High reduction planetary gear with intermediate shafts
AbstractA planetary gear having two axially adjacent ring gears (11, 12), several planet gears (10) mounted in a planet carrier (2) to rotate, and a central sun wheel (1). Two planetary gears (10) is provided each time an intermediate shaft (6) and each tree has two sets of teeth (7, 8), the smallest set of teeth (8) is provided for simultaneous engagement with two planetary gears (adjacent 10) between which the intermediate shaft (6) is located, and the second set of teeth (7), the reference circle is larger than the first, is engaged with the central sun wheel (1).
Description
DESCRIPTION OF THE PREFERRED EMBODIMENT (S)
Since the planetary gears of this type are known basically only the essential parts of the same to the invention will be briefly described herebelow.
The planetary gear having a central sun wheel 1, the input side, which is rotatably supported by a planet carrier 2. The planet carrier 2 has two side plates 3 and 4 (first and second side plates 3, 4, respectively) interconnected by intermediate webs 5. Two intermediate shaft 6 is supported in a floating manner on the
A total of four planetary gears 10 are supported on the axles 9 needle bearings on the side plates 3 and 4 of the planet carrier 2.
A stationary ring gear 11 and rotatable ring gear 12 which constitutes the output side, are engaged with the planetary gears 10.
Between the stationary ring gear (first) 11 and the rotating gear (second) 12 forming the ring gear output shaft, a main bearing 13, not shown in greater detail, is located where the rolling body tracks are integrated directly into both crowns.
To reinforce the side plate 4 of the planet carrier 2 in which the intermediate shaft 6 with its bearings 14 are
contained, said side plate 4 is reinforced in the area of the holes in the bearing support 14 by respective ribs or web 15 ( see illustration Fig points. 1 and Figs. 2-6).You can see further in Fig. 1 that the connecting lines 16 and 17 of the central points of the axes (planetary gear axes) of two planet wheels (10 meshing together with the smallest set of teeth 8 of the intermediate shaft 6 lying between them) form , in conjunction with the center axis point (axis of the intermediate shaft) 18 of the intermediate shaft member 6, as seen in the section vertical axis, an angle D of 180
Embodiments, shown in Fig. 2 through 6 are basically the same design so have remained the same reference numerals. Differ only by the design and position of the planet wheels, the ring gears and intermediate shafts with the sets of teeth thereof.
Therefore fig. Figure 2 shows a planetary gear with the planet wheels 10 and continuous cylindrical cylindrical crowns.
. Figure 3 shows a planetary gear with two graduated cylindrical planet wheel sets of teeth 10A and 10B located at each shaft 9 and the gears 11 and 12 taper ring. As shown, the axes 19 of the shafts 9 are slightly inclined with respect to the main shaft (main rotation axis) of the planetary gear 20. The inclination angle here can rise to 3 extends from the side plate 4 toward the outside in a direction toward the side plate 3.
Similarly, the longitudinal axes 21 of the intermediate shafts 6 are similarly inclined with respect to the main shaft 20 of the planetary gear. The inclined position angle may amount to approximately 2 plate 3 in the direction toward the side plate 4.
. Figure 4 shows a planetary gear with double tapered planet wheel sets of teeth 10C and 10D, 9 axes 6 located intermediate axes parallel to the axis of the main shaft 20 of the planetary gear. The sets of teeth of the two ring gears 11 and 12, obviously, here adapted to the conical twin planet wheel sets of teeth 10C and 10D.
. Figure 5 shows a planet gear that has two sets of planet wheels graduated cylindrical teeth and 10E, 10F cylindrical sprockets 11 and 12, and smaller cylindrical gear shafts 8 Intermediate 6.
. Figure 6 shows a planetary gear having continuous cylindrical planet wheel 10 as the design of FIG. 2 also shows. In the same way as in the embodiment of FIG. 3 the ring gears 11 and 12 are conical in shape and the longitudinal axes 19 of the four shafts 9, the same as the longitudinal axes 21 of the two intermediate shafts 6, are inclined towards the main axis 20 of the planetary gear.
Smaller sets of teeth 8 intermediate shafts 6 can mesh with the teeth areas of the planet wheel sets 10, which are meshed with the ring gear 11 which is farther from the large sets of teeth 7 Intermediate 6 axes. However, the reverse arrangement is also possible, ie, smaller sets of teeth 8 of the intermediate shaft 6 can mesh with the teeth areas of the sets of planetary gears 10 meshing with the ring gear 12 is closer to the largest set of teeth 7 of the intermediate shaft 6.
As can be seen, the smaller sets of teeth 8 intermediate shafts 6 and also the sets of teeth of the sun wheel 1 are each supported in a floating manner the commitments of the teeth of the respective gears that mesh therewith.
Larger sets of teeth 7, intermediate shafts 6 can be designed as separate spur gears are non-rotatably connected to the intermediate shaft 6 by means of locking assemblies shaped teeth having tooth precise position or strapping connections. The sets of teeth on at least two ring gears 11 and 12 and the planetary gears 10, as the sets of teeth of the intermediate 6 shaft meshing with the planetary gears 10 must be cut helically is , provided with involute helical cutting teeth or involute helical surfaces.
The helix angles of the sets of teeth on the planetary gears 10 must have at least approximately the same height of passage of the edge lines. The sense of direction of the two helix angles must also be the same.
The central sun wheel 1 and the sets of teeth 7 Intermediate 6 shafts meshing therewith can also have a helical cut, in which the helix angles of the sets of teeth 7 on intermediate shafts 6 have step heights at least about equal to the edge lines. The sense of direction of the two helix angles must also be equal.
Inclined positions in the longitudinal axes 19 of the shafts 9 and 21 the longitudinal axes of the intermediate shaft 6 relative to the main shaft 20, tilt positions must be selected so that the inclined positioning axes intersect the main axis train 20 at least approximately at the same point.
In the design of the planetary gears with cylindrical graduated sets of teeth 10A, 10B, and 10E, 10F (Figs. 3 and 5), respectively, must always be the same number of teeth.
As can be seen in Fig. 4, the two ring gears 11 and 12 may be inclined relative to the main axis of the sprocket in which the angles of inclination of the two ring gears 11 and 12 and sets of teeth 10C and 10D of the wheels Planetary meshing with the same extend opposite to each other.
Both sets of oppositely oriented conical teeth 10C and 10D of the planet wheels are designed to be clearly central graduated diameter.
The same applies to the design of the planetary gears with cylindrical graduated sets of teeth 10A, 10B and 10E, 10F, as shown, for example, in FIGS. 3 and 5, in which the graduation must also be clear.
A planetary wheel design with substantially cylindrical graduated sets of teeth, which should be compensated each other to form a continuous cylindrical assembly constantly teeth.
Background of the InventionPlanetary gear of this type are generally known. The planetary gears each have two sets of teeth for meshing permanently with two ring gears. They are so called Wolfrom gear coupling. The speed ratio of planet carrier to the ring gear is designated expected output ratio Wolfrom. In the planetary gear known as, the central sun wheel meshes directly with the planet wheels and is a preliminary to the planetary gears and the stationary ring gear of the two crowns. The relationship Wolfrom, multiplied by the ratio preliminary results in the overall relationship.
Many of the tasks of said planet gears, especially in robot technology, require high ratios with, for example, i = 170 or even higher. But it is often desirable that the diameter of the central sun wheel is not too small, since, for example, may be provided with a hollow shaft for receiving an end of a motor shaft or to transport robot parts. Furthermore, it is often desirable to limit the ratio of Wolfrom. However, it is disadvantageous that the values regarding tooth rolling moderate activity, noise, efficiency, heating and inertia result only a limitation of the speed of the planet carrier. On the other hand, with a limited Wolfrom relationship also becomes difficult also to achieve high overall proportions.
From the central sun wheel drive engages directly with the planetary gears in the planetary gear designs previously known to be equal to them in the module and other data gearing.
In existing solutions, obtaining high proportions brings together with the aforementioned disadvantages, the
Therefore, the problem underlying this invention is to obtain high proportions with proper use of the installation area (tightness torque), whereas, as far as possible overcome the disadvantages mentioned above or at least reduced significantly. Furthermore, the transmission quality is to be improved, namely vibration and angular transmission errors should be minimized. Also, the planetary gear must have favorable production characteristics and require no assembly costs high
side plate 4 of the planet carrier 2. Each intermediate shaft 6 has two sets of teeth, namely, a larger set of teeth 7 (which is adjacent to a first end of the intermediate shaft 6) and a smaller set of teeth 8 (located adjacent to a second end of the intermediate shaft 6). The largest set of teeth 7, which can be designed as a gear unit and is on the intermediate shaft 6 is not rotating, engages with the sun wheel 1. As you can see farther than the figures. 2 to 6, the sun wheel 1 and the largest set of teeth 7 are out of the two side plates 3 and 4, or at the outer side of the side plate 4 away from the side plate 3. The smallest set of the teeth 8 may be designed integrally with the intermediate shaft 6 or as a separate gear non-rotatably connected to the intermediate shaft 6.
SUMMARY OF THE INVENTION
The development of the planetary gear according to the invention makes possible high ratios preliminary whereby a moderate proportion of Wolfrom be selected despite a high total relationship. In addition, the internal activity of the tooth rolling, noise, efficiency, heating and inertia remain within the limits advantageous. This means that there are good conditions for the gear set to have a long-term stability. Under moderate Wolfrom relationship is also possible to use extra pinions in the number of 4, 6 or in pairs, as necessary. Also, as a general rule, a ratio of Wolfrom moderate or less optional means greater differences in the number of teeth of the two ring gears. As a result of the installation conditions, the number of planetary gears is in general directly related to the difference in number between the teeth of the two ring gears.
Moreover, a large number of planetary gears results in a good sealing of the pair. The intermediate shafts can be accommodated in the planet carrier with virtually no extra space. It is also advantageous that the central sun wheel can be designed to have a hollow shaft depending on the desired total proportion as the diameter of the sun wheel teeth always be considerably greater than in the known solutions.
Another advantage is that the module of the input stage, namely the sun wheel / second set of teeth of the intermediate shaft can be selected more accurately especially in Wolfrom known set so that a small number of teeth, and problems related to the tooth shape to it, such as undercut teeth and / or tip, do not occur.
Also, a cost advantage results from the fact that it is possible to build an entire series relation always Wolfrom also designed as only establishes the relationship between the inlet passage has to be varied.
As a result of the relationship of Wolfrom moderate cogs all burdened with high torques, which have, however, a large portion of the total weight, work more slowly, and thus produce less inertia effects. Parts of quick spinning gear, however, are loaded with relatively weak forces can be designed with relatively small bulk.
By the advantageous development of the invention, the forces of teeth largely balanced result set in the first, the teeth, the intermediate shafts' smaller, so that the support thereof becomes easier and simpler . accurate value for the angular disposition of the intermediate shafts can be selected according to the installation conditions, taking into account the combination of numbers of teeth and the number of planetary wheels.
By the characteristics of the invention gives good spatial arrangement ensures a problem-free housing of the second, larger, intermediate shafts' sets of teeth, which is of particular advantage in the case of high ratios.
The characteristics proposed in the invention allow line spaces largest active between the two sets of teeth of the intermediate shafts which facilitates support thereof.
Clearly the assembly is simplified by the characteristics of the invention. The two sets of teeth of the intermediate shafts may be precisely pre-assembled and pre-fabricated outside the planet carrier precisely according to the position of the teeth.
According to the invention, it is possible to place a single roller bearing radially intermediate shafts leading and central sun wheel is removed and then look axially from the respective commitments of teeth. Thus, it is possible to use angular mobility normally always present in a small amount, the roller bearing in question. The denture is then self-adjusting and self-centered. Self-centered tooth engagements effects of a uniform load distribution between the planet wheels. Moreover, this load compensation between the planet wheels acts to internally compensate for fixed teeth graduation errors so that they act on the output shaft to a small extent only. The advantage of this is an accurate operation with only slight vibration.
The reinforcement of the side plate of the planet carrier in accordance with the invention, it is possible to prevent local reductions in the strength of the planet carrier of the holes resulting additional support to the intermediate shafts.
Another feature of the invention is that by having the teeth of the intermediate shaft formed as spur gears non-rotatably connected, simple assembly is obtained while ensuring that the requirements of the position of the teeth.
Another feature of the invention is that the ring gear teeth set smaller intermediate shaft may be tapered. This results in adjustment gearset due to the possibility of axially adjusting the adjustment parts teeth.
The set teeth set in accordance with the invention produces a precise and silent operation with only slight vibration.
Axial support of the planet wheels can be relatively simple when provided designed features gears and helically cut teeth according to the invention. This design amply compensates specifically axial thrusts.
Furthermore, it is possible to simplify the support of the intermediate shafts as a result of good compensation forces as axial thrusts are actually clearly reduced.
Another feature is that the planetary gear may be cylindrical, which results in the inlet passage (ie, the sun wheel / second set of teeth of the intermediate shafts) insensitivity coupling teeth on axial movements in relation to sun wheel.
Another feature of the invention is that the second sets of teeth of the intermediate shafts may be cylindrical resulting in a reduction of the effects of the reaction on the total reproduction in step input as by the features according with the invention, the central sun wheel can be designed relatively large. Also, during a sun wheel self-centering, the reaction can be chosen narrower teeth commitments because errors have less effect distance. This feature also reduces the number of conical teeth sets required and the number of gear parts to be adjusted.
Another feature of the invention is that when the difference in the number of teeth between the two ring gears is selected to be at least twice as high as the number of planet wheels, the ratio is advantageously Wolfrom and activity effectively reduces inner race with the same tooth, noise, friction pairs, heating, and a pair of inertia. This is possible due to the preliminary relationship obtainable by intermediate shafts Wolfrom relationship which can be advantageously reduced in that counter.
Simple planetary gear production can be achieved by the features according to the invention. This is advantageous in that the planet wheels are at least quadrupled in the planetary gear.
Kinematically a precise engagement of the first set of teeth of the intermediate shafts with the planet wheels is achieved by a suitable rotation axis according to the invention.
Another advantageous application of the idea of the invention is a gear where commitments kinematic values teeth in both ring gears can be optimized independently of each other. This can be achieved by the features according to the invention. In this case, will generally be provided a graduation clear.
Another feature of the invention is to provide simple installation conditions.
Another advantageous application of the idea of the invention is a gear in which the values of kinematic commitments teeth both ring gears can be optimized independently of each other. At the same time, the cost of delivery of the dials and the number of bearings can be reduced. In addition, a cost reduction results from the simple production of the satellite carrier does not have axes inclined. Here, each planet wheel receives two opposing sets of conical teeth.
By the invention, the joint bevel of the planet wheels can be designed graduated especially clearly graduated.
In these steps, the relationship also Wolfrom activity is reduced and laminated inside the same tooth, the noise, the pairs of friction, heating, and a pair of inertia. This is made possible by the emphasis, to the invention, the preliminary relationship.
According to the invention, by integrating the tracks in support ring gears, clearly saves space so that more space is available in order to achieve high spatial relation to the housing of wheels within a narrow space.
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