Gear oil pump

Abstract

The utility model discloses a gear oil pump which comprises a driving gear. A driven shaft coaxially penetrates through the driving gear, the lower end of the driven shaft is fixedly connected with the driving gear, the upper end of the driven shaft is connected with the driving shaft through an overload protection structure, and the overload protection structure comprises a variable-diameter protruding part coaxially fixed to the driven shaft and a variable-diameter containing part coaxially arranged outside the variable-diameter protruding part in a sleeving mode; a driving shaft is coaxially fixed at the upper end of the variable-diameter accommodating part and is connected with a driving device; when the friction force between the variable-diameter containing part and the variable-diameter protruding part is large enough to drive the driven shaft to rotate, the variable-diameter containing part is fixedly connected with the variable-diameter protruding part, and when the friction force between the variable-diameter containing part and the variable-diameter protruding part is not large enough to drive the driven shaft to rotate, the variable-diameter containing part is rotationally connected with the variable-diameter protruding part; when the driving gear cannot rotate relatively or is difficult to rotate, the driving gear is rotationally connected with the driving device, so that the driving device rotates without load.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic pumps, and more particularly to a gear oil pump. Background Technology

[0002] Gear pumps pump or pressurize liquids by changing the working volume formed between the pump cylinder and meshing gears. When the gears rotate, the volume of the space on the disengaged side increases, creating a vacuum that draws liquid into the pump cylinder; conversely, the volume of the space on the meshing side decreases, expelling liquid from the pump cylinder. The suction and discharge chambers are separated by the gear meshing line. The discharge pressure of a gear pump depends on the resistance at the pump outlet. Because the gears continuously mesh during operation, metal debris generated during gear wear enters the liquid medium. When this metal debris accumulates in the liquid, it can easily cause the gears to jam or even stop rotating.

[0003] An internal gear oil pump (CN 102953979 A) known to the inventor includes: a pump housing, wherein a driving rotor and a driven rotor are disposed within the pump housing; wherein the driving rotor is an external gear; wherein the driven rotor is an internal gear, and the driven rotor is internally meshed with the driving rotor; the internal gear oil pump further includes: a rolling bearing; the inner ring of the rolling bearing is interference-fitted with the driven rotor, and the outer ring of the rolling bearing is interference-fitted with the pump housing.

[0004] However, the above solution has the following problems: solid impurities will be mixed in the gear oil medium. When the solid impurities accumulate to a certain amount, the driven rotor is more likely to jam due to the tight fit of the various parts of the gear pump. The jammed gear pump is prone to overload damage to the gear pump drive device. Utility Model Content

[0005] The purpose of this invention is to provide a gear oil pump that effectively protects the drive unit from overload when the gears cannot rotate relative to each other or have difficulty rotating, thereby preventing damage to the drive unit.

[0006] The present invention adopts the following technical solution:

[0007] A gear oil pump includes a drive gear; a driven shaft is coaxially inserted through the drive gear, the lower end of the driven shaft is fixedly connected to the drive gear, and the upper end of the driven shaft is connected to a drive shaft through an overload protection structure. The overload protection structure includes a variable diameter protrusion coaxially fixed to the driven shaft and a variable diameter receiving portion coaxially sleeved outside the variable diameter protrusion; the upper end of the variable diameter receiving portion is coaxially fixed to the drive shaft, and the drive shaft is connected to a drive device; when the frictional force between the variable diameter receiving portion and the variable diameter protrusion is sufficient to drive the driven shaft to rotate, the variable diameter receiving portion is fixedly connected to the variable diameter protrusion; when the frictional force between the variable diameter receiving portion and the variable diameter protrusion is insufficient to drive the driven shaft to rotate, the variable diameter receiving portion is rotatably connected to the variable diameter protrusion.

[0008] Furthermore, the variable diameter protrusion includes a receiving sleeve fixed coaxially with the driven shaft. The driven shaft is fixed at the lower end of the receiving sleeve. Two sets of protrusion receiving through holes are evenly opened circumferentially on the sleeve wall. A set of protrusions is inserted into each of the protrusion receiving through holes and the protrusions are slidably connected to the corresponding protrusion receiving through holes in the radial direction. An elastic driving part is also provided at the inner end of the two sets of evenly arranged protrusions.

[0009] Furthermore, the elastic drive unit includes a torsion spring, with the inner ends of two sets of protrusions 7 fixed at both ends of the torsion spring.

[0010] Furthermore, the protrusion is semi-arc-shaped, and the corresponding protrusion receiving hole is inserted through the outside of the semi-arc-shaped protrusion. The upper ends of the two sets of protrusions are respectively fixed to the two ends of the torsion spring; the torsion spring is always in an energy storage state.

[0011] Furthermore, the variable diameter accommodating part includes a drive sleeve fixed coaxially with the drive shaft. The inner cavity at the lower end opening of the drive sleeve is evenly provided with a plurality of protrusion accommodating grooves that are adapted to the protrusions. The protrusion accommodating grooves are V-shaped grooves.

[0012] Furthermore, the cross-section of the protrusion is circular.

[0013] Furthermore, the number of V-grooves is in double groups.

[0014] Furthermore, the radial length of the torsion spring is less than the inner diameter of the accommodating sleeve.

[0015] Furthermore, the lower end of the drive sleeve is coaxially provided with a boss, and the inner cavity of the boss is provided with a flared opening that is adapted to accommodate the sleeve.

[0016] Furthermore, a pulley is coaxially fixed to the upper part of the drive shaft.

[0017] This utility model, by setting an overload protection structure, enables the drive device to rotate in a rotatable connection with the driven shaft when the output torque is too large, allowing the drive device to rotate unloaded and avoiding damage.

[0018] This utility model, by setting a variable diameter protrusion and a variable diameter receiving part, allows the frictional force between the variable diameter receiving part and the variable diameter protrusion to change according to the magnitude of the output torque of the drive device, thereby avoiding damage to the drive device due to overload.

[0019] This invention increases the applicability of the overload protection structure by setting an elastic driving part, so that the maximum frictional force between the variable diameter protrusion and the variable diameter receiving part is achieved by changing the elastic driving part. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the pump casing in this utility model;

[0021] Figure 2 This is a schematic diagram of the variable diameter accommodating part in this utility model;

[0022] Figure 3 This is a schematic diagram of the receiving sleeve in this utility model;

[0023] Figure 4 This is a schematic diagram of the drive gear in this utility model;

[0024] Figure 5 This is a schematic diagram of the boss in this utility model;

[0025] Figure 6 This is a schematic diagram of the driven shaft in this utility model.

[0026] In the diagram, 1. Pump housing; 2. Gear ring; 3. Drive gear; 4. End cover; 5. Arc-shaped through hole; 6. Driven shaft; 7. Protrusion; 8. Variable diameter receiving part; 9. Drive shaft; 10. Receiving sleeve; 11. Protrusion receiving through hole; 12. Torsion spring; 13. Protrusion receiving groove; 14. Drive sleeve; 15. V-groove; 16. Boss. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0028] like Figures 1 to 6 As shown, the gear oil pump of this utility model includes a pump housing 1. The inner cavity of the pump housing 1 is cylindrical and the opening faces downward. A gear ring 2 is coaxially arranged in the inner cavity of the pump housing 1. The gear ring 2 is rotatably connected to the inner cavity of the pump housing 1. A drive gear 3 is eccentrically meshed in the gear ring 2. An end cover 4 is provided at the lower opening of the inner cavity of the pump housing 1. The end cover 4 is circumferentially sealed and fixed to the pump housing 1. Two sets of arc-shaped through holes 5 are symmetrically opened in the middle of the end cover 4. The two sets of arc-shaped through holes 5 correspond to the meshing and disengagement points of the gear ring 2 and the drive gear 3, respectively.

[0029] During operation, the drive gear 3 rotates along the eccentric axis, and the gear ring 2 meshing with the drive gear 3 rotates circumferentially. The space at the meshing point is continuously reduced by the compression of the drive gear 3 and the gear ring 2, forming a positive pressure. The space at the separation point is continuously increased by the separation of the drive gear 3 and the gear ring 2, forming a negative pressure. Gear oil is drawn into the inner cavity of the pump housing 1 from the separation point and is squeezed out at the meshing point as the gap between the drive gear 3 and the gear ring 2 rotates.

[0030] A driven shaft 6 is coaxially threaded through the drive gear 3. The lower end of the driven shaft 6 is fixedly connected to the drive gear 3, and the upper end of the driven shaft 6 is connected to the drive shaft 9 through an overload protection structure. The overload protection structure includes a variable diameter protrusion fixed coaxially with the driven shaft 6 and a variable diameter receiving part 8 coaxially sleeved outside the variable diameter protrusion. The upper end of the variable diameter receiving part 8 is coaxially fixed to the drive shaft 9, and the drive shaft 9 is connected to a drive device. When the frictional force between the variable diameter receiving part 8 and the variable diameter protrusion is sufficient to drive the driven shaft 6 to rotate, the variable diameter receiving part 8 is fixedly connected to the variable diameter protrusion. When the frictional force between the variable diameter receiving part 8 and the variable diameter protrusion is insufficient to drive the driven shaft 6 to rotate, the variable diameter receiving part 8 is rotatably connected to the variable diameter protrusion.

[0031] In this embodiment,

[0032] During operation, the pump body transports gear oil for extended periods. If the gear oil is not replaced promptly, solid impurities (such as metal shavings) will accumulate in it. When these solid impurities reach a certain level, the clearance between the gear ring 2 and the inner cavity of the pump housing 1 will become jammed. This means the gear ring 2 cannot rotate relative to the inner cavity of the pump housing 1, or rotation will be difficult. Consequently, the drive gear 3 meshing with the gear ring 2 will also be unable to rotate relative to the gear ring 2, or rotation will be difficult. This increases the load on the drive device connected to the drive shaft 9. When the load torque of the drive device increases to exceed its rated output torque, the excessive output torque will cause damage to the drive device. To protect the drive device and ensure that its output torque never exceeds the rated torque, when the load torque of the drive device approaches the rated value, the friction between the variable diameter receiving part 8 and the variable diameter protrusion increases to exceed the maximum static friction, causing the variable diameter receiving part 8 and the variable diameter protrusion to rotate. When the load torque of the drive device is much less than the rated value, the friction between the variable diameter receiving part 8 and the variable diameter protrusion drives the driven shaft 6 to rotate, and the variable diameter receiving part 8 and the variable diameter protrusion are fixedly connected.

[0033] To generate a predetermined frictional force between the variable diameter receiving portion 8 and the variable diameter protrusion, in this embodiment, the variable diameter protrusion includes a receiving sleeve 10 coaxially fixed with the driven shaft 6. The lower end of the receiving sleeve 10 is fixed to the driven shaft 6. Two sets of protrusion receiving through holes 11 are evenly opened circumferentially on the sleeve wall of the receiving sleeve 10. A set of protrusions 7 are inserted into each of the protrusion receiving through holes 11, and the protrusions 7 and the corresponding protrusion receiving through holes 11 are slidably connected radially. An elastic driving part is provided between the upper ends of the two sets of protrusions 7, and the elastic driving part includes a torsion spring. 12. The two ends of the torsion spring 12 are fixed to the upper ends of the corresponding protrusions 7. The protrusions 7 are semi-arc-shaped, and the outer part of the semi-arc-shaped protrusions passes through the corresponding protrusion receiving through holes 11. The torsion spring 12 is always in an energy storage state. The torsion spring 12 always drives the two sets of protrusions 7 to move outward, so that the protrusions 7 always protrude outward from the outside of the protrusion receiving through holes 11. The inner side of the variable diameter receiving part 8 cooperates with the protrusions 7 that pass through the outside of the protrusion receiving through holes 11, so that when the variable diameter receiving part 8 rotates, it drives the receiving sleeve 10 to rotate through the protrusions 7, and then drives the driven shaft 6 to rotate, so as to drive the drive gear 3 to rotate. When the drive gear 3 jams or gets stuck, when the variable diameter receiving part 8 rotates, it forces the protrusions 7 to overcome the pressure of the torsion spring 12 and enter the receiving sleeve 10. The variable diameter receiving part 8 spins freely and no longer drives the receiving sleeve 10 to rotate, preventing the drive device from being overloaded and burned out.

[0034] By changing the elastic force of the torsion spring 12, the pressure between the protrusion 7 and the inner cavity of the variable diameter receiving part 8 can be adjusted, thereby changing the friction between the protrusion 7 and the inner cavity of the variable diameter receiving part 8, thus enabling the manufacture of gear oil pumps suitable for different media and different environments.

[0035] During operation, the torsion spring 12 drives the outermost end of the protrusion 7 to press against the inner cavity of the variable diameter receiving part 8, so that friction is generated between the variable diameter receiving part 8 and the protrusion 7. When the load torque of the drive device is much less than the rated value, the friction between the variable diameter receiving part 8 and the protrusion 7 drives the driven shaft 6 to rotate.

[0036] It is difficult to drive a high-power gear oil pump using only the friction between the variable diameter receiving part 8 and the protrusion 7. In this embodiment, the variable diameter receiving part 8 includes a drive sleeve 14 coaxially fixed with the drive shaft 9. The inner cavity at the lower end opening of the drive sleeve 14 is evenly provided with several protrusion receiving grooves 13 that are adapted to the protrusion 7. The protrusion receiving grooves 13 are V-shaped grooves 15. The torsion spring 12 always drives the two sets of protrusions 7 to move outward, so that the protrusions 7 always protrude outside the protrusion receiving through hole 11 and are engaged in the corresponding receiving grooves 13. When the drive sleeve 14 rotates, it drives the receiving sleeve 10 to rotate through the cooperation of the receiving grooves 13 and the protrusions 7. When the load is too large, when the drive sleeve 14 rotates, it forces the protrusions 7 to overcome the elastic force of the torsion spring 12 and enter the receiving sleeve 10 through the receiving grooves 13. The drive sleeve 14 rotates freely and no longer drives the receiving sleeve 10 to rotate, thus avoiding burnout due to excessive load on the drive device.

[0037] For ease of installation: In this embodiment, the protrusion 7 has a circular cross-section; the number of V-grooves 15 is in double arrays; the radial length of the torsion spring 12 is less than the inner diameter of the receiving sleeve 10; the lower end of the drive sleeve 14 is also coaxially provided with a boss 16, and the inner cavity of the boss 16 is provided with a flared opening that is adapted to the receiving sleeve 10.

[0038] In this embodiment, a pulley is coaxially fixed on the upper part of the drive shaft 9.

[0039] During operation, the drive sleeve 14 rotates, and the V-groove 15 located inside the drive sleeve 14 rotates. The inclined surface inside the V-groove 15 presses against the outer surface of the protrusion 7. The pressing force is decomposed into a component force along the tangential direction of the drive sleeve 14 and a radial pressing force along the drive sleeve 14. The force between the variable diameter receiving part 8 and the protrusion 7 changes from the static friction force between the outer surface of the protrusion 7 and the variable diameter receiving part 8 to the component force of the pressing force between the outer surface of the protrusion 7 and the variable diameter receiving part 8 along the tangential direction of the drive sleeve 14. When the load is too large, the V-groove 15 can squeeze the protrusion 7 into the receiving sleeve 10 through radial pressing force, so that the drive device drives the drive sleeve 14 to rotate idling.

[0040] By changing the slope of the inner inclined surface of the V-groove 15, the component of the extrusion force along the tangential direction of the drive sleeve 14 is increased, thereby enabling the overload protection structure to be suitable for equipment with larger loads. When the load torque of the drive device is much less than the rated value, the drive device drives the drive shaft 9 to rotate, and the drive shaft 9 drives the coaxially fixed variable diameter receiving part 8 to rotate. The V-groove 15 in the inner cavity of the variable diameter receiving part 8 extrudes the outer surface of the protrusion 7. The component of the force of the V-groove 15 acting on the protrusion 7 along the tangential direction of the drive sleeve 14 drives the variable diameter protrusion to rotate. The variable diameter protrusion drives the coaxially fixed driven shaft 6 to rotate. The lower end of the driven shaft 6 is fixedly connected to the drive gear 3. The drive gear 3 rotates along the eccentric axis, and the gear ring 2 meshing with the drive gear 3 rotates circumferentially. The space at the meshing point is continuously reduced by the extrusion of the drive gear 3 and the gear ring 2, forming a positive pressure. The space at the separation point is continuously increased by the separation of the drive gear 3 and the gear ring 2, forming a negative pressure.

[0041] When the load torque of the drive device approaches the rated value, i.e. the drive gear 3 cannot rotate or has difficulty rotating, the pressure exerted by the inclined surface of the inner side of the V-groove 15 in the inner cavity of the variable diameter accommodating part 8 on the cylindrical outer surface of the protrusion 7 continues to increase. The radial component of the force exerted by the V-groove 15 on the protrusion 7 along the drive sleeve 14 continues to increase until it overcomes the elastic force of the torsion spring 12. The two sets of protrusions 7 move inward respectively. At the same time, the variable diameter accommodating part 8, which is coaxially fixed with the drive shaft 9, rotates. The rotation of the drive sleeve 14 causes the protrusion 7 to slide out of the V-groove 15, and the drive shaft 9 idles, ensuring that the torque transmitted by the drive shaft 9 is always less than the rated value.

Claims

1. A gear oil pump comprising a drive gear; characterized by: The driving gear is coaxial with the driven shaft, the lower end of the driven shaft is fixedly connected with the driving gear, the upper end of the driven shaft is connected with the driving shaft through an overload protection structure, the overload protection structure comprises a variable-diameter protruding part fixed coaxially with the driven shaft and a variable-diameter accommodating part coaxially sleeved outside the variable-diameter protruding part; the upper end of the variable-diameter accommodating part is fixed coaxially with the driving shaft, and the driving shaft is connected with a driving device; when the friction between the variable-diameter accommodating part and the variable-diameter protruding part drives the driven shaft to rotate, the variable-diameter accommodating part and the variable-diameter protruding part rotate synchronously, and when the friction between the variable-diameter accommodating part and the variable-diameter protruding part does not drive the driven shaft to rotate, the variable-diameter accommodating part and the variable-diameter protruding part rotate relatively.

2. The gerotor pump of claim 1, wherein: The variable-diameter protruding part comprises a sleeve fixed coaxially with the driven shaft, the lower end of the sleeve is fixed with the driven shaft, the cylindrical wall of the sleeve is uniformly provided with two groups of protruding part accommodating through holes in the circumferential direction, and one group of protruding parts is respectively inserted into the protruding part accommodating through holes and connected with the corresponding protruding part accommodating through holes in the radial direction; the inner ends of the two groups of uniformly arranged protruding parts are further provided with elastic driving parts.

3. The gerotor pump of claim 2, wherein: The elastic driving part comprises a torsion spring, and the two ends of the torsion spring are respectively fixed with the inner ends of the two groups of protruding parts.

4. The gerotor pump of claim 2, wherein: The protruding part is semicircular, the semicircular outer part penetrates the corresponding protruding part accommodating through hole, and the upper ends of the two groups of protruding parts are respectively fixed with the two ends of the torsion spring; the torsion spring is always in an energy storage state.

5. The gerotor pump of claim 1, wherein: The variable-diameter accommodating part comprises a driving sleeve fixed coaxially with the driving shaft, and a plurality of protruding part accommodating grooves matched with the protruding parts are uniformly arranged in the circumferential direction in the inner cavity of the opening at the lower end of the driving sleeve, and the protruding part accommodating grooves are V-shaped grooves.

6. The gerotor pump of claim 3, wherein: The cross section of the protruding part is circular.

7. The gerotor pump of claim 5, wherein: The number of V-shaped grooves is double.

8. The gerotor oil pump of claim 3, wherein: The radial length of the torsion spring is smaller than the inner diameter of the sleeve.

9. The gerotor oil pump of claim 5, wherein: The lower end of the driving sleeve is further coaxially provided with a boss, and the inner cavity of the boss is provided with a horn matched with the sleeve.

10. The gerotor oil pump of claim 5, wherein: The upper part of the driving shaft is coaxially fixed with a belt pulley.

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