Spiral bevel gear reducer

Abstract

The application discloses a spiral bevel gear reducer, which is characterized by reasonable bearing arrangement, cross-span type mounting of an input bevel gear, reasonable bearing support arrangement, improved structural rigidity, reduced radial force of a tapered roller bearing, improved bearing service life, reasonable bearing support arrangement of an output bevel gear, interference fit assembly of a deep groove ball bearing, compensation of bearing assembly gap during thermal expansion, and reduced spindle swing. The first tapered roller bearing and the second tapered roller bearing are installed face to face, and the third tapered roller bearing and the fourth tapered roller bearing are installed face to face, so that the spiral bevel gear reducer is convenient to disassemble and assemble.

Description

Technical Field

[0001] This invention relates to the field of helicopter transmission technology, and in particular to a spiral bevel gear reducer. Background Technology

[0002] The spiral bevel gear reducer is the most important reduction component in a helicopter transmission system, used to reduce and increase the torque and speed output from the engine and to reverse its direction. During operation, the spiral bevel gears are subjected to circumferential, radial, and axial forces, which are transmitted to the reducer housing through bearings. The bearing arrangement has a significant impact on bearing life, reducer housing deformation, and the stability of motion transmission. Typically, the input bevel gear is cantilevered, and the output bevel gear is spanned, both supported by a pair of tapered roller bearings arranged back-to-back. This bearing arrangement results in fewer reducer parts, a simpler housing structure, easier manufacturing, and lower cost.

[0003] However, the above installation method has the following disadvantages:

[0004] 1. Tapered roller bearings are arranged back to back, which makes the installation structure complex and disassembly difficult.

[0005] 2. The input bevel gear is installed in a cantilever manner, resulting in poor rigidity, uneven bearing stress, heavy load on the tapered roller bearings near the gear end, short lifespan, and frequent maintenance and replacement.

[0006] 3. The output bevel gear has a large installation span. When the reducer is working, the temperature rises. The bearing and the casing are made of different materials. Thermal expansion causes the installation clearance of the tapered roller bearing to increase, resulting in poor alignment and spindle oscillation.

[0007] Therefore, whether an improved spiral bevel gear reducer can be provided based on the shortcomings of the existing technology has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects in the prior art and provide a spiral bevel gear reducer.

[0009] The present invention solves the above-mentioned technical problems through the following technical solution:

[0010] A spiral bevel gear reducer, comprising:

[0011] spindle;

[0012] A gear mounting bracket is sleeved on the main shaft;

[0013] An output bevel gear is sleeved on the main shaft and connected to the gear mounting base;

[0014] An input bevel gear includes a first rod portion, a bevel tooth portion, and a second rod portion connected in sequence. The bevel tooth portion meshes with the output bevel gear. The first rod portion is located at the front end of the cone tip of the bevel tooth portion, and the second rod portion is located at the rear end of the cone tip of the bevel tooth portion.

[0015] A first tapered roller bearing is fitted onto the second rod portion;

[0016] The second tapered roller bearing is sleeved on the second rod portion and installed face-to-face with the first tapered roller bearing;

[0017] A first deep groove ball bearing is fitted onto the gear mounting seat and located above the output bevel gear;

[0018] A second deep groove ball bearing is fitted onto the first rod portion;

[0019] The third tapered roller bearing is sleeved on the main shaft and located below the output bevel gear;

[0020] The fourth tapered roller bearing is sleeved on the main shaft and located below the third tapered roller bearing. The fourth tapered roller bearing and the third tapered roller bearing are installed face to face.

[0021] The third deep groove ball bearing is fitted onto the main shaft and located below the fourth tapered roller bearing.

[0022] Preferably, the first deep groove ball bearing and the housing are fitted with an interference fit; the second deep groove ball bearing and the housing are fitted with an interference fit; and the third deep groove ball bearing and the housing are fitted with an interference fit.

[0023] Preferably, the spiral bevel gear reducer further includes:

[0024] A small gear spacer is fitted onto the second rod portion and located between the first tapered roller bearing and the second tapered roller bearing.

[0025] Preferably, the spiral bevel gear reducer further includes:

[0026] A pinion adjusting shim is fitted onto the second rod portion and located between the bevel gear portion and the first tapered roller bearing.

[0027] Preferably, the spiral bevel gear reducer further includes:

[0028] A large gear spacer is fitted onto the main shaft and located between the fourth tapered roller bearing and the third deep groove ball bearing.

[0029] Preferably, the spiral bevel gear reducer further includes:

[0030] A large gear adjusting shim is fitted onto the main shaft and located between the output bevel gear and the third tapered roller bearing.

[0031] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0032] The positive and progressive effects of this invention are as follows: The bearing arrangement of the spiral bevel gear reducer of this invention is reasonable. Through the span-type installation of the input bevel gear and the reasonable bearing support arrangement, the structural rigidity is improved, the radial force of the tapered roller bearing is reduced, and the bearing life is increased. Through the reasonable bearing support arrangement of the output bevel gear and the interference fit assembly of the deep groove ball bearing, the bearing assembly clearance during thermal expansion is compensated, and the spindle oscillation is reduced. Furthermore, the first and second tapered roller bearings are installed face-to-face, and the third and fourth tapered roller bearings are installed face-to-face, which facilitates disassembly and installation. Attached Figure Description

[0033] Figure 1 This is a partial structural schematic diagram of a spiral bevel gear reducer according to a preferred embodiment of the present invention.

[0034] Figure 2 This is a cross-sectional view of the input bevel gear according to a preferred embodiment of the present invention.

[0035] Figure 3 This is a cross-sectional view of the output bevel gear according to a preferred embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] Spindle 1

[0038] First deep groove ball bearing 2

[0039] Gear Mounting Base 3

[0040] Second deep groove ball bearing 4

[0041] Input bevel gear 5

[0042] First section 51

[0043] Conical teeth 52

[0044] Second section 53

[0045] First tapered roller bearing 6

[0046] Small gear spacer 7

[0047] Second tapered roller bearing 8

[0048] Pinion Adjustment Pad 9

[0049] Output bevel gear 10

[0050] Third tapered roller bearing 11

[0051] Fourth tapered roller bearing 12

[0052] Third deep groove ball bearing 13

[0053] Large gear spacer 14

[0054] Large gear adjusting shim 15 Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0057] It should be noted that in the claims and specification of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0058] like Figures 1-3 A spiral bevel gear reducer for helicopters is provided, comprising a main shaft 1, a gear mounting base 3, an output bevel gear 10, an input bevel gear 5, a first tapered roller bearing 6, a second tapered roller bearing 8, a first deep groove ball bearing 2, a second deep groove ball bearing 4, a third tapered roller bearing 11, a fourth tapered roller bearing 12, a third deep groove ball bearing 13, a pinion spacer 7, a pinion adjusting shim 9, a large gear spacer 14, and a large gear adjusting shim 15.

[0059] The gear mounting base 3 is sleeved on the main shaft 1, and the output bevel gear 10 is sleeved on the main shaft 1 and connected to the gear mounting base 3.

[0060] The input bevel gear 5 includes a first rod portion 51, a bevel gear portion 52, and a second rod portion 53, which are sequentially connected and integrally formed. The bevel gear portion 52 meshes with the output bevel gear 10. The first rod portion 51 is located at the front end of the cone tip of the bevel gear portion 52, and the second rod portion 53 is located at the rear end of the cone tip of the bevel gear portion 52. A first tapered roller bearing 6 is sleeved on the second rod portion 53. A second tapered roller bearing 8 is sleeved on the second rod portion 53 and is installed face-to-face with the first tapered roller bearing 6. A second deep groove ball bearing 4 is sleeved on the first rod portion 51. A pinion spacer 7 is sleeved on the second rod portion 53 and is located between the first tapered roller bearing 6 and the second tapered roller bearing 8. A pinion adjusting shim 9 is sleeved on the second rod portion 53 and is located between the bevel gear portion 52 and the first tapered roller bearing 6. That is, the input bevel gear 5 is installed in a span type, with the second deep groove ball bearing 4 arranged in front of the cone top, and the pinion adjusting shim 9, the first tapered roller bearing 6, the pinion spacer 7 and the second tapered roller bearing 8 arranged in sequence behind it.

[0061] The first deep groove ball bearing 2 is fitted onto the gear mounting seat 3 and positioned above the output bevel gear 10. The third tapered roller bearing 11 is fitted onto the main shaft 1 and positioned below the output bevel gear 10. The fourth tapered roller bearing 12 is fitted onto the main shaft 1 and positioned below the third tapered roller bearing 11, with the fourth tapered roller bearing 12 and the third tapered roller bearing 11 mounted face-to-face. That is, the third deep groove ball bearing 13 is fitted onto the main shaft 1 and positioned below the fourth tapered roller bearing 12. The large gear spacer 14 is fitted onto the main shaft 1 and positioned between the fourth tapered roller bearing 12 and the third deep groove ball bearing 13. The large gear adjusting shim 15 is fitted onto the main shaft 1 and positioned between the output bevel gear 10 and the third tapered roller bearing 11. The output bevel gear 10 is installed in a span-type manner. The first deep groove ball bearing 2 is arranged above the output bevel gear 10, and the large gear adjusting shim 15, the third tapered roller bearing 11, the fourth tapered roller bearing 12, the large gear spacer 14 and the third deep groove ball bearing 13 are arranged in sequence below it.

[0062] The input bevel gear 5 and the output bevel gear 10 are a pair of spiral bevel gears. The gears are subjected to a pair of reaction forces, which are decomposed into circumferential force, radial force and axial force in orthogonal direction. The circumferential force generates working torque, and the radial force and axial force are transmitted to the casing through the bearing.

[0063] When the reducer is working, the axial force transmission route of the input bevel gear 5 is: inner ring of the first tapered roller bearing 6 - inner ring of the second tapered roller bearing 8 - outer ring of the second tapered roller bearing 8 - casing. The radial force is transmitted to the casing in sequence through the second deep groove ball bearing 4, the first tapered roller bearing 6, and the second tapered roller bearing 8.

[0064] The axial force transmission route of the output bevel gear 10 is: inner ring of the third tapered roller bearing 11 - inner ring of the fourth tapered roller bearing 12 - outer ring of the fourth tapered roller bearing 12 - casing. The radial force is mainly transmitted to the casing through the first deep groove ball bearing 2, the third tapered roller bearing 11, and the fourth tapered roller bearing 12 in sequence.

[0065] Furthermore, the first deep groove ball bearing 2, the second deep groove ball bearing 4, and the third deep groove ball bearing 13 are all interference-fitted with the housing. Thus, when the temperature rises, the interference fit of the deep groove ball bearings compensates for the clearance between the tapered roller bearings and the housing due to their different coefficients of thermal expansion, reducing the oscillation of the spindle 1.

[0066] The spiral bevel gear reducer in this embodiment has a reasonable bearing arrangement. The input bevel gear 5 is installed with a span, and the bearing support arrangement is optimized to improve structural rigidity, reduce radial force on the tapered roller bearings, and extend bearing life. The output bevel gear 10 has a reasonable bearing support arrangement and an interference fit with the deep groove ball bearings, which compensates for bearing assembly clearances during thermal expansion and reduces spindle 1 oscillation. Furthermore, the first tapered roller bearing 6 and the second tapered roller bearing 8 are installed face-to-face, and the third tapered roller bearing 11 and the fourth tapered roller bearing 12 are installed face-to-face, facilitating disassembly and installation.

Claims

1. A spiral bevel gear reducer, characterized in that, include: spindle; A gear mounting bracket is sleeved on the main shaft; An output bevel gear is sleeved on the main shaft and connected to the gear mounting base; An input bevel gear includes a first rod portion, a bevel tooth portion, and a second rod portion connected in sequence. The bevel tooth portion meshes with the output bevel gear. The first rod portion is located at the front end of the cone tip of the bevel tooth portion, and the second rod portion is located at the rear end of the cone tip of the bevel tooth portion. A first tapered roller bearing is fitted onto the second rod portion; The second tapered roller bearing is sleeved on the second rod portion and installed face-to-face with the first tapered roller bearing; A first deep groove ball bearing is fitted onto the gear mounting seat and located above the output bevel gear; A second deep groove ball bearing is fitted onto the first rod portion; The third tapered roller bearing is sleeved on the main shaft and located below the output bevel gear; The fourth tapered roller bearing is sleeved on the main shaft and located below the third tapered roller bearing. The fourth tapered roller bearing and the third tapered roller bearing are installed face to face. The third deep groove ball bearing is sleeved on the main shaft and located below the fourth tapered roller bearing; The first deep groove ball bearing is fitted to the housing with an interference fit; the second deep groove ball bearing is fitted to the housing with an interference fit; the third deep groove ball bearing is fitted to the housing with an interference fit. Also includes: A small gear spacer is fitted onto the second rod portion and located between the first tapered roller bearing and the second tapered roller bearing; A pinion adjusting shim is fitted onto the second rod portion and located between the bevel gear portion and the first tapered roller bearing; A large gear spacer is fitted onto the main shaft and located between the fourth tapered roller bearing and the third deep groove ball bearing; A large gear adjusting shim is fitted onto the main shaft and located between the output bevel gear and the third tapered roller bearing.

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