Friction plate group mounting structure of worm gear case capable of essentially preventing reversion and protecting friction

Abstract

The utility model discloses a friction plate group mounting structure of an essentially anti-reversion friction protection worm gear case. Comprising a shell, a worm and a driving shaft, the worm is connected with a worm gear with a center hole in a matched mode. The driving shaft is arranged at the axis of the worm wheel, and an inner gear ring and an outer gear ring are fixedly sleeved on the driving shaft; a friction plate group is arranged between the worm gear and the inner and outer gear rings; a middle gear ring is sleeved and fixed in a center hole of the worm wheel, and inner teeth of the middle gear ring are matched with outer teeth of the friction plate group; inner teeth of the friction plate set are matched with outer teeth of the inner and outer gear ring, and the upper end of the friction plate set is connected with a pressure adjusting structure. When the friction plate group is subjected to an impact load, part of energy is consumed through friction; moreover, the middle gear ring in close fit with the worm gear is arranged in the worm gear, reverse impact is counteracted or reduced through the friction plate set and the middle gear ring, so that inner teeth of the worm gear are protected, and the service life of the worm gear is prolonged.

Description

Technical Field

[0001] The utility model relates to a worm gear box, in particular to a friction plate assembly installation structure of an intrinsic anti-reverse friction protection worm gear box 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, the worm gearbox is a core component in the power transmission of the motor grader's rotary system. During operation, the grader's blades are often subjected to unpredictable impact loads, resulting in transient overloads. These overloads are then applied to the worm gearbox via the rotating ring gear, often causing premature damage. To address this issue, the current approach is to add protective devices to the worm gearbox's transmission system.

[0003] For example, a Chinese patent discloses a torque-quantity adjustable friction-protected worm gearbox (CN204477267U), which includes a housing, a worm, a worm wheel, and a drive gear shaft. The drive gear shaft is fitted with internal and external teeth connected to the worm wheel. The worm wheel is coaxially mounted with the internal and external teeth, with a friction plate pack connected between the inner ring of the worm wheel and the outer ring of the internal and external teeth. A pressure plate is positioned above the friction plate pack, with a micro-adjuster and an adjustment sleeve positioned above the pressure plate. The micro-adjuster is mounted on the adjustment sleeve, with a spring connected between the lower end of the adjustment sleeve and the upper end of the pressure plate. A floating seal ring is positioned between the end of the drive gear shaft extending from the housing and the housing. This technology incorporates a friction plate pack within the worm gearbox. When the worm gearbox is subjected to an impact load, the friction plate pack slides relative to each other to mitigate the impact.

[0004] The aforementioned technology still has drawbacks: the friction plate pack requires a certain amount of clearance for installation. While the relative friction of the friction plate pack can reduce the impact force on the worm gear, the clearance between the friction plate pack and the worm wheel's internal splines still creates a reverse impact force on the worm wheel's internal splines, which can easily damage them. Furthermore, when the micro-adjuster is removed, the spring at its lower end easily springs off, making subsequent maintenance and installation inconvenient. Utility Model Content

[0005] The utility model aims to provide a friction plate assembly mounting structure of a worm gear box with inherent anti-reverse friction protection, which is used for improving the protection of the inner ring of the worm gear.

[0006] The utility model adopts the following technical solution: a friction plate assembly mounting structure of a worm gear box with inherent anti-reverse friction protection, 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, and inner and outer gear rings are fixedly mounted on the drive shaft; a friction plate assembly is arranged between the worm wheel and the inner and outer gear rings;

[0007] An intermediate gear ring is fixed in the center hole of the worm gear, and the inner teeth of the intermediate gear ring cooperate with the outer teeth of the friction plate group; the inner teeth of the friction plate group cooperate with the outer teeth of the inner and outer gear rings, and the upper end of the friction plate group is connected to a pressure regulating structure.

[0008] It further comprises: a spline transition fit is adopted between the worm wheel and the outer wall of the intermediate gear ring, and a spline clearance fit is adopted between the inner and outer gear rings and the drive shaft;

[0009] The upper friction plate in the friction plate group and the inner wall of the middle gear ring are matched with a spline clearance, and the lower friction plate in the friction plate group and the outer walls of the inner and outer gear rings are matched with a spline clearance.

[0010] The worm wheel and the worm adopt a helical pitch angle that can prevent the worm wheel and the worm from reversing.

[0011] The upper end surface of the worm wheel is fixedly connected to a limiting ring, and the limiting ring is pressed on the upper end surface of the intermediate gear ring.

[0012] A friction plate backing plate is provided at the lower end of the friction plate group, and a friction plate upper pressure plate is provided at the upper end of the friction plate group, and the pressure regulating structure is pressed on the friction plate upper pressure plate.

[0013] The pressure regulating structure includes:

[0014] a pinch wheel, fixed to the end of the drive shaft;

[0015] A plurality of ratchet shafts are connected to the periphery of the pressure wheel through threads and are evenly distributed around the drive shaft; the lower ends of the ratchet shafts extend out of the pressure wheel and are directly above the upper pressure plate of the friction plate;

[0016] A plurality of elastic pawls are installed on the periphery of the pressing wheel and are matched with the ratchet shaft in a one-to-one manner to prevent the ratchet shaft from reversing;

[0017] Multiple sets of spring discs are installed one by one between the lower end of the ratchet shaft and the side surface of the upper pressure plate of the friction plate, and are used to press the upper pressure plate of the friction plate downward.

[0018] A screw is passed through the ratchet shaft, and the lower end of the screw extends out of the ratchet shaft and is connected to the friction plate upper pressure plate through a thread.

[0019] A stepped countersunk hole is provided at the center of the ratchet shaft, and a hexagonal countersunk hole is provided at the upper end of the countersunk hole for rotating the ratchet shaft;

[0020] The screw is a countersunk screw, and the round head cap of the screw is located on the step in the countersunk hole.

[0021] The lower end of the ratchet shaft is provided with an external stop, and the lower end of the ratchet shaft is fitted into a positioning hole provided on the side of the friction plate upper pressure plate;

[0022] The spring disc is sleeved on the lower end of the ratchet shaft, and the upper and lower ends of the spring disc are respectively pressed between the ratchet shaft and the upper pressure plate of the friction plate.

[0023] The beneficial effects of the present invention are:

[0024] When the friction plate group is subjected to impact load, it consumes part of the energy through friction. In addition, a tightly matched intermediate gear ring is set inside the worm gear. The friction plate group and the intermediate gear ring offset or reduce the reverse impact, thereby protecting the internal teeth of the worm gear and extending the service life of the worm gear.

[0025] By selecting the appropriate helix angle of the worm gear and worm gear tooth profile, the self-locking function of the worm gear and worm gear is achieved when the worm gear and worm gear are reversed, thereby essentially preventing the reverse rotation of the worm gear and worm gear;

[0026] The screw design connects the ratchet shaft, friction plate upper pressure plate and spring disc into a whole, avoiding the scattering or flying of the spring disc, and improving the convenience of installation and maintenance of the entire worm gear box; the stepped countersunk hole design in the ratchet shaft also facilitates the disassembly and assembly of the ratchet shaft and internal screws, further improving installation and maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 A schematic diagram of the friction plate assembly installation structure of the worm gear box with inherent anti-reverse friction protection provided by an embodiment of the present utility model.

[0029] Figure 2 for Figure 1 Schematic top view of the worm and worm wheel.

[0030] Figure 3 for Figure 1 Schematic diagram of the worm gear and drive shaft.

[0031] Figure 4 for Figure 1 Schematic diagram of the medium pressure regulation structure.

[0032] Description of reference numerals:

[0033] 1. Housing; 2. Worm; 3. Worm gear; 31. Limiting ring; 4. Inner and outer ring gears; 5. Drive shaft; 6. Friction plate group; 61. Friction plate backing plate; 62. Friction plate upper pressure plate; 7. Intermediate ring gear;

[0034] 8. Pressure adjustment structure; 81. Pressure wheel; 82. Ratchet shaft; 821. Countersunk hole; 822. Hexagonal countersunk hole; 83. Elastic pawl; 84. Spring disc;

[0035] 9. Screws. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying 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.

[0037] Example 1:

[0038] like Figures 1 to 3 As shown, the present invention provides a friction plate assembly mounting structure for a worm gearbox with inherent anti-reverse friction protection. The structure primarily comprises a housing 1, a worm 2 rotatably mounted within the housing 1, and a drive shaft 5. A worm wheel 3 with a central hole is matingly connected to one side of the worm 2. The drive shaft 5 is positioned at the axis of the worm wheel 3. An intermediate gear ring 7, a friction plate assembly 6, and inner and outer gear rings 4 are sequentially mounted between the inner wall of the worm wheel 3 and the drive shaft 5.

[0039] Combine Figure 1 and Figure 3 As shown, the intermediate ring gear 7 is mounted on the inner wall of the worm gear 3. A limit ring 31 is fixedly connected to the upper end surface of the worm gear 3, which positions the intermediate ring gear 7 within the worm gear 3. A splined transition fit is used between the worm gear 3 and the outer wall of the intermediate ring gear 7, ensuring a tight fit and preventing relative rotation. When the worm gear case is subjected to impact loads, the worm gear 3 and the intermediate ring gear 7 do not strike each other, preventing or mitigating wear on the internal teeth of the worm gear 3. Several upper friction plates in the friction plate pack 6 have a splined clearance fit with the inner wall of the intermediate ring gear 7, while the lower friction plates in the friction plate pack 6 have a splined clearance fit with the outer walls of the inner and outer ring gears 4, facilitating the installation of the friction plate pack 6 between the intermediate ring gear 7 and the inner and outer ring gears 4. A splined clearance fit is used between the inner and outer ring gears 4 and the drive shaft 5, facilitating the installation of the friction plate pack 6 onto the drive shaft 5.

[0040] A friction plate backing plate 61 is installed at the bottom between the intermediate ring gear 7 and the inner and outer ring gears 4, supporting the lower end of the friction plate pack 6. A friction plate upper pressure plate 62 is pressed against the upper end of the friction plate pack 6. A pressure regulating structure 8 is fixed to the drive shaft 5 and presses against the friction plate upper pressure plate 62, thereby compressing the friction plate pack 6 and achieving transmission between the intermediate ring gear 7 and the inner and outer ring gears 4.

[0041] In this embodiment, since the worm gear box has the characteristic of discontinuous operation, the tooth profiles of the worm wheel 3 and the worm 2 are selected with appropriate helix angles so that the worm wheel 3 and the worm 2 are self-locked when reversed, thereby essentially preventing the worm wheel and worm from reversing.

[0042] At work;

[0043] like Figures 1 to 3 As shown, the output torque of the present invention is achieved by transmission through the worm → worm wheel → intermediate gear ring → friction plate group → inner and outer gear rings → drive shaft → grader rotating large gear ring → grader cutter body to achieve rotation; when the grader cutter body is subjected to an impact load, the impact force will be transmitted in the reverse direction along the above-mentioned output torque, and the friction plate group and the intermediate gear ring will be subjected to a certain impact, which will eventually offset or reduce the reverse force; since the worm wheel 3 and the intermediate gear ring 7 are tightly matched, the impact on the inner wall teeth of the worm wheel 3 is greatly reduced, thereby protecting the inner teeth of the worm wheel and extending the service life of the worm wheel.

[0044] Example 2:

[0045] Based on the above embodiment 1, combined with Figure 4 As shown, the pressure regulating structure 8 includes a pressure wheel 81 mounted on the upper end of the drive shaft 5. The periphery of the pressure wheel 81 faces the friction plate upper pressure plate 62. The pressure wheel 81 is provided with evenly spaced threaded holes. A ratchet shaft 82 is threadedly mounted in the threaded holes of the pressure wheel 81. The lower end of the ratchet shaft 82 extends beyond the pressure wheel 81 and faces directly above the friction plate upper pressure plate 62. Each ratchet shaft 82 is mounted on one side with an elastic pawl 83. The elastic pawl 83 slides in a horizontal groove on the pressure wheel 81. Under the action of a spring, the elastic pawl 83 presses against the ratchet shaft 82, achieving reverse self-locking of the ratchet shaft 82. This structure is prior art and will not be further described in this embodiment.

[0046] The lower end of the ratchet shaft 82 fits into a positioning hole in the upper side of the friction plate upper pressure plate 62, allowing the ratchet shaft 82 to be raised and lowered along the positioning hole. A stepped countersunk hole 821 is defined in the center of the ratchet shaft 82, with a hexagonal countersunk hole 822 located at its upper end. This facilitates removal and adjustment of the ratchet shaft 82. A countersunk screw 9 is inserted into the countersunk hole 821, with its rounded head resting on the stepped portion within the hole, preventing any interference with the removal and adjustment of the ratchet shaft 82. The lower end of the screw 9 extends beyond the ratchet shaft 82 and is threadedly connected to the friction plate upper pressure plate 62. The lower end of the ratchet shaft 82 has an external stop, and a spring disc 84 is mounted on the lower end of the ratchet shaft 82. The upper and lower ends of the spring disc 84 rest between the external stop of the ratchet shaft 82 and the friction plate upper pressure plate 62, respectively.

[0047] When working;

[0048] like Figure 4 As shown, when installing or disassembling the pressure regulating structure 8, since the upper and lower ends of the screw 9 connect the ratchet shaft 82 and the friction plate upper pressure plate 62, the ratchet shaft 82, the friction plate upper pressure plate 62 and the spring disc 84 become a whole, avoiding the spring disc 84 from scattering or flying, and improving the convenience of installation and maintenance of the entire turbine box.

[0049] 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 friction plate assembly mounting structure for a worm gearbox with inherent anti-reverse friction protection, 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) with a center hole; the drive shaft (5) is arranged at the axis of the worm wheel (3), and inner and outer gear rings (4) are fixedly mounted on the drive shaft (5); a friction plate assembly (6) is provided between the worm wheel (3) and the inner and outer gear rings (4); Its characteristics are: An intermediate gear ring (7) is fixedly mounted in the center hole of the worm wheel (3), and the inner teeth of the intermediate gear ring (7) cooperate with the outer teeth of the friction plate group (6); the inner teeth of the friction plate group (6) cooperate with the outer teeth of the inner and outer gear rings (4), and the upper end of the friction plate group (6) is connected to a pressure regulating structure (8).

2. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 1 is characterized in that: A spline transition fit is adopted between the worm wheel (3) and the outer wall of the intermediate gear ring (7), and a spline clearance fit is adopted between the inner and outer gear rings (4) and the drive shaft (5); A spline clearance fit is adopted between the upper friction plate in the friction plate group (6) and the inner wall of the middle gear ring (7), and a spline clearance fit is adopted between the lower friction plate in the friction plate group (6) and the outer walls of the inner and outer gear rings (4).

3. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 1 is characterized in that: The worm wheel (3) and the worm (2) adopt a helical pitch angle capable of preventing the worm wheel (3) and the worm (2) from reversing.

4. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 1 is characterized in that: The upper end surface of the worm wheel (3) is fixedly connected to a limiting ring (31), and the limiting ring (31) is pressed against the upper end surface of the intermediate gear ring (7).

5. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 1 is characterized in that: A friction plate backing plate (61) is provided at the lower end of the friction plate group (6), a friction plate upper pressure plate (62) is provided at the upper end of the friction plate group (6), and the pressure regulating structure (8) is pressed on the friction plate upper pressure plate (62).

6. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 5, characterized in that: The pressure regulating structure (8) comprises: A pressure wheel (81) fixed to the end of the drive shaft (5); A plurality of ratchet shafts (82) are connected to the periphery of the pressure wheel (81) through threads and are evenly distributed around the drive shaft (5); the lower ends of the ratchet shafts (82) extend out of the pressure wheel (81) and are directly above the friction plate upper pressure plate (62); A plurality of elastic pawls (83) are mounted on the periphery of the pressing wheel (81) and are matched with the ratchet shaft (82) in a one-to-one correspondence, and are used to prevent the ratchet shaft (82) from reversing; A plurality of sets of spring discs (84) are mounted one by one between the lower end of the ratchet shaft (82) and the upper side of the friction plate upper pressure plate (62) for pressing the friction plate upper pressure plate (62) downward.

7. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 6, characterized in that: A screw (9) is passed through the ratchet shaft (82), and the lower end of the screw (9) extends out of the ratchet shaft (82) and is connected to the friction plate upper pressure plate (62) via a thread.

8. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 7, characterized in that: The ratchet shaft (82) is provided with a stepped countersunk hole (821) at its center, and a hexagonal countersunk hole (822) for rotating the ratchet shaft (82) is provided at the upper end of the countersunk hole; The screw (9) is a countersunk screw, and the round head cap of the screw (9) is located on the step in the countersunk hole (821).

9. The friction plate assembly mounting structure of the worm gearbox with inherent anti-reverse friction protection according to claim 6, characterized in that: The lower end of the ratchet shaft (82) is provided with an external stop, and the lower end of the ratchet shaft (82) is fitted and inserted into a positioning hole provided on the upper side of the friction plate upper pressure plate (62); The spring disc (84) is sleeved on the lower end of the ratchet shaft (82), and the upper and lower ends of the spring disc (84) are respectively pressed between the ratchet shaft (82) and the friction plate upper pressure plate (62).

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