, which serves a positioning function.

[0046] According to one or more embodiments of the present invention, the connecting disc 10 and the fuel injection pump gear 3 are made of high-strength, high-toughness, and well-hardenable alloy structural steel 42CrMo-GB / T3077, which is tempered and nitrided, with a core hardness of 280-380HB and a surface hardness of 480-580HV. The surface treatment has a nitriding depth of 0.3-0.5mm. Magnetic particle testing is required before the fuel injection pump gear 3 is hobbed.

[0047] According to one or more embodiments of the present invention, the timing gear assembly 2, the fuel injection pump gear 3, the connecting disc 10, the bushing 8, and the common rail pump camshaft 99 are installed in the transmission housing 1; the fuel injection pump gear 3 and the connecting disc 10 are fixedly connected by eight M8×25-10.9 plates, and the connecting disc 10 is connected to the camshaft 9 of the common rail pump 12 by a 1:5 tapered surface and a semi-circular key 5, and is fixedly connected by an M24×1.5 nut 4.

[0048] Figure 6a This is a schematic diagram showing an axial cross-section of a bushing according to an embodiment of the present invention; Figure 6b yes Figure 6a A magnified view of a portion of the image.

[0049] like Figures 6a to 6b As shown, the common rail pump drive unit for diesel engines also includes: an O-ring rubber seal 11, wherein the outer circle of the bushing 8 extends into the inner hole of the transmission box 1 with clearance fit; wherein a concave groove is provided on the outer circle of the bushing 8 to install an O-ring rubber seal 106×3.55 for sealing the engine oil, wherein the O-ring rubber seal 11 is made of fluororubber.

[0050] According to one or more embodiments of the present invention, the inner hole of the bushing 8 has two sections with different inner diameters, one section being connected to the connecting plate 10 to ensure a gap of 0.036 to 0.125 mm; the other section being connected to the housing of the common rail pump 12 to provide support.

[0051] According to one or more embodiments of the present invention, the bushing 8 is made of alloy structural steel 40Cr-GB / T3078 with high strength and good comprehensive mechanical properties, heat-treated, with a hardness of 28-32HRC, and surface oxidized.

[0052] According to one or more embodiments of the present invention, the timing gear and the fuel injection pump drive gear 21 are fastened together by six M8×30-10.9 bolts 6.

[0053] According to another aspect of the present invention, a diesel engine is provided, comprising:

[0054] Crankshaft gears are used to output power;

[0055] The timing gear assembly 2 includes a timing gear and a fuel injection pump drive gear 21 that are fixedly connected, wherein the timing gear meshes with the diesel engine crankshaft gear;

[0056] The common rail pump drive unit, as described above, is located between the timing gear assembly 2 of the diesel engine and the camshaft 9 of the common rail pump 12 of the diesel engine. The fuel injection pump drive gear 21 transmits torque to the common rail pump drive unit that meshes with it, thereby driving the camshaft 9 of the common rail pump 12 to rotate and driving the common rail pump 12 to supply fuel, thus realizing the fuel supply of the common rail pump 12.

[0057] The original inline pump drive was modified. Since the common rail pump drive still uses the original injection pump drive position, i.e., driven by the original timing gear assembly, and power is transmitted through the meshing of the injection pump drive gear 21 and the injection pump gear, the design of the injection pump gear needs to consider the parameters of the mating gear, the injection pump drive gear. Therefore, the number of teeth, module, and tooth profile angle of the injection pump gear are consistent with those of the injection pump drive gear. Furthermore, due to the limitations of the injection pump gear's installation position, the design of the injection pump gear needs to consider the gear's structural strength, the threaded connection between the injection pump gear and the connecting disc, and the weight reduction requirement to reduce rotational inertia. Therefore, the injection pump gear is designed with an inner concave and outer convex shape.

[0058] For the fuel injection pump gear, the design parameters are: module m=2.5, number of teeth Z=63, pressure angle α=20°, pitch circle φ157.5, and surface roughness... Tooth tip circle φ164.1h9 ( ), tooth root circle φ152.9, roughness The total gear thickness is designed to be 20±0.3mm. To ensure proper meshing, the tooth width is designed to be 16±0.2mm. While ensuring sufficient gear strength, the gear body thickness is designed to be 10mm, with the thinnest part's thickness t guaranteed to be no less than 8mm. Eight elongated holes C are integrated with the eight M8 threaded bolt holes on the connecting plate, with a center distance of φ77±0.1. Hole C is designed as an elongated hole primarily to facilitate bolt connection and fixation between the gear and the connecting plate. The bolts are high-strength fully threaded bolts of GB / T16674.1 M8×25-10.9 with washers and a locking effect. To prevent interference between the bolt head and the timing gear assembly after installation, the gear is designed with a 10mm wide concave portion B. The minimum diameter of the concave portion B, φ108mm, must ensure the bolt head can be installed without protruding from the gear surface. The maximum diameter, φ140, must meet the tooth strength requirements. The gear inner hole is φ56. mm and the boss φ56 of the connecting plate mm clearance fit, serves a positioning function, surface roughness The right end face of the gear is close to the end face of the boss on the connecting disc, and its roughness is... To ensure smooth gear transmission and alignment, the perpendicularity of the right end face to the positioning hole must not exceed 0.03mm; the gear pump end size φ95 is designed in conjunction with the connecting plate.

[0059] The connecting plate serves two purposes: one end connects to the fuel injection pump gear, and the other end connects to the camshaft 9 of the common rail pump 12, thus driving the common rail pump 12. The boss on the connecting plate engages with the inner bore of the fuel injection pump gear for positioning. The boss is designed with a diameter of φ56. mm, length 6.5 mm, roughness It has a clearance fit with the inner bore of the fuel injection pump gear (clearance 0.03mm~0.09mm), and the end face of the fuel injection pump gear is close to the end face of the connecting plate boss, serving a positioning function. The runout of the positioning boss relative to the axis is no greater than 0.025mm, and the perpendicularity of the end face to the axis is no greater than 0.03mm; the inner bore of the connecting plate is designed with a 1:5 taper, and the surface roughness is... The common rail pump camshaft 9 is tapered and connected to the front end of the common rail pump camshaft 9, with a keyway designed. The keyway width is 5±0.015. A 5×7.5×19 key (GB / T1099.1-2003) is installed, and a semi-circular key is used for drive to achieve power transmission. The connecting plate has 8 M8 threaded holes with a center distance of φ77±0.1, which are connected to the fuel injection pump gear with 8 M8×25-10.9 bolts. The outer diameter of the connecting plate, φ97f7, extends into the bushing hole with clearance fit. Based on the structure of the transmission box and the common rail pump 12, the width dimensions of the bushing and connecting plate are designed. The total width of the connecting plate is designed to be 30±0.3, and the width of the threaded hole is 23.5±0.2.

[0060] According to the common rail pump drive device for diesel engines of the present invention, by modifying a six-cylinder diesel engine to install a high-pressure common rail system, and after calibration, debugging, and testing of the common rail diesel engine's ECU (Electronic Control Unit), the common rail diesel engine can meet the original engine's performance. A power enhancement test was conducted on the common rail diesel engine, and the exhaust temperature and detonation pressure were normal at the rated power of 330 kW. During the test, the common rail diesel engine operated smoothly and gently, with significantly reduced noise. All performance parameters met the design requirements, with the rated detonation pressure decreasing from 17 MPa to 16.2 MPa and the exhaust temperature decreasing from 550°C to 488°C. The common rail pump drive device demonstrated stable transmission reliability and no oil leakage throughout the entire operation. This indicates that the design scheme of the common rail pump drive device is feasible, effective, and has achieved substantial success.

[0061] According to the common rail pump drive device for diesel engines of the present invention, the successful development of the common rail pump drive device design provides a practical and feasible technical reference for the installation and transmission of structurally similar functional components in the research and design of diesel engines.

[0062] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. A common rail pump drive device for a diesel engine, wherein, A common rail pump drive unit is positioned between the diesel engine timing gear assembly and the camshaft of the diesel engine common rail pump. It is used to drive the common rail pump camshaft to rotate via the timing gear. The timing gear assembly includes a fixedly connected timing gear and an injection pump drive gear. The timing gear meshes with the diesel engine crankshaft gear, and the injection pump drive gear transmits torque to the meshed common rail pump drive unit, thereby rotating the common rail pump camshaft. The common rail pump drive device includes: The connecting plate is an integral hollow cylindrical structure, wherein the hollow part is a frustum cone shape. The connecting plate and the camshaft are fixed relative to each other in the circumferential direction. When the connecting plate rotates, it drives the camshaft to rotate, thereby driving the common rail pump. The fuel injection pump gear is a hollow disc with an inner concave and outer bulge. The outer peripheral edge is provided with a gear that matches the fuel injection pump drive gear. The end of the connecting disc away from the common rail pump has a radially narrowed step on its outer periphery for fitting and fixing the fuel injection pump gear. The bushing is a cylindrical structure with one end fitted on the outer circumference of the connecting disc and the other end fitted to the common rail pump. It is used to seal the oil in the transmission box and to support and slide the bearing. The fuel injection pump gear is fixedly connected to the connecting plate and meshes with the fuel injection pump drive gear. It is used to transmit power through the timing gear, the fuel injection pump drive gear and the fuel injection pump gear, and then drive the common rail pump camshaft to rotate through the connecting plate, thereby driving the common rail pump to supply fuel and realizing the fuel supply of the common rail pump.

2. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The connecting plate is an integral hollow cylindrical structure, wherein the hollow part is a 1:5 tapered frustum shape. A groove is provided on the inner wall of one side of the hollow part of the connecting plate as a keyway. The connecting plate and the camshaft are fixed circumferentially by a semi-circular key and the keyway. When the connecting plate rotates, it drives the camshaft to rotate, thereby driving the common rail pump.

3. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The connecting plate step is positioned in conjunction with the inner hole of the fuel injection pump gear, wherein the surface roughness of the step is set to... The step is clearance-fitted with the inner hole of the fuel injection pump gear, wherein the clearance range is 0.03mm to 0.09mm, and the end face of the fuel injection pump gear is close to the end face of the connecting plate step, which serves a positioning function.

4. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The connecting disc and the fuel injection pump gear are made of alloy structural steel 42CrMo-GB / T3077, which is quenched and tempered and nitrided. The core hardness is 280~380HB, the surface hardness is 480~580HV, and the surface treatment and nitriding depth is 0.3~0.5mm. Magnetic flaw detection must be performed on the fuel injection pump gear before hobbing.

5. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The timing gear assembly, fuel injection pump gear, coupling disc, bushing, and common rail pump camshaft are installed in the transmission case; the fuel injection pump gear and coupling disc are fixedly connected by eight M8×25-10.9 nuts, and the coupling disc is connected to the common rail pump camshaft by a 1:5 tapered surface and a semi-circular key, and fixedly connected by an M24×1.5 nut.

6. The common rail pump drive device for a diesel engine as described in claim 1, wherein, Also includes: The O-ring rubber seal has an outer circle that extends into the inner hole of the transmission box with a clearance fit. A concave groove is provided on the outer circle of the bushing to install an O-ring rubber seal 106×3.55 for sealing the engine oil. The O-ring rubber seal is made of fluororubber.

7. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The bushing has two sections with different inner diameters. One section is connected to the connecting plate to ensure a clearance of 0.036 to 0.125 mm; the other section is connected to the common rail pump housing to provide support.

8. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The bushing is made of alloy structural steel 40Cr-GB / T3078, which has high strength and good comprehensive mechanical properties. It is quenched and tempered, with a hardness of 28-32HRC, and surface oxidized.

9. The common rail pump drive device for a diesel engine as described in claim 1, wherein, The timing gear and the fuel injection pump drive gear are fastened together by six M8×30-10.9 bolts.

10. A diesel engine, wherein, include: Crankshaft gears are used to output power; The timing gear assembly includes a timing gear and a fuel injection pump drive gear that are fixedly connected, wherein the timing gear meshes with the crankshaft gear of the diesel engine; The common rail pump drive device, as described in any one of claims 1-9, is disposed between the timing gear assembly of the diesel engine and the camshaft of the diesel engine common rail pump. The fuel injection pump drive gear transmits torque to the common rail pump drive device meshing with it, thereby driving the camshaft of the common rail pump to rotate and driving the common rail pump to supply fuel, thus realizing the fuel supply of the common rail pump.

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