RU2800516C1 - Coaxial three-shaft reversible eight-speed gearbox - Google Patents

Abstract

FIELD: gearboxes.

SUBSTANCE: invention relates to a coaxial three-shaft reversible eight-speed gearbox. The primary and secondary shafts are installed coaxially in the housing supports of the reversible eight-speed gearbox of low specific amount of metal, the intermediate shaft gears axis is installed parallel to them. Between the parallel shafts of the gearbox there are four pairs of cylindrical gears and three shift clutches: two extreme three-position clutches and one double clutch with oppositely deployed clutches with a common gear shift fork. A conical reverse gear is installed to the front wall of the housing at the input of the input shaft.

EFFECT: increased reliability of the vehicle.

2 cl, 3 dwg

Description

The invention relates to transport engineering, in particular to the transmission of transport vehicles.

Known transmission units with stepped gear ratios, containing gears, shafts, bearings, gear shifting devices used in domestic and foreign vehicles. 1). Cars: Construction, design and calculation. Transmission./Ed. A.I. Grishkevich. Mn.: Vysh. school, 1985.–240 p. 2). Nekrasov V.I. Multi-stage transmission. Design, design and calculation: Proc. allowance. - Kurgan, Publishing House of the Kurgan State. un-ta, 2001. - 155 p.).

These units are structurally complex, metal-intensive.

The closest in design and principle of operation to the proposed reversible eight-speed gearbox (gearbox) of low metal consumption is a coaxial three-shaft eight-speed gearbox of type 8R8 using the method of free installation of gears on shafts according to patent RU No. 2176197. (Bulletin No. 33 dated 27.11.2001. Author Nekrasov V.I.).

In the 8R8 type gearbox, four pairs of gears provide 8 forward gears, and the last two pairs of gears provide 8 reverse gears. Gear shifting is carried out by four clutches: one three-position and three - double two-position, oppositely deployed, each controlled by one shift fork.

Multi-pair gearing in the gearbox allows reducing the maximum gear ratio of a pair of gears, reducing the distance between the shafts, the dimensions and the metal consumption of the unit. The extreme pairs of gears work only in one direction: the first pair from the input shaft to the intermediate, the fourth pair from the intermediate to the secondary shaft. The middle pairs of gears can transform torque in both directions.

The disadvantage of the described transmission unit is to limit the performance of the vehicle due to the impossibility of using four higher reverse gears, since when they are turned on, the gears of the fourth pair reach a high rotation speed.

The task to be solved by the claimed invention is to expand the operational capabilities of the vehicle.

The task is solved by replacing pairs of reverse gears with a reverse bevel gear, consisting of three bevel gears and a three-position shift clutch. The input shaft of the reverse gear can be installed either parallel or perpendicular to the gearbox shafts.

This technical result is achieved in that: 1. a coaxial three-shaft reversible eight-speed gearbox containing a housing in the supports of which the primary and secondary shafts are coaxially located and parallel to them the axis of the gears of the intermediate shaft, four pairs of gears are freely installed on the parallel shafts, on the primary and secondary On the shafts near the extreme pairs of gears, gear rims are fixed with three-position shift clutches located on them, on the gear rims of the middle pairs of gears, a double clutch is installed with oppositely deployed two-position clutches interconnected by a common shift fork, while the reverse gear consists of a simple three-link planetary mechanism having a carrier with axes and satellites, which are engaged with two identical bevel gears, one of them is fixed at the input of the input shaft, the second - on the input shaft installed coaxially with the input shaft, a ring gear is fixed on the input shaft, two ring gears are installed next to it, on which is located switching clutch, one crown is fixed on the housing wall, the other - on the tubular drive shaft of the carrier. 2. coaxial three-shaft reversible eight-speed gearbox according to paragraph 1, while the bevel gear of the input shaft is engaged with two gears with ring gears freely mounted on the input shaft, on which a gear ring is fixed between the gears with a three-position shift clutch located on it.

In FIG. 1 shows a kinematic diagram of a coaxial three-shaft reversible eight-speed gearbox type 8RR8 (8 forward gears and 8 reverse gears), containing 8 gears and three gear shift clutches. The input shaft of the reverse bevel gear is located parallel to the gearbox shafts. The RR reverse gear is highlighted in the diagram, in fact, its dimensions are much smaller. The input shaft support in the secondary is located at the output of the unit.

In FIG. 2 shows a kinematic diagram of a coaxial three-shaft reversible eight-speed gearbox type 8RR8 with a perpendicular arrangement of the input shaft. The input shaft support in the secondary is located at the inlet of the stepped unit.

Under the figures are the letter designations of pairs of gears ( a, b, c, d, e ).

In FIG. 3 shows a structural beam diagram of this gearbox with a table of shift clutch positions in various gears. In the lower part of the table, above the gear numbers, the pairs of gears included in the work are indicated ( bc, Pr ., ac , ab, bd, etc.). On the horizontal scales in logarithmic form, the gear ratios of pairs of gears and gears are given. The upper horizontal corresponds to the gear ratios on the secondary shaft, the lower horizontal - on the intermediate shaft. Point 0 (7) on the upper horizontal - torque input to the gearbox from the reverse bevel gear. Designations of pairs of gears are indicated on the beams. The greater the tilt of the beam to the right, the greater the gear ratio. The left tilt of the beam indicates the accelerating mode of the pair of gears. The slope of the beam of each pair of gears is constant in any part of the beam diagram. The designation "BAC" above the table indicates the order of operation of the shift clutches: the first letter "B" - the clutches change their position with each successive gear change; "A" - after two switchings; "C" - after four consecutive gear changes.

In FIG. 1, the primary 2 and secondary 3 shafts are coaxially installed in the supports of the gearbox housing 1, the axis 4 of the gears of the intermediate shaft is located parallel to them. Gears 5-8 are freely installed on coaxial primary 2 and secondary 3 shafts. On axis 4, gears 9-12 are freely mounted, meshed with gears 5-8, respectively. Gears 9 and 10, as well as 11 and 12, are combined into blocks by tubular shafts 13 and 14. Gear rim 15, with a three-position shift clutch 16 (A) installed on it, is fixed on input shaft 2 between gears 5 and 6. Gear rim 17, with a three-position shift clutch 18 (C) installed on it, fixed on the secondary shaft 3 between gears 7 and 8. The upper clutch 19 mounted on the gear rims between gears 6 and 7, the lower oppositely deployed clutch 20 mounted on the gear rims between gears 10 and 11. Clutches 19 and 20 are connected by a common switching fork 21. The driven bevel gear 22 of the reverse gear is fixed at the input of the input shaft 2. The drive bevel gear 23 of the reverse gear is mounted on the input shaft 24, on which the ring gear 25 is also fixed. Near the crown 25 there is a ring gear 26 fixed on the tubular shaft 27 of the drive of the planet carrier 28 with axes 29 and satellites 30 engaged with bevel gears 22 and 23. Next to the ring gears 25 and 27 on the wall of the housing 1, a ring gear 31 is fixed. Between these ring gears there is a coupling 32 (R) switching the operating mode of the reverse bevel gear.

In FIG. 2, the ring gear 25 is fixed at the input of the input shaft 2, the bevel gears 22 and 30 are equipped with ring gears and are located on both sides relative to the ring gear 25 of the input shaft 2.

The operation of the eight-speed gearbox is carried out as follows:

In FIG. 1 reverse bevel gear is a simple three-link PM (planetary mechanism), consisting of a carrier 28 with axles 29 and satellites 30 located on them, engaged with gears 22 and 23. Since gears 22 and 23 have the same number of teeth, the internal parameter of this PM K \u003d 1. Often such a PM is used as a symmetrical differential, in which all links are free, it equally distributes the torque supplied to it. If we stop one of the PM links, we get a gearbox.

In FIG. 1 reverse bevel gear is blocked, clutch 32 (R) in the left position (see top view) closed the ring gear 25 of the input shaft 24 with the drive gear 23 and the ring gear 26 of the tubular shaft 27 with the planet carrier 28. From the input shaft 24, along the gear ring 25, clutch 32, ring gear 26 and through the blocked reverse gear, the torque is directly supplied to the input shaft 2.

When the clutch 32 is switched to the right position (see bottom view), the carrier 28 is stopped by the tubular shaft 27, gear rims 26-31 and the clutch 32 relative to the housing 1, the PM is transformed into a gearbox. The torque from the input shaft 24 is supplied to the drive bevel gear 23, satellites 30, rotating on the axes 29 of the stopped carrier 28, is transmitted to the driven bevel gear 22, which rotates the input shaft 2 in the opposite direction.

In FIG. 2 in the left position of the clutch 32 (R), the torque from the input shaft 24 by the drive bevel gear 23 is transmitted to the left driven gear 30, through the clutch 32 to the ring gear 25 and the input shaft 2.

When switching the clutch 32 to the right position, the torque from the input shaft 24 by the driving bevel gear 23 is transmitted to the right driven gear 22, through the clutch 32 to the ring gear 25 and the input shaft 2, which rotates in the opposite direction.

First gear (a-b-c-d)

Clutch A is in the left (L) position, B and C are in the right position (see the table in Fig. 3, to the right above point 1).

On the beam diagram (see Fig. 3), this transmission is represented by four beams: the beam "a" comes out of point 0 (7) on the upper horizontal and is directed downward to the right under point 5 and 6, then a steep beam "b" to the right up to point 5, then a beam "c" to the right down and a gentle beam "d" to the right up to point 1.

The torque from the input shaft 24 of the reverse bevel gear (see Fig. 1) is transmitted to the input shaft 2, through the ring gear 15 and the clutch 16 (A) to the first pair of gears 5-9 (a), through the lower tubular shaft 13 of the gear block 9 and 10, along the second pair of gears 10-6 (c), along the upper clutch 19 (B), along the third pair of gears 7-11 (c), then along the tubular shaft 14 to the fourth pair of gears 12-8 (d), on the clutch 18 (C) on the ring gear 17 and the output shaft 3.

Second gear (a-d)

We switch the double clutches B to the left position - we turn off the second and third pairs of gears from work.

On the ray diagram, this transmission corresponds to two beams, the beam “a” comes out of point 0 and is directed downward to the right, then the gentle beam “d” to the right up to point 2.

The torque from the input shaft 24 of the reverse bevel gear to the tubular shaft 13 is transmitted as in 1st gear, then through the lower clutch 20 to the tubular shaft 14, then as in 1st gear.

Third gear (c-d)

All clutches in the right position - the third and fourth pairs of gears are in operation.

On the beam diagram, this transmission is represented by a steep beam "c", which goes from point 0 to the right down and a gentle beam "d" to the left up to point 3.

The torque from the input shaft 2 through the clutch 16 (A) is transmitted to the gear 6, through the upper clutch 19 (B) to the third pair of gears 7-11 (c), through the right tubular shaft 14 to the fourth pair of gears 12-8 (d) , then along the clutch 18 (C) to the ring gear 17 and the output shaft 3.

Fourth gear (b-d)

We switch the double clutches B to the left position - we replace the third pair with the second pair of gears.

On the beam diagram, this transmission is represented by two beams: a steep beam "b" leaves point 0 to the left down in the accelerating mode and a gentle beam "d" to the right up to point 4.

The torque from the input shaft 2 through the clutch 16 (A) is transmitted to the second pair of gears 6-10 (c), through the lower clutch 21 (B), along the right tubular shaft 14 to the fourth pair of gears 12-8 (d), further as on previous transmissions.

Fifth gear (a-b)

We switch clutches A and C to the left position, and clutches B to the right position - we replace the fourth pair with the first pair of gears.

On the beam diagram, this transmission is represented by two beams: beam "a" leaves point 0 and is directed downward to the right, then a steep beam "b" to the right up to point 5.

The torque from the input shaft 2 through the clutch 16 (A) is transmitted to the first pair of gears 5-9 (a), along the left tubular shaft 13 to the second pair of gears 10-6 (c), through the upper clutch 19 (B), along the body gears 7 (c), then along the clutch 18 (C) and as in the previous gears.

Sixth gear (a-c)

All clutches in the left position - we replace the second pair with the third pair of gears.

On the ray diagram, this transmission is represented by a ray "a", which leaves point 0 to the right down and a steep beam "c" to the left upwards in an accelerating mode to point 6.

The torque from the input shaft 2 through the clutch 16 (A) is transmitted to the first pair of gears 5-9 (a), along the left tubular shaft 13 to the third pair of gears 11-7 (c), then through the clutch 18 (C) and as on previous transmissions.

7th gear - direct

We switch clutches A and B to the right position - we turn off all pairs of gears from work.

On the ray diagram, this transmission is represented by point 7.

The torque from the input shaft 2 is transmitted through the clutch 16 (A), through the gear 6 (b), through the upper clutch 19 (B), then through the clutch 18 (C) and as in the previous gears.

Eighth gear - accelerating (b-c)

We switch clutches B to the left position - we turn on the second pair and the third pair of gears.

On the beam diagram, this transmission is represented by two beams: a steep beam "c" leaves point 0 to the right down and a gentle beam "e" to the right up to point 8.

The torque from the input shaft 2 through the clutch 16 (A) is transmitted to the second pair of gears 6-10 (c), through the lower clutch 21 (B) to the third pair of gears 11-7 (c), then through the clutch 18 (C) and as in previous episodes.

The lower part of the ray diagram (Fig. 3) shows the total reduction equal to the sum of the segments of the rays of the pairs of gears in logarithmic coordinates. P \u003d 1.5 + 0.5 + 0.5 + 3.5 \u003d 6.0. The minimum beam size belongs to the second and third pairs of gears - 0.5 intervals, the maximum beam size belongs to the fourth pair of gears - 3.5 intervals. As a rule, U _max \u003d 4. In this case, we get: lg q \u003d lg 4 / 3.5 \u003d 0.172; q = 1.486. We can get the range D \u003d q ⁷ \u003d 1.486 ⁷ \u003d 16.

For comparison: the 8-speed gearbox of the MAZ-6422 has a range of D = U ₁ / U ₈ = 7.73 / 0.71 = 10.89 with an average interval lg q = lg 10.89/7 = 1.037/7 = 0.148 ; q = 1.407. For calculations, we take q = 1.41.

Gear ratios of pairs of gears: the first pair U _a = q ^1.5 = 1.41 ^1.5 = 1.674; the second and third pairs U _b \u003d U _c \u003d q ^0.5 \u003d 1.41 ^0.5 \u003d 1.187; fourth pair U _d \u003d q ^3.5 \u003d 1.41 ^3.5 \u003d 3.33.

Range D = q ⁷ = 1.41 ⁷ = 11.08.

Gear ratios:

U ₁ = U _a U _b U _c U _d = 1.674 * 1.187 * 1.187 * 3.33 = 7.85 or U ₁ = q ⁶ = 1.41 ⁶ = 7.86.

U ₂ \u003d U _a U _d \u003d 1.674 * 3.33 \u003d 5.57 or U ₂ \u003d q ⁵ \u003d 1.41 ⁵ \u003d 5.57.

U ₃ \u003d q ⁴ \u003d 1.41 ⁴ \u003d 3.95. U ₄ \u003d q ³ \u003d 1.41 ³ \u003d 2.8. U ₅ \u003d q ² \u003d 1.41 ² \u003d 1.99.

U ₆=q = 1.41. U ₇=q ⁰ = 1.0. U ₈= 1/q = 1/1.41 = 0.71.

Checking the interval q \u003d U ₁ / U ₂ \u003d 7.86 / 5.57 \u003d 1.41.

q \u003d U ₂ / U ₃ \u003d 5.57 / 3.95 \u003d 1.41, etc.

Range check D \u003d U ₁ / U ₈ \u003d 7.86 / 0.71 \u003d 11.07.

This valueD = 11.07 will ensure the successful operation of the NTS in a wide range of operating conditions with convenient gear shifting. We received a direct gear, 6 gears with high efficiency with two-pair gearing, one gear with four-pair gearing, which provided low gear ratios in pairs of gears:U _max = 3.33.

The considered reversible eight-speed gearbox should be used primarily in road construction equipment: motor graders, rollers, etc.

Designations:

1 - gearbox housing with reverse gear;

2 - input shaft;

3 - secondary shaft coaxial to the primary;

4 - the axis of the gears of the intermediate shaft;

5-8 - gears freely mounted on coaxial primary 2 and secondary 3 shafts;

19-12 - gears freely mounted on axis 4;

13 – left tubular shaft of gears 9 and 10;

14 – right tubular shaft of gears 11 and 12;

15 - a gear ring mounted on the input shaft 2;

16 (A) - three-position switching clutch on the ring gear 15;

17 - gear rim mounted on the secondary shaft 3;

18 (C) - three-position switching clutch on the ring gear 17;

19 (B) - the upper clutch of the double clutch B between gears 6 and 7;

20 (B) - the lower clutch of the double clutch B between gears 10 and 11;

21 (B) - switching fork of clutches 19 and 20 of double clutch B;

22 - driven bevel gear of the reverse gear, fixed on the end of the input shaft 2;

23 - driving bevel gear of the reverse gear;

24 - input shaft of the reverse gear;

25 shows a ring gear attached to input shaft 23 or input shaft 2 in FIG. 2;

26 - gear ring mounted on the tubular shaft 27;

27 - tubular shaft;

28 - carrier;

29 - axes of satellite carriers;

30 - satellites or bevel gear opposite gear 22 in FIG. 2;

31 - toothed rim of the body wall 1;

32 (R) - three-position shift clutch on gear rims 25, 26 and 31.

Claims (2)

1. Coaxial three-shaft reversible eight-speed gearbox, containing a housing in the supports of which the primary and secondary shafts are coaxially located and the axis of the gears of the intermediate shaft parallel to them, four pairs of gears are freely installed on parallel shafts, gear rims are fixed on the primary and secondary shafts near the extreme pairs of gears with three-position shift clutches located on them, on the gear rims of the middle pairs of gears, a double clutch is installed with oppositely deployed two-position clutches interconnected by a common shift fork, characterized in that the reverse gear consists of a simple three-link planetary mechanism having a carrier with axles and satellites that are engaged with two identical bevel gears, one of them is fixed on the input shaft input, the second - on the input shaft installed coaxially with the input shaft, a ring gear is fixed on the input shaft, two ring gears are installed next to it, on which the shift clutch is located, one ring is fixed on the wall of the housing, the other - on the tubular drive shaft of the carrier. 2. Coaxial three-shaft reversible eight-speed gearbox according to claim 1, characterized in that the bevel gear of the input shaft is engaged with two gears with ring gears freely mounted on the input shaft, on which a gear ring is fixed between the gears with a three-position shift clutch located on it.

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