JPH07280045A - Gear transmission - Google Patents

Abstract

PURPOSE:To provide a synchronizing mechanism where the number of revolution of transmission shafts on the reduction gear side and on the transmission gear side can be rapidly synchronized when the reduction gear is engaged with the transmission gear. CONSTITUTION:Actuators 23a, 24a where a pair of friction wheels 21 having the contact surface of the prescribed width are supported by transmission shafts 8, 9 in an integratedly rotatable manner, and the inter-shaft distance of the transmission shafts 8, 9 can be changed by the small value are provided. When a reduction gear 18 is started to slide to the transmission gear 15 side, the actuator 23a is operated to the approaching side of the inter-shaft distance to bring the contact surfaces of the friction wheels 21 of the transmission shafts 8, 9 into contact with each other. When the reduction gear 18 is engaged with the transmission gear 15, the actuator 24a is operated to the separating side of the inter-shaft distance to separate the contact surfaces of the friction wheels 21 of the transmission shafts 8, 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission used in a traveling transmission system, a transmission system to a working device, or the like.

[0002]

2. Description of the Related Art As a gear transmission, a transmission shaft on the transmission upper side and a transmission shaft on the transmission lower side are arranged in parallel, and a plurality of transmission gears are fixed to one of the transmission shafts and the other transmission shaft is fixed. Many are configured so that the transmission gears can be shifted between both transmission shafts by externally fitting a plurality of transmission gears that can be slide-operated and sliding the selected transmission gears to engage and disengage from the transmission gears. is there.

[0003]

In the above-mentioned gear transmission, in order to smoothly engage the transmission gear with the transmission gear, the number of rotations of the transmission shaft on the transmission gear side and the transmission shaft on the transmission gear side are required in order to smoothly engage the transmission gear. It is necessary to synchronize with the rotation speed of. In this case, a synchromesh type that uses a synchronizer ring or a synchronizer cone is often used, but especially in the case of a gear transmission that is subject to a large load, the existing synchromesh type synchronizes the rotation speed described above. Sometimes the action is not enough. It is an object of the present invention to configure a gear transmission so that the above-mentioned rotation speed can be sufficiently tuned with a relatively simple structure.

[0004]

A feature of the present invention is that the gear transmission as described above is configured as follows. That is, [1] the transmission shaft on the transmission upper side and the transmission shaft on the transmission lower side are arranged in parallel, a plurality of transmission gears are fixed to one of both transmission shafts, and the other transmission shaft can be slidably operated. By fitting a plurality of speed change gears on the outside and sliding the selected speed change gears to engage and disengage the transmission gears, it is possible to change the speed between the two transmission shafts. A pair of friction wheels with a contact surface with a width are supported so that they can rotate together, and an actuator that changes the distance between the two transmission shafts by a small distance is provided, and the transmission gear that was separated from the transmission gear When the sliding operation starts to the occlusal side, the actuator is operated toward the side closer to the inter-axle distance to bring the contact surfaces of the friction wheels of both transmission shafts into contact with each other. Operate on the remote side Control means for separating the contact surfaces of the friction wheels of both transmission shafts from each other.

[2] In the structure of [1] above, the actuator is moved closer to the axial distance so that the contact surfaces of the friction wheels of both transmission shafts contact each other while the transmission gear is separated from the transmission gear. An auxiliary control means that can be operated is provided.

[3] In the structure of [1] or [2] above, the friction wheel of the transmission shaft on which the transmission gear is supported can be rotated integrally with the transmission shaft and can be slid integrally with the transmission gear. The contact surfaces of the friction wheels of both transmission shafts face each other when the transmission gear is separated from the transmission gear, and the contact surfaces of the friction wheels of both transmission shafts transmit when the transmission gear meshes with the transmission gear. It is set to be separated in the axial direction of the shaft.

[0007]

[Action]

[I] With the configuration as described in [1] above, for example, as shown in FIG. 1, when the transmission gear 15 separated from the transmission gear 15 is slid and engaged with the transmission gear 15, the transmission shaft 8, The inter-shaft distance of 9 is changed to the approach side by a small distance, the contact surfaces of the friction wheels 21 of both transmission shafts 8 and 9 are pressed, and the power of the transmission shaft 8 is transmitted via the friction wheel 21. The rotation speed of the transmission shaft 8 and the rotation speed of the transmission shaft 9 are synchronized with each other.

In this case, the contact surface of the friction wheel 21 is wide with a predetermined width, and the actuator 23a.
2 at which the contact surfaces of the friction wheels 21 are pressed by each other
By the point, the power of the transmission shaft 8 is sufficiently transmitted to the transmission shaft 9, and the rotation speed of the transmission shaft 8 and the rotation speed of the transmission shaft 9 are quickly synchronized. As a result, the transmission gear 18 smoothly moves to the transmission gear 1
5 can be occluded. As described above, the transmission gear 1
When 8 is engaged with the transmission gear 15, the actuator 24
The distance between the shafts of the transmission shafts 8 and 9 is changed to a small distance by a, and the contact surfaces of the friction wheels 21 of the transmission shafts 8 and 9 are separated from each other, so that the transmission gears 18 and the transmission gears 15 are interposed. It returns to the normal transmission state in which power is transmitted.

[II] When configured as in the above item [2],
As in the case of the configuration of the above [1], the "action" described in the above [I] is provided, and in addition to this, the following "action" is provided. That is, when the configuration of the above [2] is adopted, for example, as shown in FIG. 1, in a state where the transmission gear 18 is not engaged with the transmission gear 15 (a state in which power is not transmitted through the transmission gear 18 and the transmission gear 15). By operating the actuator 23a alone, the contact surfaces of the friction wheels 21 of the transmission shafts 8 and 9 can be pressed against each other.

When the power from the reciprocating engine is transmitted through the gear transmission, the noise generated by the gear teeth of the transmission gear and the transmission gear of the gear transmission repeatedly hitting each other due to the unequal rotation of the engine is generated. Power may be transmitted while being generated. Therefore, when transmitting with a light load, set the transmission gear and the transmission gear apart as described above, and press the contact surfaces of the friction wheels with the actuator to suppress noise caused by repeated gear tooth contact. However, power can be transmitted through the friction wheel.

[III] When configured as in the preceding paragraph [3], as in the case of the configuration in the preceding paragraph [1] or [2], the "action" described in the preceding paragraph [I] or [II] is provided, In addition to this, it has the following “action”. That is, when the structure as described in [3] above is adopted, the friction surfaces of the friction wheels 21 of the transmission shafts 8 and 9 face each other in a state where the transmission gear 18 is separated from the transmission gear 15, as shown in FIG. 1, for example. However, when the transmission gear 18 is slid and engaged with the transmission gear 15, the transmission gear 18 is interlocked with this.
The friction wheel 21 on the side is also slid so that the friction surface of the friction wheel 21 on the transmission gear 18 side is separated from the friction surface of the friction wheel 21 on the transmission gear 15 side in the axial direction of the transmission shafts 8, 9. Therefore, in a normal transmission state in which the transmission gear 18 is engaged with the transmission gear 15, even if the transmission shafts 8 and 9 come close to each other by a very small distance due to vibration or the like, the friction surfaces of the friction wheels 21 of the transmission shafts 8 and 9 will not contact each other. There is no contact.

[0012]

According to the first aspect of the present invention, the friction wheel having a predetermined width is pressed by the actuator, so that the rotation speed of the transmission shaft on the transmission gear side and the rotation of the transmission shaft on the transmission gear side can be changed during the gear shifting operation. The number and the number can be tuned sufficiently and quickly, the gear shifting operation can be smoothly performed, and the gear shifting operability of the gear transmission can be improved.

According to the second aspect of the invention, as in the case of the first aspect, the above-mentioned "effect of the invention" is provided. Further, according to the second aspect of the present invention, since the power can be transmitted by the friction wheels when transmitting with a light load, the power can be transmitted while suppressing the noise caused by the repeated hitting of the gear teeth. Therefore, the transmission performance of the gear transmission can be improved.

According to the third aspect, similar to the case of the first or second aspect, the "effect of the invention" of the first or second aspect is provided. According to the third aspect of the present invention, in the normal transmission state in which the transmission gear meshes with the transmission gear, it is possible to avoid contact between the friction surfaces of the friction wheels of the transmission shaft, so that the friction wheels in the normal transmission state. It is possible to suppress unnecessary heat generation and wear due to the contact between the friction surfaces of, and to improve the durability near the friction wheel.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a traveling transmission system of an agricultural tractor which is an example of a work vehicle. Power from an engine 1 is transmitted from a main clutch 2 to a second transmission shaft via a first transmission shaft 3 and a multi-plate hydraulic clutch 4. 5 is transmitted. Further, the power branched from the first transmission shaft 3 causes the third transmission shaft 6 and the one-way clutch 7 to move.
Is transmitted to the second transmission shaft 5 via.

As a result, when the hydraulic clutch 4 is operated to the transmission cutoff side, the power of the first transmission shaft 3 is changed to the third transmission shaft 6.
Also, it is transmitted to the second transmission shaft 5 at a low speed via the one-way clutch 7. On the contrary, when the hydraulic clutch 4 is operated to the transmission side, the power of the first transmission shaft 3 is transmitted to the second transmission shaft 5 at a high speed via the hydraulic clutch 4. In this way, by operating the hydraulic clutch 4 on the transmission side and the transmission cutoff side, power can be transmitted to the second transmission shaft 5 and the fourth transmission shaft 8 by shifting the power between high and low stages.

The power transmitted to the fourth transmission shaft 8 in the above-described manner is transmitted from the gear transmission 10 capable of performing a shift operation of two forward gears and one reverse gear via the fifth and sixth transmission shafts 9 and 11. The power branched from the sixth transmission shaft 11 is transmitted to the left and right front wheels 14 via the front wheel transmission shaft 13.

Next, the gear transmission 10 constructed between the fourth transmission shaft 8 and the fifth transmission shaft 9 will be described. Figure 1
As shown in, move forward on the fifth transmission shaft 9 (corresponding to the transmission shaft) 1
A high speed gear 15 (corresponding to a transmission gear), a forward second speed gear 16 (corresponding to a transmission gear) and a reverse gear 17 are fixed. A first transmission gear 18 (corresponding to a transmission gear) and a second transmission gear 19 (corresponding to a transmission gear) are slidably fitted onto the fourth transmission shaft 8 (corresponding to the transmission shaft) by a spline structure. There is.

A first friction wheel 21 (corresponding to a friction wheel) having a contact surface of a predetermined width is fixed to the first transmission gear 18 and the fifth transmission shaft 9. In this case, the outer diameter of the first friction wheel 21 of the first transmission gear 18 is set to be substantially the same as the outer diameter of the first transmission gear 18, and the outer diameter of the first friction wheel 21 of the fifth transmission shaft 9 is set to the forward direction 1 The outer diameter of the high speed gear 15 is set to be almost the same, and the normal forward movement 1
In the high speed state, the contact surfaces of the first transmission gear 18 and the first friction wheels 21 of the fifth transmission shaft 9 are apart from each other by a minute distance.

A second friction wheel 22 (corresponding to a friction wheel) having a contact surface with a predetermined width is fixed to the second transmission gear 19 and the fifth transmission shaft 9. In this case, the outer diameter of the second friction wheel 22 of the second transmission gear 19 is set to be substantially the same as the outer diameter of the second transmission gear 19, and the outer diameter of the second friction wheel 22 of the fifth transmission shaft 9 is set to the forward direction 2 The outer diameter of the high speed gear 16 is set to be substantially the same as that of the normal forward movement 2
In the high speed state, the contact surfaces of the second transmission gear 19 and the second friction wheels 22 of the fifth transmission shaft 9 are apart from each other by a minute distance.

A pair of first hydraulic cylinders 23a, 23b for pushing and operating the left and right bearing portions of the fifth transmission shaft 9 to bring the fifth transmission shaft 9 closer to the fourth transmission shaft 8 side by a minute distance.
(Corresponding to an actuator) is provided, and the left and right bearing portions of the fifth transmission shaft 9 are pushed to separate the fifth transmission shaft 9 from the fourth transmission shaft 8 by a minute distance and return to the original state. A pair of second hydraulic cylinders 24a and 24b (corresponding to actuators) are provided.

With the above structure, for example, the first transmission gear 1
Normal forward movement 1 as if 8 is engaged with forward first speed gear 15
In the speed state, the inter-axis distances of the fourth and fifth transmission shafts 8 and 9 are set such that the contact surfaces of the first friction wheels 21 and the contact surfaces of the second friction wheels 22 are separated by a minute distance. The fifth transmission shaft 9 is maintained in parallel with the fourth transmission shaft 8. When the shift lever (not shown) is operated to shift from the first forward speed state to the second forward speed state, first, the first shift gear 18 moves the first forward speed gear 1 by the shift lever.
5 is slid rightward on the paper surface to the neutral position (state shown in FIG. 1). Next, the second transmission gear 19 in the neutral position in FIG. 1 starts to be slid rightward on the paper surface.

In this case, the working oil is supplied to the first hydraulic cylinder 23b on the second forward speed gear 16 side in conjunction with the operation of the shift lever, and the second forward speed gear 16 side of the fifth transmission shaft 9 is moved to the fourth speed.
The transmission shaft 8 side is operated by a small distance. As a result, the fifth transmission shaft 9 is slightly inclined with respect to the fourth transmission shaft 8, and the contact surfaces of the second speed change gear 19 and the second friction wheel 22 of the fifth transmission shaft 9 are pressed, The power from the fourth transmission shaft 8 is transmitted to the fifth transmission shaft 9 via the second friction wheel 22, and the rotation speed of the fourth transmission shaft 8 and the rotation speed of the fifth transmission shaft 9 are changed to the second transmission gear 19. And the transmission ratio of the second forward gear 16 is synchronized.

In this way, the rotation speed of the fourth transmission shaft 8 and the fifth
When the rotation speed of the transmission shaft 9 is synchronized with the transmission ratio of the second forward gear 19 and the forward second speed gear 16, the second forward gear 19 can be smoothly engaged with the second forward gear 16.
At the same time, the second transmission gear 19 and the second transmission shaft 9
The friction surfaces of the friction wheel 22 are separated from each other in the axial direction of the fifth transmission shaft 9.

When the second speed change gear 19 engages with the second forward speed gear 16 as described above, the working oil is drained from the first hydraulic cylinder 23b on the second forward speed gear 16 side in conjunction with this, and the second forward speed gear 16 is engaged. The hydraulic oil is supplied to the second hydraulic cylinder 24b on the 16th side and is returned to the original state. This allows
Contact surfaces of both first friction wheels 21 and both second friction wheels 22
The distance between the fourth and fifth transmission shafts 8 and 9 is set to such an extent that the contact surfaces of the first and second transmission shafts 8 and 9 are separated by a minute distance.
On the other hand, the fifth transmission shaft 9 becomes parallel (the above corresponds to the control means).

In contrast to the above-described shifting operation from the first forward speed state to the second forward speed state, during the shifting operation from the second forward speed state to the first forward speed state, the first and the first forward speed gears 15 side. The two hydraulic cylinders 23a and 24a operate in the same manner as described above. Then, during the reverse gear shifting operation in which the first gear 18 is engaged with the reverse gear 17, the above-described operation of the first and second hydraulic cylinders 23a to 24b is not performed.

Further, when the vehicle is traveling forward with a light load, the gear transmission 1
1 is operated to the neutral position shown in FIG. 1, one of the first hydraulic cylinders 23a and 23b is operated with another manual switch (not shown) to supply hydraulic oil. By supplying them, the friction surfaces of the first friction wheel 21 or the friction surfaces of the second friction wheel 22 can be pressed (the above corresponds to the auxiliary control means).

As a result, the hydraulic oil is supplied to one of the first hydraulic cylinders 23a or the other first hydraulic cylinder 23b while suppressing the noise caused by the gear teeth repeatedly hitting each other due to the unequal rotation of the engine 1. Thus, the vehicle body can be moved forward in the first forward speed state or the second forward speed state by the first or second friction wheels 21 and 22.

As shown in FIGS. 2 and 1, the hydraulic clutch 4
In the second transmission shaft 5 that supports the second transmission shaft 5, the end of the second transmission shaft 5 is abutted against the block 25 that supports the bearing 20 at the end of the second transmission shaft 5. Then, the oil passages 25a and 5a for supplying the hydraulic oil to the hydraulic clutch 4 are blocked by
5 and the second transmission shaft 5, and a seal ring 26 is provided at the end of the second transmission shaft 5.

[Other Embodiments] In the structure shown in FIG. 1, the fourth transmission shaft 8 is provided with the first and second speed change gears 18 and 19, and the fifth transmission shaft 9 is provided with the first forward speed and second forward speed gears 15 and 16. However, the fourth transmission shaft 8 may be provided with the first transmission gear 18 and the forward second speed gear 16, and the fifth transmission shaft 9 may be provided with the second transmission gear 19 and the forward first speed gear 15.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a traveling transmission system in an agricultural tractor.

FIG. 2 is a sectional view of a block that supports an end portion of a second transmission shaft in the traveling transmission system.

[Explanation of symbols]

 8, 9 Transmission shaft 15, 16 Transmission gear 18, 19 Speed change gear 21, 22 Friction wheel 23a, 23b, 24a, 24b Actuator

Claims (3)

[Claims] 1. A transmission shaft (8) on the transmission upper side and a transmission shaft (9) on the lower transmission side are arranged in parallel, and a plurality of transmission gears are provided on one of the both transmission shafts (8), (9). (15),
(16) is fixed, and a plurality of transmission gears (18) and (19) which can be slidably operated are fitted onto the other transmission shaft (8) to fit the selected transmission gears (18) and (19). By sliding the gears to engage and disengage the transmission gears (15) and (16), it is possible to change the speed between the transmission shafts (8) and (9). , (9) each have a pair of friction wheels (21), (22) each having a contact surface of a predetermined width rotatably supported integrally, and the inter-shaft distance between the two transmission shafts (8), (9) is small. Actuators (23a) and (2
3b), (24a), (24b), and the transmission gears (18), (19) apart from the transmission gears (15), (16) are engaged with the transmission gears (15), (16). When the slide operation is started to the side, the actuators (23a), (23b), (24a), (24b)
By operating the shafts closer to the shaft distance, the transmission shafts (8),
When the contact surfaces of the friction wheels (21) and (22) of (9) are brought into contact with each other and the transmission gears (18) and (19) are engaged with the transmission gears (15) and (16), the actuator (23a) , (23b), (24a), (24b) are actuated to the distance side of the shaft distance, and both transmission shafts (8),
A gear transmission including control means for separating the contact surfaces of the friction wheels (21) and (22) of (9) from each other. 2. In a state where the transmission gears (18), (19) are separated from the transmission gears (15), (16),
Friction wheels (21), (2) of both transmission shafts (8), (9)
The actuators (23a), (23b), (24a), (24b) so that the contact surfaces of 2) come into contact with each other.
2. The gear transmission according to claim 1, further comprising: an auxiliary control unit that can be operated to approach the shaft distance. 3. Friction wheels (21), (22) of a transmission shaft (8) on which said speed change gears (18), (19) are supported.
Is configured so as to be rotatable integrally with the transmission shaft (8) and capable of sliding operation integrally with the transmission gears (18) and (19), and the transmission gears (18) and (19) are connected to the transmission gear (15). ),
Both the transmission shafts (8) in a state of being separated from (16),
The contact surfaces of the friction wheels (21) and (22) of (9) face each other, and the transmission gears (18) and (19) are connected to the transmission gear (1
5) and (16) in the state of being occluded, the transmission shafts (8),
The gear transmission according to claim 1 or 2, wherein the contact surfaces of the friction wheels (21) and (22) of (9) are set apart from each other in the axial direction of the transmission shafts (8) and (9).