Speed change gear system

Speed change gear system

Abstract
A gear system speed change to provide at least four speed ranges, and a forward movement speed reverse drive range includes two planetary gear sets of single pinion type and the planetary gear mechanism of double pinion type , two clutches, brakes and three. As a result of the engagement and disengagement of the clutches and brakes, the moving of each planetary gear sets are correctly set to achieve various speed ranges.
Description

Background of the Invention
1. Field of the Invention
The present invention relates generally to speed gear shifting systems and more particularly to a system of speed change gears being adapted for application to hydraulic couplings used in motor vehicles, especially cars.
Two. Description of the Prior Art
Is preferable to use at least four gear sets within the systems of speed change gears of large vehicles, such as, for example, trucks and buses, and in order to achieve a speed change mechanism that has more Four shift speed, three, four or even more sets, single pinion type single or double pinion planetary gear sets have hitherto been combined. While the combination of these gears can vary widely, it is preferable however, the following conditions be met:1. The output shaft must be attached to the same elements within each speed range.Two. In order to reduce the circumferential speed of the bearings of each element of the planetary gear set, the number of revolutions should be small.Three. Tooth load, ie, the tangential force of each element must be small in order to maintain the strength of the gear teeth.April. The set of meshing gears must always attain conditions for the number of teeth required. For example, the sun gear whose diameter is to be minimized, and each planetary pinion gear must have the required number of teeth.May. Within the planetary gear assembly, the coupling ratio between the elements must be simple and distance from each other should be small.June. During speed changes, which are used in friction engagement means during forward motion, these changes in speed must be available through a single coupling means.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention is to provide a gear ratio which provides at least four speed ranges for the forward drive range and reverse drive speeds by the use of two sets planetary gear type and one single pinion planetary gear set of single pinion type double, two clutches and three brakes, so that the movable elements of each planetary gear sets are suitably coupled as a result of coupling or disengagement of the clutches and brakes to achieve the different rates of speed.
BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference characters designate similar parts or corresponding parts throughout the several views, and in which:. 1A is a schematic view of one embodiment of a system for speed change gear constructed in accordance with the present invention and the disclosure of co-operation parts;. 2A is a schematic view similar to that of FIG. 1 showing yet another embodiment of the present invention;. 3A is a schematic view similar to that of FIG. 1 showing yet still another embodiment of the present invention;. 4A is a schematic view similar to that of FIG. 1 showing yet still another embodiment of the present invention;. 5A is a schematic view similar to that of FIG. 1 showing yet another embodiment of the present invention;. 6A is a schematic view similar to that of FIG. 1 showing, however, a further embodiment of the present invention;. 7A is a schematic view similar to that of FIG. 1 showing, however, a still further embodiment of the present invention;. 8A is a schematic view similar to that of FIG. 1 showing, however, a still further embodiment of the present invention, and. 9A is a schematic view similar to that of FIG. 1 showing, however, a still further embodiment of the present invention.Description of the Preferred EmbodimentsReferring now to the drawings and more particularly to FIG. 1A thereof, the gear system described speed change mechanism includes a first planetary gear generally indicated by the reference character X1 double pinion type, second planetary gear mechanism indicated generally by reference character X2 of the single pinion type and a third planetary gear mechanism generally indicated by reference character X3 single pinion type, all of which is interposed between an output shaft and an input shaft. The first planetary gear set is X1 comprising a first sun gear S1, first planetary gear P1 coupled with the first sun gear S1, a second planetary gear P. CH2 engaged with the first planetary gear P1, a first ring gear RG.sub.1 entangled with the second planetary gear P2, and a first carrier C1 rotatably supporting the first and second planetary gears P1, P2, while the second gear X2 planetary second gear also includes a plot S2, a third planetary gear P3 engaged with the second sun gear S2, a second ring gear with the third RG.sub.2 tangled P3 planetary gear and a second carrier C2 rotatably supporting the third planetary gear and P3 is connected to the output shaft.The third planetary gear set X3 includes a third sun gear S3, a fourth planetary gear P4 engaged with the third sun gear S3, a third ring gear RG.sub. 3 entangled with the fourth planetary gear P4, C3 and a third carrier rotatably supporting the fourth planetary gear P4. Second RG.sub.2 ring gear, the third carrier C3 and the first carrier C1 are connected in series with one another and a first clutch CL.sub.1 serves to engage or disengage the second ring RG.sub.2 gear, the third carrier C3 and the first carrier C1 to the input shaft. RG.sub.1 the first ring gear and third ring gear RG.sub.3 are operated similarly coupled together and a second clutch Cl2 serves to engage or disengage the first ring gear and RG.sub .1 RG.sub.3 the third ring gear with the input shaft. Further, a third clutch CL.sub.3 serves to engage or disengage the first sun gear and the input shaft S1.A first brake B1 is interposed between the first sun gear S1 and the gear housing in order to be able to lock the first sun gear S1 to the housing when the brake is actuated and the first Similarly, a second brake B2 is interposed between the housing and the set of elements comprising the second RG.sub.2 ring gear, the third carrier C3 and the first carrier C1 to be able to lock to the housing when the second brake is actuated . The second sun gear S2 and sun gear S3 third drive are engaged, and a third brake B3 is disposed between the housing and the second and third sun gears S2 and S3 so as to be able to block the second and third sun gears S2 and S3 to the housing when the brake is actuated.The following equations are given as characteristic of the planetary gear sets X1, X2 and X3:n.sub.rg.sbsb.1 - (1 - i1) n.sub.c.sbsb.1 - n.sub.s.sbsb.1 i1 = 0n.sub.rg.sbsb.2 - (1 + i2) n.sub.s.sbsb.2 n.sub.c.sbsb.2 + i2 = 0n.sub.rg.sbsb.3 - (1 + I3) n.sub.s.sbsb.3 n.sub.c.sbsb.3 + I3 = 0in which:N.sub.RG.sbsb.1, N.sub.RG.sbsb.2, N.sub.RG.sbsb.3 = the speed of the gears first, second and third ring;N.sub.C.sbsb.1, N.sub.C.sbsb.2, N.sub.C.sbsb.3 = the speed of the carriers first, second and third;N.sub.S.sbsb.1, N.sub.S.sbsb.2, N.sub.S.sbsb.3 = the number of revolutions of the first, second and third sun gears, andI1, I2, I3 = radial relationships to each crown of each sun gear.Within this embodiment, radial relationships within each speed range are I1 = 0.419, I2 = 0.548, I3 = 0.548. Table 1B shows the relationship between the clutch operation CL.sub.1, Cl2 and CL.sub.3 and brakes B1, B2 and B3 with respect to the gear ratio in each speed range in which fn (n = 1, 2, 3, ...) denotes a forward speed range, such as, for example, F1 designates the first forward speed range, F. CH2 designates the second forward speed range, etc. and Rn (n = 1, 2, ...) designates a reverse speed range, such as, for example, R1 designates the first reverse speed range, and can see that a reduction gear ratio of 1: 1.00 can be obtained conveniently and selectively using two of the clutches CL.sub.1, Cl2 and CL.sub.3. Table 1C shows the relationship regarding the number of revolutions and the tangential forces of each of the elements of the planetary gear sets within each speed range. The relationship between the number of revolutions based on the assumption that the number of revolutions of the input shaft 1, while the tangential forces which are designated based on the assumption that the input shaft torque exerted on the ring gear is 1, the tangential forces of the planetary gears being equal to those of the sun gears and ring gears.

In Table 1C, like reference characters designate identical or corresponding parts shown in Table 1B, and further, to designate a particular speed range, B denotes an element of the planetary gear set, N denotes the number of revolutions, and W denotes the tangential force. Because the reduction gear ratio of the fourth forward speed range F4 is 1: 1.00, the number of revolutions N of each planet gear, ring gear, and the carrier is 1.00, the number of revolutions N of individual sun gear, ring gear and the support is 1.00, and the number of revolutions N of each planetary gear is 0.00. W tangential forces therefore considerably less than those produced in other speed ranges. Within other speed range, the torque of the input shaft is transmitted through all elements of a single motor connected, while conversely, the torque of the input shaft of the fourth speed range is distributed F4 all elements as a result of participation at least two clutches, and therefore it is clear that the tangential forces resulting from the elements of said speed range are smaller than those occurring as a result of the transmission of torque from the input shaft as a result of only a clutch coupling. Thereafter, a discussion of the number of revolutions N and tangential forces W within the speed range that has the gear reduction ratio of 1: 1.00 is ignored.