Balancing shaft gear anti-backlash mechanism

Abstract

The utility model belongs to motorcycle engine technical field discloses a balance axle gear gap eliminating mechanism, including balance axle main body, its one end is equipped with balance axle main gear, is equipped with balance axle auxiliary gear and elastic baffle ring in proper order on the wheel hub of balance axle main gear, is equipped with the torsional component between balance axle main gear and balance axle auxiliary gear, and the torsional component includes the leaf spring with opening, provides torsional load through the leaf spring pre-torsion, eliminates the gear pair meshing gap when high -speed operation, is equipped with the compression assembly between balance axle auxiliary gear and elastic baffle ring, including first flat pad, butterfly washer and second flat pad, adjusts the axial compression force of butterfly washer through replacing the first flat pad and second flat pad of different thickness, ensures that gear pair is closely engaged at idling, generates stable whistle sound. The utility model simple and compact structure, the assembly maintenance is convenient, effectively reduces the gear transmission noise and vibration, effectively promotes the engine acoustic quality and the running stability.

Description

Technical Field

[0001] This utility model belongs to the field of motorcycle engine technology, specifically relating to a balance shaft gear backlash elimination mechanism. Background Technology

[0002] In motorcycle engines, the balance shaft mechanism meshes with the crankshaft gear via balance shaft gears, driving the balance shaft to rotate and counteract the inertial forces generated by the crankshaft and piston movements. It is a key component for reducing engine vibration and improving smoothness of operation. The balance shaft is connected to the crankshaft via gears and maintains synchronous operation. However, in actual operation, due to manufacturing tolerances, wear, and thermal expansion, there will be meshing clearance between the gear pairs. This clearance can cause impacts, vibrations, and noise when the gears are running at high speeds. Therefore, under idling conditions, certain specific frequencies of whistling sounds may not be produced due to loose gear meshing, affecting the engine's acoustic quality.

[0003] Existing backlash elimination solutions mostly employ structures such as "multi-spring linkage," "eccentric shaft adjustment," or "hydraulic clamping." These methods are not only complex, requiring multiple precision components and resulting in high manufacturing costs, but also present challenges in assembly. Subsequent adjustments (such as fine-tuning the whistle volume) require disassembling multiple components, leading to inconvenient maintenance. Furthermore, they struggle to simultaneously ensure high-speed stability and optimal acoustic performance at idle. Therefore, it is necessary to provide a simple, low-cost, and easily adjustable balance shaft gear backlash elimination mechanism. Utility Model Content

[0004] The purpose of this utility model is to provide a backlash elimination mechanism for a balance shaft gear, so as to solve the problems of complex structure, high manufacturing cost, difficult assembly and inconvenient maintenance in the existing technology.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A backlash elimination mechanism for a balance shaft gear includes a balance shaft body, a balance shaft main gear sleeved at one end of the balance shaft body, a balance shaft secondary gear and an elastic retaining ring sleeved on the hub of the balance shaft main gear; a torque adjusting component is provided between the balance shaft main gear and the balance shaft secondary gear, the torque adjusting component is used to apply a torsional load to the balance shaft secondary gear; a clamping component is provided between the balance shaft secondary gear and the elastic retaining ring, the clamping component is used to apply an axial clamping force to the balance shaft secondary gear.

[0006] To facilitate adjustment of the whistle volume under idling and other operating conditions, the clamping assembly includes a first flat washer, a butterfly washer, and a second flat washer in sequence. Both the first and second flat washers have various thicknesses. By replacing the first and second flat washers with different thicknesses, the axial clamping force applied by the butterfly washer to the balance shaft gear can be adjusted.

[0007] To better eliminate the transmission backlash between the main gear and the auxiliary gear of the balance shaft, the torque adjustment assembly includes a leaf spring with an opening. The openings on both ends of the leaf spring are respectively provided with a first positioning pin and a second positioning pin. The main gear and the auxiliary gear of the balance shaft are respectively provided with a first positioning hole and a second positioning hole. The first positioning pin and the second positioning pin are respectively inserted into the first positioning hole and the second positioning hole.

[0008] Furthermore, it also includes a pin, with insertion holes provided on both the main gear and the secondary gear of the balance shaft, and the pin is inserted into the insertion holes of the secondary gear and the main gear of the balance shaft in sequence.

[0009] Furthermore, the hub of the balance shaft main gear has an annular groove, and an elastic retaining ring is disposed in the annular groove.

[0010] Compared with the prior art, the present invention has the following beneficial technical effects: This invention employs a torque adjustment assembly, which overcomes the friction between the main gear and the secondary gear of the balance shaft through the tension of the leaf spring. This allows the secondary gear of the balance shaft to follow the movement of the main gear of the balance shaft under high-speed conditions, eliminating meshing backlash and reducing impact, vibration, noise, and gear wear.

[0011] This invention employs a clamping assembly that provides continuous clamping force through a butterfly washer, ensuring that the balance shaft secondary gear remains tightly pressed against the primary gear. This enhances the meshing tightness of the gear pair, resulting in a noticeable whistling effect under idling and other operating conditions. By replacing the first and second flat washers of different thicknesses, the clamping force of the butterfly washer can be finely adjusted, achieving precise control over the volume and quality of the idling whistling sound to meet different product requirements. Furthermore, it is convenient to debug and maintain, requiring no disassembly of complex structures.

[0012] The torque adjustment assembly and clamping assembly of this utility model have a compact structure, a small number of parts, and all of them are standardized parts, resulting in low manufacturing and procurement costs and a simple assembly process. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a partial exploded view of the structure of this utility model; Figure 3 This is a partial sectional view of the present invention along the AA direction. In the diagram: balance shaft body 1, balance shaft main gear 2, hub 21, ring groove 22, first positioning hole 23, balance shaft secondary gear 3, second positioning hole 31, elastic retaining ring 4, pin 5, torque adjusting assembly 6, leaf spring 61, first positioning pin 62, second positioning pin 63, clamping assembly 7, first flat washer 71, butterfly washer 72, second flat washer 73. Detailed Implementation

[0014] The following detailed description illustrates the specific implementation method: Example

[0015] like Figure 1-3 As shown, a backlash elimination mechanism for a balance shaft gear includes a balance shaft body 1. A balance shaft main gear 2 is sleeved on the right end of the balance shaft body 1. A balance shaft secondary gear 3 and an elastic retaining ring 4 are sleeved on the hub 21 of the balance shaft main gear 2. An annular groove 22 is opened on the hub 21 of the balance shaft main gear 2, and the elastic retaining ring 4 is engaged in the annular groove 22. Both the balance shaft main gear 2 and the balance shaft secondary gear 3 have insertion holes, and pins 5 are inserted into the insertion holes on the balance shaft secondary gear 3 and the balance shaft main gear 2 in sequence.

[0016] like Figure 2 and 3 As shown, a torque adjustment assembly 6 is provided between the main gear 2 and the secondary gear 3 of the balance shaft. The torque adjustment assembly 6 is used to apply a torsional load to the secondary gear 3 of the balance shaft. The torque adjustment assembly 6 includes a leaf spring 61 with an opening. A first positioning pin 62 and a second positioning pin 63 are provided at the opening of the leaf spring 61. The first positioning pin 62 and the second positioning pin 63 are respectively fixed to the left and right end faces of the leaf spring 61. The main gear 2 and the secondary gear 3 of the balance shaft are respectively provided with a first positioning hole 23 and a second positioning hole 31. The first positioning pin 62 and the second positioning pin 63 are respectively inserted into the first positioning hole 23 and the second positioning hole 31, so that the leaf spring 61 is in a pre-torsion state.

[0017] When the engine is running at high speed, the torque adjustment component 6, through the elastic tension of the leaf spring 61, generates a preloaded torque on the balance shaft secondary gear 3 relative to the balance shaft primary gear 2, causing the balance shaft primary gear 2 and the balance shaft secondary gear 3 to rotate in opposite directions. This allows the tooth surfaces of the balance shaft primary gear 2 and the balance shaft secondary gear 3 to fit tightly against the tooth surfaces on both sides of the crankshaft gear, respectively. Together, they fill the gap between the gear meshing pairs, completely eliminating the impact space on the tooth surfaces during high-speed rotation, achieving shock-free and smooth transmission, and avoiding vibration and noise.

[0018] The pin 5 is used to axially position the main gear 2 and the auxiliary gear 3 of the balance shaft, preventing axial movement of the main gear 2 and the auxiliary gear 3 during high-speed torsion. This ensures that the tooth surfaces of the main gear 2 and the auxiliary gear 3 are always precisely aligned with the tooth surfaces of the crankshaft gear, avoiding backlash failure due to axial offset and further ensuring the stability of high-speed operation.

[0019] like Figure 2 and 3As shown, a clamping assembly 7 is provided between the balance shaft auxiliary gear 3 and the elastic retaining ring 4. The clamping assembly 7 is used to apply axial clamping force to the balance shaft auxiliary gear 3. The clamping assembly 7 includes a first flat washer 71, a butterfly washer and a second flat washer 73 from right to left. The first flat washer 71 and the second flat washer 73 both include various thicknesses. By replacing the first flat washer 71 and the second flat washer 73 with different thicknesses, the axial clamping force applied to the balance shaft auxiliary gear 3 by the butterfly washer 72 can be adjusted.

[0020] When the engine is idling, the clamping assembly 7 provides continuous axial clamping force through the butterfly washer, which prevents the balance shaft secondary gear 3 from axially moving due to low driving force at idle. This ensures that the balance shaft secondary gear 3 is always close to the balance shaft main gear 2, thereby ensuring that the combined structure of the balance shaft main gear 2 and the balance shaft secondary gear 3 is always in close contact with the tooth surface of the crankshaft gear, eliminating the gap between them. This produces a stable and clear whistling sound at the gear meshing point, improving the acoustic quality of the engine.

[0021] By replacing the first flat washer 71 or the second flat washer 73 with different thicknesses, the compression of the butterfly washer can be adjusted. The greater the compression, the stronger the axial clamping force, and the higher the fit between the balance shaft main gear 2, the balance shaft secondary gear 3 and the crankshaft gear; conversely, the clamping force is weakened and the fit is reduced, so as to meet the needs of different products.

[0022] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A backlash elimination mechanism for a balance shaft gear, comprising a balance shaft body (1), wherein a balance shaft main gear (2) is sleeved at one end of the balance shaft body (1), characterized in that: A balance shaft secondary gear (3) and an elastic retaining ring (4) are fitted on the hub (21) of the balance shaft main gear (2); a torque adjustment component (6) is provided between the balance shaft main gear (2) and the balance shaft secondary gear (3), the torque adjustment component (6) is used to apply torsional load to the balance shaft secondary gear (3); a clamping component (7) is provided between the balance shaft secondary gear (3) and the elastic retaining ring (4), the clamping component (7) is used to apply axial clamping force to the balance shaft secondary gear (3).

2. The backlash elimination mechanism for the balance shaft gear according to claim 1, characterized in that: The clamping assembly (7) includes a first flat washer (71), a butterfly washer, and a second flat washer (73) in sequence. The first flat washer (71) and the second flat washer (73) both include various thicknesses. By replacing the first flat washer (71) and the second flat washer (73) with different thicknesses, the axial clamping force applied by the butterfly washer (72) to the balance shaft gear (3) can be adjusted.

3. The backlash elimination mechanism for the balance shaft gear according to any one of claims 1 or 2, characterized in that: The torque adjustment assembly (6) includes a leaf spring (61) with an opening. The openings at both ends of the leaf spring (61) are respectively provided with a first positioning pin (62) and a second positioning pin (63). The main gear (2) of the balance shaft and the secondary gear (3) of the balance shaft are respectively provided with a first positioning hole (23) and a second positioning hole (31). The first positioning pin (62) and the second positioning pin (63) are respectively inserted into the first positioning hole (23) and the second positioning hole (31).

4. The backlash elimination mechanism for the balance shaft gear according to claim 3, characterized in that: It also includes a pin (5), and both the balance shaft main gear (2) and the balance shaft secondary gear (3) are provided with insertion holes. The pin (5) is inserted into the insertion holes of the balance shaft secondary gear (3) and the balance shaft main gear (2) in sequence.

5. The backlash elimination mechanism for the balance shaft gear according to claim 3, characterized in that: The hub (21) of the balance shaft main gear (2) has an annular groove (22), and the elastic retaining ring (4) is disposed in the annular groove (22).

Images