Lubricating oil pump overload protection device and overload protection method

Abstract

The invention discloses a lubricating oil pump overload protection device and an overload protection method, and belongs to the field of lubricating oil pump protection. An oil scavenger pump driving spline shaft is sequentially sleeved with a first oil scavenger pump driving gear and a second oil scavenger pump driving gear, and one end of the second oil scavenger pump driving gear is sleeved with one end of an oil supply pump driving gear shaft; a gap is reserved between the oil supply pump driving gear shaft and the oil scavenger pump driving spline shaft; a first oil scavenger pump driven gear, a second oil scavenger pump driven gear and an oil supply pump driven gear are arranged on the driven shaft, and the driven gears are meshed with corresponding driving gears; oil outlets are formed in the positions, corresponding to the first oil scavenging pump driven gear, the second oil scavenging pump driven gear and the oil supply pump driven gear, of the driven shaft. When the first and second oil scavenger pump driven gears, the oil supply pump driven gear and the driven shaft are abnormally worn, metal particles and particles flow through the driven shaft to block the oil outlet hole and the gaps between the first and second oil scavenger pump driven gears and between the oil supply pump driven gear and the driven shaft, so that the first and second oil scavenger pump driven gears and the oil supply pump driven gear are prevented from rotating; the torque transmission device is simple in structure, reliable in torque transmission and accurate in centering, and faults caused by abnormal conditions are reduced.

Description

Technical Field

[0001] The invention belongs to the field of lubricating oil pump protection, and in particular relates to a lubricating oil pump overload protection device and an overload protection method. Background Art

[0002] The oil pump, which is currently widely used in the lubricating oil system of aircraft engines, is the core device of the entire system. The lubricating oil system provides the engine's bearings, gears and splines with an appropriate amount of lubricating oil for lubrication and cooling to ensure the normal operation of the engine's bearings, gears and splines. The lubricating oil pump can continuously output the required lubricating oil flow according to the changes in the engine's working state, and deliver the lubricating oil to the engine's bearings, gears and splines for lubrication and cooling. It also draws the lubricating oil used for lubrication and cooling in each cavity back into the oil tank to form a cycle to ensure the normal and stable operation of the system.

[0003] Gear oil pump is a widely used type, which uses the meshing rotation of two gears of the same size to transfer the oil from the inlet to the outlet. In the gear oil pump, one gear is the driving gear and the other is the driven gear.

[0004] In the prior art, the driving gear of the oil supply pump (or oil return pump) is driven by a driving shaft, and the driven gear is fixed on another shaft and rotates freely. Once the oil return pump fails, it cannot continue to work, while the driving shaft in the oil supply pump continues to work and the oil supply pump continues to provide lubricating oil, resulting in excessive lubricating oil in the bearing part, serious internal leakage, and a fire hazard. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an overload protection device and an overload protection method for a lubricating oil pump, which have a simple structure, reliable torque transmission, and accurate centering, thereby ensuring that the lubricating oil pump can work reliably while ensuring safety and reducing failures caused by abnormal situations.

[0006] The present invention is achieved through the following technical solutions: A lubricating oil pump overload protection device comprises a return oil pump driving spline shaft and a driven shaft horizontally arranged on a housing; The first oil return pump driving gear and the second oil return pump driving gear are arranged on the oil return pump driving spline shaft in sequence through a spline sleeve, and one end of the second oil return pump driving gear away from the oil return pump driving spline shaft is arranged on one end of the oil supply pump driving gear shaft through a spline sleeve, and a gap is left between the oil supply pump driving gear shaft and the oil return pump driving spline shaft to form an active driving gear shaft assembly; The driven shaft is provided with a first oil return pump driven gear, a second oil return pump driven gear and a fuel supply pump driven gear in sequence with clearance fit, the first oil return pump driven gear is meshed with the first oil return pump driving gear, the second oil return pump driven gear is meshed with the second oil return pump driving gear, and the fuel supply pump driven gear is meshed with the gear on the fuel supply pump driving gear shaft; The driven shaft is provided with radially distributed oil outlet holes at positions corresponding to the first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear.

[0007] Preferably, bushings are installed on the inner cylindrical surfaces of the first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear, and the driven shafts are clearance-matched with the corresponding bushings.

[0008] Preferably, the driven shaft is located above the return oil pump driving spline shaft, and two first hollow cylindrical sections and second hollow cylindrical sections coaxially distributed with the driven shaft are arranged in the driven shaft at intervals, the length of the first hollow cylindrical section is greater than that of the second hollow cylindrical section, and the oil outlet hole is connected to the first hollow cylindrical section.

[0009] Preferably, the shell is a hollow cylinder with a support plate fixed at the opening, the return oil pump driving spline shaft and one end of the driven shaft are arranged in the support plate, and the other end of the driven shaft and the other end of the oil supply pump driving gear shaft are plugged into the bottom plate of the shell.

[0010] Furthermore, a support ring is horizontally extended outward from the opening of the shell, the support ring is fitted with the inner end of the support plate, and a pressure cover is fitted with the outer end of the support plate. The support ring, the support plate and the pressure cover are fixedly connected by a first bolt and a first nut that cooperate with each other.

[0011] Further, the longitudinal section of the driving gear of the first oil return pump is T-shaped, and the longitudinal sections of the driving gear shaft of the second oil return pump and the driving gear shaft of the oil supply pump are both cross-shaped; A corresponding groove is provided at one end of the first oil return pump driving gear opposite to the second oil return pump driving gear, one end of the second oil return pump driving gear is inserted into the groove of the first oil return pump driving gear and a gap is left with the first oil return pump driving gear, one end of the oil supply pump driving gear shaft has an external spline, and the external spline at one end of the oil supply pump driving gear shaft is meshed with the internal spline at the corresponding end of the second oil return pump driving gear.

[0012] Further, it also includes a first inner shell, a second inner shell, a third inner shell and a baffle, the shell being an outer shell, the driven gear of the oil supply pump and the gears on the driving gear shaft of the oil supply pump having the same length and being aligned with each other, forming an oil supply pump, the driven gear of the first oil return pump and the gear parts of the driving gear of the first oil return pump having the same length and being aligned with each other, forming a first oil return pump, the driven gear of the second oil return pump and the gear parts of the driving gear of the second oil return pump having the same length and being aligned with each other, forming a second oil return pump; One side of the baffle is fitted with the bottom plate of the shell, and the other side of the baffle is fitted with the oil supply pump. A first inner shell is fitted between the oil supply pump and the second oil return pump, a second inner shell is fitted between the second oil return pump and the first oil return pump, and a third inner shell is fitted at the outer end of the first oil return pump. A first through hole corresponding to the driven shaft is respectively provided on the baffle, the first inner shell, the second inner shell and the third inner shell, a second through hole corresponding to the other end of the driving gear shaft of the oil supply pump is provided on the baffle, a third through hole corresponding to one end of the driving gear shaft of the oil supply pump and a corresponding end of the driving gear of the second oil return pump is provided on the first inner shell, a fourth through hole corresponding to the other end of the driving gear of the second oil return pump is provided on the second inner shell, and a fifth through hole corresponding to the narrow end of the driving gear of the first oil return pump is provided on the third inner shell; The other end of the driven shaft passes through the first through holes on the baffle, the first inner housing, the second inner housing and the third inner housing in sequence and is then plugged into the bottom plate of the housing; the other end of the driving gear shaft of the oil supply pump passes through the second through hole and is then plugged into the bottom plate of the housing; one end of the driving gear shaft of the oil supply pump and one corresponding end of the driving gear of the second oil return pump are plugged into the third through hole; the other end of the driving gear of the second oil return pump is plugged into the fourth through hole; the narrow end of the driving gear of the first oil return pump is plugged into the fifth through hole; the first inner housing, the second inner housing, the third inner housing, the baffle and the bottom plate of the housing are fixedly connected by second bolts and second nuts that cooperate with each other.

[0013] Furthermore, it also includes a positioning pin, and the third inner shell and the driven shaft are respectively provided with a sixth through hole and a seventh through hole which are plugged into and cooperate with the upper and lower ends of the positioning pin. The sixth through hole is cylindrical, and the longitudinal section of the seventh through hole is T-shaped, and the upper end diameter is smaller than the sixth through hole. The lower end of the positioning pin is fixedly inserted in the seventh through hole and extends out of the driven shaft, and the upper end of the positioning pin is fixedly inserted in the sixth through hole, and the upper end surface of the positioning pin is higher than the third inner shell.

[0014] Furthermore, the narrow end of the first oil return pump driving gear, the rod portion of the other end of the second oil return pump driving gear, and the junction of the oil supply pump driving gear shaft and the second oil return pump driving gear are sequentially provided with a first oil inlet hole, a second oil inlet hole and a third oil inlet hole, the first oil inlet hole is connected with the corresponding oil outlet hole on the driven shaft through the oil through hole in the third inner shell body, the second oil inlet hole is connected with the corresponding oil outlet hole on the driven shaft through the oil through hole in the second inner shell body, the third oil inlet hole is connected with the corresponding oil outlet hole on the driven shaft through the oil through hole in the first inner shell body, and the first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear are respectively provided with a first oil outlet hole, a second oil outlet hole and a third oil outlet hole connected with the corresponding oil outlet holes on the driven shaft.

[0015] A lubricating oil pump overload protection method, based on any one of the lubricating oil pump overload protection devices described above, comprises the following process: S1, the oil return pump drives the spline shaft to drive the first oil return pump driving gear, the second oil return pump driving gear and the oil supply pump driving gear shaft to rotate, the first oil return pump driving gear drives the first oil return pump driven gear to rotate on the driven shaft to form the first oil return pump, the second oil return pump driving gear drives the second oil return pump driven gear to rotate on the driven shaft to form the second oil return pump, and the gear on the oil supply pump driving gear shaft drives the oil supply pump driven gear to rotate on the driven shaft to form the oil supply pump; S2: When the driven gear of the first oil return pump, the driven gear of the second oil return pump, the driven gear of the oil supply pump and the driven shaft are abnormally worn, metal shavings particles appear, and the particles flow through the driven shaft, blocking the oil outlet hole and the gap between the driven gear of the first oil return pump, the driven gear of the second oil return pump, the driven gear of the oil supply pump and the driven shaft, thereby preventing the rotation of the driven gear of the first oil return pump, the driven gear of the second oil return pump and the driven gear of the oil supply pump, and further preventing the rotation of the driving spline shaft of the oil return pump, and the oil supply pump stops supplying oil, thereby realizing overload protection of the lubricating oil pump. Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses an overload protection device for a lubricating oil pump. The return oil pump driving spline shaft, the first return oil pump driving gear, the second return oil pump driving gear and the oil supply pump driving gear shaft are meshed together through splines to form an active driving gear shaft assembly. The return oil pump driving spline shaft and the oil supply pump driving gear shaft are not in direct contact, and a certain gap is left, which can ensure that the two shafts can rotate in a certain range in the axial, radial and angular directions without interfering with each other. The return oil pump driving spline shaft and the oil supply pump driving gear shaft are connected to the second return oil pump driving gear through splines, which not only ensures reliable torque transmission, but also ensures reliable centering, and adapts to changes within a certain angle range. The first return oil pump driven gear is meshed with the first return oil pump driving gear, the second return oil pump driven gear is meshed with the second return oil pump driving gear, and the oil supply pump driven gear is meshed with the gear on the oil supply pump driving gear shaft, and the corresponding driven gear can be driven to rotate through the corresponding driving gear, thereby forming an oil supply pump and a return oil pump. The driven shaft is provided with radially distributed oil outlet holes at the positions corresponding to the first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear, so as to facilitate the outflow of lubricating oil. The first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear are matched with the driven shaft clearance, so as to facilitate the flow of lubricating oil and form liquid film lubrication. When the first oil return pump driven gear, the second oil return pump driven gear, the oil supply pump driven gear and the driven shaft are abnormally worn, and larger and more metal shavings particles appear, larger and more metal shavings particles flow through the driven shaft. Since the oil outlet hole of the driven shaft is small and the matching clearance with the corresponding driven gear is also small, it will cause metal jamming, so that the driven shaft and the corresponding driven gear are bonded, and the rotation of the driven gear is prevented, resulting in a larger load on the rotation of the lubricating oil pump, and the rotation of the return pump driving spline shaft is prevented. When metal chips are blocked seriously and the load is large, the corresponding gears are stuck, generating large reverse torque, causing the return oil pump to drive the spline shaft to twist and deform, and in severe cases, it will break, and the lubricating oil system will stop supplying oil to the engine, causing the lubricating oil pressure of the system to drop, thereby avoiding engine fire and pollution accidents caused by oil leakage at the sealing part of the bearing cavity. The present invention has a simple structure, reliable torque transmission, and accurate centering. In the case of abnormal return oil pump failure, the oil supply pump can stop working, ensuring the safety of the use of the lubricating oil system, and can be applied to the lubricating oil pump of the aircraft engine lubricating oil system, improving the reliability of the engine operation.

[0016] The present invention discloses an overload protection method for a lubricating oil pump. The oil return pump drives a spline shaft to drive a first oil return pump driving gear, a second oil return pump driving gear and an oil supply pump driving gear shaft to rotate. The first oil return pump driving gear drives the first oil return pump driven gear to rotate on the driven shaft to form a first oil return pump. The second oil return pump driving gear drives the second oil return pump driven gear to rotate on the driven shaft to form a second oil return pump. The gear on the oil supply pump driving gear shaft drives the oil supply pump driven gear to rotate on the driven shaft to form an oil supply pump. When the first oil return pump driven gear, the second oil return pump driven gear, the oil supply pump driven gear and the driven shaft are abnormally worn, causing the entire lubricating oil system to malfunction, larger and more metal chips particles will be generated. These particles will flow through the driven shaft, and then block the oil outlet hole and the gap between the first oil return pump driven gear, the second oil return pump driven gear, the oil supply pump driven gear and the driven shaft, further preventing the rotation of the first oil return pump driven gear, the second oil return pump driven gear and the oil supply pump driven gear, and then preventing the rotation of the return pump drive spline shaft, and finally stopping the oil supply pump from supplying oil to the engine, causing the system's lubricating oil pressure to drop, thereby avoiding engine fire and pollution accidents caused by oil leakage at the bearing cavity seal, and finally achieving overload protection for the lubricating oil pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the overload protection device of the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the structure of the spline shaft driving the medium return oil pump.

[0019] Figure 3 yes Figure 1 Schematic diagram of the structure of the driving gear of the second oil return pump.

[0020] Figure 4 yes Figure 1 Schematic diagram of the structure of the driving gear shaft of the oil supply pump.

[0021] Figure 5 yes Figure 1 Schematic diagram of the structure of the driven shaft.

[0022] Figure 6 yes Figure 1 Schematic diagram of the structure of the driven gear of the oil supply pump.

[0023] In the figure: 1-return oil pump driving spline shaft, 2-first return oil pump driving gear, 3-second return oil pump driving gear, 4-supply oil pump driving gear shaft, 5-supply oil pump driven gear, 6-second return oil pump driven gear, 7-first return oil pump driven gear, 8-locating pin, 9-driven shaft, 10-first bolt, 11-first nut, 12-housing, 13-pressure cover, 14-second bolt, 15-second nut, 16-first inner housing, 17-second inner housing, 18-third inner housing, 19-baffle, 20-bushing, 21-support plate. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0025] The present invention provides an overload protection device for a lubricating oil pump, wherein overload means that the tooth surface of the corresponding gear is subjected to excessive force, such as Figure 1 As shown, it includes a return oil pump driving spline shaft 1 and a driven shaft 9 horizontally arranged on a housing 12, and the return oil pump driving spline shaft 1, a first return oil pump driving gear 2, a second return oil pump driving gear 3, a supply oil pump driving gear shaft 4, a supply oil pump driven gear 5, a second return oil pump driven gear 6, a right return oil pump driven gear 7, a positioning pin 8, a driven shaft 9, a first inner housing 16, a second inner housing 17, a third inner housing 18 and a baffle 19. The lubricating oil pump is composed of a supply oil pump and a return oil pump, and these pumps are installed in an outer housing, that is, the housing 12. The rotating parts return oil pump driving spline shaft 1, the first return oil pump driving gear 2, the second return oil pump driving gear 3 and the supply oil pump driving gear shaft 4 belong to the active drive assembly, and the supply oil pump driven gear 5, the second return oil pump driven gear 6, the right return oil pump driven gear 7, and the driven shaft 9 belong to the driven assembly.

[0026] The active drive assembly is divided into 4 sections, including a return oil pump drive spline shaft 1 with external splines, a first return oil pump driving gear 2 with internal splines, a second return oil pump driving gear 3 with internal splines at both ends, and a supply oil pump driving gear shaft 4 with external splines, which are meshed together through splines. Specifically, the spline end of the return oil pump drive spline shaft 1 is provided with a first return oil pump driving gear 2 and a second return oil pump driving gear 3 through an external spline sleeve from the outside to the inside, and the end of the second return oil pump driving gear 3 away from the return oil pump drive spline shaft 1 is provided at one end of the supply oil pump driving gear shaft 4 through an internal spline sleeve. The hollow part of the outer end of the return oil pump drive spline shaft 1 is connected to the input shaft to form an active drive gear shaft assembly. The return oil pump drive spline shaft 1 and the supply oil pump driving gear shaft 4 are not in direct contact, and a certain gap is left to ensure that the two shafts can rotate within a certain range in the axial, radial and angular directions without interfering with each other.

[0027] The oil return pump driving spline shaft 1 with external splines and the oil supply pump driving gear shaft 4 with external splines are connected to the second oil return pump driving gear 3 with internal splines at both ends through splines, which can ensure reliable torque transmission and reliable centering, and adapt to changes within a certain angle range.

[0028] The driven assembly is composed of a driven shaft 9 and a fuel supply pump driven gear 5, a second fuel return pump driven gear 6, and a first fuel return pump driven gear 7. All driven gears (first fuel return pump driven gear 7, second fuel return pump driven gear 6, and fuel supply pump driven gear 5) are clearance-matched with the driven shaft 9 in sequence from outside to inside, and can rotate around the driven shaft 9. The driven gears are meshed with the corresponding driving gears (the first oil return pump driven gear 7 is meshed with the first oil return pump driving gear 2, the second oil return pump driven gear 6 is meshed with the second oil return pump driving gear 3, and the oil supply pump driven gear 5 is meshed with the gear on the oil supply pump driving gear shaft 4). The gears on the oil supply pump driven gear 5 and the oil supply pump driving gear shaft 4 are the same length and are aligned with each other to form an oil supply pump. The gear parts of the first oil return pump driven gear 7 and the first oil return pump driving gear 2 are the same length and are aligned with each other to form a first oil return pump. The gear parts of the second oil return pump driven gear 6 and the second oil return pump driving gear 3 are the same length and are aligned with each other to form a second oil return pump.

[0029] As a preferred embodiment, the present invention has copper bushings installed on the inner cylindrical surfaces of the driven gears (the first oil return pump driven gear 7, the second oil return pump driven gear 6 and the oil supply pump driven gear 5). In order to show their positions more clearly, Figure 6 A specific illustration is given in Figure 6 It is the structure of the oil supply pump driven gear 5, and can also be the first oil return pump driven gear 7 and the second oil return pump driven gear 6, wherein the bushing is recorded as bushing 20, and the inner cylindrical surface of the driven gear and the outer cylindrical surface of the bushing 20 are tightly matched to ensure that they rotate together during operation. Therefore, the driven shaft 9 is clearance-matched with the corresponding bushing on the driven gear.

[0030] In the present invention, the oil return pump driving spline shaft 1 is located below the driven shaft 9, the housing 12 is specifically a hollow cylinder, a support plate 21 is fixed at the opening, one end of the oil return pump driving spline shaft 1 and one end of the driven shaft 9 are both arranged (with a gap) in the support plate 21, and the other end of the driven shaft 9 and the other end of the oil supply pump driving gear shaft 4 are both plugged (with a gap) on the bottom plate of the housing 12. Specifically, a support ring extends horizontally outward at the opening of the housing 12, the support ring is fitted with the inner end of the support plate 21, and a pressure cover 13 is fitted at the outer end of the support plate 21, and the support ring, the support plate 21 and the pressure cover 13 are fixedly connected by the first bolt 10 and the first nut 11 that cooperate with each other.

[0031] like Figure 2As shown, the oil return pump driving spline shaft 1 is distributed in a stepped manner along the axial direction, such as Figure 3 and Figure 4 As shown, the longitudinal sections of the second oil return pump driving gear 3 and the oil supply pump driving gear shaft 4 are both cross-shaped, the first oil return pump driving gear 2 is half of the second oil return pump driving gear 3 along the axial center, and its longitudinal section is T-shaped, and the end of the first oil return pump driving gear 2 opposite to the second oil return pump driving gear 3 is provided with a corresponding groove, and one end of the second oil return pump driving gear 3 is inserted into the groove of the first oil return pump driving gear 2 and leaves a gap with the first oil return pump driving gear 2.

[0032] Figure 1 In the embodiment, the bottom plate of the housing 12 is fitted with the inner side of the baffle 19, and the outer side of the baffle 19 is fitted with the oil supply pump. The first inner housing 16 is fitted and distributed between the oil supply pump and the second oil return pump. Similarly, the second inner housing 17 is fitted and distributed between the second and first oil return pumps, and the third inner housing 18 is fitted and distributed at the outer end of the first oil return pump. In order to facilitate installation and positioning, through holes corresponding to the driven shaft 9 are respectively opened on the baffle 19, the first inner housing 16, the second inner housing 17 and the third inner housing 18. For the convenience of description, they are not repeated in words with the subsequent through holes and are recorded as the first through holes. Similar to the subsequent through holes, they are not required to be in Figure 1 The marks in the middle are only for the purpose of clearly describing the installation method of the first inner housing 16, the second inner housing 17, the third inner housing 18 and the baffle 19. The baffle 19 is provided with a second through hole corresponding to the other end of the oil supply pump driving gear shaft 4, the first inner housing 16 is provided with a third through hole corresponding to one end of the oil supply pump driving gear shaft 4 and the corresponding end of the second oil return pump driving gear 3, further, the second inner housing 17 is provided with a fourth through hole corresponding to the other end of the second oil return pump driving gear 3, and the third inner housing 18 is provided with a fifth through hole corresponding to the narrow end of the first oil return pump driving gear 2. In this way, the other end of the driven shaft 9 can be inserted into the bottom plate of the housing 12 after passing through the first through holes on the baffle 19, the first inner housing 16, the second inner housing 17 and the third inner housing 18 in sequence. Similarly, the other end of the oil supply pump driving gear shaft 4 can pass through the second through hole and be inserted into the bottom plate of the housing 12, one end of the oil supply pump driving gear shaft 4 and the corresponding end of the second oil return pump driving gear 3 can be inserted into the third through hole, the other end of the second oil return pump driving gear 3 can be inserted into the fourth through hole, and the narrow end of the first oil return pump driving gear 2 can be inserted into the fifth through hole, so that the first inner housing 16, the second inner housing 17, the third inner housing 18, the baffle 19 and the bottom plate of the housing 12 can be fixedly connected by the second bolts 14 and the second nuts 15 that cooperate with each other.

[0033] like Figure 5As shown, the driven shaft 9 is made of hollow cylindrical material, and the interior is hollow and separated into two parts, one end is longer (the first hollow cylindrical section), and the other is shorter (the second hollow cylindrical section), and the first hollow cylindrical section and the second hollow cylindrical section are coaxially distributed with the driven shaft 9. The longer section is connected to the corresponding part of the driven gear (the first return oil pump driven gear 7, the second return oil pump driven gear 6 and the oil supply pump driven gear 5) and is provided with radially distributed oil outlet holes to facilitate the outflow of lubricating oil. The narrow end of the first oil return pump driving gear 2, the rod portion of the other end of the second oil return pump driving gear 3, and the junction of the oil supply pump driving gear shaft 4 and the second oil return pump driving gear 3 are sequentially provided with the first, second and third oil inlet holes (all of which are conventional designs). The first oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft 9 through the V-shaped oil through hole in the third inner housing 18, the second oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft 9 through the V-shaped oil through hole in the second inner housing 17, and the third oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft 9 through the V-shaped oil through hole in the first inner housing 16. Correspondingly, the first oil return pump driven gear 7, the second oil return pump driven gear 6 and the oil supply pump driven gear 5 are respectively provided with the first, second and third oil outlet holes (all of which are conventional designs) connected to the corresponding oil outlet holes on the driven shaft 9. The lubricating oil passes through the oil passage holes (i.e. the V-shaped oil passage holes mentioned above) on the first inner housing 16, the second inner housing 17, and the third inner housing 18, and enters the hollow interior of the driven shaft 9 through the radial bottom of the driven shaft 9. The lubricating oil directly lubricates the clearance between the corresponding bushing mating surfaces through a row of holes on the driven shaft 9. The inner cylindrical surface of the bushing and the outer cylindrical surface of the driven shaft 9 are clearance-matched, which facilitates the flow of lubricating oil and forms liquid film lubrication.

[0034] The present invention provides a sixth through hole on the third inner housing 18 for plugging with the upper end of the locating pin 8, and provides a seventh through hole on the driven shaft 9 for plugging with the lower end of the locating pin 8. The sixth through hole is specifically cylindrical, and the longitudinal section of the seventh through hole is T-shaped, and the upper end diameter is smaller than the sixth through hole. The lower end of the locating pin 8 is fixedly inserted in the seventh through hole and extends out of the driven shaft 9, and the upper end of the locating pin 8 is fixedly inserted in the sixth through hole. The upper end surface of the locating pin 8 is higher than the third inner housing 18. Therefore, the locating pin 8 is a stepped segmented structure, which can ensure that the driven shaft 9 does not rotate when the lubricating oil pump is working.

[0035] The present invention provides a lubricating oil pump overload protection method. When a lubricating oil system fails, the first oil return pump driven gear 7, the second oil return pump driven gear 6, the oil supply pump driven gear 5 and the driven shaft 9 are abnormally worn, and large and more metal shavings appear, which brings hidden dangers to the safe and reliable operation of the engine. Large and more metal shavings flow through the driven shaft 9. Since the oil outlet of the driven shaft 9 is small, the matching clearance of the bushing corresponding to the driven gear (the corresponding driven gear when there is no bushing) is also small, which will block the oil outlet and the clearance, resulting in metal stagnation, so that the driven shaft and the bushing (the corresponding driven gear when there is no bushing) are bonded, preventing the rotation of the driven gear, resulting in a large load on the rotation of the lubricating oil pump, and preventing the rotation of the return pump drive spline shaft 1. The metal shavings are seriously blocked. When the load is large, the corresponding gear is stuck, generating a large reverse torque, causing the return pump drive spline shaft 1 to twist and deform. In severe cases, it will break and the lubricating oil system stops supplying oil.

[0036] The oil supply pump is placed at the farthest end of the input shaft of the active drive assembly. When the gear of any stage of the oil return pump fails, the oil supply pump will stop supplying oil to the engine, causing the system's lubricating oil pressure to drop, thereby avoiding engine fires and pollution accidents caused by oil leakage at the bearing cavity seal.

Claims

1. A lubricating oil pump overload protection device, characterized in that: It comprises an oil return pump driving spline shaft (1) and a driven shaft (9) which are horizontally arranged on a housing (12); The oil return pump driving spline shaft (1) is provided with a first oil return pump driving gear (2) and a second oil return pump driving gear (3) in sequence through a spline sleeve, and one end of the second oil return pump driving gear (3) away from the oil return pump driving spline shaft (1) is provided on one end of the oil supply pump driving gear shaft (4) through a spline sleeve, and a gap is left between the oil supply pump driving gear shaft (4) and the oil return pump driving spline shaft (1); The driven shaft (9) is clearance-matched with a first oil return pump driven gear (7), a second oil return pump driven gear (6) and an oil supply pump driven gear (5) in sequence; the first oil return pump driven gear (7) is meshed with the first oil return pump driving gear (2); the second oil return pump driven gear (6) is meshed with the second oil return pump driving gear (3); and the oil supply pump driven gear (5) is meshed with a gear on the oil supply pump driving gear shaft (4); The driven shaft (9) is provided with radially distributed oil outlet holes at locations corresponding to the first oil return pump driven gear (7), the second oil return pump driven gear (6) and the oil supply pump driven gear (5).

2. The lubricating oil pump overload protection device according to claim 1, characterized in that: The inner cylindrical surfaces of the first oil return pump driven gear (7), the second oil return pump driven gear (6) and the oil supply pump driven gear (5) are all equipped with bushings, and the driven shaft (9) is clearance-matched with the corresponding bushings.

3. The lubricating oil pump overload protection device according to claim 1, characterized in that: The driven shaft (9) is located above the oil return pump driving spline shaft (1), and two first hollow cylindrical sections and second hollow cylindrical sections coaxially distributed with the driven shaft (9) are arranged in the driven shaft (9) at intervals, the length of the first hollow cylindrical section is greater than that of the second hollow cylindrical section, and the oil outlet hole is connected to the first hollow cylindrical section.

4. The lubricating oil pump overload protection device according to claim 1, characterized in that: The housing (12) is in the shape of a hollow cylinder, with a support plate (21) fixed at the opening. The oil return pump driving spline shaft (1) and one end of the driven shaft (9) are arranged in the support plate (21), and the other end of the driven shaft (9) and the other end of the oil supply pump driving gear shaft (4) are plugged into the bottom plate of the housing (12).

5. The lubricating oil pump overload protection device according to claim 4, characterized in that: A support ring is provided at the opening of the shell (12) extending outwardly horizontally, the support ring is fitted with the inner end of the support plate (21), and a pressure cover (13) is fitted with the outer end of the support plate (21), and the support ring, the support plate (21) and the pressure cover (13) are fixedly connected by means of first bolts (10) and first nuts (11) that cooperate with each other.

6. The lubricating oil pump overload protection device according to claim 5, characterized in that: The longitudinal section of the first oil return pump driving gear (2) is T-shaped, and the longitudinal sections of the second oil return pump driving gear (3) and the oil supply pump driving gear shaft (4) are both cross-shaped; A corresponding groove is formed at one end of the first oil return pump driving gear (2) opposite to the second oil return pump driving gear (3); one end of the second oil return pump driving gear (3) is inserted into the groove of the first oil return pump driving gear (2) and a gap is left between the first oil return pump driving gear (2); one end of the oil supply pump driving gear shaft (4) has an external spline, and the external spline at one end of the oil supply pump driving gear shaft (4) meshes with the internal spline at the corresponding end of the second oil return pump driving gear (3).

7. The lubricating oil pump overload protection device according to claim 6, characterized in that: It also includes a first inner housing (16), a second inner housing (17), a third inner housing (18) and a baffle (19), wherein the housing (12) is an outer housing, the gears on the driven gear (5) of the oil supply pump and the driving gear shaft (4) of the oil supply pump are of the same length and aligned with each other, forming an oil supply pump, the gear parts of the driven gear (7) of the first oil return pump and the driving gear (2) of the first oil return pump are of the same length and aligned with each other, forming a first oil return pump, and the gear parts of the driven gear (6) of the second oil return pump and the driving gear (3) of the second oil return pump are of the same length and aligned with each other, forming a second oil return pump; One side of the baffle (19) is fitted with the bottom plate of the housing (12), and the other side of the baffle (19) is fitted with the oil supply pump. A first inner housing (16) is fitted between the oil supply pump and the second oil return pump, a second inner housing (17) is fitted between the second oil return pump and the first oil return pump, and a third inner housing (18) is fitted on the outer side of the first oil return pump. The baffle (19), the first inner housing (16), the second inner housing (17) and the third inner housing (18) are respectively provided with a shaft connected to the driven shaft (9 ), a first through hole corresponding to the other end of the oil supply pump driving gear shaft (4) is formed on the baffle (19), a second through hole corresponding to the other end of the oil supply pump driving gear shaft (4) is formed on the first inner housing (16), a third through hole corresponding to one end of the oil supply pump driving gear shaft (4) and the corresponding end of the second oil return pump driving gear (3) is formed on the first inner housing (16), a fourth through hole corresponding to the other end of the second oil return pump driving gear (3) is formed on the second inner housing (17), and a fifth through hole corresponding to the narrow end of the first oil return pump driving gear (2) is formed on the third inner housing (18); The other end of the driven shaft (9) passes through the first through holes on the baffle plate (19), the first inner housing (16), the second inner housing (17) and the third inner housing (18) in sequence and is then plugged into the bottom plate of the housing (12); the other end of the oil supply pump driving gear shaft (4) passes through the second through hole and is then plugged into the bottom plate of the housing (12); one end of the oil supply pump driving gear shaft (4) and a corresponding end of the second oil return pump driving gear (3) are plugged into the third through hole; the other end of the second oil return pump driving gear (3) is plugged into the fourth through hole; the narrow end of the first oil return pump driving gear (2) is plugged into the fifth through hole; the first inner housing (16), the second inner housing (17), the third inner housing (18), the baffle plate (19) and the bottom plate of the housing (12) are fixedly connected by second bolts (14) and second nuts (15) that cooperate with each other.

8. The lubricating oil pump overload protection device according to claim 7, characterized in that: It also includes a positioning pin (8), and the third inner housing (18) and the driven shaft (9) are respectively provided with a sixth through hole and a seventh through hole that are plugged into and matched with the upper and lower ends of the positioning pin (8), the sixth through hole is cylindrical, the longitudinal section of the seventh through hole is T-shaped, and the upper end diameter is smaller than the sixth through hole, the lower end of the positioning pin (8) is fixedly inserted in the seventh through hole and extends out of the driven shaft (9), the upper end of the positioning pin (8) is fixedly inserted in the sixth through hole, and the upper end surface of the positioning pin (8) is higher than the third inner housing (18).

9. The lubricating oil pump overload protection device according to claim 7, characterized in that: A first oil inlet hole, a second oil inlet hole and a third oil inlet hole are sequentially provided at the narrow end of the first oil return pump driving gear (2), the rod portion at the other end of the second oil return pump driving gear (3), and the junction of the oil supply pump driving gear shaft (4) and the second oil return pump driving gear (3). The first oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft (9) through the oil through hole in the third inner housing (18), the second oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft (9) through the oil through hole in the second inner housing (17), and the third oil inlet hole is connected to the corresponding oil outlet hole on the driven shaft (9) through the oil through hole in the first inner housing (16). The first oil return pump driven gear (7), the second oil return pump driven gear (6) and the oil supply pump driven gear (5) are respectively provided with a first oil outlet hole, a second oil outlet hole and a third oil outlet hole connected to the corresponding oil outlet hole on the driven shaft (9).

10. A lubricating oil pump overload protection method, characterized in that: The lubricating oil pump overload protection device according to any one of claims 1 to 9 comprises the following process: S1, the oil return pump driving spline shaft (1) drives the first oil return pump driving gear (2), the second oil return pump driving gear (3) and the oil supply pump driving gear shaft (4) to rotate, the first oil return pump driving gear (2) drives the first oil return pump driven gear (7) to rotate on the driven shaft (9) to form a first oil return pump, the second oil return pump driving gear (3) drives the second oil return pump driven gear (6) to rotate on the driven shaft (9) to form a second oil return pump, and the gear on the oil supply pump driving gear shaft (4) drives the oil supply pump driven gear (5) to rotate on the driven shaft (9) to form an oil supply pump; S2, when the first oil return pump driven gear (7), the second oil return pump driven gear (6), the oil supply pump driven gear (5) and the driven shaft (9) are abnormally worn, metal shavings appear, and the particles flow through the driven shaft (9), blocking the oil outlet hole and the gap between the first oil return pump driven gear (7), the second oil return pump driven gear (6), the oil supply pump driven gear (5) and the driven shaft (9), thereby preventing the first oil return pump driven gear (7), the second oil return pump driven gear (6) and the oil supply pump driven gear (5) from rotating, thereby preventing the oil return pump drive spline shaft (1) from rotating, and the oil supply pump stops supplying oil, thereby achieving overload protection for the lubricating oil pump.

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