Design method of spur-face gear transmission for high-speed rotary dobby

Abstract

The present invention provides a design method for a spur-face gear transmission for a high-speed rotary dobby. The method replaces the Gleason-toothed spiral bevel gear pair between the dobby's drive shaft and cam output mechanism with a spur face gear pair. Based on the relevant parameters of the bevel and gear pinions of the spiral bevel gear pair, the corresponding parameters of the spur and face gears of the replaced spur face gear pair are calculated. This method achieves orthogonal transmission and increased speed without changing any parts or interfaces in the dobby except for the gear profile. The structure is simple to install, lightweight, and space-saving. Its point contact characteristics are unaffected by installation errors, ensuring consistent motion and high versatility.

Description

Technical Field

[0001] The patent of this invention belongs to the technical field of gear transmission structure for textile machinery, and in particular relates to a design method of spur-face gear transmission for high-speed rotating multi-arm machines. Background Art

[0002] Dobbies, as shedding devices in textile machinery, typically utilize a single-stage spiral bevel gear pair transmission structure. The driving gear is driven by a drive shaft (1), and the motion output from the driven gear is transmitted to the longitudinal frame via a cam output mechanism (2), driving the corresponding textile machinery. The high-speed development of textile machinery depends on the speed and accuracy of the rotary dobby, which in turn is directly dependent on the gear transmission at the input end. Currently, the most advanced rotary dobbies utilize a point-contact Gleason-tooth spiral bevel gear pair for their input end gear transmission, with the large and small gears determined by the dobby's structural dimensions. This point-contact spiral bevel gear pair has several drawbacks that limit the high-speed motion accuracy of the dobby: First, it requires high assembly precision to ensure proper point contact properties and contact trajectory; second, the large gear's shape dictates its large size and weight, making it the largest and heaviest component on the dobby, making high-speed motion accuracy difficult to achieve; third, its manufacturing cost is high, and to ensure point contact properties, the small bevel gears are actually adapted gears machined using a matching process, resulting in inconsistent meshing properties between different small bevel gears and the large gear. To this end, the present invention discloses a spur-face gear transmission for a dobby machine. The driving gear in this gear transmission adopts the simplest spur-tooth cylindrical gear among gears, and the size of the face gear adopts the structural dimensions that will not interfere with the driven gear in the spiral bevel gear pair, so as to ensure that no parts and interfaces in the dobby machine other than the gear tooth profile are changed. This spur-face gear transmission is simple to install, and its point contact characteristics are not affected by installation errors, which can ensure the consistency of the dobby machine's movement. During use, there is no need to adjust the installation position of the spur gear to adapt to the point contact trajectory requirements of the face gear. In addition, the production cost of the spur-tooth cylindrical gear is low and it is easy to replace after damage. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0004] A spur-face gear transmission design method for a high-speed rotary dobby is proposed. The Gleason-tooth spiral bevel gear pair between the drive shaft and the cam output mechanism in the dobby is replaced with a spur-face gear pair. The driving gear connected to the drive shaft is replaced by a spur cylindrical gear instead of the small bevel gear of the spiral bevel gear pair, and the driven gear connected to the cam output mechanism is replaced by a face gear instead of the large gear of the spiral bevel gear pair.

[0005] First measure the following parameters:

[0006] The shaft diameter of the drive shaft; the maximum outer diameter of the small bevel gear of the spiral bevel gear pair ; Module and pressure angle of spiral bevel gear pair;

[0007] Then determine the parameters of the spur gear and face gear as follows:

[0008] Mounting hole diameter of spur gear d n Equal to the diameter of the drive shaft;

[0009] Number of teeth on spur gears z p Calculated by formula 1:

[0010] Formula 1

[0011] in, is the tooth addendum coefficient of the spur gear; d pa The diameter of the tooth tip circle of the spur gear shall not be greater than the maximum outer diameter of the small bevel gear of the spiral bevel gear pair being replaced. ; m is The module of the spur gear and the module of the spur gear m and pressure angle α The module and pressure angle correspond to the same values as those of the spiral bevel gear pair being replaced;

[0012] The outer radius of the face gear teeth R of , inner radius R if Calculated by Equation 2 and Equation 3 respectively:

[0013] Formula 2

[0014] Formula 3

[0015] The teeth of the face gear are made by gear shaping. m Take the module value corresponding to the spur gear, α Take the pressure angle value corresponding to the spur gear; z s The number of teeth of the gear shaping cutter ， The number of teeth of the spur gear z p The relationship satisfies formula 4:

[0016] Formula 4

[0017] The number of teeth of the gear shaping cutter z s Ratio of teeth to spur gearsz p One to three more teeth are required to ensure that the face gear machined by the gear shaping cutter and the spur gear formed by the spur gear are in point contact.

[0018] Furthermore, in Equation 2 and Equation 3, take and , the number of teeth of the gear shaping cutter is known z s , modulus m , pressure angle α , solve for the number of teeth of the face gear z f ;in, The diameter of the center through hole opened in the center of the large gear for the lubrication system pipeline to pass through, It is twice the distance from the hole wall of the locating piece installation hole closest to the wheel axle center on the large gear wheel seat to the wheel axle centerline.

[0019] Furthermore, the maximum outer diameter of the wheel seat of the face gear D p The value is not greater than the maximum outer diameter of the wheel seat of the large gear , the thickness of the wheel seat of the face gear h The value of 1 is not greater than the thickness of the wheel seat of the large gear .

[0020] Furthermore, the outer diameter of the face gear teeth R of Should meet 2 R of < D h ,this D h The distance between the wall of the locating piece installation hole opened on the face gear wheel seat and the closest to the wheel axle center for installing the locating piece and the wheel axle centerline is twice the distance.

[0021] Compared with the existing technology, the beneficial effects of the present invention are:

[0022] The present invention replaces the transmission between the drive shaft and the cam output mechanism of a high-speed rotary dobby machine with a spur-face gear transmission, designs and calculates the replaced spur-face gear transmission structure based on the dimensions of the original gear pair, ensures that the improvement is based on the premise that any parts and interfaces other than the gear tooth profile in the dobby machine are not changed, and calculates the theoretical reference position of the spur-face gear transmission based on the meshing principle to achieve orthogonal transmission and speed increase; the structure is simple to install and has the characteristics of being lightweight and space-saving; its point contact characteristics will not be affected by installation errors, and the consistency of the dobby machine's movement can be ensured.

[0023] The present invention ensures that the point contact trajectory requirements of the face gear can be adapted without adjusting the installation position of the spur gear, and the determination of various parameters of the spur cylindrical gear and the face gear is simple and quick, with high versatility.

[0024] In gear transmission systems, gears on high-speed shafts often face a high risk of damage. However, adopting a spur-face gear transmission solution can significantly reduce production costs and easily replace damaged gears. Furthermore, spur gear transmission has relatively loose installation accuracy requirements, which not only simplifies the installation process but also significantly reduces installation costs. It is worth mentioning that this transmission method exhibits high fault tolerance along the tooth surface, effectively handling minor deviations during installation, thereby ensuring the stable operation of the transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the original transmission structure of the dobby machine targeted by the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the small bevel gear in the original transmission structure;

[0027] Figure 3 This is a structural diagram of the large gear in the original transmission structure;

[0028] Figure 4 Schematic diagram of the structure of a multi-arm machine replaced with a spur-face gear transmission;

[0029] Figure 5 It is a structural diagram of a spur gear;

[0030] Figure 6 It is a structural diagram of the face gear;

[0031] Figure 7 This is a schematic diagram of the spur-face gear transmission structure in the present invention. DETAILED DESCRIPTION

[0032] In order to clearly and completely describe the purpose and technical solutions of the present invention and make its advantages more clearly understood, the following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, not all of them, and are only used to explain the embodiments of the present invention, not to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Figure 1The figure shows the structure of a dobby machine using a spiral bevel gear pair for transmission before improvement. In the figure, the driving gear driven by the drive shaft 1 is the small bevel gear 3 of the spiral bevel gear pair, and the driven gear is the large gear 4 of the spiral bevel gear pair. The motion output by the large gear 4 is transmitted to the longitudinal frame through the cam output mechanism 2 to drive the corresponding textile machinery to work.

[0034] The primary design principle of the present invention in replacing the spiral bevel gear pair with the spur-face gear transmission is not to change any parts and interfaces in the dobby except the gear tooth profile. Figure 4 As shown, a spur gear 5 is used as the driving gear in the new transmission structure (spur-face gear transmission), that is, the driving gear is replaced by the small bevel gear 3 in the spiral bevel gear pair with the spur gear 5.

[0035] Depend on Figure 2 As shown, the small bevel gear has a hole diameter of The mounting hole is installed on the drive shaft 1, and the large end outer diameter of the small bevel gear It determines the minimum distance and relative relationship between the driving gear and the housing in the radial direction.

[0036] Before replacement, it is necessary to measure the relevant parameters and dimensions of the original curved bevel gear pair between the rotary dobby drive shaft 1 and the cam output mechanism 2, including the following parameters:

[0037] Drive shaft 1 diameter ;

[0038] The distance from the axis of the drive shaft 1 to the bottom surface of the large gear 4 wheel seat of the spiral bevel gear pair ;

[0039] The diameter of the central through hole opened in the center of the large gear 4 of the spiral bevel gear pair for the lubrication system pipeline to pass through , the distance from the hole wall of the positioning piece installation hole closest to the wheel axle center on the large gear 4 wheel seat to twice the distance from the wheel axle center line , the maximum outer diameter of the large gear 4 wheel seat , and the thickness of the large gear 4 wheel seat Among them, the large gear 4 is fixedly driven by its wheel seat and the cam output mechanism 2, not by the transmission shaft, because the lubrication system is installed ( Figure 1 (not shown) and to save space, the pipeline of the lubrication system needs to pass through the center hole of the large gear 4 and then be connected to the cam output mechanism 2.

[0040] Module of spur gears m and pressure angle α Directly take the module and pressure angle of the replaced spiral bevel gear pair, and the number of teeth of the spur gear zp It can be calculated by formula 1 described in the invention content.

[0041] in, The tooth height coefficient of the spur gear can be determined by national standards. This can ensure that the spur gear 5 does not interfere with the housing of the dobby transmission structure and also meet the requirements of the spur gear hub.

[0042] Tip circle diameter of spur gear 5 d pa Take the outer diameter of the large end of the small bevel gear 3 The spur gear will be directly mounted on the existing drive shaft 1, so the diameter of the mounting hole of the spur gear is d n The size is directly taken from the diameter of the drive shaft Other structural parameters can be adjusted according to the structural parameters of the drive shaft, which will not be described in detail in this article. The basic parameters of the spur gear designed in this way have been basically determined, and its appearance and dimensions are shown in the following figure. Figure 5 and Figure 7 shown.

[0043] Figure 3 The following figure shows the large gear in the spiral bevel gear pair used in the dobby machine. In this embodiment, there are four types of 14 different holes on the circumference of the large gear for mounting other accessories on the dobby machine. In accordance with the principle of not changing other parts and interfaces of the dobby machine except the gears, these holes are retained and their sizes are strictly guaranteed. Therefore, it is necessary to retain Figure 3 The wheel seat thickness of the large gear 4 shown in , and the maximum outer diameter of the wheel seat . Maximum outer diameter of the face gear wheel seat D p The number and specifications of the threaded holes on the wheel seat for installation and connection should be consistent with the corresponding parameters of the wheel seat of the large gear of the original spiral bevel gear pair in the dobby machine. From this, the wheel seat size used for face gear processing and the size, position, countersunk hole size, etc. on it can be determined to ensure that no bolt is replaced. Therefore, the maximum outer diameter of the wheel seat of face gear 6 can be determined. D p The value is not greater than the maximum outer diameter of the wheel seat of the large gear 4 , the thickness of the wheel seat of the face gear 6 h The value of 1 is not greater than the wheel seat thickness of the large gear 4 .

[0044] Also, see Figure 6 As shown, the outer diameter of the teeth of the newly designed face gear R of Should meet 2 R of < Dh ,this D h The distance between the wall of the locating piece installation hole closest to the wheel axle center opened on the face gear wheel seat for installing the locating piece and the wheel axle center line is twice the distance, so that sufficient installation space can be left on the wheel seat for the above-mentioned threaded installation locating pieces to avoid interference between the locating piece and the spur gear 5.

[0045] like Figure 3 and Figure 6 As shown, the center of the large gear in the spiral bevel gear pair has a diameter of The central functional hole of the face gear wheel seat is used to install other parts. According to the principle of not changing other parts and interfaces of the dobby machine except the gear, the diameter of the central functional hole of the face gear wheel seat is d w Should be equal to the diameter of the central functional hole of the large gear , from which the inner diameter of the face gear teeth can be determined R if Should meet 2 R if > d w .

[0046] The teeth of the face gear 6 are obtained by gear shaping. The module and pressure angle of the gear shaping cutter correspond to the module of the spur gear. m and pressure angle α， Number of teeth on the gear shaping cutter z s Generally, the number of teeth of the spur gear is taken as the ratio z p The number of teeth on the face gear produced by the gear shaping cutter is 1 to 3 more to ensure point contact between the face gear produced by the gear shaping cutter and the spur gear formed by the spur-face gear transmission. Therefore, the number of teeth on the gear shaping cutter used to process the face gear can be calculated using Equation 4 described in the Summary of the Invention.

[0047] Next, we can determine the outer diameter of the face gear teeth R of and inner diameter R if , which are calculated by Formula 2 and Formula 3 described in the content of the invention respectively.

[0048] Equation 2 and Equation 3 are implicit functions. and , due to the number of teeth of the gear shaping cutter z s , modulus m , pressure angle α If all are known, the number of teeth of the face gear can be solved z f .

[0049] Number of teeth on the face gearz f This is the initial value, because the face gear will produce undercutting and top cutting during machining, and undercutting and top cutting are mainly affected by the pressure angle of the gear shaping cutter. α、 Tooth ratio of face gear to gear shaping cutter i=z f / z s According to the top cutting and undercutting conditions of face gear transmission, the corresponding R of，max and R if，min .verify R of and R if Is it reasonable? By adjusting the number of teeth of the face gear z f to make it match.

[0050] The assembly diagram of the spur-face gear transmission designed in the above manner is as follows: Figure 7 To ensure that the spur gear and the face gear mesh correctly, the height of the boss containing the face gear teeth can be adjusted ( h 2- h 1) Adjust the overall thickness of the face gear h 2Achieve guaranteed meshing size h 0, this h 0 is also the distance from the axis of the drive shaft 1 to the bottom surface of the face gear wheel seat, ensuring that the gearbox structure and size are not changed. Figure 7 Tooth width Bp and pitch circle radius of spur gears r p or Figure 5 Pitch circle diameter in d p The adjustment is not complicated and will not be described in detail in this article.

[0051] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A design method for a spur-face gear transmission for a high-speed rotary dobby machine, characterized in that: The Gleason-tooth spiral bevel gear pair between the drive shaft and the cam output mechanism in the dobby machine is replaced with a spur face gear pair. The driving gear connected to the drive shaft is replaced with a spur cylindrical gear instead of the small bevel gear of the spiral bevel gear pair, and the driven gear connected to the cam output mechanism is replaced with a face gear instead of the large gear of the spiral bevel gear pair. First measure the following parameters: The shaft diameter of the drive shaft; the maximum outer diameter of the small bevel gear of the spiral bevel gear pair ; Module and pressure angle of spiral bevel gear pair; Then determine the parameters of the spur gear and face gear as follows: Mounting hole diameter of spur gear d n Equal to the diameter of the drive shaft; Number of teeth on spur gears z p Calculated by formula 1: Formula 1 in, is the tooth addendum coefficient of the spur gear; d pa The diameter of the tooth tip circle of the spur gear shall not be greater than the maximum outer diameter of the small bevel gear of the spiral bevel gear pair being replaced. ; m is the module of the spur gear, and the module of the spur gear m and pressure angle α The module and pressure angle correspond to the same values as those of the spiral bevel gear pair being replaced; External radius of face gear teeth R of , inner radius R if Calculated by Equation 2 and Equation 3 respectively: Formula 2 Formula 3 The teeth of the face gear are made by gear shaping. m Take the module value corresponding to the spur gear, α Take the pressure angle value corresponding to the spur gear; z s The number of teeth of the gear shaping cutter ， The number of teeth of the spur gear z p The relationship satisfies formula 4: Formula 4 The number of teeth of the gear shaping cutter z s Ratio of teeth to spur gears z p One to three more teeth.

2. The method for designing a spur-face gear transmission for a high-speed rotary dobby according to claim 1, characterized in that: In Equation 2 and Equation 3, take and , the number of teeth of the gear shaping cutter is known z s , modulus m , pressure angle α , solve for the number of teeth of the face gear z f ;in, The diameter of the center through hole opened in the center of the large gear for the lubrication system pipeline to pass through, It is twice the distance from the hole wall of the locating piece installation hole closest to the wheel axle center on the large gear wheel seat to the wheel axle centerline.

3. The method for designing a spur-face gear transmission for a high-speed rotary dobby according to claim 1, wherein: Maximum outer diameter of the wheel seat of the face gear D p The value is not greater than the maximum outer diameter of the wheel seat of the large gear , the thickness of the wheel seat of the face gear h The value of 1 is not greater than the thickness of the wheel seat of the large gear .

4. The method for designing a spur-face gear transmission for a high-speed rotary dobby according to claim 1, wherein: The outer diameter of the face gear teeth R of Should meet 2 R of < D h ,this D h The distance between the wall of the locating piece installation hole opened on the face gear wheel seat and the closest to the wheel axle center for installing the locating piece and the wheel axle centerline is twice the distance.

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