CN103267114B - Vertical worm and worm gear mechanism with self-lubricating function - Google Patents

Abstract

The invention provides a vertical worm and worm gear mechanism with a self-lubricating function. The mechanism mainly comprises a worm gear, a worm, an oil scraping cover, a special-shaped sealing element and the like. The worm gear matches with the oil scraping cover in movement to drive oil from the bottom to a worm and worm gear meshing area, so that meshing surfaces are lubricated and cooled sufficiently. Boundary conditions of leakage caused by shear flow under oil differential pressure are computed to obtain a reasonable matching range between the worm gear and the oil scraping cover. The vertical worm and worm gear mechanism with the self-lubricating function is simple in structure, reliable in working and suitable for long-time operation, and transmission efficiency and mounting and use flexibility of a worm and worm gear reducer are improved greatly.

Description

Vertical worm and gear mechanism with self-lubricating function

Technical Field

The invention relates to a worm gear mechanism, in particular to a vertical worm gear mechanism.

Background

The worm gear transmission is used for transmitting motion and power between staggered shafts, and has the advantages of large transmission ratio, compact structure, stable transmission, self-locking property and the like, but the transmission efficiency of the worm gear transmission is low (generally only 0.7-0.9), so that the application occasions are limited, meanwhile, the transmission heating value is large, the tooth surface is easy to wear, and the like, and the high requirements are provided for the processing technology and the material selection of the worm gear, the structural parameters of the worm gear are mainly researched for the former, and the transmission lubrication mode is mainly improved for the latter. Currently, the lubrication of worm and gear transmissions can be divided into two categories: 1. the oil pool is lubricated and is suitable for horizontal worm and gear transmission; 2. the auxiliary oil pump sprays oil to the friction part for lubrication, and is suitable for a vertical worm and gear transmission mode.

Considering the problems of large friction force, large friction surface, and very little oil in the friction surface caused by large transmission ratio of the worm gear and worm only by the dipping of the outside of the gear surface, the chinese utility model No. 200420039396.2 discloses an internal oil pool lubricating mode of worm gear and worm transmission, which realizes the sufficient lubrication of the friction surface of the worm gear and worm by opening the through-hole oil ducts of the inlet and outlet of the oil ducts on the two surfaces of the worm gear, but the mode is not suitable for the situation that the worm is vertically placed, and is a lubricating mode at the cost of weakening the strength of the worm. In the chinese invention patent No. 200710035077.2, a worm gear with dynamic and static pressure lubrication in an engagement area is disclosed by a method of arranging labyrinth teeth on the outer side of the worm and arranging helical blades on the end face, a good lubricating oil film can be formed on a friction surface, but for a worm gear reducer working for a long time, the mode is easy to cause serious heating of oil and large oil stirring loss; the utility model discloses an utilize and attach petrol pump to the lubricated mode of vertical worm gear to friction surface department oil spout in 201120360481.9, the better solution vertical worm gear driven lubrication and the friction problem of generating heat, but the pressure that the oil spout produced the inside fluid of speed reducer can cause the leakage of fluid, attaches the production application cost of petrol pump greatly increased speed reducer simultaneously, also is difficult for processing the deep hole at the worm middle part.

Therefore, a new technical solution is needed to solve the above problems.

Disclosure of Invention

In order to solve the problems, the invention provides a vertical worm and gear mechanism with a self-lubricating function, which can achieve a good lubricating function and has a simple and easily-realized whole mechanism structure.

In order to achieve the purpose, the invention can adopt the following technical scheme:

a vertical worm and gear mechanism with a self-lubricating function comprises a box body, a worm wheel and a worm which are arranged in the box body and are meshed with each other, wherein the worm is vertically arranged in the box body, and an oil scraping cover for coating the outer edge of the worm wheel is further arranged; and sealing parts are respectively clamped between the two side walls and the worm wheel, an oil inlet channel is formed among the side walls, the sealing parts and the worm wheel, one side of the oil inlet channel is communicated with the inlet, and the other side of the oil inlet channel is communicated with the meshing position of the worm wheel and the worm.

The vertical worm and gear mechanism with the self-lubricating function is provided with the oil scraping cover, the sealing piece and the side face of the worm gear are matched to form the oil inlet channel, and when the worm gear rotates, lubricating liquid can be brought into the oil inlet channel from the inlet to the meshing position of the worm and gear through the lubricating liquid at the bottom of the box body, so that lubrication is realized. Compared with the prior art, the vertical worm and gear transmission mechanism with the self-lubricating function has the advantages of simple structure and reliable work, and greatly improves the transmission efficiency and the installation and use flexibility of the worm and gear speed reducer. In addition, the oil pressure in the vertical worm and gear transmission mechanism with the self-lubricating function is small, and the leakage amount of lubricating liquid is greatly reduced.

Drawings

Fig. 1 is a schematic front sectional view of a vertical worm and gear mechanism with a self-lubricating function according to the present invention.

Fig. 2 is a schematic top sectional view of the vertical worm and gear mechanism with self-lubricating function of the present invention.

Fig. 3 is a partial sectional view of the vertical worm and gear mechanism with self-lubricating function, in which the worm wheel is matched with the oil scraping cover.

Detailed Description

Referring to fig. 1 and 2, the invention discloses a vertical worm and gear mechanism with a self-lubricating function, which comprises a box body 1, a worm wheel 4 and a worm 6, wherein the worm wheel 4 and the worm 6 are arranged in the box body 1 and are meshed with each other, and the worm 6 is vertically arranged in the box body 1. The oil scraping cover 3 is arranged to cover the outer edge of the worm wheel 4, and the oil scraping cover 3 comprises an inlet 11 positioned at the bottom and side walls 12 covering two sides of the outer edge of the worm wheel 4; and sealing elements 2 are respectively clamped between the two side walls 12 and the worm wheel 4, oil inlet channels 13 are formed among the side walls 12, the sealing elements 2 and the worm wheel 4, one side of each oil inlet channel 13 is communicated with the inlet 11, and the other side of each oil inlet channel 13 is communicated with the meshing position of the worm wheel and the worm. The sealing elements 2 are arranged on two end faces of the worm wheel 4 matched with the oil scraping cover 3, so that the lubricating liquid 7 is prevented from leaking along the end faces of the worm wheel 4. The upper end and the lower end of the worm 6 are vertically supported in the box body 1 through a tapered roller bearing 5, the lower end of the worm is sealed by a bearing end cover, and the upper end of the worm extends out of the box body 1 to be used as an input shaft end of the transmission mechanism; the worm wheel 4 is supported in the case 1 by an output shaft 9 in the horizontal direction via a bearing and is engaged with the worm 6, and the oil scraping cover 3 is fixed in the case 1 by a support frame 10. The oil scraping cover 3 in the embodiment is formed by connecting an oil scraping cover front cover 3A and an oil scraping cover rear cover 3B which are positioned at two sides of a worm wheel 4 and matched with each other, and sealing pieces 2 are respectively arranged on the inner wall of the oil scraping cover front cover 3A and the inner wall of the oil scraping cover rear cover 3B. In this embodiment, in order to save materials, the side wall 12 of the oil scraping cover 3 only covers two sides of the outer edge of the worm wheel 4, and in other embodiments, the surface area of the oil scraping cover 2 covering the worm wheel 4 is further enlarged to achieve the same effect, which is not described herein again.

Further, the radial clearance between the worm wheel 4 and the oil scraping cover 3 is set to be h, which is shown in detail in fig. 3. Because the worm wheel 4 and the oil scraping cover 3 move relatively, the lubricating liquid generates pressure difference shearing flow in the radial gap, namely the oil scraping leakage amount of the worm wheel 4 is considered, and the value range of the gap h is calculated according to the condition that the boundary condition of full lubrication and cooling of the meshing surface of the worm wheel and the maximum oil scraping amount of the worm wheel 4 are met:

$0<h<\frac{{24}^{1/3}\mathrm{AB}+2^{1/3}{(9A^{2}C+\sqrt{3A^3(-4B^3+27{\mathrm{AC}}^2)})}^{2/3}}{6^{2/3}A{(9A^{2}C+\sqrt{3A^3(-4B^3+27{\mathrm{AC}}^2)})}^{1/3}}$

wherein,

representing the oil hydraulic differential flow coefficient;

representing the shear flow coefficient of the oil liquid;

c ═ V')/b, where b represents the thickness of the worm gear and V ═ m²z₂bβ/2, the displacement of the worm gear rotating to the top end of the oil scraping cover; v' represents a lubricating oil boundary condition value satisfying sufficient lubrication and cooling of a meshing surface;

ρ represents the lubricant density; g represents the gravitational acceleration;

beta represents a central angle corresponding to the special-shaped sealing element; mu represents the dynamic viscosity of the oil;

m represents the module of the worm wheel; n represents the worm gear speed;

z₂indicating a worm gear tooth number; h is_aIndicates the worm gear tooth top height coefficient;

in the present embodiment, the oil scraping cover 3 is provided with an opening 14 at the worm gear meshing part, so that the oil scraping cover 3 does not interfere with the worm 6. Of course, in other embodiments, the oil scraping cover 3 may be disposed to wrap the portion of the worm 6, as long as the oil scraping cover 3 and the worm 6 do not interfere with each other, which is not described herein again.

Furthermore, the wrap angle of the oil seal area of the worm wheel 4 matched with the oil scraping cover 3 is 4 pi/3. Both ends of the bottom of the oil scraping cover 3 are provided with inlets, so that the lubricating liquid 7 can be brought to the meshing position of the worm gear no matter the worm gear 4 rotates clockwise or anticlockwise. According to the figure 1, if the worm wheel 4 rotates anticlockwise, the lubricating liquid 7 flows down along the meshing surface under the action of gravity after being brought to the highest point by the worm wheel 4, so that the meshing surface is fully lubricated from top to bottom, a large amount of heat is taken away, and the worm and gear transmission efficiency is greatly improved, which is the best lubrication mode of the invention. However, when the worm wheel 4 rotates clockwise, the lubricating liquid 7 can be brought to the meshing position from bottom to top for lubrication, so that the invention can simultaneously adapt to two rotating modes of the worm wheel 4 clockwise and anticlockwise.

Furthermore, the liquid level of the lubricating liquid 7 in the box body 1 reaches 1/3 of the radius of the worm wheel 4, and a cooling water pipe 8 is arranged at the bottom of the box body 1 and is used for introducing cold water to cool the lubricating liquid 7. The whole system of the invention has simple structure, so the installation space of the cooling water pipe 8 is enough and the installation is convenient.

Claims (6)

1. The utility model provides a vertical worm gear mechanism with self-lubricating function, includes box (1), installs in box (1) and intermeshing's worm wheel (4) and worm (6), worm (6) vertically set up in box (1), its characterized in that: the oil scraping cover (3) is arranged to coat the outer edge of the worm wheel (4), and the oil scraping cover (3) comprises an inlet (11) positioned at the bottom and side walls (12) covering two sides of the outer edge of the worm wheel (4); sealing elements (2) are respectively clamped between the two side walls (12) and the worm wheel (4), oil inlet channels (13) are formed among the side walls (12), the sealing elements (2) and the worm wheel (4), one sides of the oil inlet channels (13) are communicated with the inlet (11), and the other sides of the oil inlet channels are communicated with the meshing position of the worm wheel and the worm.

2. The vertical worm-gear mechanism with self-lubricating function according to claim 1, characterized in that: set up worm wheel (4) and scrape oil cover (3) radial clearance that cooperatees and be h, clearance h value range does:

$0<h<\frac{{24}^{1/3}\mathrm{AB}+2^{1/3}{(9A^{2}C+\sqrt{3A^3({-4B}^3+27{\mathrm{AC}}^2)})}^{2/3}}{6^{2/3}A{({9A}^{2}C+\sqrt{{3A}^3({-4B}^3+27{\mathrm{AC}}^2)})}^{1/3}}$

wherein,

representing the oil hydraulic differential flow coefficient;

representing the shear flow coefficient of the oil liquid;

c ═ V')/b, where b represents the thickness of the worm gear and V ═ m²z₂b beta/2 represents the displacement of the worm gear rotating to the top end of the oil scraping cover; v' represents a lubricating oil boundary condition value satisfying sufficient lubrication and cooling of a meshing surface;

ρ represents the lubricant density; g represents the gravitational acceleration;

beta represents a central angle corresponding to the special-shaped sealing element; mu represents the dynamic viscosity of the oil;

m represents the module of the worm wheel; n represents the worm gear speed;

z₂indicating a worm gear tooth number; h is_aDenotes the worm gear tooth top height coefficient.

3. The vertical worm-gear mechanism with self-lubricating function according to claim 2, characterized in that: the oil scraping cover is provided with an opening at the meshing position of the worm gear and the worm.

4. The vertical worm-gear mechanism with self-lubricating function according to claim 1, 2 or 3, characterized in that: the upper end and the lower end of the worm (6) are vertically supported in the box body (1) through a tapered roller bearing (5), the lower end of the worm is sealed by a bearing end cover, and the upper end of the worm extends out of the box body (1) to be used as an input shaft end of the transmission mechanism; the worm wheel (4) is supported in the box body (1) along the horizontal direction by an output shaft (9) through a bearing and is meshed with the worm (6), and the oil scraping cover (3) is fixed in the box body (1) through a supporting frame (10).

5. The vertical worm-gear mechanism with self-lubricating function according to claim 4, characterized in that: the wrap angle of the oil seal area matched with the oil scraping cover (3) is 4 pi/3, and two ends of the bottom of the oil scraping cover are provided with inlets.

6. The vertical worm-gear mechanism with self-lubricating function according to claim 1, 2 or 3, characterized in that: the liquid level of the lubricating oil (7) in the box body (1) reaches 1/3 of the radius of the worm wheel (4), and a cooling water pipe (8) is arranged at the bottom of the box body (1) and is filled with cold water to cool the lubricating oil (7).