Lower curved needle driving and lubricating mechanism of flat seaming machine

Abstract

The utility model discloses a lower curved needle driving lubricating mechanism of a flat seaming machine, which comprises a front shaft sleeve arranged in a machine base, a curved needle driving shaft capable of rotating and axially moving is arranged in the front shaft sleeve, the front shaft sleeve is provided with a first mounting part and a second mounting part which are matched with the curved needle driving shaft, and an oil seal inner cavity is arranged between an oil seal and the first mounting part. A first cavity is formed between the first mounting part and the second mounting part, and is provided with a communication port communicated with the outside of the front shaft sleeve; a second cavity for injecting lubricating oil is arranged between the second mounting part and the rear end of the front shaft sleeve, and the front shaft sleeve is provided with an oil inlet and an oil outlet which are communicated with the second cavity; and an air pressure balance hole for communicating the oil seal inner cavity with the first cavity is formed in the first mounting part. Air pressure balance of the oil seal inner cavity and the first cavity is maintained through the air pressure balance hole, lubricating oil in the oil seal inner cavity can flow back to the first cavity conveniently, the oil seal is prevented from being disengaged from the front shaft sleeve, lubricating oil seepage is avoided, and the service life is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of sewing equipment technology, specifically a lower looper drive lubrication mechanism for a coverstitch machine. Background Technology

[0002] Patent No. 201910068398.5 discloses a drive structure for a looper needle in a coverstitch sewing machine and a method for reducing skipped stitches in the machine. The invention includes a machine housing, a main shaft, a needle, and a looper needle. Multiple needles are vertically arranged on the machine housing. The drive structure includes a slide bar frame and a slide bar horizontally arranged on the slide bar frame. The looper needle is fixed to the end of the slide bar and faces downward towards the needle. The drive structure also includes a drive assembly that enables the slide bar frame to oscillate intermittently around its circumference, and the drive assembly enables the looper needle to maintain a consistent gap with each needle when passing through each needle thread loop. A transmission assembly is connected to the main shaft to drive the slide bar to move downward towards the needle.

[0003] The patent disclosure has certain flaws. The slide rod requires lubrication during high-speed operation. In existing technology, the slide rod is movably mounted within the front axle sleeve, with lubricating oil injected between the sleeve and the slide rod, and the end of the sleeve sealed by an oil seal. However, during use, the movement of the slide rod within the oil seal causes oil droplets to leak from the connection between the seal and the front axle sleeve, resulting in seal failure. Summary of the Invention

[0004] This utility model addresses the aforementioned technical problems by providing a lubrication mechanism for the lower looper drive of a coverstitch sewing machine, which effectively prevents lubricating oil leakage from the oil seal and the front bushing, resulting in a good sealing effect and improved service life.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a lower looper drive lubrication mechanism for a coverstitch sewing machine, including a front bushing installed in the machine base, a looper drive shaft that can rotate and move axially inside the front bushing, an oil seal fitted at the front end of the front bushing, the front bushing having a first mounting part and a second mounting part that cooperate with the looper drive shaft, an oil seal inner cavity between the oil seal and the first mounting part, a first chamber between the first mounting part and the second mounting part, the first chamber having a communication port connecting to the outside of the front bushing; a second chamber for injecting lubricating oil is provided between the second mounting part and the rear end of the front bushing, the front bushing having an oil inlet and an oil outlet connecting to the second chamber; and an air pressure balance hole for connecting the oil seal inner cavity and the first chamber is provided in the first mounting part.

[0006] To optimize the above technical solution, the present invention also includes the following improved technical solutions.

[0007] The oil seal mentioned above is made of elastic rubber. The oil seal has a fixing part that is interference-fitted with the outer peripheral surface of the front end of the front axle sleeve, and an abutting part that is interference-fitted with the bent needle drive shaft.

[0008] The aforementioned connecting port is located at the bottom of the first chamber, and the connecting port is connected to a connecting pipe via a pipe fitting.

[0009] The aforementioned pressure balance hole is positioned at a height higher than the oil level in the inner cavity of the oil seal.

[0010] The aforementioned front axle is fitted with multiple air pressure balance holes.

[0011] The aforementioned base has a mounting plate with mounting holes for mounting the front axle sleeve, and a sealing ring is provided between the front axle sleeve and the mounting holes.

[0012] The aforementioned base has an oil chamber on the rear side of the mounting plate, and an oil box is installed below the oil chamber.

[0013] The oil inlet and outlet of the aforementioned front axle sleeve are both located inside the oil chamber, and the rear end of the front axle sleeve is connected to the oil chamber.

[0014] The end of the aforementioned connecting pipe is located inside the oil chamber, and the height of the end opening of the connecting pipe is higher than the liquid level inside the oil box.

[0015] The top of the aforementioned front axle sleeve is equipped with a wire guide plate.

[0016] Compared with the prior art, the lower bend needle drive lubrication mechanism of the present invention maintains the air pressure balance between the inner cavity of the oil seal and the first chamber through the air pressure balance hole, which facilitates the return of lubricating oil in the inner cavity of the oil seal to the first chamber, prevents the oil seal from separating from the front bushing, ensures the sealing effect between the oil seal and the front bushing, prevents lubricating oil leakage, and extends service life. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of this embodiment.

[0018] Figure 2 yes Figure 1 Cross-sectional view.

[0019] Figure 3 This is a three-dimensional structural diagram of the cover-up sewing machine.

[0020] Figure 4 yes Figure 3 Cross-sectional view. Detailed Implementation

[0021] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0022] Figures 1 to 4 The diagram shown is a structural schematic of this utility model.

[0023] The reference numerals in the attached drawings are as follows: base 1, mounting plate 11, mounting hole 12, oil chamber 13, oil box 2, liquid level 2a, front shaft sleeve 3, first mounting part 31, second mounting part 32, first chamber 33, second chamber 34, oil inlet 35, oil outlet 36, connecting port 37, air pressure balance hole 38, needle drive shaft 4, oil seal 5, oil seal inner cavity 51, fixing part 52, abutting part 53, sealing ring 6, wire guide plate 7, pipe joint 8, connecting pipe 9.

[0024] like Figure 1 and Figure 2 As shown, the present invention discloses a lower looper drive lubrication mechanism for a cover stitch machine, including a front bushing 3 installed in the machine base 1, and a looper drive shaft 4 that can rotate and move axially inside the front bushing 3.

[0025] An oil seal 5 is fitted onto the front end of the front axle sleeve 3. The front axle sleeve 3 has a first mounting portion 31 and a second mounting portion 32 that mate with the needle drive shaft 4. An oil seal cavity 51 is provided between the oil seal 5 and the first mounting portion 31. A first chamber 33 is provided between the first mounting portion 31 and the second mounting portion 32. A second chamber 34 for injecting lubricating oil is provided between the second mounting portion 32 and the rear end of the front axle sleeve 3. A wire guide plate 7 is provided on the top of the front axle sleeve 3. The first chamber 33 has a connecting port 37 that connects to the outside of the front axle sleeve 3. The connecting port 37 is located at the bottom of the first chamber 33. An oil inlet 35 and an oil outlet 36 are formed on the front axle sleeve 3 corresponding to the second chamber 34.

[0026] The inner diameter of the first chamber 33 is larger than the inner diameter of the first mounting portion 31 and the inner diameter of the second mounting portion 32, and the first chamber 33 forms a stepped surface with the first mounting portion 31 and the second mounting portion 32 respectively. The inner diameter of the second chamber 34 is larger than the inner diameter of the second mounting portion 32, and the second chamber 34 forms a stepped surface with the second mounting portion 32.

[0027] The oil seal 5 is made of elastic rubber. The oil seal 5 has a fixing part 52 that is interference-fitted with the outer peripheral surface of the front end of the front axle sleeve 3, and an abutting part 53 that is interference-fitted with the bent needle drive shaft 4. The first mounting part 31 of the front axle sleeve 3 has a pressure balance hole 38 for connecting the inner cavity 51 of the oil seal and the first chamber 33. The height of the pressure balance hole 38 is higher than the oil level in the inner cavity 51 of the oil seal. The pressure balance hole 38 maintains the pressure balance between the inner cavity 51 of the oil seal and the first chamber 33, preventing lubricating oil from seeping out.

[0028] like Figure 3 and Figure 4As shown, the base 1 has a mounting plate 11 with mounting holes 12 for mounting the front axle sleeve 3. A sealing ring 6 is provided between the front axle sleeve 3 and the mounting hole 12. A screw is provided on the top of the mounting plate 11, with the lower end of the screw abutting against the outer wall of the front axle sleeve 3, fixing the front axle sleeve 3 in the mounting hole 12. An oil chamber 13 is provided on the rear side of the mounting plate 11 of the base 1, and an oil box 2 is installed below the oil chamber 13. The oil inlet 35 and oil outlet 36 of the front axle sleeve 3 are both located in the oil chamber 13, and the rear end of the front axle sleeve 3 communicates with the oil chamber 13. The connecting port 37 of the front axle sleeve 3 is connected to a connecting pipe 9 through a pipe joint 8. The end of the connecting pipe 9 is located in the oil chamber 13, and the height of the end of the connecting pipe 9 is higher than the liquid level 2a in the oil box 2.

[0029] When the bender drive shaft 4 reciprocates, the oil injection assembly in the oil chamber 13 sprays oil towards the oil inlet 35 and the rear end of the front bushing 3. Lubricating oil enters the second chamber 34 from the oil inlet 35 and the rear end of the second chamber 34, lubricating the bender drive shaft 4. The bender drive shaft 4 drives the lubricating oil in the second chamber 34 to flow along the inner wall of the second mounting part 32 between the second chamber 34 and the first chamber 33. The lubricating oil in the second chamber 34 is discharged along the rear end of the second chamber 34 and the oil outlet 36. Because the oil supply is greater than the return oil, the flow rate of lubricating oil from the second chamber 34 to the first chamber 33 is greater than the flow rate from the first chamber 33 to the second chamber 34, causing lubricating oil to accumulate in the first chamber 33.

[0030] The bent needle drive shaft 4 drives the lubricating oil in the first chamber 33 to flow along the inner wall of the first mounting part 31 between the first chamber 33 and the oil seal cavity 51. The lubricating oil in the first chamber 33 flows out from the connecting port 37 and then enters the oil box 2 through the connecting pipe 9. When the lubricating oil flows along the inner wall of the first mounting part 31 into the oil seal cavity 51, the lubricating oil is blocked by the oil seal 5, achieving a sealing effect.

[0031] The bendable needle drive shaft 4 reciprocates axially and rotates at high speed within the front bushing 3 and oil seal 5. If the front bushing 3 is not equipped with a pressure balance hole 38, the bendable needle drive shaft 4 cannot drive the lubricating oil from the oil seal cavity 51 to the first chamber 33 during axial retraction because the oil seal cavity 51 is relatively closed. When the bendable needle drive shaft 4 moves forward axially, the flow rate of lubricating oil to the oil seal cavity 51 is greater than the flow rate of lubricating oil to the first chamber 33 during axial retraction, causing lubricating oil to gradually accumulate in the oil seal cavity 51.

[0032] Meanwhile, the contact part 53 of the oil seal 5 repeatedly rubs against the bent needle drive shaft 4, generating heat. The air pressure in the inner cavity 51 of the oil seal increases, and the oil seal 5 expands due to heat. This causes the fixing part 52 of the oil seal 5 to detach from the outer peripheral surface of the front end of the front bushing 3. The lubricating oil in the inner cavity 51 of the oil seal will seep outward along the mounting surface of the fixing part 52, resulting in seal failure.

[0033] After setting the air pressure balance hole 38, the air pressure balance between the inner cavity 51 of the oil seal and the first chamber 33 is maintained, which facilitates the return of the lubricating oil in the inner cavity 51 of the oil seal to the first chamber 33, prevents the oil seal 5 from separating from the front axle sleeve 3, ensures the sealing effect between the oil seal 5 and the front axle sleeve 3, and prevents the lubricating oil from seeping out.

[0034] The front axle sleeve 3 may also have multiple air pressure balance holes 38 at its front end, which can be all disposed in the first mounting part 31 of the front axle sleeve 3. The air pressure balance holes 38 extend axially, and the height of each air pressure balance hole 38 is preferably higher than the oil level in the oil seal cavity 51, so as to maintain the air pressure balance between the oil seal cavity 51 and the first chamber 33, thereby ensuring the lubrication and sealing effect. The shape of the air pressure balance hole 38 can be straight or curved.

[0035] The preferred embodiment of this utility model has been described, and various changes or modifications made by those skilled in the art will not depart from the scope of this utility model.

Claims

1. A lower looper drive lubrication mechanism for a coverstitch sewing machine, comprising a front bushing (3) installed in a machine base (1), wherein a looper drive shaft (4) capable of rotation and axial movement is provided within the front bushing (3), characterized in that: The front end of the front axle sleeve (3) is fitted with an oil seal (5). The front axle sleeve (3) has a first mounting part (31) and a second mounting part (32) that cooperate with the bent needle drive shaft (4). There is an oil seal cavity (51) between the oil seal (5) and the first mounting part (31). There is a first chamber (33) between the first mounting part (31) and the second mounting part (32). The first chamber (33) has a connecting port (37) that connects to the outside of the front axle sleeve (3). There is a second chamber (34) for injecting lubricating oil between the second mounting part (32) and the rear end of the front axle sleeve (3). The front axle sleeve (3) has an oil inlet (35) and an oil outlet (36) that connect to the second chamber (34). There is a pressure balance hole (38) in the first mounting part (31) for connecting the oil seal cavity (51) and the first chamber (33).

2. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 1, characterized in that: The oil seal (5) is made of elastic rubber. The oil seal (5) has a fixing part (52) that is interference-fitted with the outer peripheral surface of the front end of the front bushing (3). The oil seal (5) has an abutting part (53) that is interference-fitted with the bent needle drive shaft (4).

3. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 2, characterized in that: The connecting port (37) is located at the bottom of the first chamber (33), and the connecting port (37) is connected to a connecting pipe (9) through a pipe fitting (8).

4. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 3, characterized in that: The pressure balance hole (38) is positioned at a height higher than the oil level in the oil seal cavity (51).

5. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 4, characterized in that: The front axle sleeve (3) has multiple air pressure balance holes (38).

6. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 5, characterized in that: The base (1) has a mounting plate (11) inside, and the mounting plate (11) has a mounting hole (12) for mounting the front axle sleeve (3). A sealing ring (6) is provided between the front axle sleeve (3) and the mounting hole (12).

7. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 6, characterized in that: The base (1) has an oil chamber (13) on the rear side of the mounting plate (11), and an oil box (2) is installed below the oil chamber (13).

8. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 7, characterized in that: The oil inlet (35) and oil outlet (36) of the front axle sleeve (3) are both located in the oil chamber (13), and the rear end of the front axle sleeve (3) is connected to the oil chamber (13).

9. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 8, characterized in that: The end of the connecting pipe (9) is located inside the oil chamber (13), and the height of the end opening of the connecting pipe (9) is higher than the liquid level (2a) in the oil box (2).

10. The lower looper drive lubrication mechanism of a coverstitch machine according to claim 9, characterized in that: The front axle sleeve (3) is provided with a wire guide plate (7) at the top.

Images