Folding-shaft multi-worm middle-pushing type high-precision turbine rotary table

Abstract

The invention discloses a folding-shaft multi-worm middle-pushing type high-precision turbine rotary table, and belongs to the field of machinery. Comprising three parts: a worm gear, a worm and a folding shaft or a bevel gear; a folding shaft hole or a bevel gear used for being in sliding fit with the folding shaft part is machined at the end of the worm, the axis of the folding shaft hole is parallel to the axis of the inserted folding shaft part, and the bevel gear and the worm are coaxial in position. According to the basic assembly relation, the shell and the supporting component are used for installing and restraining the steel ball ring groove and the worm bearing of the worm gear; the worm shaft hole and the worm gear shaft hole are connected into a whole through the supporting component. The end part bearing is a conventional bearing and directly restrains the end part of the worm, or the semi-cylindrical middle part retaining bearing is equivalent to a toothless cylindrical surface matched with the middle part of a bearing bush; the bending angle of the bending part of the bending shaft is 90-180 degrees, the straight shaft sections of the two shaft sections are inserted into the bending shaft hole in the end of the bending shaft and are in sliding fit with the bending shaft hole, and the bending shaft can be widely used as a power rotating table of a machine tool.

Description

[Technical field]

[0001] The present invention belongs to the field of mechanical technology, and is specifically a worm gear reduction turntable with multiple worms and more tooth contacts to improve the running accuracy and increase the rigidity. [Background Technology]

[0002] The worm gear structure is often used to transmit motion and power between two staggered axes. The worm wheel and worm are equivalent to the gear and rack in their middle plane, and the worm is similar in shape to the screw.

[0003] Basic parameters: module m, pressure angle, worm diameter coefficient q, lead angle, number of worm heads, number of worm wheel teeth, tooth top height coefficient (take 1) and top clearance coefficient (take 0.2). Among them, module m and pressure angle refer to the module and pressure angle of the worm shaft surface, that is, the module and pressure angle of the worm wheel end surface, and they are all standard values; worm diameter coefficient q is the ratio of the worm pitch circle diameter to its module m.

[0004] Operation characteristics: A large transmission ratio can be obtained, which is more compact than the staggered helical gear mechanism. 2. The meshing tooth surfaces of the two wheels are in line contact, and its load-bearing capacity is much higher than that of the staggered helical gear mechanism. 3. The worm drive is equivalent to a spiral drive, which is a multi-tooth meshing drive, so the transmission is smooth and the noise is very low. 4. It has self-locking properties. When the lead angle of the worm is smaller than the equivalent friction angle between the meshing gear teeth, the mechanism has self-locking properties and can achieve reverse self-locking, that is, only the worm can drive the worm wheel, and the worm wheel cannot drive the worm. For example, the self-locking worm mechanism used in lifting machinery can play a safety protection role in its reverse self-locking property. 5. The transmission efficiency is low and the wear is severe. Worm gear meshing

[0005] During transmission, the relative sliding speed between meshing gear teeth is high, so the friction loss is large and the efficiency is low. On the other hand, the axial force of the worm is large, and the high relative sliding speed causes serious wear and heat generation on the tooth surface. In order to dissipate heat and reduce wear, more expensive materials with good anti-friction and wear resistance and good lubrication devices are often used, which results in high costs.

[0006] Pros and Cons Overview:

[0007] Compared with other forms of gear transmission, worm gear transmission (including machine tool turntable) has the following advantages and disadvantages.

[0008] advantage:

[0009] *Single-stage speed ratio is large:

[0010] The single-stage speed ratio of circular gear transmission and bevel gear transmission is generally about 1 / 10 at most, while the worm gear transmission with a speed ratio of 1 / 70-1 / 100 is easy to make. Therefore, the worm gear reducer can achieve a large speed ratio with a smaller size. It is often a comparison between the worm gear reducer with a speed ratio of 1 / 5, 1 / 25, 1 / 70, 1 / 150 and the helical gear reducer. Their transmission power is 30 horsepower and the input shaft speed is 1200 rpm.

[0011] * Low noise and vibration during operation: When the circular gear and the bevel gear are engaged, they are mainly in rolling contact, while the worm gear is mainly in sliding contact, so there are fewer factors that generate noise and vibration. For this reason, escalators, elevators, moving sidewalks, and pollution prevention machines in recent years all prefer to use worm gear reducers.

[0012] * Use worm gear reducer. The shafts can be arranged vertically without intersecting each other: the arrangement of the worm shaft and the worm wheel shaft can sometimes save the installation area of ​​the prime mover and the driven machine while being convenient and reasonable.

[0013] * Can prevent reversal: When the worm lead angle is smaller than the friction angle, the worm wheel cannot drive the worm in theory, which means that a self-locking worm transmission device can be designed. However, in reality, the friction coefficient of the tooth surface changes from static friction coefficient to dynamic friction coefficient due to vibration and other reasons, so it sometimes rotates slowly, and it is difficult to achieve complete self-locking.

[0014] Disadvantages: Existing worm gear mechanisms all use a common high-friction tooth contact operation mode. In addition to low transmission efficiency and tooth gap, the contact area of ​​the contact line between teeth is also very limited.

[0015] *Low efficiency: Compared with other forms of N-wheel transmission, worm gear transmission has large tooth surface friction loss and low efficiency when transmitting power. At present, due to the improvement of manufacturing methods, it can achieve an efficiency close to the theoretical value. Some worm gear transmissions have an efficiency of 98% when the speed ratio is 1 / 5 and the worm speed is 180 rpm. However, with the same center distance, if the speed ratio is 1 / 70 and the worm speed is 200 rpm, the efficiency is about 60%.

[0016] * Tooth surface adhesion is easy to occur: For cylindrical gears with involute tooth profile, if the tooth surface is under load, the gear tooth contact state changes to a better state due to the deformation of each part, while the gear tooth contact state of worm gear transmission changes to a worse state, that is, the gear surface oil film is deformed in the direction of rupture, which is easy to cause tooth surface adhesion. Therefore, the gear tooth contact state and bearing clearance during assembly should be adjusted according to the deformation amount. It is also necessary to perform the running-in operation as carefully as possible.

[0017] * Lifespan and cost issues: Worm gear transmission uses copper alloy materials. Since there are generally no special gear cutting machines, the gear cutting efficiency is low, and manual tooth surface trimming is very time-consuming. [Summary of the invention]

[0018] Purpose of the present invention:

[0019] The disadvantages of the existing technology are overcome, the contact area between the worm wheel and the worm is improved to be larger, and the unfavorable factors such as low transmission efficiency and transmission stiffness, and limited service life are improved.

[0020] Features of the present invention:

[0021] The primary feature is that the contact area and number of teeth are greatly increased, which greatly overcomes the inherent defect of limited contact area of ​​teeth; while greatly reducing the value of tooth contact pressure, the service life will also be greatly increased. Another great progress is the creative provision of the shaft transmission mechanism between the two worms, which can realize the torque transmission of the two connecting rod shafts in a compact and minimal slip.

[0022] The key technology of the present invention is:

[0023] Create the conditions for folded shaft connection, compact shaft connects multiple worm gears to achieve high torque output.

[0024] Specific content of the invention:

[0025] The folded-shaft multi-worm mid-push high-precision turbine turntable (also called reducer) includes three major components: a worm wheel, a worm, and a folded shaft (coupling component: or bevel gear); the structure of the worm wheel includes a worm wheel disc (power output disc) and worm wheel helical teeth and a portion for installing bearings; the structure of the worm includes a worm shaft and spiral teeth, and a folded-shaft hole for slidingly fitting with the folded-shaft shaft portion is processed at the end of the worm, and the axis of the folded-shaft hole is parallel to the axis of the inserted folded-shaft shaft portion; the housing includes an upper cover body, a lower cover body, and an output shaft hole; the supporting component includes an end bearing or a middle retaining bearing; the folded shaft serves as a coupling transmission component, and its structure includes: a folded portion and a shaft portion.

[0026] The detailed structure of each component is as follows: the worm wheel includes a worm wheel disc (power output shaft), worm wheel helical teeth, and worm wheel steel ball ring grooves; the side of the worm (pair) has spiral teeth, which can be a continuous tooth shape; it can also be toothless in the middle, and the two ends of the worm have a spindle-shaped structure with spiral teeth; when there is no tooth in the middle of the worm, a middle retaining bearing is required to enable the middle shaft of the worm to obtain a larger diameter space and have greater mechanical strength.

[0027] Assembly relationship: The housing and support components are used to install and constrain the steel ball ring groove and worm bearing of the worm wheel; because the support component connects the worm shaft hole and the worm wheel shaft hole into a whole, and the worm wheel and worm are free to rotate under the support and constraint of the bearing, a driving relationship is formed between the worm wheel and the worm. The end bearing is a conventional bearing, and the middle retaining bearing is a semi-cylindrical (equivalent to a bushing) bearing to maintain the diameter of the middle as much as possible (for strength requirements). If it is not necessary to maintain strength, a conventional bearing can also be used.

[0028] The structure of the multi-worm is: extend the worm shaft, use the coupling transmission component to connect the end shafts of the two worms, and form a hand-in-hand coupling connection form; the most important coupling component is the folding shaft; the folding shaft is to bend a section of straight shaft at a certain angle, and the bending angle of the folded part is 90-180 degrees. The straight shaft sections of the two shaft sections are inserted into the folding shaft holes at the end of the folding shaft, and they are in a sliding fit relationship; the folding shaft can be 1-20, eccentrically installed; the structure of the multi-worm has good transmission stiffness, good transmission linearity, and good transmission stiffness; because the contact geometric line is long enough, it also has good transmission accuracy (using bevel gears for transmission has a greater disadvantage: due to the small contact area, the transmission stiffness is limited, the wear is aggravated, and the accuracy cannot be continuously guaranteed).

[0029] In addition, in order to increase the thrust, the spiral and groove for accommodating the steel balls of the worm and the worm wheel can be single-start or multi-start, and the number of corresponding return channels is also increased to the number of multi-start; the reason for considering multi-start is that under the mathematical geometric relationship of the relative uniform rotation of the closed ring groove of the spiral body and the worm wheel disc, only the steel balls in the local groove and spiral groove can meet the close contact relationship of operation without too large a gap, so multiple worm couplings are required to meet the requirements of large load torque;

[0030] Working principle of the folded-axis multi-worm mid-push high-precision turbine turntable:

[0031] The present invention is the same as the conventional worm gear transmission; the difference is that it includes a multi-worm linkage mode and there is no tooth in the middle of the worm to obtain a larger diameter in the middle of the worm as the shaft (high mechanical strength); the mathematical principle of the folding shaft connection is that when the folding shaft holes of two adjacent worms are inserted by the shaft of the folding shaft, the two worms are connected together. Due to the sliding matching relationship between the folding shaft holes and the folding shaft, the two fixed-axis rotating worms are constrained in mathematical and physical conditions to only respond and cooperate with each other at the same angular velocity and synchronization; this forms a more favorable coupling state than the bevel gear transmission.

[0032] Further: In addition to using a folded shaft, the transmission of multiple worm shafts can also be directly transmitted using two bevel gears fixed to the ends of the worm shafts;

[0033] Further: the worm has spiral teeth on the side, which can be a continuous tooth shape; or it can be a spindle-shaped structure with no teeth in the middle and spiral teeth on both ends of the worm;

[0034] The technical progress of the present invention is that it completely overcomes the defect of insufficient rigidity of the worm gear system and provides a coupling-type multi-worm worm gear transmission module, which has the advantages of high precision, high rigidity (transmission torque) and long life. [Drawings]

[0035] The present invention will be further described below with reference to the accompanying drawings with regard to preferred embodiments of the present invention:

[0036] [ Figure 1 ] Overall schematic diagram of the folded-axis multi-worm mid-push high-precision turbine turntable.

[0037] [ Figure 2 ]Cross-section diagram of the folded-axis multi-worm mid-push high-precision turbine turntable.

[0038] [ Figure 3}Explosion diagram of the folded-axis multi-worm mid-push high-precision turbine turntable.

[0039] [ Figure 4}Exploded view of the turntable core components.

[0040] [ Figure 5 ] Schematic diagram of the transmission of the worm gear's folding shaft coupling.

[0041] [ Figure 6 ] Schematic diagram of bevel gear transmission

[0042] Description of the numbers in the figure:

[0043] 1 Worm gear

[0044] 1-1 Worm gear (power output disc)

[0045] 1-2 Worm gear helical gear

[0046] 1-3 steel ball ring groove

[0047] 1-4 Turbine axis

[0048] 2 Worm

[0049] 2-1 spiral teeth

[0050] 2-2 Worm shaft (power input shaft)

[0051] 2-3 Folding shaft hole

[0052] 2-4 Worm axis

[0053] 2-5 Middle axis

[0054] 3 Shell and support components

[0055] 3-1 Upper cover body

[0056] 3-2 lower cover body

[0057] 3-3 Output shaft hole

[0058] 3-4 end bearings

[0059] 3-5 Middle retaining bearing

[0060] 3-6 Bearing ring

[0061] 3-7 Adjustment and fixing hole

[0062] 3-8 Internal thread of bearing ring

[0063] 4 Folding shaft (coupling transmission component)

[0064] 4-1 Fold

[0065] 4-2 Shaft

[0066] 4-3 Folding axis

[0067] 5 steel balls

[0068] 6 Bevel gear

[0069] 7 Axis

[0070] 8 Worm extension shaft

[0071] [Implementation Case]

[0072] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 Shown:

[0073] Figure 1 The invention is an overall schematic diagram of a folded-axis multi-worm mid-push high-precision turbine turntable, comprising three major components: a worm wheel (1), a worm (pair) (2), and a folded axis (4); wherein the structure of the worm wheel (1) comprises a worm wheel disc (1-1) (often used as a power output disc) and worm wheel helical teeth (1-2); the structure of the worm (2) comprises a worm shaft (2-2), a middle shaft position (2-5), and spiral teeth (2-1); and a folded shaft hole (2-3) for slidingly cooperating with a folded shaft portion (4-2) of the folded shaft (4), a folded portion (4-1), and a shaft portion (4-2) connected to the folded portion are processed at the end of the worm (2); the housing and supporting components comprise an upper cover body (3-1), a lower cover body (3-2), an output shaft hole (3-3); an end bearing (3-4), a middle retaining bearing (3-5), and an adjustment and fixing hole (3-7).

[0074] Assembly relationship: From Figure 2 , Figure 3 , Figure 4 , Figure 5 It can be seen that the housing and supporting components are used to install and constrain the middle of the steel ball ring groove (1-3) of the worm wheel (1), and the bearing ring (3-6) (cooperating with the inner thread (3-8) of the bearing ring, and holding the steel balls) in combination with the clamped steel balls (5) (the steel balls are arranged in a ring, just placed between the upper cover and the lower cover and the steel ball ring groove of the worm wheel) to maintain the fixed axis rotation of the turbine around its turbine axis (1-4); and the upper cover body (3-1) and the lower cover body (3-2) are used as supporting components to connect the worm shaft hole and the worm wheel shaft hole into a whole, and the worm wheel (1) and the worm (2) are both free to rotate under the support and constraint of the bearing (independent bearings can be used or steel balls (5) can be placed in the steel ball ring groove processed on the corresponding steel ball ring groove to form a self-matching bearing), so that a vertical driving relationship is formed between the worm wheel (1) and the worm (2). The worm bearings are also diversified (positioned at the end, middle, or in the form of a semi-circumferential bearing shell). The end bearing (3-4) at the outermost worm point is a conventional bearing or a self-matching bearing. The middle retaining bearing (3-5) is a semi-cylindrical (equivalent to a bearing shell) bearing type to maintain the diameter of the middle as much as possible (for strength requirements). If it is not necessary to maintain strength, a conventional bearing can also be used. The multi-worm coupling is completed by using a folding shaft (2) as a transmission component. The folding shaft portion (4-2) of the folding shaft (4) is inserted into the folding shaft hole (2-3) at the end of the worm and slidably fits. The folding shaft axis (4-3) is parallel to the inserted worm axis (2-4).

[0075] The basic working principle of the folded-axis multi-worm mid-push high-precision turbine turntable:

[0076] Its basic working principle is the same as that of a conventional worm gear transmission, the difference being the working mode of multiple worm linkage; in order to obtain high mechanical strength and rigidity, the folding shaft coupling structure is one of the most effective operating modes; the mathematical principle of the folding shaft is: when the folding shaft holes (2-3) of two adjacent worms (2) are inserted by the folding shaft portion (4-2), the two connected fixed-axis rotating worms are restricted to have the same rotation speed and angular displacement; at the same time, the folding shaft hole (2-3) and the folding shaft portion (4-2) are in a sliding cooperation motion relationship, because the mathematical and physical conditions constrain the two fixed-axis rotating worms to only respond and cooperate with each other at the same angular velocity and synchronization; thus, a more favorable coupling state is formed than the bevel gear transmission.

[0077] like[ Figure 6} as shown:

[0078] The bevel gear (6) installed at the shaft end of the worm extension shaft (8) can also meet the torque transmission of the worm with two non-parallel axes (7); it is obvious that the bevel gear transmission requires a zero (micro) clearance transmission mode, which requires the two gears to be close together, and there is a large contact force at the tooth contact point, which places very stringent requirements on the surface shape, accuracy and strength of the gear.

Claims

1. A folding-shaft multi-worm mid-push high-precision turbine turntable, comprising three major components: a worm wheel, a worm, a folding shaft or a bevel gear; wherein the structure of the worm wheel comprises a worm wheel disc and worm helical teeth; the structure of the worm comprises a worm shaft and spiral teeth, and a folding-shaft hole or a bevel gear for slidingly cooperating with the folding-shaft shaft portion is processed at the end of the worm, the axis of the folding-shaft hole is parallel to the axis of the inserted folding-shaft shaft portion, and the position relationship of the bevel gear and the worm is a coaxial relationship; in addition, the structural housing comprises an upper cover body, a lower cover body, and an output shaft hole; The supporting components for keeping the worm running include: end bearings or middle retaining bearings; the folding shaft is a coupling transmission component that replaces the bevel gear, and its structure includes: a folding part and a shaft part; the basic assembly relationship: the housing and the supporting components are used to install and constrain the steel ball ring groove and worm bearing of the worm wheel; because the supporting component connects the worm shaft hole and the worm wheel shaft hole into a whole, and the worm wheel and the worm are free to rotate under the support and constraint of the bearing, a driving relationship is formed between the worm wheel and the worm; the end bearing is a conventional bearing that directly constrains the end of the worm, or a middle retaining bearing of a semi-cylinder, which is equivalent to a bearing shell, directly constraining the toothless cylindrical surface in the middle of the worm; the folding shaft is to bend a section of straight shaft at a certain angle, and the bending angle of the folding part is 90-180 degrees. The straight shaft sections of the two shaft sections are inserted into the folding shaft holes at the end of the folding shaft, and are in a sliding fit relationship; the folding shaft can be 1-20, eccentrically installed; Basic working principle: The present invention is the same as the conventional worm gear transmission; the difference is that it includes a multi-worm linkage mode and has no teeth in the middle of the worm, so that the larger diameter of the middle of the worm is obtained as the shaft part suitable for high mechanical strength; the mathematical principle of the folding shaft connection is that when the folding shaft holes of two adjacent worms are inserted by the shaft part of the folding shaft, the two worms are connected together. Due to the sliding matching relationship between the folding shaft holes and the folding shaft, the two fixed-axis rotating worms can only respond and cooperate with each other at the same angular velocity and synchronously under mathematical and physical conditions; thus, a more favorable coupling state is formed than the bevel gear transmission. Its characteristics are: The present invention adopts a multi-worm structure: the traditional coupling parts of the multi-worm are folded shafts or bevel gears; by processing 1-20 folded shaft holes parallel to the worm shaft at the end of the worm, which cooperate with the inserted folded shaft to connect two adjacent worms to form a hand-in-hand coupling connection; or coaxial bevel gears for mutual driving are processed at the end of the worm.

2. The multi-worm component according to claim 1, characterized in that: The worm can be a continuous helical tooth shape or a worm with helical teeth at only two ends, and a toothless coaxial cylindrical surface in the middle, which is used to cooperate with the middle bearing to form a support; the worm with continuous helical teeth uses bearings at both ends of the worm as operating support.

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