Exposed injection lead screw assembly and injection molding machine thereof

Abstract

The utility model relates to an exposed injection lead screw assembly and an injection molding machine thereof, the exposed injection lead screw assembly comprises a lead screw and a lead screw nut, the driving end of the lead screw is inserted into a bearing, and a grease injection hole penetrating through the inner side and the outer side is formed in the lead screw nut; the grease injection hole is filled with grease; the bearing is wrapped in a closed oil cavity, and the oil cavity is filled with lubricating oil. By the adoption of the design of the exposed lead screw, only the bearing part is lubricated through the closed oil cavity, the requirement for high-precision sealing is greatly reduced, and a complex cylinder barrel sealing structure in traditional oil immersion lubrication is avoided. Therefore, the processing and assembling difficulty is reduced, and the risk of lubricating oil leakage caused by sealing failure is reduced, so that the manufacturing cost and the maintenance cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, specifically an exposed injection screw assembly and its injection molding machine. Background Technology

[0002] In the injection mechanism of an injection molding machine, a motor-driven injection screw is typically used to perform injection and reset actions. As the injection screw rotates, it drives the screw nut axially, thereby pushing the screw to complete the injection. To ensure stable operation of the injection screw and reduce friction and wear, effective lubrication is essential.

[0003] Currently, the common lubrication method is oil immersion lubrication, which involves injecting a certain amount of lubricating oil into a sealed cylinder to provide oil bath lubrication for the injection screw, screw nut, and drive bearing. While this structure provides sufficient lubrication, it also has the following drawbacks:

[0004] 1. The structure of the sealed cylinder is complex, requiring a high-precision sealing design to prevent lubricating oil leakage, which increases processing and assembly costs.

[0005] 2. After long-term operation, the lubricating oil may deteriorate due to impurities or oxidation, requiring regular replacement and resulting in high maintenance costs.

[0006] 3. Oil-immersed lubrication structures require a large oil cavity space, resulting in a bulky overall structure that is not conducive to lightweight equipment design.

[0007] Therefore, while existing oil-immersion lubrication methods can meet lubrication requirements, there is still room for improvement in terms of cost, maintenance, and structural optimization. A more efficient, lower-cost, and easier-to-maintain lubrication solution is urgently needed to improve the economy and reliability of injection molding machines. Utility Model Content

[0008] To address the technical problems in the background art, this utility model discloses an exposed injection screw assembly and its injection molding machine.

[0009] This utility model provides an exposed injection screw assembly, including a screw and a screw nut. The drive end of the screw is inserted into a bearing, and the screw nut has a grease injection hole that extends through the inner and outer sides.

[0010] The grease injection hole is filled with grease;

[0011] The bearing is enclosed in a sealed oil chamber, which is filled with lubricating oil.

[0012] Furthermore, there are two bearings, designated as the first bearing and the second bearing, installed at both ends of the bearing housing; the outer end of the bearing housing is equipped with an end cover, and the inner end is equipped with a sealing plate, which are sealed by an outer skeleton oil seal and an inner skeleton oil seal respectively; an oil cavity is formed between the bearing housing, the end cover and the sealing plate.

[0013] Furthermore, the sealing plate is integrally formed and set at the end of the lead screw.

[0014] Furthermore, the bearing housing is mounted on the injection base, which is mounted on the guide rail of the injection molding machine frame; a sleeve is inserted into the injection base; an inner skeleton oil seal connects the sealing plate and the sleeve; the sealing plate, sleeve, injection base, bearing housing, end cap, and lead screw form an oil cavity.

[0015] Furthermore, the diameter of the sealing plate is larger than the diameter of the lead screw nut.

[0016] Furthermore, a disc for connecting the lead screw is provided between the sealing plate and the first bearing; an inner skeleton oil seal is connected between the disc and the sleeve; the inner diameter of the sleeve is larger than the diameter of the lead screw nut; an oil cavity is formed between the disc, sleeve, injection base, bearing housing, end cover and lead screw.

[0017] This utility model also provides an injection molding machine, including an exposed injection screw assembly.

[0018] The beneficial effects of this utility model are:

[0019] 1. By adopting an exposed lead screw design, only the bearing section is lubricated with a closed oil chamber, significantly reducing the need for high-precision seals and avoiding the complex cylinder seal structure of traditional oil-immersion lubrication. This not only reduces the difficulty of machining and assembly but also reduces the risk of lubricating oil leakage due to seal failure. In addition, the disc design increases the inner diameter of the sleeve, allowing the lead screw assembly to be disassembled and installed unimpeded from the right side, thereby reducing manufacturing and maintenance costs.

[0020] 2. The lead screw and nut are lubricated by grease. The grease has high viscosity and strong adhesion, which can firmly adhere to the friction surface and is not easy to fall off. It does not require frequent replenishment and its lubrication effect is longer-lasting and more stable.

[0021] 3. The exposed design eliminates the need for a large-capacity oil chamber required for traditional oil immersion lubrication, making the overall structure more compact, reducing the weight of the equipment, which is conducive to the lightweight design of injection molding machines, and at the same time provides more space flexibility for the layout of other functional components.

[0022] 4. By using zoned lubrication (grease-lubricated lead screw and nut + lubricating oil-lubricated bearings), the lubrication effect of key components is ensured while reducing the amount of lubricating oil used and the frequency of replacement, thus lowering operating costs. Furthermore, the exposed lead screw facilitates daily inspection and localized maintenance, further improving the operability and long-term reliability of the equipment. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a front sectional view of the present invention;

[0025] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0026] In the diagram: 1. Lead screw; 2. Lead screw nut; 3. Grease injection hole; 4. Oil chamber; 5. First bearing; 6. Second bearing; 7. Bearing housing; 8. End cap; 9. Sealing plate; 10. Outer skeleton oil seal; 11. Inner skeleton oil seal; 12. Injection base; 13. Sleeve; 14. Disc; 15. First limiting recess; 18. Second limiting recess; 19. Locking nut; 20. Oil filling hole; 21. Plasticizing base; 91. Connecting part. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0028] Example 1:

[0029] like Figure 1 and Figure 2 As shown, this utility model discloses an exposed injection screw assembly, including a screw 1 and a screw nut 2. The driving end of the screw 1 is inserted into a bearing to achieve a rotatable connection; this driving end is connected to the drive shaft of a motor, enabling the motor to drive the screw 1 to rotate. The screw nut 2 is fixedly connected to a plasticizing base 21. The screw of the injection molding machine is mounted on the plasticizing base 21. When the plasticizing base 21 moves towards the mold, molten plastic is injected into the mold. The other end of the screw 1 is supported by the combined action of the screw nut 2 and the plasticizing base 21.

[0030] The lead screw nut 2 has multiple grease injection holes 3 that extend through both the inner and outer sides; the grease injection holes 3 are filled with grease for lubrication between the lead screw 1 and the lead screw nut 2. The grease has high viscosity and strong adhesion, which allows it to adhere firmly to the friction surface, making it less likely to fall off and eliminating the need for frequent replenishment. Its lubrication effect is longer-lasting and more stable.

[0031] by Figure 1 For reference, two bearings are provided on the right end of the lead screw 1, designated as the first bearing 5 and the second bearing 6. The first bearing 5 and the second bearing 6 are mounted on the bearing housing 7, which is fixedly mounted on the injection base 12 of the injection molding machine by bolts. The left and right ends of the bearing housing 7 are respectively provided with a first limiting recess 15 and a second limiting recess 18. The first bearing 5 is engaged in the first limiting recess 15, and the second bearing 6 is engaged in the second limiting recess 18.

[0032] The right end of the lead screw 1 is provided with an integrally formed radially protruding sealing plate 9, which abuts against the left side of the first bearing 5. The lead screw 1 is located on the right side of the second bearing 6 as a screw rod, and a locking nut 19 is threaded onto the screw rod for pre-tightening the first bearing 5 and the second bearing 6. An end cover 8 is installed on the right end of the bearing housing 7 and is fixed by bolts. The end cover 8 is sealed to the bearing housing 7 by a snap-fit ​​O-ring, and the end cover 8 is sealed to the lead screw 1 by an outer skeleton oil seal 10.

[0033] A disc 14, which is connected to the lead screw 1, is connected between the sealing plate 9 and the first bearing 5. The disc 14 and the sealing plate 9 are sealed by a snap-fit ​​O-ring. A cylindrical connecting part 91 extends to the left from the outer end of the disc 14. An inner hole is provided on the left side of the injection base 12, and a sleeve 13 is snapped into the inner hole. The inner diameter of the sleeve 13 is larger than the outer diameter of the lead screw nut 2. A mounting plate extends radially outward from the left side of the sleeve 13 and is fixed to the injection base 12 by bolts. The outer surface of the sleeve 13 is sealed to the wall of the inner hole by a snap-fit ​​O-ring. A recessed retaining platform is provided on the right end of the inner side of the sleeve 13, and an inner skeleton oil seal 11 is snapped into the retaining platform. The inner side of the inner skeleton oil seal 11 is interference-fitted with the outer side of the connecting part 91.

[0034] The design of the disc 14 has the following effects: 1. It reduces the diameter of the sealing plate 9, thereby making the raw material diameter for processing the lead screw 1 smaller and the cost lower; 2. It increases the inner diameter of the sleeve 13, allowing the lead screw 1, disc 14, first bearing 5, second bearing 6, bearing seat 7, locking nut 19 and end cap 8 to be connected as a whole before being disassembled and assembled with the injection base 12 without being obstructed by the sleeve 13. This makes the operation simple and convenient, reduces assembly time, and lowers costs.

[0035] The above arrangement creates a closed oil cavity 4 between the disc 14, sleeve 13, injection base 12, bearing housing 7, end cap 8, and lead screw 1, with both the first bearing 5 and the second bearing 6 located within the oil cavity 4. An oil filling hole 20, communicating with the oil cavity 4, is provided at the bottom of the injection base 12. This hole is used to inject lubricating oil into the oil cavity 4 to lubricate the first bearing 5 and the second bearing 6; it also serves to drain the lubricating oil from the oil cavity 4 for maintenance. The left end of the first bearing 5 extends beyond the bearing housing 7 to expand the space of the oil cavity 4, allowing it to hold more lubricating oil and providing better lubrication for the bearing.

[0036] Compared to existing technologies, the advantages of this embodiment are: 1. By adopting an exposed lead screw 1 design, only the bearing portion is lubricated using a closed oil chamber 4, significantly reducing the need for high-precision sealing and avoiding the complex cylinder sealing structure of traditional oil-immersion lubrication. This not only reduces the difficulty of processing and assembly but also reduces the risk of lubricating oil leakage due to seal failure. In addition, the design of the disc 14 increases the inner diameter of the sleeve 13, allowing the lead screw assembly to be disassembled and assembled without obstruction from the right side, thereby reducing manufacturing and maintenance costs. 2. The lead screw nut 2 and lead screw 1 are lubricated by grease. The grease has high viscosity and strong adhesion, which can firmly adhere to the friction surface, making it difficult to fall off and eliminating the need for frequent replenishment. Its lubrication effect is longer-lasting and more stable. 3. The exposed design eliminates the need for the large-capacity oil chamber 4 required by traditional oil-immersion lubrication, making the overall structure more compact, reducing the weight of the equipment, which is conducive to the lightweight design of the injection molding machine, and at the same time providing more space flexibility for the layout of other functional components. 4. By using zoned lubrication (grease-lubricated lead screw and nut 2 + lubricating oil-lubricated bearings), the lubrication effect of key components is ensured while reducing the amount of lubricating oil used and the frequency of replacement, thus lowering operating costs. Furthermore, the exposed lead screw 1 facilitates daily inspection and localized maintenance, further improving the operability and long-term reliability of the equipment.

[0037] Example 2:

[0038] This utility model also discloses an injection molding machine, including an exposed injection screw assembly as described in Embodiment 1.

[0039] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An exposed injection screw assembly, comprising a screw (1) and a screw nut (2), wherein the drive end of the screw (1) is inserted into a bearing, characterized in that: The lead screw nut (2) is provided with a grease injection hole (3) that runs through the inner and outer sides; The grease injection hole (3) is filled with grease; The bearing is enclosed in a closed oil cavity (4), which is filled with lubricating oil.

2. The exposed injection screw assembly according to claim 1, characterized in that: There are two bearings, designated as the first bearing (5) and the second bearing (6), which are installed at both ends of the bearing housing (7); The bearing housing (7) is equipped with an end cap (8) at its outer end and a sealing plate (9) at its inner end, which are sealed by an outer skeleton oil seal (10) and an inner skeleton oil seal (11), respectively. The bearing housing (7), end cover (8) and sealing plate (9) form an oil cavity (4).

3. The exposed injection screw assembly according to claim 2, characterized in that: The sealing plate (9) is integrally formed and disposed at the end of the lead screw (1).

4. The exposed injection screw assembly according to claim 3, characterized in that: The bearing housing (7) is mounted on the injection base (12), and the injection base (12) is mounted on the guide rail of the injection molding machine frame; A sleeve (13) is inserted into the injection base (12); The inner skeleton oil seal (11) is connected between the sealing plate (9) and the sleeve (13); The sealing plate (9), sleeve (13), injection base (12), bearing seat (7), end cap (8) and lead screw (1) form an oil cavity (4).

5. An exposed injection screw assembly according to claim 4, characterized in that: The diameter of the sealing plate (9) is larger than the diameter of the lead screw nut (2).

6. An exposed injection screw assembly according to claim 5, characterized in that: A disc (14) for connecting the threaded rod (1) is provided between the sealing plate (9) and the first bearing (5); The inner skeleton oil seal (11) is connected between the disc (14) and the sleeve (13); The inner diameter of the sleeve (13) is larger than the diameter of the lead screw nut (2); The oil cavity (4) is formed between the disc (14), sleeve (13), injection base (12), bearing seat (7), end cap (8) and lead screw (1).

7. An injection molding machine, characterized in that: Includes an exposed injection screw assembly as described in any one of claims 1-6.

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