Torque adjusting mechanism of friction protection worm gear case

Abstract

The utility model discloses a torque adjusting mechanism of a friction protection worm gear case. Comprising a shell, a worm, a worm gear and a driving shaft, the worm gear and the driving shaft transmit torque through the friction plate group; the pressure adjusting structure is used for controlling the pressure of the friction plate group and comprises an adjusting nut which is in threaded connection with the upper end of the driving shaft; a radial sliding hole is formed in the adjusting nut, and a reset spring and a pawl are mounted in the sliding hole; a one-way tooth locking mechanism is arranged between the inner end of the pawl and the driving shaft. The reset spring abuts between the outer end of the pawl and the spring gland. The spring disc is sleeved on the driving shaft, the upper surface of the inner ring abuts against the end face of the adjusting nut, and the lower surface of the outer ring presses against the end face of the friction plate group through the friction plate upper pressing plate. According to the utility model, through the combination of the adjusting nut and the spring disc, the pressure on the friction plate group can be conveniently adjusted, so that the friction plate group can be uniformly stressed under the action of the pressure adjusting structure, and the accurate control on the output torque is realized.

Description

Technical Field

[0001] The utility model relates to a worm gear box, in particular to a torque regulating mechanism of a friction protection worm gear box, which is suitable for worm gear boxes used for rotary driving of cutter bodies of various types of graders in the engineering machinery industry. Background Art

[0002] In the construction machinery industry, worm gearboxes are the core component for transmitting power to the motor grader's rotary system. Currently, worm gearboxes used in domestic motor graders are either those that directly rotate the drive shaft at the worm center through worm gear meshing or those that utilize torque protection with multiple sets of circumferentially distributed compression springs.

[0003] The first type has no torque protection. During the use of the motor grader, the motor grader blade is often subjected to unpredictable impact loads. Such huge impact loads react on the worm gear box, causing early damage to the drive shaft teeth and other parts of the worm gear box;

[0004] Although the second type has a torque protection system, it has many parts and a complex structure, which makes it difficult to manufacture and has high production costs. At the same time, since the pressure adjustment of multiple sets of circumferentially distributed compression springs is not easy to be balanced, the friction plate is unevenly damaged, which affects the service life of the worm gear box and thus the long-term effective operation of the grader. Utility Model Content

[0005] The utility model aims to provide a torque regulating mechanism for a friction protection worm gear box which has a simple structure and is convenient to adjust.

[0006] The utility model adopts the following technical solution: a torque adjustment mechanism of a friction protection worm gear box, comprising a housing, a worm and a drive shaft rotatably mounted in the housing; the worm is cooperatively connected to a worm wheel with a center hole; the drive shaft is arranged at the axis of the worm wheel, a friction plate group is provided between the drive shaft and the worm wheel, and torque is transmitted between the worm wheel and the drive shaft through the friction plate group;

[0007] The end of the drive shaft is equipped with a pressure regulating structure for pressing the friction plate group;

[0008] The pressure regulating structure includes:

[0009] An adjusting nut is connected to the upper end of the drive shaft through a thread, and the lower end of the drive shaft is a power output end; a sliding hole is formed on the adjusting nut and passes through the adjusting nut in a radial direction;

[0010] A spring disc is mounted on the drive shaft; the inner ring of the spring disc abuts against the end face of the adjusting nut, and the outer ring of the spring disc presses against the end face of the friction plate group;

[0011] A spring pressure cover is fixedly mounted on the outside of the adjusting nut; the spring pressure cover covers the outer end of the sliding hole;

[0012] A ratchet is slidably mounted in the sliding hole; a one-way locking tooth mechanism is provided between the inner end of the ratchet and the outer peripheral surface of the drive shaft.

[0013] A return spring is installed in the sliding hole; the return spring is pressed between the outer end of the pawl and the spring pressure cover.

[0014] It is further provided that: the upper end of the adjusting nut is sealed, and the upper end of the adjusting nut has a hexagonal head;

[0015] A mounting hole is provided on the shell at a position opposite to the adjusting nut, and a cover plate is connected to the mounting hole.

[0016] Two symmetrical sliding holes are provided on the side wall of the adjusting nut, and the cross-section of the sliding holes is square.

[0017] A copper sleeve is installed between the lower end of the adjusting nut and the shell.

[0018] The upper end of the drive shaft is provided with an external thread that cooperates with the adjusting nut; the drive shaft above the external thread is provided with axial ratchet grooves evenly distributed around the axis of the drive shaft; the inner end of the pawl is relatively matched with the axial ratchet groove.

[0019] The upper end of the spring pressure cover is provided with an inner retaining ring which is in close contact with the upper end surface of the adjusting nut. The inner retaining ring is connected to the upper end of the adjusting nut through a screw.

[0020] A friction plate pad is installed at the bottom of the friction plate group, and a friction plate upper pressure plate is installed at the top of the friction plate group. The spring disc in the pressure regulating structure is pressed on the friction plate upper pressure plate.

[0021] Inner and outer gear rings are provided between the friction plate group and the drive shaft;

[0022] The upper friction plate in the friction plate group is spline-matched with the inner wall of the worm wheel, the lower friction plate in the friction plate group is spline-matched with the outer walls of the inner and outer gear rings, and the inner walls of the inner and outer gear rings are spline-matched with the drive shaft.

[0023] The beneficial effects of the utility model are: flexible transmission of torque is achieved through the friction plate group and the pressure adjustment structure; when subjected to excessive impact, the friction plate group can slide to absorb the impact energy and protect other parts of the worm gear box from damage;

[0024] By adjusting the combination of the nut and the spring disc, the pressure on the friction plate group can be easily adjusted, thereby achieving precise control of the output torque. The friction plate group can be evenly stressed by the pressure adjustment structure, avoiding the problem of uneven stress on the friction plates and damage caused by the difficulty in balanced pressure adjustment. This solution has a simpler structure and significantly reduces the number of parts, which not only reduces manufacturing costs but also simplifies the assembly process and improves production efficiency.

[0025] The design of the cover makes the installation and adjustment of the pressure regulating structure more convenient, facilitates the maintenance and care of the worm gear box, and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a structural schematic diagram of a torque adjustment mechanism of a friction protection worm gear box of the present invention.

[0028] Figure 2 for Figure 1 Enlarged view of the middle drive shaft and pressure adjustment structure.

[0029] Figure 3 for Figure 2 Center AA view.

[0030] Figure 4 It is a structural schematic diagram of the adjusting nut in the utility model.

[0031] Figure 5 for Figure 4 Middle BB view.

[0032] Figure 6 It is a structural schematic diagram of the drive shaft in the utility model.

[0033] Figure 7 for Figure 6 Center CC view.

[0034] Description of reference numerals:

[0035] 1. Housing; 11. Cover plate; 2. Worm; 3. Worm wheel; 4. Inner and outer ring gears; 5. Drive shaft; 51. External thread; 52. Axial ratchet groove; 6. Friction plate assembly; 61. Friction plate backing plate; 62. Friction plate upper pressure plate;

[0036] 7. Pressure regulating structure; 71. Adjusting nut; 711. Sliding hole; 712. Hexagonal head; 72. Spring disc; 73. Spring gland; 731. Inner retaining ring; 74. Ratchet; 75. Return spring; 76. Copper sleeve. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example 1:

[0039] like Figures 1 to 3 As shown, the present invention provides a torque adjustment mechanism for a friction-protected worm gearbox. A worm 2 and a drive shaft 5 are rotatably mounted within a housing 1. A worm wheel 3 is coupled to the worm 2, and a friction plate pack 6 is disposed between the drive shaft 5 and the worm wheel 3. Torque is transmitted between the worm wheel 3 and the drive shaft 5 via the friction plate pack 6. A pressure adjustment structure 7 presses against one end of the friction plate pack 6, providing a certain pressure.

[0040] The pressure regulating structure 7 includes an adjusting nut 71 connected to the upper end of the driving shaft 5 by thread. Figures 3 to 5 As shown, the sidewall of the adjusting nut 71 is provided with two symmetrical sliding holes 711, each with a square cross-section. A pawl 74 and a return spring 75 are slidably mounted in each sliding hole 711. A spring pressure cap 73 fits over the adjusting nut 71. The upper end of the spring pressure cap 73 has an inner retaining ring 731 that abuts against the upper end of the adjusting nut 71. The inner retaining ring 731 is screwed to the upper end of the adjusting nut 71. The return spring 75 abuts between the outer end of the pawl 74 and the spring pressure cap 73, pushing the pawl 74 toward the drive shaft 5. A one-way locking mechanism is provided between the inner end of the pawl 74 and the outer circumference of the drive shaft 5, ensuring that the adjusting nut 71 can only rotate in one direction on the drive shaft 5. A spring disc 72 is mounted on the drive shaft 5. The inner ring of the spring disc 72 abuts against the lower end of the adjusting nut 71, while the outer ring of the spring disc 72 presses against the end surface of the friction plate pack 6.

[0041] Recombination Figure 6 and Figure 7As shown, the upper end of the drive shaft 5 is provided with an external thread 51 for cooperating with the adjusting nut 71. The drive shaft 5 above the external thread 51 is provided with an axial ratchet groove 52 evenly distributed around the axis of the drive shaft 5. The inner end of the pawl 74 has a wedge-shaped tooth that cooperates with the axial ratchet groove 52. The wedge-shaped tooth can slide downward along the axial ratchet groove 52. The wedge-shaped tooth and the circumferentially evenly distributed axial ratchet groove 52 form a Figure 3 The one-way locking tooth mechanism shown enables the adjusting nut 71 to rotate on the drive shaft 5 in only one direction.

[0042] When using;

[0043] After all the parts are assembled in sequence, use a torque wrench to clamp the hexagonal head on the upper end of the adjusting nut 71 and turn it clockwise. During this process, the axial ratchet groove 52 pushes the pawl 74 to retract, and the adjusting nut 71 moves downward, the spring disc 72 is pressed downward and deformed, and presses the friction plate group 6. Then, the pawl 74 is pushed by the return spring 75 to re-engage the axial ratchet groove 52 on the upper end of the drive shaft 5, forming a reverse locking, preventing the adjusting nut 71 from moving back due to vibration during use.

[0044] Tighten the adjusting nut 71 repeatedly in sequence until the spring disc 72 is pressed downward and deformed to an appropriate amount, thereby achieving the adjustment of the rated output torque;

[0045] Before the product is finalized, the tightening torque of the adjusting nut 71 and the output torque of the drive shaft 5 are measured in multiple batches using a torque testing machine to obtain a "tightening torque-output torque relationship curve". This relationship curve can accurately guide the assembly of the worm gear box and the rapid adjustment and recovery of the output torque of the flat bottom machine on site.

[0046] Example 2:

[0047] Based on the above embodiment 1, combined with Figure 1 and Figure 2 As shown, to facilitate installation and adjustment of the pressure regulating structure 7, a mounting hole is provided on the housing 1 opposite the adjusting nut 71. A cover plate 11 is screwed to the mounting hole. Removing the cover plate allows for easier access to the adjusting nut 71. The upper end of the adjusting nut 71 is sealed and has a hexagonal head 712, which can be turned using a tool. A copper sleeve 76 is installed between the lower end of the adjusting nut 71 and the housing 1 to support the adjusting nut 71 and the drive shaft 5.

[0048] Example 3:

[0049] Based on the above embodiment 1, combined with Figure 1 and Figure 2As shown, a friction plate backing plate 61 is mounted on the bottom of the friction plate pack 6, and a friction plate upper pressure plate 62 is mounted on the top of the friction plate pack 6. The outer ring of the spring disc 72 in the pressure regulating structure 7 presses against the friction plate upper pressure plate 62, thereby compressing the friction plate pack 6. In this embodiment, an inner and outer ring gear 4 is disposed between the friction plate pack 6 and the drive shaft 5. The upper friction plate of the friction plate pack 6 is splined to the inner wall of the worm gear 3, the lower friction plate of the friction plate pack 6 is splined to the outer wall of the inner and outer ring gear 4, and the inner wall of the inner and outer ring gear 4 is splined to the drive shaft 5.

[0050] During operation, the worm 2 drives the worm wheel 3, and the worm wheel 3 drives the upper friction plate in the friction plate group 6. The upper friction plate in the friction plate group 6 and the lower friction plate in the friction plate group 6 fit together under the action of the pressure regulating structure 7 to realize the transmission of torque. The lower friction plate in the friction plate group 6 drives the inner and outer gear rings 4 and the drive shaft 5, and finally realizes the transmission of power from the worm to the drive shaft.

[0051] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A torque adjustment mechanism for a friction-protected worm gear box, comprising a housing (1), a worm (2) and a drive shaft (5) rotatably mounted in the housing (1); the worm (2) is cooperatively connected to a worm wheel (3) having a center hole; the drive shaft (5) is arranged at the axis of the worm wheel (3), a friction plate group (6) is provided between the drive shaft (5) and the worm wheel (3), and torque is transmitted between the worm wheel (3) and the drive shaft (5) via the friction plate group (6); Its characteristics are: The end of the drive shaft (5) is provided with a pressure regulating structure (7) for pressing the friction plate group (6); The pressure regulating structure (7) comprises: An adjusting nut (71) is connected to the upper end of the driving shaft (5) through a thread, and the lower end of the driving shaft (5) is a power output end; a sliding hole (711) is provided on the adjusting nut (71) and passes through the adjusting nut (71) in a radial direction of the adjusting nut (71); A spring disc (72) is mounted on the drive shaft (5); the inner ring of the spring disc (72) is pressed against the end surface of the adjusting nut (71), and the outer ring of the spring disc (72) is pressed against the end surface of the friction plate group (6); A spring pressure cover (73) is fixedly mounted on the outside of the adjusting nut (71); the spring pressure cover (73) covers the outer end of the sliding hole (711); A ratchet (74) is slidably mounted in the sliding hole (711); a one-way locking tooth mechanism that is relatively matched is provided between the inner end of the ratchet (74) and the outer peripheral surface of the drive shaft (5); A return spring (75) is installed in the sliding hole (711); the return spring (75) is pressed between the outer end of the pawl (74) and the spring pressure cover (73).

2. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: The upper end of the adjusting nut (71) is sealed, and the upper end of the adjusting nut (71) has a hexagonal head (712); A mounting hole is provided on the housing (1) at a position opposite to the adjusting nut (71), and a cover plate (11) is connected to the mounting hole.

3. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: Two symmetrical sliding holes (711) are provided on the side wall of the adjusting nut (71), and the cross section of the sliding holes (711) is square.

4. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: A copper sleeve (76) is installed between the lower end of the adjusting nut (71) and the housing (1).

5. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: The upper end of the drive shaft (5) is provided with an external thread (51) that cooperates with the adjusting nut (71); the drive shaft (5) above the external thread (51) is provided with axial ratchet grooves (52) evenly distributed around the axis of the drive shaft (5); the inner end of the ratchet (74) is relatively matched with the axial ratchet groove (52).

6. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: The upper end of the spring pressure cover (73) has an inner retaining ring (731) that is in close contact with the upper end surface of the adjusting nut (71), and the inner retaining ring (731) is connected to the upper end of the adjusting nut (71) via a screw.

7. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: A friction plate backing plate (61) is installed at the bottom of the friction plate group (6), a friction plate upper pressure plate (62) is installed at the top of the friction plate group (6), and the spring disc (72) in the pressure regulating structure (7) is pressed on the friction plate upper pressure plate (62).

8. The torque adjustment mechanism of the friction protection worm gear box according to claim 1, characterized in that: An inner and outer gear ring (4) is provided between the friction plate group (6) and the drive shaft (5); The upper friction plate in the friction plate group (6) is spline-matched with the inner wall of the worm wheel (3), the lower friction plate in the friction plate group (6) is spline-matched with the outer walls of the inner and outer gear rings (4), and the inner walls of the inner and outer gear rings (4) are spline-matched with the drive shaft (5).

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