CN2256962Y - Circulation ball type rolling worm gear - Google Patents

Abstract

The utility model belongs to a mechanical driving device for a worm gear and a worm rod. Standard steel balls (2) are arrayed in an enclosed roller chain along a specially designed rolling path between a worn rod (1) and a worm gear (3). When the worm rod rotates, the steel balls rolls in a circulation mode with the worm rod and pushes the worm gear to rotate and to do retarded motion. The utility model has advantages that the utility model changes the sliding friction of the traditional worm gear pair into the rolling friction for enhancing the driving efficiency and prolong the service life, and the worm gear is made from ferrous materials for saving the valuable copper alloy. Because a rolling body adopts the national standard steel ball series, the utility model is suitable for forming a serialized, standardized, generalized novel mechanical driving device.

Description

Circulating ball formula rolling worm gear pair

The utility model belongs to a kind of new mechanical driving mechanism.Specifically a kind of circulating rolling worm gear pair.

Worm drive is the mechanical transmission that a kind of ancient and don't broken hair exhibition is upgraded.Along with the development that machine manufacturing and instrument are made, it has been widely used in aspect transmitting movement and power such as lathe, metallurgy, mine, oil, chemical industry, building, lifting transportation, light industry, weaving, food, instrument, ordnance weapons, electronics tracking and astronomical instrument.Particularly in some calibration machineries, worm and worm wheel have become a kind of irreplaceable mechanical transmission component.Why purposes is very extensive in worm drive, is because it has following advantage:

1, single staged transmission ratio is big.The single staged transmission ratio of ordinary gear transmission generally is no more than 10, and worm geared single staged transmission ratio can reach 70～100 easily, even the lathe that the has worm drive of rotary table employing at a slow speed, and its single staged transmission ratio reaches more than 1000; 2, stable drive, noise is little; 3, can realize self-locking.But worm drive has following shortcoming again: 1, transmission efficiency is low.Friction loss because worm screw (steel) and worm gear (bronze) are meshed is big (the sliding friction coefficient is 0.1～0.15), so worm geared efficient is low.When single-stage driving bigger, the angle of lead of worm screw again hour, its transmission efficiency is often below 50%; 2, be easy to generate gummed and wearing and tearing.The mating surface of conventional worm transmission is the line contact, and when bearing load, the oil film between the gear teeth destroys easily, forms dry friction, and produces more heat, and therefore gummed and wearing and tearing are principal modes that worm drive was lost efficacy; 3, cost height.In order to improve worm geared anti-bonding and wear-resistant ability, the gear ring of worm gear is made with Cuprum alloy or other high-abrasive material often.

At the shortcoming of traditional worm gear pair, Designers are in order to improve the number that its transmission efficiency has adopted increases worm screw, thereby increase the way (even now do brought be increasing substantially of manufacturing cost and difficulty) of angle of lead;

Improve worm screw shape (as cylndrical surface, toroid helicoids worm etc.) and surface of contact shape (as Ah its's Mead, the straight exterior feature of normal direction, involute and type cone envelope worm screw etc.), and the lubricating structure that improves in the worm drive reduces or reduces heat and the wearing and tearing that produce in the transmission;

In order to reduce the consumption of noble metal Cuprum alloy, large-scale worm gear is just taken turns toothed portion and is adopted the Cuprum alloy manufacturing, though can save the valuable non-ferrous metal of part like this, makes the structure complicated of worm gear and has increased assembling difficulty.

However, bring back the time be nearly tens types of worm screw difformities; The increase of number of threads has brought the making of complex proprietary cutter; Make the worm gear material and still be unable to do without valuable non-ferrous metal--bell metal or albronze.

In Patent Office of the People's Republic of China, consulted following relevant utility model patent: (only these three parts)

1, notification number: CN2042132U, application number: 88209852.7, the model utility title is: the V-type trough roller moves the tooth worm gear pair;

2, notification number: CN2114729U, application number: 91225527.7, the model utility title is: the rolling worm gearing;

3, notification number: CN21107420U, application number: 91232583.6, the model utility title is: the worm and worm gear of band rolling element.

Consult " publication of handbook China Machine Press of modern mechanism, No. 054, Xindeng, capital word, number of the edition ISBN7-111-03806-1/TH.461.The mechanism's legend that mechanism's atlas in the recent foreign patent document is provided in the book and had replenished in the Japanese literature in 1980～1991 years.Search the relevant worm gear pair driving mechanism of letter legend totally 10 examples (the 134th page of the 78th～87 example of the first volume) in this book, have only (1) (2) in the 82nd example " worm drive of band edge face pinwheel " and the 83rd example " the arc rotary surface worm drive of band pinwheel " and the above-mentioned patent application very similar.

Above-mentioned model utility can be looked into generation to corresponding example in some particular application, as worm screw roll type in the automobile steering device and worm screw pin type (seeing " automobile construction " for details turns to structure one joint that is to describe).But for general Worm and worm-wheel gearing, just be difficult to popularize and implement this structure, reason is mode of structure, roller bolt and the worm screw surface of contact of this rolling element difficulty that all can bring in the concrete practicality such as little.

One common ground is arranged in above-mentioned model utility, promptly all want the sliding friction transmission of traditional worm gear pair is become the rolling friction transmission.Different is, and their select the mode difference of rolling element, are " can around the rigidity rolling element of its axle rotation " as what adopt in (1) (2) the model utility; As what adopt in (3) the model utility is to utilize " retainer " with the rolling type kind of drive in " rolling element is installed in rotation on the spiral chute of worm screw ".Just because of this, above-mentioned model utility has implemented certain difficulty.Main cause has 2 points: first is " can around the rigidity rolling element that its axle is rotated " its " axle " intensity and " rolling element " and the little defective that all can bring transmitted power to descend of worm screw surface of contact after substituting worm-gear tooth; Second is because " retainer " " fixed " mutually with worm screw, " rolling element " of its maintenance is though occur rolling relatively when contacting with worm gear, and between " rolling element " and " retainer " will more serious sliding friction phenomenon appear because of stressed contact back, can bring bad consequence to the transmission of worm and gear again conversely.

The purpose of this utility model is exactly that the defective that will overcome prior art provides a kind of circulating ball formula rolling worm gear pair, it can make the sliding friction transmission of traditional worm gear pair become the rolling friction transmission, it can improve the transmission efficiency of worm-and-wheel gear, reduce wear, and it can replace the material of Cuprum alloy as new type worm wheel with ferrous metal.

It is such realization that this reality has novel purpose: use standard steel ball (2) to be arranged in the ball chain of sealing along the raceway of particular design between worm screw (1) and worm gear (2).When worm screw (1) was rotated, steel ball (2) i.e. was circulating rolling thereupon, promoting worm gear (3) and rotating and do retarded motion.

Owing to be designed to the steel ball (2) of a string cycle arrangement in the utility model between worm screw (1) and the worm gear (3), compared with prior art like this on its meshing relation in above-mentioned model utility of searching " the rigidity rolling element that can rotate around its axle " and the structure of " rolling element and rolling element retainer worm screw are housed " simpler, more practical; And Surface of action is arranged with " intensity " ball, so transmitted power is bigger.The thread form of worm and worm wheel all adopts single circular arc or two circular arc grooved in the utility model.Novel worm screw can be the cylndrical surface worm screw, also can be toroid helicoids worm (also claiming hourglass screw), has unified machining shape, can reduce various special purpose machine tools and various complex cutting tool; Worm and worm wheel all can adopt the ferrous metal manufacturing in the utility model, can save the valuable non-ferrous metal that uses on traditional worm gear.Because steel replaces Cuprum alloy, the raising of mechanical property, under the constant situation of transmission parameter, the volume of novel transmission mechanism, weight also can reduce to some extent; The utility model is owing to select the rolling element of NBS steel ball series as the new type worm wheel pair, and the structure of circulating ball formula is suitable for to make the utility model form seriation, standardization, unitized novel mechanical driving mechanism in addition.

Concrete structure of the present utility model is drawn by following embodiment and accompanying drawing thereof.

Fig. 1 is the utility model circulating ball formula rolling worm gear pair plan view;

Fig. 2 is the utility model A-A sectional view;

Fig. 3 is a raceway partial enlarged drawing in the utility model.

In each accompanying drawing:

1, worm screw; 2, steel ball; 3, worm gear; 4, worm-wheel shaft; 5, transfer the crack cover; 6, housing; 7, housing; 8, ball sheath.

Fig. 1 represents is according to a kind of novel worm type of reduction gearing that the utility model proposes, and it is by worm screw 1, ball 2, and worm gear 3, worm-wheel shaft 4 is transferred crack cover 5, and housing 6,7 and ball sheath 8 are formed.

In Fig. 3, all be processed with arc groove on worm screw 1 and the worm gear 3, ball 2 transmitting movement that can in its groove, roll.

Describe the structural feature of the utility model circulating ball formula rolling worm gear pair below in detail and realize best way of the present utility model:

1, the standard accurate steel balls (2) through quenching is arranged in the ball chain of sealing along the raceway of particular design between worm screw (1) and worm gear (3), and when worm screw (1) was rotated, steel ball (2) promptly rolled thereupon, moves in circles.

2, the raceway on worm screw (1) and the worm gear (3) all can be designed to single circular arc type or two circular arc type groove.

3, worm gear pair can be designed to the rolling worm gear pair of the circulating ball formula of various series according to modulus series and steel ball standard, help seriation, standardized designs.

4, the steel ball of every circulating ball chain (2) should not design too much, and worm screw (1) can be designed to bull, and each all has circulation raceway separately.

5, worm screw (1) shape can adopt cylindrical worm, and (being used for single head) relatively simple for structure more, but transmitted power is limited, generally is used in the less place of transmitted power.

Worm screw (1) shape also can adopt toroid helicoids worm (also claiming hourglass screw), and than the cylindrical worm complex structure, difficulty of processing is big, but transmitted power is also bigger.Because worm screw (1) is more with the number of teeth that worm gear (3) contacts, and should adopt bull modulus screw thread.

6, the lubricating system of circulating steel ball (2) may be selected to be:

△ grease lubrication mode---generally be used in low speed;

The outer lubricating system---(at worm and wheel appearance raceway lubricating system)---of △ lubricating cup formula is suitable for middle and high speed;

Lubricating system (at worm screw inner loop raceway lubricating system) in the △ oil pump injects---be suitable at a high speed.

The circulating rolling of excellent lubrication and steel ball (2), novel worm gear pair no longer have dry friction and give birth to hot phenomenon generation.

7, worm gear (3) does not re-use valuable non-ferrous metal manufacturings such as bronze or albronze.

8, for the ease of adjusting crack between worm screw (1), worm gear (3) and the steel ball (2), design has the crack of accent cover (5) at worm gear (3) two ends.Transfer crack cover (5) (because its relative housing bore in upper bearing (metal) hole is an eccentric structure) thereby the distance at change worm gear (3) center and worm screw (1) center by rotation, reach the purpose of adjusting play.

Claims (3)

1, a kind of circulating ball formula rolling worm gear pair, form by worm screw (1), standard accurate steel balls (2), worm gear (3), it is characterized in that the standard accurate steel balls (2) through quenching is arranged in the ball chain of sealing along the raceway of particular design between worm screw (1) and worm gear (3).

2, circulating ball formula rolling worm gear pair according to claim 1 is characterized in that described worm screw (1) is cylindrical worm and toroid helicoids worm, and the modulus thread groove above it is shaped as single circular arc or Gothic groove, can be single head and bull; Profile of tooth on the described worm gear (3) also is corresponding single circular arc or two circular arc flute profile.

3, circulating ball formula rolling worm gear pair according to claim 1 is characterized in that the raceway of described particular design is meant: the circular arc flute profile modulus spiral shell of worm screw (1) outer surface spins; Circular arc flute profile tooth on the worm gear (3); Circle groove in two bead guiding grooves on the worm screw (1) and the ball of worm screw (1) internal surface; And and worm gear (3) bi-side join and form to surround the ball sheath (8) of worm screw (1) and steel ball (2).

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