differential

Abstract

This disclosure relates to a differential, which includes a planetary shaft and two planetary gears respectively loosely fitted at both ends of the planetary shaft. Both planetary gears and the planetary shaft can rotate relative to a preset rotation center line, wherein the preset rotation center line is located between the two planetary gears and is perpendicularly intersecting the planetary shaft. An annular gap is formed between the planetary shaft and the planetary gears. The differential includes: an oil passage opened inside the planetary shaft, the two ends of the oil passage being closed and extending at least partially to the position where the planetary shaft and the planetary gears mate; an oil hole opened on the peripheral wall of the planetary shaft corresponding to the planetary gear and communicating between the oil passage and the annular gap; and a first sealing ring and a second sealing ring disposed between each planetary gear and the planetary shaft, and axially spaced on the outer wall of the planetary shaft to seal the annular gap. The oil passage, the oil hole, and the annular gap form an oil reservoir for filling with lubricating oil.

Description

Technical Field

[0001] This disclosure relates to the field of differential technology, and more specifically, to a differential. Background Technology

[0002] Under differential operating conditions, the planetary gear shaft and planetary gears in a differential are prone to wear and burning failures. Existing differentials typically employ an oil-slinging lubrication system within the gearbox, where lubricating oil is swung up and guided into the differential for lubrication. Related technologies often use oil guide grooves on the differential housing and spiral oil guide grooves on the planetary gear shafts to guide the swung lubricating oil into the differential. However, it takes time for the lubricating oil to reach the differential, and the amount flowing into the mating parts is relatively small. Furthermore, in the initial stages of differential operation, the lubricating oil cannot quickly reach the mating parts, especially in colder regions during winter when the lubricating oil viscosity is higher, preventing the swung lubricating oil from entering the differential. Under these conditions, differential burning failures are more likely to occur. Utility Model Content

[0003] The purpose of this disclosure is to provide a differential that at least partially solves the technical problems existing in the related art.

[0004] To achieve the above objectives, this disclosure provides a differential, which includes a planetary shaft and two planetary gears respectively loosely fitted at both ends of the planetary shaft. Both the two planetary gears and the planetary shaft are rotatable relative to a predetermined rotation center line, wherein the predetermined rotation center line is located between the two planetary gears and perpendicularly intersects the planetary shaft. An annular gap is formed between the planetary shaft and the planetary gears. The differential includes:

[0005] An oil passage is formed within the planetary shaft, the two ends of which are closed and extend at least partially to the position where the planetary shaft mates with the planetary gear;

[0006] An oil hole, corresponding to the planetary gear, is formed on the peripheral wall of the planetary shaft and connects between the oil passage and the annular gap; and

[0007] A first sealing ring and a second sealing ring are disposed between each planetary gear and the planetary shaft, and are axially spaced and fitted onto the outer wall of the planetary shaft to seal the annular gap.

[0008] The oil passage, the oil hole, and the annular gap together form an oil storage space for filling with lubricating oil.

[0009] Optionally, the planetary gear has a central hole that mates with the planetary shaft, and a groove is formed on the inner wall of the central hole that surrounds the planetary shaft, the groove forming the annular gap.

[0010] Optionally, the planetary gear has two annular grooves coaxial with the planetary shaft on the inner wall of the central hole. The two annular grooves are located on opposite sides of the groove in the axial direction of the planetary shaft. The first sealing ring and the second sealing ring are embedded in the two annular grooves in a one-to-one correspondence and are elastically compressed radially between the annular gaps.

[0011] Optionally, the two ends of the oil passage are respectively formed as an open end and a closed end, and the differential further includes a sealing element for sealing the open end.

[0012] Optionally, the sealing element is detachably connected to the opening end.

[0013] Optionally, the differential further includes:

[0014] Housing for accommodating the planetary shaft and the planetary gears; and

[0015] Two limiting pins are symmetrically positioned radially against the space between the housing and the planetary shaft.

[0016] Optionally, one end of the limiting pin is fixedly connected to the housing, and the planetary shaft has a limiting groove that is radially recessed into the planetary shaft at the other end corresponding to the limiting pin, so that the limiting pin can abut against it.

[0017] Optionally, the end of the planetary shaft extends outward from the planetary gear, and the limiting pin is disposed near the end of the planetary shaft.

[0018] Optionally, the limiting groove is formed at the closed end.

[0019] Optionally, the number of oil holes is multiple, and the multiple oil holes are arranged at circumferential intervals along the planetary axis.

[0020] By employing the above technical solution, a first and a second sealing ring are used between each planetary gear and planetary shaft to seal the annular gap. This ensures that the lubricating oil is always contained within the sealed oil storage space formed by the annular gap, oil holes, and oil passages. The lubricating oil not only does not decrease over time or with the rotation of the differential, but it can also quickly reach the mating position between the planetary shaft and planetary gear. This not only prevents differential burn-out but also improves the timeliness and reliability of lubrication between the planetary gear and planetary shaft.

[0021] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a cross-sectional view of a differential provided in an exemplary embodiment of this disclosure;

[0024] Figure 2 This is a partial cross-sectional view of a differential provided in an exemplary embodiment of this disclosure;

[0025] Figure 3 This is a cross-sectional view of a planetary axis provided in an exemplary embodiment of this disclosure;

[0026] Figure 4 This is a cross-sectional view of a planetary gear provided in an exemplary embodiment of this disclosure.

[0027] Explanation of reference numerals in the attached figures

[0028] 1-Oil passage; 11-Open end; 12-Closed end; 2-Oil hole; 31-First sealing ring; 32-Second sealing ring; 4-Blocking component; 5-Planetary shaft; 51-Limiting groove; 6-Planetary gear; 61-Annular groove; 7-Housing; 8-Limiting pin; 9-Annular gap; 10-Half shaft gear. Detailed Implementation

[0029] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0030] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the corresponding component itself. Terms such as "first" and "second" used in this disclosure are for distinguishing one element from another and do not have sequential or importance. Furthermore, in the following description, when referring to the accompanying drawings, the same reference numerals in different drawings denote the same or similar elements.

[0031] Reference Figures 1-4This disclosure provides a differential, which may include a planetary shaft 5 and two planetary gears 6 respectively loosely fitted at both ends of the planetary shaft 5. Here, "loosely fitted" means that the planetary gears 6 are coaxially fitted on the planetary shaft 5, and the planetary gears 6 can rotate relative to the planetary shaft 5 (i.e., there is no key connection between the planetary gears 6 and the planetary shaft 5, allowing the planetary gears 6 to "free-spin" on the planetary shaft 5). Both planetary gears 6 and the planetary shaft 5 can rotate relative to a predetermined rotation center line, which is located between the two planetary gears 6 and perpendicularly intersecting the planetary shaft 5. An annular gap 9 may be formed between the planetary shaft 5 and the planetary gears 6, and lubricating oil can be introduced into the annular gap 9 to prevent friction between the planetary shaft 5 and the planetary gears 6 from causing high-temperature erosion and failure. The differential provided in this disclosure may include an oil passage 1, an oil hole 2, a first sealing ring 31, and a second sealing ring 32. Figure 1 As shown, oil passage 1 can be formed inside planetary shaft 5, and both ends of oil passage 1 can be closed. Both ends of oil passage 1 can extend at least partially to the position where planetary shaft 5 mates with planetary gear 6, so that sufficient lubricating oil can be stored in oil passage 1 to meet lubrication requirements. Oil passage 1 can be coaxially arranged with planetary shaft 5 to avoid insufficient local oil supply caused by eccentric oil passage 1, ensuring uniform distribution of lubricating oil and improving lubrication reliability. Oil hole 2 can be formed on the peripheral wall of planetary shaft 5 corresponding to planetary gear 6, and oil hole 2 can connect oil passage 1 and annular gap 9. Based on the closed arrangement at both ends of oil passage 1, by correspondingly setting oil hole 2 in the radial direction of oil passage 1, lubricating oil can accumulate pressure inside oil passage 1 and then be forced to flow out from oil hole 2 in the radial direction of oil passage 1, thereby accurately and timely flowing into annular gap 9 to lubricate between planetary shaft 5 and planetary gear 6. Figure 1 As shown, a set of axial sealing rings, including a first sealing ring 31 and a second sealing ring 32, can be respectively set at the position corresponding to each planetary gear 6. The first sealing ring 31 and the second sealing ring 32 can be axially spaced on the outer wall of the planetary shaft 5 on both sides of the oil hole 2 to seal the two ends of the annular gap 9 in the axial direction, so that a sealed oil storage space can be formed between the annular gap 9, the oil hole 2 and the oil passage 1. In this way, the lubricating oil can always be contained in the oil storage space to lubricate the planetary shaft 5 and the planetary gear 6 in real time.

[0032] Through the above technical solution, by using a first sealing ring 31 and a second sealing ring 32 between each planetary gear 6 and planetary shaft 5 to seal the annular gap 9, the lubricating oil can always be contained in the sealed oil storage space formed between the annular gap 9, the oil hole 2 and the oil passage 1. The lubricating oil will not decrease with time and the rotation of the differential, and it can quickly reach the mating position between the planetary shaft 5 and the planetary gear 6. While avoiding differential burn-out, it also improves the timeliness and reliability of lubrication between the planetary gear 6 and the planetary shaft 5.

[0033] The oil storage space can be filled with lubricating oil. Under the action of centrifugal force, the more lubricating oil there is, the greater the oil pressure generated. The oil film formed on the mating surface between planetary gear 6 and planetary shaft 5 is more stable, which is more beneficial for reducing wear.

[0034] Reference Figure 1 and Figure 2 The planetary gear 6 may have a central hole that can mate with the planetary shaft 5, and a groove surrounding the planetary shaft 5 may be formed on the inner wall of the central hole, so that the inner diameter of the planetary gear 6 corresponding to the groove position is further larger than the outer diameter of the planetary shaft 5. The groove can form an annular gap 9, thereby reserving more space for lubricating oil filling between the planetary gear 6 and the planetary shaft 5, thereby increasing the lubricating oil storage capacity to extend the lubrication cycle and effectively avoiding the risk of component wear and overheating due to insufficient lubrication.

[0035] Reference Figure 1 and Figure 2 The planetary gear 6 has two annular grooves 61 formed on the inner wall of its central hole. In the circumferential direction of the planetary shaft 5, the two annular grooves 61 are located on opposite sides of the groove. The first sealing ring 31 and the second sealing ring 32 can be correspondingly embedded in the two annular grooves 61. The two annular grooves 61 are coaxial with the planetary shaft 5 to ensure the assembly accuracy of the first sealing ring 31 and the second sealing ring 32 and to ensure a sealing effect. When the first sealing ring 31 and the second sealing ring 32 are respectively embedded in the two annular grooves 61, they can be elastically compressed radially between the annular gaps 9 to provide a radial sealing effect on the annular gaps 9, thereby more effectively preventing lubricant leakage. In the embodiments provided in this disclosure, the first sealing ring 31 and the second sealing ring 32 can be detachably connected to the two annular grooves 61 respectively, so that the first sealing ring 31 or the second sealing ring 32 can be replaced when it reaches the end of its service life. This not only ensures the reliability of the differential during use, but also eliminates the need to replace the entire differential when the first sealing ring 31 or the second sealing ring 32 fails, thus reducing the maintenance cost of the differential.

[0036] Furthermore, referring to Figure 4The inner contours of the two annular grooves 61 can be matched with the outer contours of their corresponding first sealing ring 31 or second sealing ring 32, respectively. Specifically, the inner contour of the annular groove 61 for installing the first sealing ring 31 can match the outer contour of the first sealing ring 31, and the inner contour of the annular groove 61 for installing the second sealing ring 32 can match the outer contour of the second sealing ring 32. This arrangement ensures that the first sealing ring 31 and the second sealing ring 32 can fit tightly against the inner wall of the annular groove 61 after installation, thereby ensuring the reliability of the seal on the annular gap 9. It is understood that this disclosure does not limit the number or outer contour of the first sealing ring 31 and the second sealing ring 32, such as whether their axial dimensions are the same. The number or axial dimensions of the first sealing ring 31 and the second sealing ring 32 can be adaptively adjusted according to the sealing requirements of their installation position, as long as the sealing strength of the first sealing ring 31 and the second sealing ring 32 on the annular gap 9 can be ensured, and the lubricating oil will not leak.

[0037] Reference Figures 1-3 The oil passage 1 can be formed into an open end 11 and a closed end 12 at its two ends, respectively. The differential can also include a sealing element 4 for sealing the open end 11. In the embodiments provided in this disclosure, during assembly, lubricating oil can be added to the oil passage 1 through the open end 11. The sealing element 4 can be constructed as a columnar structure whose outer contour matches the inner contour of the open end 11. The sealing element 4 and the open end 11 can be detachably connected by plugging and unplugging. In this way, when the lubricating oil needs to be replaced, the sealing element 4 can be pulled out from the open end 11 to drain the old lubricating oil. After the new lubricating oil has been added, the sealing element 4 can be inserted into the open end 11 to seal the open end 11, thereby achieving the sealing of the oil passage 1.

[0038] Reference Figure 1 The differential may also include a housing 7 and two limiting pins 8. The planetary shaft 5, planetary gears 6, and two limiting pins 8 can be housed in the housing 7 to encapsulate and protect the planetary shaft 5, planetary gears 6, and other internal components such as the limiting pins 8. The housing 7 also transmits power and supports the rotational movement of the planetary gears 6 and the half-shaft gears 10. The specific power transmission method is well known to those skilled in the art and will not be described in detail here. The two limiting pins 8 can be arranged radially symmetrically relative to the planetary shaft 5 and abut against the housing 7 and the planetary shaft 5 respectively. When the planetary shaft 5 experiences radial displacement, the limiting pins 8 on both sides can simultaneously provide a counter-supporting force to counteract the radial force, thereby preventing radial displacement of the planetary shaft 5. The simultaneous abutment of the planetary shaft 5 by the limiting pins 8 on both sides also limits the axial and circumferential movement of the planetary shaft 5, preventing axial movement caused by inertia or impact, thereby improving the reliability of the differential during operation.

[0039] Reference Figure 1 and Figure 3 One end of the limiting pin 8 can be fixedly connected to the housing 7. In the embodiments provided in this disclosure, the limiting pin 8 can be welded to the housing 7. The other end of the limiting pin 8 can be used to cooperate with the planetary shaft 5. The planetary shaft 5 can have a limiting groove 51 that is radially recessed into the planetary shaft 5 at the other end of the limiting pin 8. The limiting pin 8 can abut against and partially extend into the limiting groove 51, thereby further limiting the movement of the planetary shaft 5, preventing the planetary shaft 5 from moving when subjected to external force, and ensuring the relative position stability of the planetary shaft 5, the planetary gear 6, and the housing 7. In the embodiments provided in this disclosure, the gear in the limiting groove 51 along the axial direction of the planetary shaft can be matched with the outer diameter of the limiting pin 8, thereby ensuring the stability of the cooperation between the limiting groove 51 and the limiting pin 8. At the same time, the planetary shaft 5 is fixed by the rigid abutment between the limiting pin 8 and the limiting groove 51, without the need for additional complex limiting devices, improving the compactness between components while occupying less space, and also reducing the risk of limiting failure due to loosening.

[0040] Reference Figure 1 The end of the planetary shaft 5 can extend outward from the planetary gear 6. The limiting pin 8 can be set close to the end of the planetary shaft 5 so that the limiting force applied by the limiting pin 8 to the planetary shaft 5 can act directly on the end of the planetary shaft 5. On the one hand, it can better limit the axial, circumferential and radial movement of the planetary shaft 5, and on the other hand, it can avoid interference between the limiting pin 8 and the planetary gear 6 or the half shaft gear 10.

[0041] Reference Figures 1-3 The limiting pin 8 can be formed at the closed end 12, so that the position of the planetary shaft 5 where the limiting pin 8 abuts has sufficient strength, and avoids deformation of the planetary shaft 5 when the limiting pin 8 abuts at the open end 11, because the rigidity of the open end 11 is less than that of the closed end 12 due to the hollow interior. This ensures the stability and reliability of the assembly between components.

[0042] In the embodiments provided in this disclosure, there can be multiple oil holes 2, which can be arranged at intervals along the circumference of the planetary shaft 5. Multiple oil holes 2 can supply oil simultaneously at different locations, allowing lubricating oil to be uniformly distributed throughout the annular gap 9 along the circumference, thereby quickly forming an oil film within the annular gap 9. This design not only shortens the oil flow path and reduces lubrication blind spots but also significantly reduces the risk of localized overheating and wear. Furthermore, when an oil hole 2 experiences poor oil supply due to blockage by impurities, other oil holes 2 can still maintain lubrication. By providing multiple oil holes 2, the situation where lubrication failure occurs due to the failure of a single oil hole 2 is effectively avoided.

[0043] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0044] 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, this disclosure will not describe the various possible combinations separately.

[0045] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A differential, comprising a planetary shaft and two planetary gears respectively loosely fitted at both ends of the planetary shaft, wherein the two planetary gears and the planetary shaft are rotatable relative to a predetermined rotation center line, wherein the predetermined rotation center line is located between the two planetary gears and perpendicularly intersects the planetary shaft, characterized in that, An annular gap is formed between the planetary shaft and the planetary gears, and the differential includes: An oil passage is formed within the planetary shaft, the two ends of which are closed and extend at least partially to the position where the planetary shaft mates with the planetary gear; An oil hole, corresponding to the planetary gear, is formed on the peripheral wall of the planetary shaft and connects between the oil passage and the annular gap; and A first sealing ring and a second sealing ring are disposed between the planetary gear and the planetary shaft, and are axially spaced and fitted onto the outer wall of the planetary shaft to seal the annular gap. The oil passage, the oil hole, and the annular gap together form an oil storage space for filling with lubricating oil.

2. The differential of claim 1, wherein, The planetary gear has a central hole that mates with the planetary shaft, and a groove is formed on the inner wall of the central hole that surrounds the planetary shaft, the groove forming the annular gap.

3. The differential of claim 2, wherein, The planetary gear has two annular grooves coaxial with the planetary shaft on the inner wall of the central hole. The two annular grooves are located on opposite sides of the groove in the axial direction of the planetary shaft. The first sealing ring and the second sealing ring are embedded in the two annular grooves in a one-to-one correspondence and are elastically compressed radially between the annular gaps.

4. The differential of claim 1, wherein, The oil passage is formed into an open end and a closed end at its two ends, respectively, and the differential also includes a sealing element for sealing the open end.

5. The differential of claim 4 wherein, The sealing element is detachably connected to the opening end.

6. The differential of claim 4 wherein, The differential also includes: Housing for accommodating the planetary shaft and the planetary gears; and Two limiting pins are symmetrically positioned radially against the space between the housing and the planetary shaft.

7. The differential of claim 6 wherein, One end of the limiting pin is fixedly connected to the housing, and the planetary shaft has a limiting groove that is radially recessed into the planetary shaft at the other end corresponding to the limiting pin, so that the limiting pin can abut against it.

8. The differential according to claim 6 or 7, characterized in that The end of the planetary shaft extends outward from the planetary gear, and the limiting pin is located near the end of the planetary shaft.

9. The differential of claim 7 wherein, The limiting groove is formed at the closed end.

10. The differential of claim 1, wherein, The number of oil holes is multiple, and the multiple oil holes are arranged at circumferential intervals along the planetary axis.

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