Synchronizer gear shifting structure with low tooth alignment rate

Abstract

A synchronizer gear shifting structure with the low tooth alignment rate comprises a transmission shaft, a front transmission gear, a synchronizer and a rear transmission gear, a first sliding sleeve outer guide is arranged on the periphery, close to one end of the synchronizer, of a sliding sleeve of the synchronizer, a sliding sleeve inner guide is arranged on the periphery, close to one end of the sliding sleeve, of the synchronizer, and a front transmission gear guide matched with the first sliding sleeve outer guide structure is arranged in the front transmission gear. And a transmission shaft guide matched with the guide structure in the sliding sleeve is arranged on the transmission shaft. Through reasonable arrangement of component structures, the design of guiding first and then gear entering is adopted in the whole, and the gear engaging success rate is greatly increased; the floating deviation of the front transmission gear / the rear transmission gear relative to the transmission shaft is filled by the outer guide fit with a smaller gap, so that better coaxiality is obtained, the tooth alignment probability is reduced, meanwhile, the front transmission gear / the rear transmission gear is suitable for double-floating or single-floating design, the low tooth alignment rate can be realized, and better gear shifting smoothness is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy-duty commercial vehicle transmissions, and in particular relates to a synchronizer shifting structure with a low gear matching ratio. Background Art

[0002] Currently, heavy-duty commercial vehicle AMT is developing in the direction of high torque and high speed ratio, with increasingly higher requirements for gear shifting quality. In particular, there must be no power interruption under harsh working conditions such as heavy-load climbing. As the differential gear is the most frequently used gear, the success rate of gear shifting is naturally very important.

[0003] The differential gear of commercial vehicle AMT adopts synchronizer shifting. Although the existing synchronizer shifting can improve the success rate of gear shifting by controlling the speed difference of gear shifting, due to the floating between the drive shaft and the shift gear and the large moment of inertia, the gear-matching phenomenon still occurs from time to time. The gear-matching phenomenon will not only produce obvious noise, but also prolong the gear shifting time, and seriously cause gear shifting failure and temporary power interruption. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a synchronizer shifting structure with a low gear matching ratio to solve the problems of noise, prolonged shifting time and gear engagement failure caused by the existing gear matching phenomenon.

[0005] To achieve the above object, the technical solution adopted by the present invention includes:

[0006] A low gear ratio synchronizer shifting structure comprises a transmission shaft, and also comprises a front transmission gear, a synchronizer and a rear transmission gear which are coaxially sleeved in sequence on the outer periphery of the transmission shaft, the synchronizer can slide axially along the transmission shaft between the front transmission gear and the rear transmission gear; the synchronizer sleeve is provided with a first sleeve outer guide near the outer periphery of one end thereof, and a sleeve inner guide near the inner periphery of one end thereof, the front transmission gear is provided with a front transmission gear guide which matches the first sleeve outer guide structure, and the transmission shaft is provided with a transmission shaft guide which matches the sleeve inner guide structure.

[0007] Preferably, a second sleeve outer guide is provided on the outer periphery of the other end of the synchronizer sleeve, and a rear transmission gear guide matching the second sleeve outer guide structure is provided inside the rear transmission gear.

[0008] Preferably, an internal spline of the front transmission gear is provided at one end of the front transmission gear close to the synchronizer, and the front transmission gear guide is located on the inner side of the internal spline of the front transmission gear; an internal spline of the rear transmission gear is provided at one end of the rear transmission gear close to the synchronizer, and an external spline of the sleeve is provided on the outer periphery of the middle section of the sleeve to match the internal spline structure of the front transmission gear and the internal spline structure of the rear transmission gear, and external spline shaping of the sleeve is provided at both ends of the external spline of the sleeve.

[0009] Preferably, the outer guide of the sliding sleeve is clearance matched with the guide of the front transmission gear, and the inner guide of the sliding sleeve is clearance matched with the guide of the transmission shaft.

[0010] Preferably, the outer guide of the second sliding sleeve is clearance-matched with the guide of the rear transmission gear.

[0011] Preferably, a limiting protrusion is coaxially provided on one side of the transmission shaft guide of the transmission shaft, and a transmission shaft external spline and a supporting transmission section are coaxially provided in sequence on the other side of the transmission shaft guide; the front transmission gear is coaxially sleeved on the limiting protrusion; the rear transmission gear is coaxially sleeved on the supporting transmission section; the sliding sleeve of the synchronizer is coaxially sleeved on the transmission shaft between the front transmission gear and the rear transmission gear, and the inner periphery of the other end of the sliding sleeve is provided with an internal spline of the sliding sleeve matching the external spline structure of the transmission shaft.

[0012] Preferably, the sliding sleeve can slide axially along the transmission shaft and be limited circumferentially relative to the transmission shaft.

[0013] Preferably, the front transmission gear and the rear transmission gear can rotate circumferentially along the transmission shaft and be axially limited.

[0014] Preferably, there is a clearance fit between the front transmission gear and the transmission shaft.

[0015] Preferably, a bearing is coaxially provided between the rear transmission gear and the supporting transmission section.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] (1) The synchronizer shifting structure with low gear ratio of the present invention has reasonable arrangement of component structure, and the cooperation between the outer guide of the sliding sleeve and the front transmission gear guide / rear transmission gear guide, and the inner guide of the sliding sleeve and the transmission shaft guide. When engaging a gear, the synchronizer first synchronizes the rotation speed of the transmission gear and the sliding sleeve to create a low speed difference gear engaging condition. At the same time, the guide sections cooperate with each other to improve the coaxiality and smoothly engage the gear. The overall design of guiding first and then engaging the gear is adopted, which greatly improves the success rate of engaging the gear.

[0018] (2) The synchronizer shifting structure of the present invention has a low gear-matching ratio. By rationally setting the component structure, the floating deviation of the front transmission gear / rear transmission gear relative to the transmission shaft is compensated by the outer guide with a smaller gap, thereby obtaining better coaxiality and improving the success rate of one-time gear shifting. At the same time, it is applicable to both the front transmission gear / rear transmission gear of double floating and single floating design, and can achieve a low gear-matching ratio, providing better gear shifting smoothness.

[0019] (3) The synchronizer shifting structure with low gear ratio of the present invention realizes a low speed difference and high coaxiality gear shifting environment by rationally setting the component structure and finely trimming the tooth ends of the splines. Only a small gear shifting force is required to shift gears, which fundamentally improves the gear shifting success rate and reduces noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the synchronizer shifting structure with a low gear ratio of the present invention;

[0022] Figure 2 for Figure 1 A cross-sectional view of the forward gear limit position;

[0023] Figure 3 for Figure 1 Schematic diagram of the structure of the middle transmission shaft;

[0024] Figure 4 for Figure 1 Schematic diagram of the structure of the middle front transmission gear;

[0025] Figure 5 for Figure 1 The structural diagram of the middle synchronizer sleeve;

[0026] Figure 6 for Figure 1 Structural schematic diagram of the modification of the outer spline of the middle sleeve (6a is a CAD drawing of the modification of the outer spline of the sleeve, and 6b is a three-dimensional drawing of the modification of the outer spline of the sleeve);

[0027] Figure 7 for Figure 1 A cross-sectional view of the moment of shifting into forward gear;

[0028] Figure 8 for Figure 1 A cross-sectional view of the rearward gear shift limit position;

[0029] The symbols in the figure represent:

[0030] Transmission shaft 1, front transmission gear 2, synchronizer 3, rear transmission gear 4, bearing 5,

[0031] Transmission shaft external spline 11, transmission shaft guide 12, limiting convex part 13, supporting transmission section 14;

[0032] Front transmission gear internal spline 21, front transmission gear guide 22;

[0033] High-speed cone ring 31, spoke plate 32, low-speed cone ring 33, sliding sleeve 34; sliding sleeve outer spline 341, sliding sleeve inner spline 342, first sliding sleeve outer guide 3431, second sliding sleeve outer guide 3432, sliding sleeve inner guide 344, sliding sleeve outer spline modification 345. DETAILED DESCRIPTION

[0034] The invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the invention.

[0035] It should be noted that the directional terms mentioned in this article, such as "inner cavity", "inner periphery", "inner wall" and "outside", are consistent with the specific directions on the paper of the drawings in the specification or the corresponding directions of the space shown in the drawings; all components and equipment in the present invention, unless otherwise specified, are all components and equipment known in the prior art.

[0036] A low gear ratio synchronizer shifting structure comprises a transmission shaft 1, and also comprises a front transmission gear 2, a synchronizer 3 and a rear transmission gear 4 which are coaxially sleeved on the outer periphery of the transmission shaft 1 in sequence, wherein the synchronizer 3 can slide along the axial direction of the transmission shaft 1 between the front transmission gear 2 and the rear transmission gear 4; a first sleeve outer guide 3431 is provided on the outer periphery of a sleeve 34 of the synchronizer 3 near one end thereof, and a sleeve inner guide 344 is provided on the inner periphery of one end thereof; a front transmission gear guide 22 which matches the first sleeve outer guide 3431 in structure is provided in the front transmission gear 2, and a transmission shaft guide 12 which matches the sleeve inner guide 344 in structure is provided on the transmission shaft 1;

[0037] Its function is: the synchronizer 3 slides axially along the transmission shaft 1 and mechanically contacts the front transmission gear 2 or the rear transmission gear 4 to realize the linkage of the front transmission gear 2 or the rear transmission gear 4. Through the cooperation of the first sleeve outer guide 3431 and the front transmission gear guide 22, as well as the sleeve inner guide 344 and the transmission shaft guide 12, when shifting forward, the synchronizer 3 first synchronizes the rotation speed of the front transmission gear 2 and the synchronizer 3 sleeve 34 to create a low speed difference gear shifting condition. At the same time, the guide sections cooperate with each other to improve the coaxiality and smoothly shift into gear. The overall design of guiding first and then shifting gears greatly improves the success rate of shifting gears, and can also be applied to shifting structures with large transmission gaps.

[0038] Specifically, the sliding sleeve 34 of the synchronizer 3 is provided with a second sliding sleeve outer guide 3432 near the outer periphery of the other end thereof, and the rear transmission gear 4 is provided with a rear transmission gear guide matching the structure of the second sliding sleeve outer guide 3432;

[0039] Its function is: through the cooperation between the second sleeve outer guide 3432 and the rear transmission gear guide, when shifting gears backward, the synchronizer first synchronizes the rotation speed of the rear transmission gear 4 and the sleeve 34 to create a low speed difference gear shifting condition. At the same time, the guide sections cooperate with each other to improve the coaxiality and smoothly shift into gear. The overall design of guiding first and then shifting gears greatly improves the success rate of shifting gears, and can also be applied to gear shifting structures with large transmission clearances.

[0040] The transmission shaft guide 12 of the transmission shaft 1 disclosed in this embodiment is coaxially provided with a limiting convex portion 13 on one side, and the transmission shaft external spline 11 and the supporting transmission section 14 are coaxially provided on the other side of the transmission shaft guide 12 in sequence; the front transmission gear 2 is coaxially sleeved on the limiting convex portion 13; the rear transmission gear 4 is coaxially sleeved on the supporting transmission section 14; the sliding sleeve 34 of the synchronizer 3 is coaxially sleeved on the transmission shaft 1 between the front transmission gear 2 and the rear transmission gear 4, and the inner circumference of the other end of the sliding sleeve 34 is provided with a sliding sleeve internal spline 342 matching the structure of the transmission shaft external spline 11. The front transmission gear 2 disclosed in this embodiment is clearance-matched with the transmission shaft 1, and the bearing 5 is coaxially provided between the rear transmission gear 4 and the supporting transmission section 14. The first sliding sleeve external guide 3431 is clearance-matched with the front transmission gear guide 22, and the sliding sleeve internal guide 344 is clearance-matched with the transmission shaft guide 12; the second sliding sleeve external guide 3432 is clearance-matched with the rear transmission gear guide.

[0041] Specifically, a front transmission gear internal spline 21 is provided in the front transmission gear 2 at one end close to the synchronizer 3, and a front transmission gear guide 22 is located on the inner side of the front transmission gear internal spline 21; a rear transmission gear internal spline is provided in the rear transmission gear 4 at one end close to the synchronizer 3; a sleeve external spline 341 matching the front transmission gear internal spline 21 and the rear transmission gear internal spline structure is provided on the outer periphery of the middle section of the sleeve 34; sleeve external spline modifications 345 are provided at both ends of the sleeve external spline 341.

[0042] The synchronizer 3 sleeve 34 disclosed in the present embodiment adopts a full-stroke inner guide design. Whether shifting forward to enter the front transmission gear 2 or shifting backward to enter the rear transmission gear 4, the inner guide 344 of the sleeve is in a sliding fit with the transmission shaft guide 12, which improves the coaxiality, makes it easier to shift, and can better adapt to harsh shifting conditions; both sides of the synchronizer 3 sleeve 34 are provided with outer guides, which cooperate with the inner guides of the front transmission gear / rear transmission gear, and in addition, the guide matching clearance is smaller than the matching clearance between the transmission shaft and the transmission gear; when the outer spline 341 of the synchronizer 3 sleeve 34 is about to collide with the inner spline 21 of the front transmission gear / the inner spline of the rear transmission gear, the guide section has already taken effect, and at this time, the floating deviation of the front transmission gear / the rear transmission gear relative to the transmission shaft 1 is filled by the outer guide with a smaller clearance, thereby obtaining better coaxiality and reducing the probability of tooth alignment. At the same time, whether the front transmission gear / the rear transmission gear is a double floating design or a single floating design, it is applicable, and a low tooth alignment rate can be achieved, providing better gear shifting smoothness.

[0043] The outer splines 341 of the sleeve, the inner splines 21 of the front transmission gear and the inner splines of the rear transmission gear disclosed in this embodiment have been finely trimmed on the tooth ends, and a tapered chamfered corner design, i.e., spline shaping, has been adopted, so that the splines can be staggered after colliding when shifting gears more smoothly; in a low speed difference, high coaxiality gear shifting environment, only a smaller gear shifting force is required to achieve gear shifting, which fundamentally improves the success rate of gear shifting.

[0044] like Figure 2 , Figure 7 and Figure 8 As shown, during the gear shifting process, the spoke plate 32 pushes the sleeve 34 to move axially under the gear shifting force, and the inner guide 344 of the sleeve always slides on the transmission shaft guide 12. Since the matching clearance is very small, a good coaxiality is obtained; when the forward gear is engaged (the same is true for the backward gear), the high gear cone ring 31 presses the front transmission gear 2, synchronizes the rotation speed of the front transmission gear 2 and the sleeve 34 of the synchronizer 3, and ensures that the two are within a small speed difference range; then, before the inner spline 21 of the front transmission gear and the outer spline 34 of the synchronizer sleeve are about to collide, the front transmission gear guide 22 and the first sleeve outer guide 3431 have begun to cooperate, as shown in FIG. Figure 7 As shown in the enlarged figure, at this time, the chamfer of the guide section contacts first, and even if there is a large floating deviation, the gear can be smoothly engaged under the action of the chamfer of the guide section and the gear engaging force, and the outer guide matching clearance is small, which can provide good coaxiality for the subsequent gear engaging process; accordingly, at the time of gear engaging, due to the existence of the outer spline modification 345 of the synchronizer sleeve, the splines will be easily staggered after colliding, and the gear engaging process will be smoother. This structure is also applied to the inner spline 21 of the front transmission gear, which can significantly reduce the tooth ratio; as shown in FIG. Figure 2 As shown, it is a schematic diagram of the shifting structure shifting forward to the extreme position. At this time, the floating deviation of the front drive gear 2 relative to the drive shaft 1 is replaced by a smaller inner and outer guide matching clearance, the transmission clearance becomes smaller, and the noise of the shifting structure is reduced.

[0045] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0047] In addition, the various different implementation modes disclosed in this solution may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the content invented by the present disclosure.

Claims

1. A low gear ratio synchronizer shifting structure, comprising a transmission shaft (1), and also comprising a front transmission gear (2), a synchronizer (3) and a rear transmission gear (4) which are coaxially sleeved on the outer periphery of the transmission shaft (1) in sequence, characterized in that: The synchronizer (3) can slide axially along the transmission shaft (1) between the front transmission gear (2) and the rear transmission gear (4); The sliding sleeve (34) of the synchronizer (3) is provided with a first sliding sleeve outer guide (3431) near the outer periphery of one end thereof, and a sliding sleeve inner guide (344) near the inner periphery of one end thereof; a front transmission gear guide (22) matching the structure of the first sliding sleeve outer guide (3431) is provided inside the front transmission gear (2); and a transmission shaft guide (12) matching the structure of the sliding sleeve inner guide (344) is provided on the transmission shaft (1).

2. The low gear ratio synchronizer shifting structure according to claim 1, characterized in that: The sliding sleeve (34) of the synchronizer (3) is provided with a second sliding sleeve outer guide (3432) near the outer periphery of the other end thereof, and the rear transmission gear (4) is provided with a rear transmission gear guide that matches the structure of the second sliding sleeve outer guide (3432).

3. The low gear ratio synchronizer shifting structure according to claim 2, characterized in that: The front transmission gear (2) is provided with a front transmission gear internal spline (21) at one end close to the synchronizer (3); the front transmission gear guide (22) is located inside the front transmission gear internal spline (21); the rear transmission gear (4) is provided with a rear transmission gear internal spline at one end close to the synchronizer (3); a sleeve external spline (341) matching the front transmission gear internal spline (21) and the rear transmission gear internal spline structure is provided on the outer periphery of the middle section of the sleeve (34); and sleeve external spline shaping (345) is provided at both ends of the sleeve external spline (341).

4. The low gear ratio synchronizer shifting structure according to claim 3, characterized in that: The outer guide (343) of the sliding sleeve is clearance-matched with the front transmission gear guide (22), and the inner guide (344) of the sliding sleeve is clearance-matched with the transmission shaft guide (12).

5. The low gear ratio synchronizer shifting structure according to claim 3, characterized in that: The second sliding sleeve outer guide (3432) is clearance-matched with the rear transmission gear guide.

6. The low gear ratio synchronizer shifting structure according to any one of claims 1 to 5, characterized in that: A limiting convex portion (13) is coaxially provided on one side of the transmission shaft guide (12) of the transmission shaft (1), and a transmission shaft external spline (11) and a supporting transmission section (14) are coaxially provided in sequence on the other side of the transmission shaft guide (12); The front transmission gear (2) is coaxially sleeved on the limiting convex portion (13); The rear transmission gear (4) is coaxially sleeved on the supporting transmission section (14); The sliding sleeve (34) of the synchronizer (3) is coaxially sleeved on the transmission shaft (1) between the front transmission gear (2) and the rear transmission gear (4), and the inner periphery of the other end of the sliding sleeve (34) is provided with a sliding sleeve inner spline (342) matching the structure of the outer spline (11) of the transmission shaft.

7. The low gear ratio synchronizer shifting structure according to claim 6, characterized in that: The sliding sleeve (34) can slide axially along the transmission shaft (1) and be circumferentially limited relative to the transmission shaft (1).

8. The low gear ratio synchronizer shifting structure according to claim 7, characterized in that: The front transmission gear (2) and the rear transmission gear (4) can rotate circumferentially along the transmission shaft (1) and are axially limited.

9. The low gear ratio synchronizer shifting structure according to claim 8, characterized in that: The front transmission gear (2) and the transmission shaft (1) are clearance-fitted.

10. The low gear ratio synchronizer shifting structure according to claim 8, characterized in that: A bearing (5) is coaxially arranged between the rear transmission gear (4) and the supporting transmission section (14).

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