Double-rotating-speed driving system suitable for continuous drilling operation of laminated materials in aviation field and operation technology and application of double-rotating-speed driving system

Abstract

The invention discloses a double-rotating-speed driving system suitable for continuous drilling operation of laminated materials in the aviation field and an operation technology and application of the double-rotating-speed driving system. When a motor rotates in the forward direction or the reverse direction, power is selectively transmitted to one of two gear shafts through two one-way clutches; a third gear shaft is independently arranged between the two gear shafts, so that the center distance between the two gear shafts and the rotation direction of the gears are adjusted; the three gear shafts are all provided with gears, transmission of the two gear shafts is output from the fourth gear shaft or the fifth gear shaft under the meshing action of the gears, then different speed changing gears are obtained, the electric drill speed changing device has the advantages of being compact in structure, reliable in speed changing and free of manual operation, the power requirement of an electric drill under the double-rotating-speed working condition can be accurately matched, and the working efficiency is improved. And the requirement for continuous drilling operation of different laminated materials in the aviation field is met.

Description

Technical Field

[0001] This invention relates to the field of gearbox transmission technology for power tools, specifically to a dual-speed drive system suitable for continuous drilling operations on aerospace laminated materials, its operating process, and applications, particularly suitable for handheld automatic feed drills with differentiated requirements for output speed and torque. This invention achieves efficient transmission of drive motor power through different transmission paths by controlling the rotation direction of the motor, meeting the diverse speed requirements of the electric drill under different working conditions. Furthermore, it consists of a motor, five gears, and two one-way clutches forming a three-parallel shaft gear train, simplifying the entire drive system and reducing its overall size. Background Technology

[0002] In practical applications of power tools, different work scenarios impose varying requirements on the tool's output speed. This demand is particularly prominent and stringent in the drilling of laminated materials in the aerospace manufacturing field. Aerospace laminated materials are typically composed of a variety of materials with vastly different properties. Typical laminated structures often include aluminum alloys, composite materials, titanium alloys, and high-strength steels. These materials exhibit significant differences in strength and suitable cutting speeds, as detailed in the table below:

[0003] Because aerospace laminated structures require continuous drilling with the same drill bit, the drill bit must simultaneously handle two extreme demands during machining: when dealing with high-strength and high-toughness materials such as titanium alloys and high-strength steel, it needs to operate at low speeds to ensure sufficient torque output and avoid drill bit jamming or breakage; while when machining aluminum alloys and some composite materials, it needs to switch to high-speed mode to improve cutting efficiency and reduce material sticking. Therefore, a transmission system with multi-speed adjustment capabilities and convenient switching has become a core technical requirement for power tools used in aerospace laminated material machining.

[0004] Currently, most multi-speed transmission solutions for electric drills on the market rely on multi-gearbox structures (CN119860425B). Different transmission ratios are achieved by manually switching the gear meshing positions, thereby changing the output speed. However, this traditional solution has significant drawbacks: firstly, manual operation depends on the operator, which cannot meet the cycle time requirements of automated production; secondly, the manual switching mechanism increases the overall size and weight of the electric drill, hindering the ease of operation for handheld tools; and thirdly, mechanical impacts during gear switching can lead to accelerated gear wear and reduced lifespan of the transmission system.

[0005] Patent CN102092456B proposes a speed-changing mechanism based on the forward and reverse rotation of a motor. This system uses four sets of parallel shafts, with two clutches of different speeds and torques acting on the same shaft. Patent JP6599013B2 proposes another motor speed-changing assembly composed of four sets of parallel shafts. Patents JP4789000B2 and CN119483100A propose a speed-changing mechanism based on a planetary gear structure, utilizing the forward and reverse rotation of a motor. However, the application scenarios, transmission torque, and speed range of the above solutions are not well-suited for this project. Therefore, developing a compact, reliable, and low-cost dual-speed transmission system is a key direction for addressing the pain points of existing electric drill transmission technology. Summary of the Invention

[0006] Purpose of the invention: In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a dual-speed drive system suitable for continuous drilling of aerospace laminated materials, as well as its operation process and application. It is applicable to the continuous drilling of aircraft structural laminated materials (aluminum alloy + composite material + titanium alloy) by aerospace automatic feed drills, where different materials have different requirements for the speed and torque of the power source. It has the advantages of being lightweight and taking into account both high torque density and high speed density.

[0007] Technical solution: To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A dual-speed drive system for continuous drilling of laminated materials in the aerospace field includes three shaft systems. Shaft system I: the motor output shaft (31), gear shaft d (35), and one-way clutch a (21) are on the same axis. Shaft system II: the gear shaft b (33), gear shaft c (34), and one-way clutch b (22) are on the same axis. Shaft system III: the gear shaft a (32) is on an independent shaft system (3) and serves to connect the gears on the motor output shaft (31) and gear shaft b (33), or to connect the gears on gear shaft c (34) and gear shaft d (35). One-way clutches a (21) and b (22) are respectively located inside the motor output shaft (31) and gear shaft c (34).

[0008] By switching the engagement and disengagement states of the two one-way clutches, the power output end of the gearbox (gear shaft c (34) or gear shaft d (35)) can achieve different speed outputs when the drive motor rotates forward and reverse.

[0009] The drive motor is an internal rotor motor, and the system can withstand a motor output torque of <12Nm and a speed of <4000rpm.

[0010] Each gear shaft is fitted with a corresponding gear, and bearings are placed on one or both sides of the gear shaft; that is, gear a (11) is machined on the motor output shaft (31), and the two form a whole; gear shaft a (32) is fixed on the housing, and gear b (12) is sleeved on gear shaft a (32) through bearing (41) so that gear b (12) can rotate around the gear shaft a (32); gear c (13) is machined on gear shaft b (33), and the two form a whole; gear d (14) is machined on gear shaft c (34), and the two form a whole; gear e (15) is machined on gear shaft d (35), and the two form a whole; In this design, gear 12 mainly serves to adjust the center distance of the gear shaft and the direction of gear rotation.

[0011] The number of teeth of gears a (11) to e (15) are Z1, Z2, Z3, Z4, and Z5, respectively; Shaft system II uses gear shaft c (34) as the output shaft. The gear positions of the transmission in the forward and reverse rotation of the motor are: Z1 / Z3, Z5 / Z4. Shaft system I uses gear shaft d (35) as the output shaft. The gear shift positions of the transmission in the forward and reverse rotation of the motor are: 1, Z1 / Z3*Z4 / Z5.

[0012] The preferred tooth ratio of gear Z1 / Z3 is 1 to 2.5, and the preferred tooth ratio of gear Z5 / Z4 is 0.5 to 1.5.

[0013] The above-mentioned dual-speed drive system for continuous drilling of laminated materials in the aerospace field operates as follows: when the motor rotates in the forward or reverse direction, it selects to transmit power to one of the two gear shafts through two one-way clutches; a third gear shaft is independently set between the two gear shafts to adjust the center distance between the two gear shafts and the direction of gear rotation; gears are set on all three gear shafts, and under the action of gear meshing, the transmission of the two gear shafts is selected to be output from the fourth or fifth gear shaft, thereby obtaining different speed gears to meet the needs of continuous drilling of different laminated materials in the aerospace field.

[0014] If the output shaft is a gear shaft c34, there are two power transmission paths: Output I: One-way clutch a (21) is engaged, one-way clutch b (22) is disengaged, and power is transmitted through shaft I. The transmission sequence of this transmission path is: motor output shaft (31) → clutch a (21) → gear shaft b (35) → gear shaft c (34). Output II: One-way clutch b (22) is engaged, one-way clutch a (21) is disengaged, and power is transmitted through shaft 2. The transmission sequence of the transmission path is: motor output shaft (31) → gear c (13) → one-way clutch b (22) → gear shaft c (34).

[0015] If the output shaft is a gear shaft d 35, there are two power transmission paths: Output III: One-way clutch a (21) is engaged, one-way clutch b (22) is disengaged, and power is transmitted through shaft I. The transmission sequence of this transmission path is: motor output shaft (31) → clutch a (21) → gear shaft b (35). Output IV: One-way clutch b (22) is engaged, one-way clutch a (21) is disengaged, and power is transmitted through shaft 2. The transmission sequence of the transmission path is: motor output shaft (31) → gear c (13) → one-way clutch b (22) → gear shaft c (34) → gear shaft b (35).

[0016] An automatic feed drill for aviation includes a dual-speed drive system (101) for continuous drilling of laminated materials in the aviation field and other drive system components (102), which together drive a rotary feed compound screw (103).

[0017] This invention also provides an application of the above-mentioned dual-speed drive system in continuous drilling operations of laminated materials in the aerospace field, which takes into account both high torque density and high speed density.

[0018] Beneficial effects: In this invention, the rotating gear shaft c34 and gear shaft d35 can be adapted to serve as power output shafts, which greatly increases the design flexibility and reduces the spatial configuration of the entire system. Attached Figure Description

[0019] Figure 1 : A schematic diagram of the overall structure of the dual-speed drive system applicable to continuous drilling operations of aerospace laminated materials according to the present invention; Figure 2 : Figure 1 Exploded view of intermediate speed gear set 2; Figure 3 : Schematic diagram of the transmission path in configuration 1 state; Figure 4 Schematic diagram of the transmission path in configuration 2 state; Figure 5 : Layout diagram with gear shaft 35 as the output shaft; Figure 6 : Layout diagram with gear shaft 34 as the output shaft; Figure 7 : Power transmission path diagram when the motor rotates in reverse under configuration 1; Figure 8 : Power transmission path diagram when the motor rotates in the forward direction under configuration 1; Figure 9 : A schematic diagram of the dual-speed drive system of this invention applied to automatic feed drilling.

[0020] The main reference numerals in the attached drawings are explained as follows: Motor-1, Gear set-2, Housing-3; Gear a-11, Gear b-12, Gear c-13, Gear d-14, Gear e-15; One-way clutch a-21, One-way clutch b-22; Motor output shaft 31, Gear shaft a-32, Gear shaft b-33, Gear shaft c-34, Gear shaft d-35; Bearing f-41, Bearing a-42, Bearing b-43, Bearing c-44, Bearing d-45, Bearing e-46, Dual-speed drive system-101, Other drive system components-102, Compound lead screw-103. Detailed Implementation

[0021] The technical solution of the present invention will be described below with reference to specific embodiments: like Figure 1 As shown, a dual-speed drive system 101 suitable for continuous drilling of aerospace laminated materials includes a motor 1, a gear set 2, and a housing 3. The gear set 2 is connected to the output end of the motor, and the housing 3 is disposed outside the gear set 2.

[0022] like Figure 9 As shown, the aforementioned dual-speed drive system is applied to automatic feed drilling in the aerospace field. The dual-speed drive system 101, together with other drive system components 102, drives the rotary feed composite screw 103. It has the advantages of small size, easy portability and operation, and for continuous drilling operations of laminated materials with greatly different performance characteristics in the aerospace field, it has multiple speed adjustment functions and convenient switching.

[0023] Figure 2 This is an exploded view of gear set 2. Gear set 2 includes three parallel shaft gear trains: Shaft system I: motor output shaft 31 / gear shaft d35 and one-way clutch a21 are coaxial; Shaft system III: gear shaft a32 is on an independent axis and serves to connect gear a11 and gear c13 or gear d14 and gear e15; Shaft system II: gear shaft b33 / gear shaft c34 and one-way clutch b22 are coaxial.

[0024] Each shaft corresponds to a gear; gear a11 is machined on the motor output shaft 31, and the two together form a single unit. Gear shaft a32 is fixed to the housing, and gear b12 is fitted onto gear shaft a32 via bearing f41, allowing gear b12 to rotate along gear shaft a32. Gear c13 is machined on gear shaft b33, and the two together form a single unit; gear d14 is machined on gear shaft c34, and the two together form a single unit; gear e15 is machined on gear shaft d35, and the two together form a single unit.

[0025] The number of teeth of gears a11 to e15 are Z1, Z2, Z3, Z4, and Z5, respectively.

[0026] A one-way clutch a21 is housed inside the motor output shaft 31 via an interference fit, and the smooth rod portion of the gear shaft d35 is inserted into the one-way clutch a21. Similarly, a one-way clutch b22 is housed inside the gear shaft c34 via an interference fit, and the smooth rod portion of the gear shaft b33 is inserted into the one-way clutch b22. The function of the one-way clutch is to allow its internal shaft to rotate freely in only one direction, while allowing it to engage in the other direction to transmit torque.

[0027] Bearing a 42 is placed on the left side of gear shaft b33; bearings b43 and c44 are placed on the left and right sides of gear shaft c34; and bearings d45 and e46 are placed on the left and right sides of gear shaft d35. Since the focus here is on demonstrating the layout of the speed change mechanism, the fixed bearings of the motor rotor shaft are not shown.

[0028] like Figure 8 As shown, when the motor output shaft 31 rotates forward, assuming that the one-way clutch a21 is in the disengaged state and the one-way clutch b22 is in the engaged state, the power is transmitted through the motor rotor shaft 31 → gear a11 → gear b12 → gear c13 → gear shaft b33 → one-way clutch b22 → gear shaft c34 → output load.

[0029] like Figure 7 As shown, when the motor output shaft 31 reverses, assuming that the one-way clutch a21 is engaged and the one-way clutch b22 is disengaged, the power is transmitted through the motor rotor shaft 31 → one-way clutch a21 → gear shaft d35 → gear e15 → gear d14 → gear shaft c34 → output load.

[0030] The transmission method of the system described in this invention has two configurations. The operating principle of configuration 1 is as follows: Figure 3As shown, during system operation, gear a11 meshes with gear b12, gear b12 meshes with gear c13, and gear d14 meshes with gear e15. In this configuration, if gear shaft c34 is used as the output shaft (shaft system II), the transmission gears are Z1 / Z3 and Z5 / Z4. In this configuration, if gear shaft d35 is used as the output shaft (shaft system I), the transmission gears are 1, Z1 / Z3*Z4 / Z5.

[0031] The operating principle of configuration 2 is as follows: Figure 4 As shown, during system operation, gear a11 meshes with gear c13, gear d14 meshes with gear b12, and gear b12 meshes with gear e15. In this configuration, if gear shaft c34 is used as the output shaft (shaft system II), the transmission gears are: Z1 / Z3, Z5 / Z4. In this configuration, if gear shaft d35 is used as the output shaft (shaft system I), the transmission gears are: 1, Z1 / Z3*Z4 / Z5.

[0032] In this invention, gear b12 mainly serves to adjust the center distance of the gear shaft and the direction of gear rotation.

[0033] The output shaft of this invention can be either gear shaft c34 or gear shaft d35. Figure 5 , 6 A typical layout diagram of these two types of output shafts is given. The output form of the gear shaft can be external spline, internal spline, flat key, thread, etc. Example

[0034] Figure 7 , 8 The power transmission paths of the motor in reverse and forward rotation are illustrated using configuration 1 (with gear shaft c34 as the output shaft). In configuration 1, gear shaft 12 is located between the motor output gear shaft 11 and gear shaft 13.

[0035] Reference Figure 7 As shown, when motor 1 rotates in the reverse direction, the one-way clutch a21 is engaged. Therefore, the power of motor 1 is transmitted to gear shaft d35 through one-way clutch a21. Gear shaft d35 transmits the power to gear 14 through gear e15, and then to load A through gear shaft 34. At this time, the rotation direction of load A is opposite to the rotation direction of motor 1, that is, the rotation direction is forward. In this case, the rotation direction of load A is opposite to the rotation direction of motor 1, and the output reduction ratio of motor is Z5 / Z4.

[0036] When motor 1 rotates in the forward direction, one-way clutch a 21 is disengaged and one-way clutch b 22 is engaged. Therefore, the power of motor 1 is transmitted through motor output gear a 11, gear a 11 transmits power to gear b 12, gear b 12 transmits power to gear c 13, and gear c 13 rotates in the forward direction relative to gear 14. It can transmit power to gear shaft 34 through one-way clutch 22, and then to load A. In this case, the rotation direction of load A is the same as the rotation direction of motor, and the output reduction ratio of motor is Z1 / Z3.

[0037] In this way, by adjusting the gear ratios Z1, Z3, Z4, and Z5, the drive system can output power at two different reduction ratios, thereby meeting different power requirements. In this embodiment, the specific details are shown in Tables 1-4: Table 1

[0038] Table 2

[0039] Table 3

[0040] Table 4

[0041] The basic principles and main features of the present invention, as well as its advantages, have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An operating process for a dual-speed drive system suitable for continuous drilling of laminated materials in the aerospace field, characterized in that, When the motor rotates in the forward or reverse direction, it selects to transmit power to one of the two gear shafts through two one-way clutches. A third gear shaft is independently set between the two gear shafts to adjust the center distance between the two gear shafts and the direction of gear rotation. Gears are set on all three gear shafts. Under the action of gear meshing, the transmission of the two gear shafts can be selected to be output from the fourth or fifth gear shaft, thereby obtaining different speed gears to meet the needs of continuous drilling operations of different laminated materials in the aerospace field.

2. The operating process of the dual-speed drive system for continuous drilling of laminated materials in the aerospace field according to claim 1, characterized in that, By switching the engagement and disengagement states of the two one-way clutches, the power of the drive motor is transmitted to the output shaft via different transmission paths when rotating forward and in reverse, thereby achieving differentiated output at the two speeds of the output shaft. If the output shaft is a gear shaft c(34), there are two power transmission paths: Output I: One-way clutch a (21) is engaged, one-way clutch b (22) is disengaged, and power is transmitted through shaft I. The transmission sequence of this transmission path is: motor output shaft (31) → clutch a (21) → gear shaft d (35) → gear shaft c (34). Output II: One-way clutch b (22) is engaged, one-way clutch a (21) is disengaged, and power is transmitted through shaft system 2. The transmission sequence of the transmission path is: motor output shaft (31) → gear c (13) → one-way clutch b (22) → gear shaft c (34). If the output shaft is a gear shaft d(35), there are two power transmission paths: Output III: One-way clutch a (21) is engaged, one-way clutch b (22) is disengaged, and power is transmitted through shaft I. The transmission sequence of this transmission path is: motor output shaft (31) → clutch a (21) → gear shaft d (35). Output IV: One-way clutch b (22) is engaged, one-way clutch a (21) is disengaged, and power is transmitted through shaft 2. The transmission sequence of the transmission path is: motor output shaft (31) → gear c (13) → one-way clutch b (22) → gear shaft c (34) → gear shaft d (35).

3. A dual-speed drive system for continuous drilling of laminated materials in the aerospace field, characterized in that, It includes three shaft systems, among which, Shaft system I: The motor output shaft (31), gear shaft d (35), and one-way clutch a (21) are on the same axis; Shaft system II: Gear shaft b (33) and gear shaft c (34), and one-way clutch b (22) are on the same axis; Shaft system Ⅲ: Gear shaft a (32) is located on an independent shaft system (3), which serves to connect the motor output shaft (31) with the gear on gear shaft b (33), or to connect the gear shaft c (34) with the gear on gear shaft d (35); One-way clutch a (21) and one-way clutch b (22) are respectively located inside the motor output shaft (31) and gear shaft c (34); By switching the engagement and disengagement states of the two one-way clutches, the power output end of the gearbox can achieve different speeds when the drive motor rotates forward and in reverse, thanks to the gear shaft c (34) or gear shaft d (35).

4. A dual-speed drive system for continuous drilling of laminated materials in the aerospace field, as described in claim 3, is characterized in that... Each gear shaft is fitted with a corresponding gear, and bearings are placed on one or both sides of the gear shaft; that is, gear a (11) is machined on the motor output shaft (31), and the two form a whole; gear shaft a (32) is fixed on the housing, and gear b (12) is sleeved on gear shaft a (32) through bearing (41) so that gear b (12) can rotate around the gear shaft a (32); gear c (13) is machined on gear shaft b (33), and the two form a whole; gear d (14) is machined on gear shaft c (34), and the two form a whole; gear e (15) is machined on gear shaft d (35), and the two form a whole; The number of teeth of gears a (11) to e (15) are Z1, Z2, Z3, Z4, and Z5, respectively; Shaft system II uses gear shaft c (34) as the output shaft. The gear positions of the transmission in the forward and reverse rotation of the motor are: Z1 / Z3, Z5 / Z4. Shaft system I uses gear shaft d (35) as the output shaft. The gear shift positions of the transmission in the forward and reverse rotation of the motor are: 1, Z1 / Z3*Z4 / Z5.

5. The dual-speed drive system for continuous drilling of laminated materials in the aerospace field according to claim 4, characterized in that, The dimensions of gear a (11) and gear d (14) are larger than those of gear c (13) and gear e (15); the tooth ratio of gear Z1 / Z3 is preferably 1~2.5, and the tooth ratio of gear Z5 / Z4 is preferably 0.5~1.

5.

6. The dual-speed drive system for continuous drilling of laminated materials in the aerospace field according to claim 3, characterized in that, The drive motor is an internal rotor motor, and the system can withstand a motor output torque of <12Nm and a speed of <4000rpm.

7. An automatic feed drilling machine for aircraft, characterized in that, Including the dual-speed drive system (101) of claim 3 for continuous drilling of laminated materials in the aerospace field, and other drive system components (102), which together drive the rotary feed composite screw (103).

8. The dual-speed drive system described in claim 3 is applied to continuous drilling operations of laminated materials in the aerospace field, taking into account both high torque density and high speed density.

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