RU197614U1 - Self-locking freewheel coupling - Google Patents

Abstract

The invention relates to the field of mechanical engineering, in particular to the design of a self-locking freewheel as part of a wheel gearbox of a cross-country vehicle. The self-locking freewheel contains: a leading inner drum 1 and a driven outer drum 2 (Fig. 1) located coaxially relative to each other. The leading inner drum has four tangent slices on its surface (Fig. 2). A separator 5 is mounted on the neck of the driving inner drum 1 and rotates freely on it. The separator 5 (Fig. 3) has grooves (Fig. 4), which include brackets 4, in these grooves the bracket 4 has the ability to translate relative to the separator 5. Between the separator 5 and the bracket 4 is installed an elastic element 6, made in the form of a twisted springs. The separator 5 performs only rotational motion, the restriction of axial movement is created by the restrictive ring 7. The leading inner drum 1 is connected by a spline connection to the driven gear 9. All rotating parts are held in the gear housing 11 by rolling bearings 8. The driven gear 9 is connected to the gear cover via a rolling bearing 8 10. The device provides simultaneous pinching of the rollers; the cylindrical shape of the rollers with an increased contact spot contributes to an increase in permissible loads, and, accordingly, contributes to the transfer of more torque; the brackets are placed in grooves in the separator, which allows you to change the distance from the axis of rotation of the inner drive drum to the axis of rotation of the rollers, thereby increasing the reliability of the structure. The device allows for more reliable transmission of torque, eliminates the interaxle differential from the vehicle structure, and also provides automatic response of the device when a torque difference appears on the wheel and the drive shaft, and, as a result, increase the resource of a high-cross-country vehicle. 4 ill.

Description

The invention relates to the field of mechanical engineering, in particular to the design of a self-locking freewheel as part of a wheel gearbox of a cross-country vehicle.

A known model of a device kinematically connected with half shafts, consisting of an outer ring and an inner ring located coaxially relative to each other, grooves are provided on the outer surface of the inner ring with pairs of wedges made in the form of a body of revolution. Between the outer ring and the inner ring there is an additional ring, moreover, the grooves of the inner ring form double wedge-shaped slots with an additional ring located to each other by the vertices of their sharp corners. The inner ring is in contact with the additional ring through the wedges, the outer ring being in contact with the additional ring through a spike-groove connection, and the spike is installed in the groove with gaps in which the elastic elements are located. (Patent for utility model RU No. 155896, IPC7 F16H 48/20, published October 20, 2015).

The disadvantages of the known model are the low reliability of the design and low operational life. This is due to the fact that the wedges in the wedge-shaped slots due to the elastic elements are in constant contact with the intermediate ring. Due to the difference in torque between the inner and intermediate rings, the wedges are subject to premature wear.

As a prototype, a device is considered comprising a cup-shaped body and an inner ring with coaxially arranged inner sprocket and crackers arranged in two rows and sliding on the surface of the inner sprocket, according to a utility model, the inner sprocket is made in two parts, each of which the cross section has its outer surface in the form of a "ratchet", located mirror-relative to each other, forming wedge-shaped slots with a cup in which crackers are located. Moreover, the crackers are barrel-shaped (Patent for utility model RU No. 134269 MPK7 F16H 48/20, published on 11/10/2013 - prototype).

This design is the closest to the proposed technical essence and is taken as the closest analogue (prototype).

The disadvantages of the known model adopted for the prototype are the non-simultaneous jamming of certain wedges included in pairs, as a result of which a rigid connection of the inner and outer rings and the rapid wear of crackers having a barrel-shaped form are formed. This is due to the fact that crackers in the design of the known differential mechanism, due to the lack of free-wheeling stops, roll into wedge-shaped slots, where they form a rigid connection of the inner ring with the outer ring. In addition, due to the barrel-shaped shape of crackers, the area of the contact spot decreases, which contributes to premature wear of crackers.

The technical result of the model of a self-locking freewheel coupling of a cross-country vehicle is aimed at improving the reliability of the device and increasing the resource of the off-road vehicle.

The technical result of the model is achieved by the fact that in a self-locking clutch consisting of a leading inner drum and a driven outer drum, which are located coaxially relative to each other, tangential slices are made on the outer surface of the driving inner drum, cylindrical rollers are located in tangent slices, the rollers are mounted on brackets, the brackets enter the grooves of the separator, and are held by elastic elements; the leading inner drum contacts through the rollers with the driven outer drum, wherein, during the rotation of the inner driving drum, the rollers, slipping in tangential sections along the surface of the inner driving drum, enter into pinching with the external driven drum; when the bracket makes translational movement, the distance increases from the axis of rotation of the inner drive drum to the axis of rotation of the rollers. When the leading inner drum slows down, the elastic elements return the rollers to their original position, the clutch is disconnected.

The novelty of the technical solution lies in the fact that by fixing the rollers to the brackets mounted on the separator, with the possibility of translational motion, and held by elastic elements, conditions are created for trouble-free and reliable operation of the device and, as a result, reliable operation of the self-locking freewheel and whole vehicle.

The installation of rollers with brackets on the separator streamlines the operation of the rollers, eliminating the possibility of pinching individual rollers, which also ensures reliable operation of the device.

The introduction into the design of the drive of the inner drum with tangential slices on its surface excludes the possibility of pinching the rollers in both directions of rotation simultaneously, thereby eliminating the possibility of jamming of the coupling.

The availability of the bracket for translational motion relative to the separator allows you to change the distance from the center axis of the drive of the inner drum to the center of the axis of the rollers, which is a necessary condition for the failure-free operation of the structure.

The cylindrical shape of the rollers increases the contact area of the driving inner drum with the rollers and the rollers with the external driven drum, which increases the margin of safety of the product.

The supply of elastic elements of the brackets ensures the return of the rollers to their original position, thereby increasing the resource of the device.

The use of this device as part of a wheel gearbox of a high-cross-country vehicle eliminates the need to use the cross-axle differential in the composition of the vehicle and at the same time improves its cross-country ability.

Analysis of the proposed solution allows us to conclude that it meets the conditions of patentability of a utility model.

The proposal is illustrated by drawings, which depicts a diagram of a limited-slip differential in the composition of a wheel gearbox of a cross-country vehicle and a diagram of individual components of the differential design.

The proposed device contains:

the leading inner drum 1 and the driven outer drum 2 (Fig. 1), located coaxially relative to each other. The leading inner drum has four tangent sections on its surface (see Fig. 2). A separator 5 is mounted on the neck of the driving inner drum 1 and rotates freely on it. The separator 5 (Fig. 3) has grooves (see Fig. 4), which include the brackets 4, in these grooves the bracket 4 is able to translate relative to the separator 5. Between the separator 5 and the bracket 4 is installed an elastic element 6, made in the form twisted spring. The separator 5 performs only rotational motion, the restriction of axial movement is created by the restrictive ring 7. The leading inner drum 1 has a spline connection with the driven gear 9. All rotating parts are held in the gear housing 11 by rolling bearings 8. The driven gear 9 is mounted on the gear cover through the rolling bearing 8 10.

The proposed self-locking clutch freewheel vehicle cross-country works as follows.

At the initial moment of movement of the vehicle through the driven gear of the gearbox 9 to the leading inner drum 1 receives torque (Fig. 1). The driving inner drum 1 starts to rotate. Having a moment of inertia, the rollers 3 begin to roll into a narrow part of the grooves (Fig. 2) and are pinched, forming a rigid connection of the leading inner drum 1 with the driven outer drum 2 through the rollers 3. The separator 5 performs a delimiting function - it keeps the position of the brackets 4 at the same angle. This achieves the synchronous turning on and off of the rollers 3 in a pinch, ensuring reliable operation of the device. As a result of a rigid connection with the leading inner drum 1, the outer driven drum 2 also starts to rotate. Due to the operation of the device, the wheel begins to rotate.

When the vehicle is moving during a turn, the wheel external to the center of rotation needs to travel a longer path during the turn than the wheel that is closer to the center of rotation. As a result, the wheel external to the center of rotation begins to increase the angular velocity of rotation, transferring it to the driven outer drum 2. The driven outer drum 2 starts to rotate faster than the driving inner drum 1 of the clutch. As a result, the rollers 3 are rolled out from the narrow part of the tangent sections. The elastic elements 6 return the brackets 4 to their original position, while the rollers 3 cease to touch the driven outer drum 2, as a result of which the rollers are not accidentally rolled into the oppositely located narrow part of the wedge-shaped cut and, accordingly, the clutch is blocked. During the rotation of the vehicle, a wheel with a smaller turning radius works in the “leading” mode, and a wheel with a large turning radius works without slipping in the “driven” mode.

When the vehicle is in reverse, the freewheel operates in the same way as when the vehicle is moving forward.

When reversing a vehicle in reverse, the differential works in the same way as when cornering while the vehicle is moving forward.

Application of the utility model will allow: to achieve stable transmission of torque by the differential, to exclude cases of unwanted blocking of the device when the vehicle is turning, reduce wear on parts, increase the durability of the structure and increase the life of the vehicle.

Claims (1)

The device of a self-locking freewheel coupling of a high-cross-country vehicle, characterized in that a separator is added to the device’s design to limit the movement of the rollers, while maintaining the placement of the brackets at the same angle, contributing to the simultaneous jamming of the rollers; the cylindrical shape of the rollers with an increased contact spot contributes to an increase in permissible loads, and, accordingly, contributes to the transfer of more torque; the brackets are placed in the grooves in the separator, which allows you to change the distance from the axis of rotation of the inner drive drum to the axis of rotation of the rollers, thereby increasing the reliability of the structure.

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