A gear lubrication structure

Abstract

The present invention discloses a gear lubrication structure, including a shaft and a gear; one end face of the gear is limited by a shoulder on the shaft, and the other end is a part to be lubricated; both end faces of the gear are provided with at least one first end face groove and at least one second end face groove; a sleeve is provided between the inner ring of the gear and the outer wall of the shaft; the sleeve is located between the shoulder and the part to be lubricated, and a spiral oil groove is provided on the surface of the sleeve; the lubricating oil flows in from the first end face groove, passes through the spiral oil groove, and flows out from the second end face groove. The present invention designs a complete lubricating oil import and export path to promote the flow of the lubricating oil to achieve the purpose of heat dissipation. An inlet oil pool is formed by chamfering design, and the end face oil grooves on the left and right end faces of the gear and the spiral oil groove of the sleeve form a complete splash lubricating oil import and export path, which not only ensures good lubrication of the gear and the sleeve but also can fully dissipate heat, and has high reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of gearboxes, and specifically relates to a gear lubrication structure. Background Art

[0002] As Figure 1 、 Figure 2 and Figure 3 shown, in the existing three-shaft gearbox, power is transmitted from the first shaft 1 to the constantly meshing gear 2, and then to the gear 4 through the intermediate shaft gear meshing with it. The gear 4 is a gear for gears, and the power is output through the connection of the synchronizer 3 between the gear 4 and the second shaft 7. When no gear is engaged, the gear 4 is sleeved on the second shaft 7, and there is relative rotation between the gear 4 and the second shaft 7. Needle roller bearings 5 and a bushing 6 are installed in the radial direction and clamped between the right end face 311 of the gear housing and the left end face 711 of the shoulder of the second shaft. There is a gap between the gear end face and 311, 711. The bushing 6 is radially interference-fitted on the second shaft 7 and rotates with the second shaft. In a gearbox without active lubrication, all gears and bearings on the first shaft and the second shaft rely on the intermediate shaft gear to stir the oil for splash lubrication. In order to introduce oil into the needle roller bearing 5, a plurality of concentric or eccentric straight grooves 43 are machined on the left and right end faces of the gear, and the bushing 6 is a smooth shaft.

[0003] In the existing technical solution, the edge line of the straight groove is perpendicular to the tangential direction of the outer circle of the gear end face, and no oil sump is provided between the outer circle of the gear end face and the shoulder of the second shaft, resulting in the lubricating oil entering along the tangential direction being unable to be reliably introduced into and discharged from the bearing (when the gear rotates, there is a relative tangential speed between the lubricating oil and the gear), the lubricating oil cannot flow smoothly, and the bearing cannot be sufficiently cooled. At this time, only a needle roller bearing with a relatively small coefficient of friction can be installed between the bushing and the gear, resulting in a high cost; for high-gear gears, due to the small outer diameter of the gear, the spoke 41 will be relatively thin, affecting the strength of the gear.

[0004] The existing solution adds a needle roller bearing, resulting in high costs, thin spokes, and low reliability of the gear.

[0005] The Chinese patent "A Differential Gear Lubrication Structure", with the publication number CN211501553U and the publication date of September 15, 2020, discloses a differential gear lubrication structure. The differential consists of a differential planetary gear and a differential half shaft gear. A first lubricating oil groove is provided on the spherical surface of the differential planetary gear, and a second lubricating oil groove is provided on the mounting surface of the differential half shaft gear. The groove on the gear end face is an inclined groove, but the optimal inclination angle and its calculation method are not given, and the oil inlet effect is limited. Summary of the Invention

[0006] Aiming at the problems existing in the background art, the present invention provides a gear lubrication structure with strong oil storage capacity and good lubrication effect.

[0007] To achieve the above object, the gear lubrication structure designed by the present invention is characterized in that: it includes a shaft and a gear; one end face of the gear is limited by a shoulder on the shaft, and the other end is a component to be lubricated;

[0008] At least one first end face groove and at least one second end face groove are provided on both end faces of the gear;

[0009] A bushing is provided between the inner ring of the gear and the outer wall of the shaft; the bushing is located between the shoulder and the component to be lubricated, and a spiral oil groove is provided on the surface of the bushing;

[0010] The lubricating oil flows in from the first end face groove, and after passing through the spiral oil groove, it flows out from the second end face groove.

[0011] As a preferred solution, along the oil inlet direction:

[0012] If the gear rotates counterclockwise, the first end face groove and the spiral oil groove are left-handed, and the second end face oil groove is right-handed;

[0013] If the gear rotates clockwise, the first end face groove and the spiral oil groove are right-handed, and the second end face oil groove is left-handed.

[0014] In this way, effective oil scraping and oil guiding can be achieved, making the smoothness and heat dissipation effect better.

[0015] Preferably, the spiral angles of the first end face oil groove and the second end face oil groove are the same, and the range of the spiral angle α of the end face groove is: 45° ≤ α ≤ sin^(-1)(r / R), where r is the inner circle radius of the gear end face and R is the outer circle radius of the gear end face.

[0016] Preferably, the groove widths of the first end face oil groove and the second end face oil groove are the same, and the range of the groove width B of the end face groove is: B ≥ B_2 = r - r^2 / R, where r is the inner circle radius of the gear end face and R is the outer circle radius of the gear end face.

[0017] Preferably, the groove depths of the first end face oil groove and the second end face oil groove are the same, and the range of the groove depth of the end face groove is 1.5 mm to 3.0 mm.

[0018] Preferably, a first chamfer is provided at one end of the shoulder close to the first end face oil groove. In this way, an oil pool is formed at the oil inlet, which is beneficial to the collection of lubricating oil.

[0019] Preferably, protruding ends are provided at both ends of the gear; the first end face groove and the second end face groove are provided on the protruding ends.

[0020] More preferably, a second chamfer is provided on the protruding end where the first end face groove is located. In this way, an oil pool is formed at the oil inlet, which is beneficial to the collection of lubricating oil.

[0021] As another preferred solution, the cross-section of the spiral oil groove is arc-shaped, and the range of its groove depth h is 0.7 mm ≤ h ≤ 1 mm. In this way, the oil inlet volume and the oil storage volume can be guaranteed.

[0022] Preferably, the range of the distance L1 from the top of the spiral oil groove is 2 mm ≤ L1 ≤ 5 mm.

[0023] Preferably, there are n spiral grooves, n ≥ 2, and n is a natural number. In this way, the oil inlet volume and the oil storage volume can be guaranteed.

[0024] Preferably, the distance L3 between adjacent spiral oil grooves is L3 = L / i·n, where L is the length of the bushing, n is the number of heads of the spiral groove, and i = 1, 2, 3….

[0025] The beneficial effects of the present invention are as follows: Aiming at the working condition where the rolling friction of the gear changes to sliding friction, the present invention designs a complete lubricating oil import and export path to promote the flow of the lubricating oil so as to achieve the purpose of heat dissipation.

[0026] An inlet oil pool is formed through the chamfer design, and the end face oil grooves on the left and right end faces of the gear and the spiral oil grooves of the bushing form a complete splashing lubricating oil import and export path, which not only ensures good lubrication between the gear and the bushing but also can fully dissipate heat, with high reliability.

[0027] The present invention details the structure and parameter definition process of the end face and bushing spiral oil grooves adapted to the oil flow. It is not only convenient for processing and has good dynamic balance of the structure, but also increases the lubricating oil flow rate and has sufficient lubrication.

[0028] The present invention eliminates the needle roller bearing, reduces the cost; for gears with a relatively small outer diameter, the spoke thickness is increased, and the gear has high strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an assembly schematic diagram of the prior art

[0030] Figure 2 is a structural schematic diagram of the prior gear

[0031] Figure 3 is a structural schematic diagram of the prior bushing

[0032] Figure 4 is an assembly schematic diagram of the present invention

[0033] Figure 5 is a structural schematic diagram of the gear of the present invention

[0034] Figure 6 is a structural schematic diagram of the bushing of the present invention

[0035] Figure 7 is a front view schematic diagram of the gear of the present invention

[0036] Figure 8 Schematic diagram of the oil flow rebound principle

[0037] Figure 9 Schematic diagram of the minimum value of the spiral angle of the gear end face groove in the present invention

[0038] Figure 10 Schematic diagram of the maximum value of the spiral angle of the gear end face groove in the present invention

[0039] Figure 11 Schematic diagram of the parameters of the spiral groove of the bushing in the present invention

[0040] Figure 12 Schematic diagram of the oil flow trajectory in the present invention

[0041] Figure 13 Schematic diagram of the structure of another embodiment of the present invention Detailed implementation manners

[0042] The technical solutions (including the preferred technical solutions) of the present invention will be further described in detail below by way of the accompanying drawings and by listing some alternative embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0045] In order to be applicable to all nested gearshift gears, the needle roller bearing needs to be cancelled. As a result, since the rolling friction is changed to sliding friction, the requirements for lubrication and heat dissipation are relatively high. To promote the flow of lubricating oil, the present invention designs a complete lubricating oil inlet and outlet path to effectively promote the flow of lubricating oil for heat dissipation purposes. The gear lubrication structure designed by the present invention includes a shaft and a gear; one end face of the gear 4 is limited by a shaft shoulder on the shaft, and the other end is a component to be lubricated; at least one first end face groove and at least one second end face groove are provided on both end faces of the gear 4; a bushing is provided between the inner ring of the gear and the outer wall of the shaft; the bushing is located between the shaft shoulder and the component to be lubricated, and a spiral oil groove is provided on the surface of the bushing; the lubricating oil flows in from the first end face groove, passes through the spiral oil groove, and then flows out from the second end face groove.

[0046] Along the oil inlet direction: if the gear rotates counterclockwise, the first end face groove and the spiral oil groove are left-handed, and the second end face oil groove is right-handed; if the gear rotates clockwise, the first end face groove and the spiral oil groove are right-handed, and the second end face oil groove is left-handed.

[0047] Hereinafter, it is assumed that the synchronizer 3 is installed on the left side of the gear 4, and the splashed lubricating oil cannot enter from the synchronizer, and can only enter from the right end of the gear 4.

[0048] As Figures 4 to 6 shown, the outer diameter of the shaft shoulder 612 of the second shaft 6 is larger than the outer diameter of the right end face 43 of the gear, and there is a first chamfer 613 at the edge of the shaft shoulder and a second chamfer 431 at the edge of the right end face 43 of the gear. In this way, an oil sump is formed at the oil inlet, which is beneficial to the collection of lubricating oil. The second end face groove is machined on the left end face 42 of the gear, the first end face c groove is machined on the right end face 43 of the gear, and the spiral oil groove is machined on the outer circle of the bushing 5. Along the oil inlet direction, that is Figure 4 as viewed from right to left in

[0049] Assume that the rotation direction of the gear is counterclockwise. As Figure 7 shown, the above setting is the first case of the present invention. Then, the rotation directions of the first end face groove and the spiral oil groove of the bushing are left-handed, and the option of the second end face groove is right-handed. In this way, the oil can be effectively scraped and guided, resulting in better smoothness and heat dissipation effects.

[0050] In the first case, as Figures 7 to 12 shown, the width of the right end face groove of the gear is B, the spiral angle is α, o1 is the center of the gear, o3 is the intersection point of the right edge of the first end face groove and the outer circle 432 of the end face, and o2 is the intersection point of o1o3 and the inner circle 433 of the end face. That is: r is the radius of the inner circle 433 of the end face, and R is the radius of the outer circle 432 of the end face.

[0051] The spiral angle α min As Figure 9, when the gear 4 rotates counterclockwise, a fan-shaped oil flow 46 is formed on the outer circle 432 of the end face. For the convenience of explanation, it is simplified into oil flows A, B, and C. Part of it adheres to the right edge 442 of the groove and flows to the inner circle 433 of the end face, and the other part forms oil flows A', B', and C' after rebounding from the right edge 442 of the groove. The rebounding principle is shown in Figure 8 , when a fluid hits a smooth wall surface at high speed, it will rebound. The rebound angle β = γ. When β = γ = 45°, the direction of the incoming oil flow and the rebounding oil flow are perpendicular. When A', B', and C' all fall within the min fan-shaped area of ∠α, they will not touch other edges, which is the optimal oil inlet direction. Oil flow A is the tangential oil flow of the outer circle 432 of the end face, perpendicular to the radial line o3o1. According to the rebounding principle, oil flow A' is formed. A' falls along the radial o3o1 as the critical oil inlet. α min = 45° can ensure rebounding along the radial direction. To ensure that oil flow A' does not touch the left edge of the groove, the left edge 441 of the groove is parallel to the right edge 442 of the groove and passes through o2, which is the minimum critical groove width B min , according to the trigonometric function relationship:

[0052]

[0053] Helix angle α max Such as Figure 10 , draw a tangent line to the inner circle 433 of the end face through o3, and the intersection point with the inner circle 433 of the end face is o4. At this time, the right edge 442 of the groove reaches the maximum angle α max , any larger angle will not allow for a smooth transition with the inner circle 433 of the end face.

[0054] According to the trigonometric function relationship:

[0055]

[0056]

[0057] Because α max > α min , according to the rebounding principle, the oil flows A', B', and C' Figure 8 swing to the right by a certain angle and completely fall within the max fan-shaped area of ∠α. Draw a line parallel to 442 through o2 to obtain the left edge 441 of the groove, and the groove width is B2.

[0058]

[0059] If the situation of α max < 45° occurs through the calculation of equation (3), it indicates that the ratio of the diameters of the inner and outer circles of the end face is unreasonable, and it is necessary to increase r or decrease R.

[0060] Through the above analysis, the parameters of the end face groove are defined as follows:

[0061] (1) Helix angle of the end face groove

[0062] (2) Width of the end face groove

[0063] (3) Depth of the end face groove: 1.5 mm to 3 mm;

[0064] (4) To reduce the dynamic unbalance of the gear and facilitate machining, the end face grooves are evenly arranged circumferentially, and the number is ≥ 2;

[0065] In another embodiment of the present invention, the end face oil grooves on each end face are evenly spaced.

[0066] In another embodiment of the present invention, the end face oil grooves on the two end faces are symmetrically arranged.

[0067] (5) The parameters of the left and right end face grooves of the gear are the same, but when observed along the oil inlet direction, the helix directions are opposite.

[0068] Figure 11 These are the parameters of the shaft sleeve 5. L is the length of the shaft sleeve, L3 is the distance between adjacent spiral oil grooves. The profile of the spiral oil groove adopts an arc structure, which is convenient for machining. The depth is h, and the distance between the tops of the grooves is L1. Assuming the number of starts of the spiral oil groove is n, one start means there is only one spiral line, and n starts mean there are n spiral lines, then

[0069]

[0070] This can ensure that the number of turns of the spiral oil groove is an integer and reduce the dynamic unbalance of the shaft sleeve. To ensure sufficient contact length, increase the oil inlet flow rate and oil storage volume, the number of starts n of the spiral oil groove 51 is ≥ 2, 2 mm ≤ L1 ≤ 5 mm, 0.7 mm ≤ h ≤ 1 mm.

[0071] The following introduces the second situation of the present invention. The synchronizer 3 is installed on the left side of the gear 4. The splashed lubricating oil cannot enter from the synchronizer, and can only enter from the right end of the gear 4. The rotation direction of the gear is counterclockwise.

[0072] In the second situation, the oil inlet direction is still as Figure 4 shown, and the oil enters from right to left. In the second situation, the parameters of the first end face groove, the second end face groove, and the spiral oil groove refer to the first situation. However, at this time, along the oil inlet direction, the helix directions of the first end face groove and the spiral oil groove are right-handed, and the helix direction of the second end face groove is left-handed.

[0073] As Figure 13 shown, assume that the synchronizer 3 is installed on the right side of the gear 4. The splashed lubricating oil cannot enter from the synchronizer, and can only enter from the left end of the gear 4. In this embodiment, the oil inlet direction is Figure 13 shown as entering from left to right.

[0074] ForFigure 13 For the shown oil inlet direction, there still exist the situations where the gear rotates counterclockwise and clockwise, which have no substantial differences from the above-mentioned first and second situations, and thus will not be elaborated here.

[0075] According to the oil inlet direction and the rotation direction of the gear, end face grooves and spiral oil grooves with different helix directions are selected, and the purpose is to achieve better oil inlet, oil guiding and oil outlet.

[0076] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention and do not limit the present invention. Any modifications, combinations, substitutions, improvements, etc. made under the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A gear lubrication structure, characterized in that: It includes a shaft and a gear; one end face of the gear is limited by a shoulder on the shaft, and the other end is a component to be lubricated; at least one first end face groove and at least one second end face groove are provided on both end faces of the gear; a bushing is provided between the inner ring of the gear and the outer wall of the shaft; the bushing is located between the shoulder and the component to be lubricated, and a spiral oil groove is provided on the surface of the bushing; lubricating oil flows in from the first end face groove, passes through the spiral oil groove, and then flows out from the second end face groove; Along the oil inlet direction: If the gear rotates counterclockwise, the first end face groove and the spiral oil groove are left-handed, and the second end face oil groove is right-handed; If the gear rotates clockwise, the first end face groove and the spiral oil groove are right-handed, and the second end face oil groove is left-handed; The spiral angles of the first end face oil groove and the second end face oil groove are the same, and the range of the spiral angle α of the end face groove is: , where r is the inner circle radius of the gear end face, and R is the outer circle radius of the gear end face.

2. The gear lubrication structure according to claim 1, wherein: The groove widths of the first end face oil groove and the second end face oil groove are the same, and the range of the end face groove width B is: , where r is the inner circle radius of the gear end face and R is the outer circle radius of the gear end face.

3. The gear lubrication structure according to claim 2, wherein: The depths of the first end face oil groove and the second end face oil groove are the same, and the range of the depth of the end face groove is 1.5 mm to 3.0 mm.

4. The gear lubrication structure according to claim 1 or 2 or 3, characterized in that: A first chamfer is provided at one end of the shoulder close to the first end face oil groove.

5. The gear lubrication structure according to claim 4, characterized in that: Both ends of the gear are provided with protruding ends; the first end face groove and the second end face groove are provided on the protruding ends; a second chamfer is provided on the protruding end where the first end face groove is located.

6. The gear lubrication structure according to claim 1 or 5, characterized in that: The cross-section of the spiral oil groove is arc-shaped, and the range of its groove depth h is .

7. The gear lubrication structure according to claim 6, wherein: The range of the distance L1 from the top of the spiral oil groove is .

8. The gear lubrication structure according to claim 7, wherein: There are n helical oil grooves, , and n is a natural number.

9. The gear lubrication structure according to claim 8, characterized in that: Distance between adjacent spiral oil grooves , where L is the length of the bushing, n is the number of starts of the spiral oil groove, and i = 1, 2, 3, ….

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