JP7393183B2 - Countershaft brake device and transmission mechanism - Google Patents

Description

Embodiments of the present invention relate to a countershaft brake device and a transmission mechanism.

BACKGROUND ART Conventionally, a transmission for a vehicle is known that has a main shaft that supports a plurality of main gears so as to be able to idle, and a countershaft that supports a plurality of counter gears that mesh with the plurality of main gears. In such a transmission, by meshing one of the main gears with a sleeve connected to the main shaft, the main shaft can be adjusted at a gear ratio that requires rotation of the input shaft connected to the power source. transmitted to.

In such a transmission, in order to suppress gear noise, it is necessary to synchronize the rotational speed of the main shaft and the rotational speed of the main gear when the main gear and the sleeve are engaged with each other. In order to synchronize the rotational speed of the main shaft and the rotational speed of the main gear, a countershaft brake device may be used to apply braking force to the countershaft of the transmission.

For example, Patent Document 1 below describes a brake cover fastened to a brake case, a brake shaft connected to a countershaft, a plurality of outer discs having external teeth splined to the brake cover, and splined to the brake shaft. A countershaft brake mechanism is described that includes a plurality of inner discs that have internal teeth that rotate integrally with the brake shaft, and a brake pressing member that brings the plurality of outer discs and the plurality of inner discs into pressure contact. .

JP 2017-20526 Publication

The countershaft brake mechanism of Patent Document 1 can be removed from the transmission case for maintenance work by releasing the connection between the brake case and the brake cover. When reinstalling this countershaft brake mechanism in the transmission case, the internal teeth of the multiple inner discs must be aligned in phase, that is, the tips of the internal teeth must be aligned in the axial direction of the brake shaft within the brake cover. In this state, it is necessary to mesh the internal teeth of the plurality of inner discs with the spline grooves of the brake shaft. During this work, since the joining position of the spline groove of the brake shaft and the plurality of inner disks is hidden by the brake cover, the operator has to engage the plurality of inner disks with the brake shaft by groping. Therefore, it takes time to attach the countershaft brake mechanism to the transmission case, reducing the efficiency of maintenance of the countershaft brake mechanism.

Therefore, it is desired to improve the maintainability of the countershaft brake device.

In one aspect, a main shaft is rotatably provided within a transmission case and supports a plurality of main gears, and a main shaft is provided in parallel to the main shaft within a transmission case and supports a plurality of counter gears that mesh with the plurality of main gears. A countershaft brake device is provided that is attached to a transmission having a countershaft and that applies braking force to the countershaft. The countershaft brake device includes a housing that is removably attached to the transmission case, a brake shaft that is connected to the countershaft, and is arranged so as to be spaced apart from each other in the axial direction of the brake shaft so as to rotate integrally with the brake shaft. a plurality of rotating plates that engage the brake shaft; and a plurality of non-rotating plates that are disposed between the plurality of rotating plates so as to face the plurality of rotating plates and that engage the housing so as to be non-rotatable with respect to the housing. and a pressing member that presses the plurality of rotating plates and the plurality of non-rotating plates to bring the plurality of rotating plates and the plurality of non-rotating plates into pressure contact when the countershaft is braked. The housing includes a first housing and a second housing that are axially separable from each other, the first housing defining a first space that accommodates a plurality of rotating plates and a plurality of non-rotating plates; The second housing defines a second space that accommodates the pressing member.

In the countershaft brake device, the first housing defines a first space that accommodates the plurality of rotating plates and the plurality of non-rotating plates, and the second housing defines a second space that accommodates the pressing member. has been completed. Here, by separating the second housing from the first housing, the first space in which the plurality of rotating plates and the plurality of non-rotating plates are accommodated can be exposed to the outside. This makes it possible to perform maintenance on the countershaft brake device without removing the entire housing from the transmission case. Furthermore, since multiple rotating plates can be engaged with the brake shaft while visually checking the coupling position between the brake shaft and the multiple rotating plates, it is possible to improve the work efficiency of maintenance such as replacing rotating plates. Become.

In one embodiment, the first housing has an inner circumferential surface formed with a spline groove extending parallel to the axial direction, and the non-rotating plate has external teeth that mesh with the spline groove of the first housing. may be formed. By meshing the spline grooves extending parallel to the axial direction with the external teeth of the non-rotating plate, rotation of the non-rotating plate can be restricted while allowing movement of the non-rotating plate in the axial direction.

In one embodiment, the first housing may be constructed from a stronger material than the second housing. By configuring the first housing from a material with high strength, it is possible to prevent damage to the first housing when regulating the rotation of the non-rotating plate.

In one embodiment, the first housing may be made of a ferrous material, and the second housing may be made of aluminum. By constructing the first housing from iron-based material, the strength of the first housing can be increased, and by constructing the second housing from aluminum, it is possible to reduce the weight of the countershaft brake device. .

In one embodiment, the brake shaft may be formed with a spline groove extending parallel to the axial direction, and the plurality of rotating plates may be formed with internal teeth that mesh with the spline groove of the brake shaft. Thereby, the rotary plate can be rotated integrally with the brake shaft while allowing the rotary plate to move in the axial direction.

In one embodiment, it may further include an elastic member that biases the pressing member in a direction away from the plurality of friction plates and the plurality of separate plates. By urging the pressing member in a direction away from the plurality of friction plates and the plurality of separate plates, frictional force is not generated between the plurality of rotating plates and the plurality of non-rotating plates except during braking. be able to.

In one embodiment, a bolt member extending along the axial direction is connected to the second housing, and a spring functioning as an elastic member may be provided between the bolt member and the pressing member. . By connecting the bolt member to the second housing, when the first housing and the second housing are separated, the elastic member, the bolt member, and the pressing member can be removed together with the second housing.

The transmission mechanism according to one aspect includes a main shaft that is rotatably provided in a transmission case and supports a plurality of main gears, and a plurality of main shafts that are provided in parallel to the main shaft in the transmission case and mesh with the plurality of main gears. It includes a countershaft that supports a counter gear, and a countershaft brake device that applies braking force to the countershaft. The countershaft brake device includes a housing that is removably attached to the transmission case, a brake shaft that is connected to the countershaft, and is arranged so as to be spaced apart from each other in the axial direction of the brake shaft so as to rotate integrally with the brake shaft. a plurality of rotating plates that engage the brake shaft; and a plurality of non-rotating plates that are disposed between the plurality of rotating plates so as to face the plurality of rotating plates and that engage the housing so as to be non-rotatable with respect to the housing. and a pressing member that presses the plurality of rotating plates and the plurality of non-rotating plates to bring the plurality of rotating plates and the plurality of non-rotating plates into pressure contact when the countershaft is braked. The housing includes a first housing and a second housing that are axially separable from each other, the first housing defining a first space that accommodates a plurality of rotating plates and a plurality of non-rotating plates; The second housing defines a second space that accommodates the pressing member.

According to the above-described configuration, it is possible to improve the workability of maintenance of the countershaft brake device of the transmission mechanism.

According to one aspect and various embodiments of the present invention, maintainability of a countershaft brake device can be improved.

FIG. 1 is a cross-sectional view schematically showing a transmission mechanism according to an embodiment. FIG. 1 is a cross-sectional view of a countershaft brake device of one embodiment.

Hereinafter, countershaft brake devices and transmission mechanisms according to various embodiments will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are given the same reference numerals, and duplicate explanations of the same or equivalent parts will be omitted.

FIG. 1 is a sectional view showing a transmission mechanism according to an embodiment. The transmission mechanism 1 shown in FIG. 1 is disposed behind the engine E, and transmits the driving force generated by the engine E to the drive wheels of the vehicle at a predetermined gear ratio.

As shown in FIG. 1, the transmission mechanism 1 includes a transmission 2. As shown in FIG. The transmission 2 has a transmission case 3. A clutch case 6 is connected to the engine E side of the transmission case 3. A partition wall 6a is provided between the transmission case 3 and the clutch case 6. An input shaft 10 that outputs the driving force of the engine E to the transmission 2 is housed within the clutch case 6 . Input shaft 10 is connected to engine E via clutch 7 and flywheel 8. The input shaft 10 is rotatably supported by the partition wall 6a.

A main shaft 4 and a countershaft 5 are housed within the transmission case 3. The main shaft 4 is provided coaxially with the input shaft 10 within the transmission case 3. The front end of the main shaft 4 is rotatably connected to the rear end of the input shaft 10 via a bearing. The main shaft 4 is rotatably supported by a partition wall 3a of the transmission case 3 via a bearing. The rotation of the main shaft 4 is transmitted to the drive wheels of the vehicle via a propeller shaft or the like.

The countershaft 5 is arranged apart from the main shaft 4 and extends parallel to the main shaft 4. The front end of the countershaft 5 is rotatably supported by the partition wall 6a via a bearing. The rear end of the countershaft 5 is rotatably supported by a partition wall 3a inside the transmission case 3 via a bearing. The countershaft 5 transmits the rotation of the input shaft 10 to the main shaft 4 using a predetermined combination of gears.

Further, an oil pump 9 is provided on the front end side of the countershaft 5. The oil pump 9 is supported by the partition wall 6a and is configured to be operated by rotation of the countershaft 5. When the countershaft 5 rotates, the oil pump 9 sucks lubricating oil stored in an oil pan (not shown) and pumps the lubricating oil to a flow path 4e, which will be described later.

A splitter high gear 10b is supported at the rear end of the input shaft 10 so as to be rotatable relative to the input shaft 10. A plurality of main gears 4a, 4b, 4c, and 4d are supported on the main shaft 4 so as to be rotatable relative to the main shaft 4. The counter shaft 5 supports a plurality of counter gears 5a, 5b, 5c, 5d, and 5e fixed to the counter shaft so as to rotate together with the counter shaft 5.

Splitter high gear 10b meshes with counter gear 5e, and counter gears 5a, 5b, 5c, and 5d mesh with main gears 4a, 4b, 4c, and 4d, respectively. The transmission 2 has a plurality of sleeve-type switching mechanisms. This switching mechanism connects the input shaft 10 and the splitter high gear 10b via the sleeve, and connects one main gear among the plurality of main gears 4a, 4b, 4c, and 4d to the main shaft 4 via the sleeve. As a result, the power input from the engine E to the input shaft 10 is transmitted to the main shaft 4 via the counter shaft 5 in a changed speed, and is output from the main shaft 4 as driving force.

A flow path 4e for lubricating oil is formed inside the main shaft 4. The flow path 4e extends along the main shaft 4 in the axial direction and branches. The lubricating oil supplied to the flow path 4e by the rotation of the countershaft 5 is supplied to, for example, the splitter high gear 10b and the main gears 4a, 4b, 4c, and 4d.

Furthermore, the transmission mechanism 1 further includes a countershaft brake device 20. The countershaft brake device 20 is provided at the rear of the transmission 2. The countershaft brake device 20 controls the rotational speed of the countershaft 5 so that the difference between the rotational speed of one of the main gears 4a, 4b, 4c, and 4d and the rotational speed of the main shaft 4 is within a predetermined range. It has the function of slowing down the speed.

Hereinafter, details of the countershaft brake device 20 will be explained with reference to FIG. 2. FIG. 2 is a cross-sectional view of the countershaft brake device 20.

As shown in FIG. 2, the countershaft brake device 20 includes a housing 24, a brake shaft 26, a plurality of friction plates (a plurality of rotating plates) 28, a plurality of separate plates (a plurality of non-rotating plates) 30, and a brake piston 32. We are prepared.

The brake shaft 26 is provided coaxially with the countershaft 5 and connected to the countershaft 5. The brake shaft 26 is spline-coupled or key-coupled to the rear end of the countershaft 5, for example, and rotates integrally with the countershaft 5. The brake shaft 26 has a brake hub 27. The brake hub 27 has a cylindrical shape centered on the axis of the brake shaft 26, and is provided at the rear end of the brake shaft 26. A spline groove 27a extending parallel to the axis of the brake shaft 26 is formed on the outer peripheral surface of the brake hub 27.

The housing 24 is a metal container having a substantially cylindrical shape with the axis AX as its central axis, and defines an internal space that accommodates a plurality of friction plates 28, a plurality of separate plates 30, and a brake piston 32. The housing 24 is bolted to a brake case 22 fixed to the rear of the transmission case 3. That is, the housing 24 is removably provided to the transmission case 3 via the brake case 22. When the housing 24 is attached to the transmission case 3, the axis AX of the housing 24 coincides with the axis of the brake shaft 26. In the following, when the housing 24 is attached to the transmission case 3, the direction toward the countershaft 5 along the axis AX will be referred to as the front, and the direction opposite to the countershaft 5 along the axis AX will be referred to as the front. is sometimes called backward.

As shown in FIG. 2, the housing 24 includes a first housing 40 and a second housing 50. The first housing 40 is removably attached to the transmission case 3 by, for example, bolts, and the second housing 50 is removably attached to the first housing 40. The first housing 40 and the second housing 50 are configured separately from each other and can be separated from each other in the direction of the axis AX. The first housing 40 and the second housing 50 may be made of different materials. The first housing 40 may be made of a material stronger than the second housing 50, such as a ferrous material. On the other hand, the second housing 50 may be made of a material that is lighter than the first housing 40, such as aluminum.

Each of the first housing 40 and the second housing 50 is formed with a flange in which a through hole is formed, and by inserting bolts into these through holes, the first housing 40 and the second housing 50 are connected. may be connected to each other. By removing these bolts, the first housing 40 and the second housing 50 are separated in the direction of the axis AX. When the housing 24 is attached to the transmission case 3, the first housing 40 is disposed on the front side of the second housing 50.

As shown in FIG. 2, the first housing 40 has a cylindrical portion 42 and a front wall portion 44. As shown in FIG. The cylindrical portion 42 has a cylindrical shape whose central axis coincides with the axis AX. The cylindrical portion 42 has an inner peripheral surface in which a spline groove 42a extending parallel to the axis AX is formed. The front wall portion 44 is connected to the cylindrical portion 42 so as to close the front opening of the cylindrical portion 42 . A circular opening 44a is formed in the center of the front wall 44, passing through the front wall 44 along the axis AX. The brake hub 27 of the brake shaft 26 is inserted through this opening 44a and placed inside the first housing 40.

A first space S1 having a substantially annular cross-sectional shape is defined between the first housing 40 and the brake hub 27. A plurality of friction plates 28 and a plurality of separate plates 30 are provided in the first space S1. Each of the plurality of friction plates 28 has an annular plate shape whose center axis is the axis AX, and extends radially outward from the outer peripheral surface of the brake hub 27. These plurality of friction plates 28 are arranged spaced apart from each other in the direction of the axis AX. Each of the plurality of friction plates 28 provides an annular friction surface facing in the direction of the axis AX.

Internal teeth 28 a are formed on the inner peripheral edges of the plurality of friction plates 28 , and the internal teeth 28 a mesh with spline grooves 27 a of the brake hub 27 . On the other hand, the outer peripheral edges of the plurality of friction plates 28 are spaced apart from the inner peripheral surface of the first housing 40. Therefore, the plurality of friction plates 28 rotate integrally with the brake shaft 26 while being engaged with the brake hub 27 of the brake shaft 26 . Further, the plurality of friction plates 28 are configured to be slidable along the spline groove 27a of the brake hub 27 in the direction of the axis AX.

The plurality of separate plates 30 are arranged between the plurality of friction plates 28 so as to face the plurality of friction plates 28 in the direction of the axis AX. The plurality of separate plates 30 have an annular plate shape with the axis AX as the central axis. In the embodiment shown in FIG. 2, the plurality of friction plates 28 and the plurality of separate plates 30 are arranged alternately in the direction of the axis AX.

The inner circumferential edges of the plurality of separate plates 30 have an inner diameter larger than the outer diameter of the brake hub 27 and are spaced apart from the outer circumferential surface of the brake hub 27. On the other hand, external teeth 30a are formed on the outer peripheral edges of the plurality of separate plates 30, and the external teeth 30a mesh with the spline grooves 42a of the first housing 40. Since the spline grooves 42a extend parallel to the axis AX, the external teeth 30a of the plurality of separate plates 30 engage with the spline grooves 42a of the first housing 40, so that the plurality of separate plates Rotation around the axis AX of 30 is restricted. Therefore, the plurality of separate plates 30 cannot rotate with respect to the first housing 40. Further, the plurality of separate plates 30 are configured to be slidable in the direction of the axis AX along the spline groove 42a of the first housing 40.

An end plate 34 is further provided in the first space S1. The end plate 34 has an annular plate shape whose center axis is the axis AX, and is provided between the front wall portion 44 of the first housing 40 and the friction plate 28. The inner peripheral edge of the end plate 34 is spaced apart from the outer peripheral surface of the brake hub 27. On the other hand, external teeth are formed on the outer peripheral edge of the end plate 34, and the external teeth mesh with the spline groove 42a of the first housing 40. Therefore, the end plate 34 is provided non-rotatably with respect to the first housing 40.

The second housing 50 has a cylindrical portion 52, a rear wall portion 54, and a protrusion 56. The cylindrical portion 52 has a cylindrical shape whose central axis coincides with the axis AX. The front end surface 52a of the cylindrical portion 52 faces the rear end surface 42b of the cylindrical portion 42. An O-ring 36 may be provided between the front end surface 52a of the cylindrical portion 52 and the rear end surface 42b of the cylindrical portion 42 to seal between the rear end surface 42b and the front end surface 52a.

The rear wall portion 54 is connected to the cylindrical portion 52 so as to close the opening on the rear side of the cylindrical portion 52. The protruding portion 56 protrudes from the inner surface of the rear wall portion 54 toward the first housing 40 along the axis AX. A bolt hole extending along the axis AX is formed in the protrusion 56. A bolt member 35 extending along the axis AX is screwed into this bolt hole. The bolt member 35 has a bolt body portion 35a located inside the bolt hole of the protrusion 56, and a flange portion 35b whose diameter is enlarged with respect to the bolt body portion 35a.

The second housing 50 defines a second space S2. The second space S2 is a space having an annular cross-sectional shape defined by the inner peripheral surface of the cylindrical portion 52, the inner surface of the rear wall portion 54, and the outer peripheral surface of the protruding portion 56. When the first housing 40 and the second housing 50 are connected, the first space S1 and the second space S2 are continuous with each other. A cylindrical brake piston (pressing member) 32 is accommodated in the second space S2. The brake piston 32 is configured to be slidable in the direction of the axis AX within the second space S2.

An elastic member 58 is provided between the brake piston 32 and the flange portion 35b of the bolt member 35. The elastic member 58 may be a spring attached around the bolt member 35. The elastic member 58 is provided in a compressed state in the axis AX direction between the flange portion 35b and the brake piston 32, and moves the brake piston 32 toward the rear wall portion 54 side, that is, the plurality of friction plates 28 and the plurality of separate plates. 30 in a direction away from it.

As described above, the first housing 40 defines the first space S1 therein, and the plurality of friction plates 28 and the plurality of separate plates 30 provided in the first space S1 are placed outside the first housing 40. covered from The second housing 50 defines a second space S2 therein, and covers the brake piston 32 provided in the second space S2 from the outside.

A pressurizing chamber 62 is formed between the brake piston 32 and the rear wall portion 54. A fluid tank 68 is connected to the pressurizing chamber 62 via a ventilation hole 64 and a connecting pipe 66 formed in the second housing 50 (see FIG. 1). The connecting pipe 66 is provided with a valve 70 . Compressed air is stored in the fluid tank 68, and when the valve 70 is opened, the compressed air in the fluid tank 68 is supplied to the pressurizing chamber 62 through the connecting pipe 66. When compressed air is supplied to the pressurizing chamber 62, the internal pressure of the pressurizing chamber 62 increases, so that the brake piston 32 resists the urging force of the elastic member 58 and moves the plurality of friction plates 28 and the plurality of separate plates 30. It slides to the side and presses the plurality of friction plates 28 and the plurality of separate plates 30. When the plurality of friction plates 28 and the plurality of separate plates 30 are pressed, the plurality of friction plates 28 and the plurality of separate plates 30 are brought into pressure contact and a frictional force is generated. This frictional force is transmitted to the brake shaft 26 via the plurality of friction plates 28, and the rotation of the countershaft 5 is braked.

On the other hand, when the valve 70 is closed and compressed air is not supplied to the pressurizing chamber 62, the brake piston 32 is pressed toward the rear wall portion 54 by the urging force of the elastic member 58, and the brake piston 32 It is arranged at a position spaced apart from the plate 30 (see FIG. 2). At this time, no frictional force acts between the plurality of friction plates 28 and the plurality of separate plates 30, and no braking force is generated on the countershaft 5.

In one embodiment, as shown in FIG. 1, the countershaft brake device 20 may further include a control device 80. The control device 80 has a function of controlling the operation of the countershaft brake device 20. The control device 80 is an electronic control unit that includes a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like. The control device 80 realizes various functions by, for example, loading a program stored in a ROM into a RAM, and executing the program loaded into the RAM by a CPU. The control device 80 has a function of sending a control signal to the valve 70 to control opening and closing of the valve 70.

For example, when the vehicle is shifted up, the control device 80 opens the valve 70 in order to brake the countershaft 5. When the valve 70 is opened, the brake piston 32 presses the plurality of friction plates 28 and the plurality of separate plates 30 by the compressed air in the fluid tank 68, causing friction between the plurality of friction plates 28 and the plurality of separate plates 30. Force arises. As a result, the rotational speed of the countershaft 5 decreases. When the difference between the rotational speed of the main gear and the rotational speed of the main shaft 4 falls within a predetermined range as the rotational speed of the countershaft 5 decreases, the control device 80 closes the valve 70. When the valve 70 is closed, the brake piston 32 is moved to a position separated from the plurality of friction plates 28 and the plurality of separate plates 30 by the urging force of the elastic member 58, and the braking of the countershaft 5 is stopped. . Then, the main gear and the main shaft 4 are coupled by the sleeve in a state where the rotational speed of the main gear and the rotational speed of the main shaft 4 are synchronized. This suppresses gear noise from occurring.

Next, the effects of the countershaft brake device 20 according to one embodiment will be explained.

First, an example of a method of replacing the friction plate 28 when the first housing 40 and the second housing 50 are not separated as in a conventional countershaft brake device will be described. In this case, the entire housing 24 is removed from the brake case 22. Next, the end plate 34 is removed from the housing 24 and the worn friction plate 28 is replaced with a new friction plate 28. Next, with the internal teeth 28a of the plurality of friction plates 28 aligned in phase, that is, with the tips of the internal teeth 28a aligned in the axis AX direction, the plurality of friction plates 28 and the plurality of separate plates 30 are assembled. It is held within the housing 24. Next, the internal teeth 28a of the plurality of friction plates 28 are engaged with the spline grooves 27a of the brake hub 27, and then the housing 24 is fastened to the brake case 22.

As mentioned above, when attaching the conventional countershaft brake device to the transmission case 3, it is necessary to match the phases of the internal teeth 28a of the plurality of friction plates 28. It must be carried out by a trained worker using a special jig. Furthermore, when meshing the internal teeth 28a of the plurality of friction plates 28 with the spline grooves 27a, since the connecting position of the internal teeth 28a and the spline grooves 27a is hidden by the housing 24, the operator can easily engage the internal teeth 28a and the spline grooves 27a. It is not possible to visually check the joining position with the groove 27a, and it is necessary to engage the internal teeth 28a and the spline groove 27a by groping. Therefore, it takes time to remove and install the countershaft brake device, which causes a decrease in maintenance work efficiency.

Next, an example of a method for replacing the friction plate 28 of the countershaft brake device 20 according to the above embodiment will be described. In this case, first, with the first housing 40 attached to the brake case 22, the connection between the first housing 40 and the second housing 50 is released, and the first housing 40 is moved in the direction of the axis AX. The second housing 50 is separated. As a result, the brake piston 32, bolt member 35, and elastic member 58 housed in the second space S2 are removed together with the second housing 50, and the plurality of friction plates 28 and the plurality of separate plates 30 are housed. The first space S1 is exposed to the outside. Next, the operator inserts his/her hand through the rear opening of the first housing 40 and slides the worn friction plate 28 backward to remove it from the brake hub 27, and attaches a new friction plate 28. . At this time, the operator can replace the friction plates 28 one by one while visually checking the joining position between the internal teeth 28a and the spline grooves 27a. Next, the second housing 50 is fastened to the first housing 40 together with the brake piston 32, bolt member 35, and elastic member 58.

As described above, in the countershaft brake device 20 according to one embodiment, by separating the first housing 40 and the second housing 50, the friction plates 28 can be adjusted without adjusting the phases of the plurality of friction plates 28. etc. can be exchanged. Therefore, the time required to replace the friction plate 28 can be shortened, and maintenance work efficiency can be improved. In the above example, replacement of the friction plate 28 was explained, but when replacing or inspecting parts other than the friction plate 28, such as the plurality of separate plates 30, the brake piston 32, the bolt member 35, and the elastic member 58, Also, the operation can be performed without adjusting the phases of the plurality of friction plates 28. Therefore, the maintainability of the countershaft brake device 20 can be improved.

Furthermore, since the first housing 40 restricts the rotation of the plurality of separate plates 30, high strength is required. In the embodiment described above, since the first housing 40 is made of a high-strength iron-based material, it is possible to prevent the first housing 40 from being damaged. Furthermore, since the second housing 50 is made of relatively lightweight aluminum, the weight of the countershaft brake device 20 can be reduced.

Although the transmission mechanisms and countershaft brake devices according to various embodiments have been described above, various modifications can be made without being limited to the embodiments described above and without changing the gist of the invention.

For example, in the above embodiment, the main shaft 4 supports the plural main gears so as to be able to idle, and the counter shaft 5 supports the plural counter gears so as to rotate integrally with the counter shaft 5. may support a plurality of main gears so as to rotate integrally with the main shaft 4, and the countershaft 5 may support a plurality of countergears such that they can idle. Even in this case, the countershaft brake device 20 reduces the rotational speed of the countershaft 5, so that the rotational speed of the counter gear and the rotational speed of the countershaft 5 can be synchronized.

Further, in the above embodiment, compressed air is supplied from the fluid tank 68 to the pressurizing chamber 62, but the pressurizing chamber 62 may be supplied with a fluid different from compressed air. For example, a liquid may be supplied to the pressurizing chamber 62 as the fluid.

Further, in the above embodiment, a spring is used as the elastic member 58, but if it is possible to bias the brake piston 32 in a direction away from the plurality of friction plates 28 and the plurality of separate plates 30, it is possible to use a spring other than a spring. Elastic members may also be used.

DESCRIPTION OF SYMBOLS 1... Transmission mechanism, 2... Transmission, 3... Transmission case, 4... Main shaft, 4a, 4b, 4c, 4d... Main gear, 5... Counter shaft, 5a, 5b, 5c, 5d, 5e... Counter gear, 20... Counter shaft brake device, 24... Housing, 40... First housing, 50... Second housing, 26... Brake shaft, 27a, 42a... Spline groove, 28a... Internal teeth, 30a... External teeth, 32... Brake piston ( pressing member), 35... bolt member, 58... elastic member, S1... first space, S2... second space.

Claims (7)

A main shaft rotatably provided within a transmission case and supporting a plurality of main gears, and a plurality of counter gears provided parallel to the main shaft within the transmission case and meshing with the plurality of main gears. A countershaft brake device that is attached to a transmission having a countershaft and applies braking force to the countershaft,
a housing that is removably attached to the transmission case;
a brake shaft connected to the countershaft;
a plurality of rotating plates arranged spaced apart from each other in the axial direction of the brake shaft and engaged with the brake shaft so as to rotate integrally with the brake shaft;
a plurality of non-rotating plates disposed between the plurality of rotating plates so as to face the plurality of rotating plates and engaged with the housing so as to be non-rotatable with respect to the housing;
a pressing member that presses the plurality of rotating plates and the plurality of non-rotating plates to bring the plurality of rotating plates and the plurality of non-rotating plates into pressure contact when the countershaft is braked;
Equipped with
The housing includes a first housing and a second housing that are separable from each other in the axial direction, and the first housing has a first space that accommodates the plurality of rotating plates and the plurality of non-rotating plates. the second housing defines a second space that accommodates the pressing member ;
the first housing and the second housing are made of different materials,
The countershaft brake device , wherein the first housing is made of a material with higher strength than the second housing . The first housing has an inner circumferential surface in which a spline groove extending parallel to the axial direction is formed,
The countershaft brake device according to claim 1, wherein the non-rotating plate is formed with external teeth that mesh with the spline groove of the first housing. The countershaft brake device according to claim 1 or 2 , wherein the first housing is made of iron-based material and the second housing is made of aluminum. A spline groove extending parallel to the axial direction is formed in the brake shaft,
The countershaft brake device according to any one of claims 1 to 3 , wherein the plurality of rotating plates are formed with internal teeth that mesh with the spline grooves of the brake shaft. The countershaft brake device according to any one of claims 1 to 4 , further comprising an elastic member that urges the pressing member in a direction away from the plurality of rotating plates and the plurality of non-rotating plates. A bolt member extending along the axial direction is connected to the second housing, and a spring functioning as the elastic member is provided between the bolt member and the pressing member. The countershaft brake device according to item 5 . a main shaft rotatably provided within the transmission case and supporting a plurality of main gears;
a countershaft that is provided in parallel to the main shaft within the transmission case and supports a plurality of counter gears that mesh with the plurality of main gears;
a countershaft brake device that applies braking force to the countershaft;
Equipped with
The countershaft brake device includes:
a housing that is removably attached to the transmission case;
a brake shaft connected to the countershaft;
a plurality of rotating plates arranged spaced apart from each other in the axial direction of the brake shaft and engaged with the brake shaft so as to rotate integrally with the brake shaft;
a plurality of non-rotating plates disposed between the plurality of rotating plates so as to face the plurality of rotating plates and engaged with the housing so as to be non-rotatable with respect to the housing;
a pressing member that presses the plurality of rotating plates and the plurality of non-rotating plates to bring the plurality of rotating plates and the plurality of non-rotating plates into pressure contact when the countershaft is braked;
including;
The housing includes a first housing and a second housing that are separable from each other in the axial direction, and the first housing has a first space that accommodates the plurality of rotating plates and the plurality of non-rotating plates. the second housing defines a second space that accommodates the pressing member ;
the first housing and the second housing are made of different materials,
The transmission mechanism , wherein the first housing is made of a stronger material than the second housing .

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