RU2716396C1 - Continuously variable transmission with increased range of transmission ratio - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to the field of machine building. Continuously variable transmission for small car contains housing, reverse mechanism, differential, variator transmission. Driven impeller of variator transmission consists of two sections moving axially relative to each other by means of splined connection and a locking device for limiting axial movement of the pulley connected to the driven shaft, transmitting rotation to the reverse mechanism by means of a gear connection and a differential installed in rolling bearings in the housing of the gearbox for driving wheels driving. Variation of variator and transmission ratio modes is performed automatically depending on engine rotation frequency and road resistance.

EFFECT: higher range of transmission ratios.

1 cl, 8 dwg

Description

The invention relates to the field of automotive technology, specifically to a continuously variable transmission and can be used in gearboxes (speeds).

A known variator design (see patent RU 2286495 C1, publication date 10.27.2006), containing a planetary mechanism consisting of a carrier, rigidly fixed to the shaft and connected through this shaft to the engine of the car, gear satellites are mounted on the carrier, kinematically connected to the outer wheel planetary mechanism and the central wheel, the satellites can rotate both around its own axis, and together with the carrier, the outer wheel and the central wheel are placed on the shaft and can rotate on this shaft, in addition, the outer Leso has a kinematic connection with a gear wheel, the axis of rotation of the carrier and the axis of rotation of the wheel kinematically connected to the outer wheel of the planetary mechanism are offset from each other, each gear satellite is rigidly connected, via a shaft, to another carrier, the gear satellites and carrier have the ability to rotate as around the axis, together with the carrier rigidly mounted on the shaft, and around its own axis, on the carriers rigidly connected to the gear satellites, there are several more conical non-gear satellites s. The disadvantage of this design is the low maintainability.

A known construction of the variator (see patent RU 139501 U1, publication date 11/19/2013), containing the leading and driven modules covered by a flexible working body, placed in them with the possibility of radial movement of the gear for interaction with a flexible working body, a tension device, characterized in that each module is made in the form of paired wheels located coaxially of the driving and driven wheels, which can be rotated relative to each other, with radial grooves made in the driven wheel and curved grooves in the driven wheel, while the axis of the gears can simultaneously move along the radial and curved grooves of the driven and driving twin wheels, the gears are fixed to the axles by means of an overrunning clutch, and the tensioning device is made of at least one spring, one end of which is fixed to the outer diameter of the drive wheel, and second on the outer diameter of the driven wheel. The disadvantage of this design is the high inertia of the mechanisms.

A known variator design (see patent RU 6240, publication date 04/16/1998), containing the drive and driven shafts, mounted on them axially movable and stationary in the direction of the hemispheres, and a ball-type centrifugal device that interacts with the movable disk, characterized in that the guides the pressure device is a curved surface. With an increase in the rotational speed of the crankshaft, the centrifugal device pushes the belt to a large diameter, increasing the gear ratio of the variator. When reducing the speed of the crankshaft, the gear ratio decreases. The disadvantage of this design is the low range of regulation of gear ratios.

The objective of the invention is to increase the range of gear ratios of a continuously variable transmission.

The technical result achieved by the invention is to implement the following technical solutions:

- telescopic pulley;

- telescopic pulley locking mechanism.

To achieve the technical result, the following transmission design is proposed (Fig. 1). The proposed continuously variable transmission combines in one case a V-belt transmission with an increased gear ratio range, a reverse mechanism, a main transmission, a differential, and a flywheel protective housing.

V-belt drive is installed in a separate housing, behind the gearbox. This design solution is made for a more convenient replacement of the variator belt and to increase the life of the V-belt transmission. The housings of the reverse gear and final drive are separated so that oil from the lubrication system does not get into the variator. This is ensured by lip seals.

In the upper part of the variator housing, a tide is made to install a gear shift mechanism.

The design of the gearbox, consisting of the cover of the gearbox 1, 2 - cylindrical main gear 2, the reverse mechanism of rotation 3, the mounting brackets to the car body 4, the case of the variator 5, V-belt transmission 6, the cover of the V-belt transmission 7 (Fig. 2).

The reverse gear is engaged using gear couplings. This design solution allows to increase the V-belt transmission resource.

When moving forward, rotation is transmitted directly through the variator. When the reverse gear is engaged, the torque is transmitted to the main gear through a cylindrical gear transmission, and the V-belt drive is completely stationary.

The design of the rear cover 7 of the variator allows you to easily open access to the variator belt (Fig. 6).

The rear cover of the variator 7 allows you to access the main components of the gearbox. In order to carry out repairs or periodic maintenance of a continuously variable transmission, it is enough to remove the back cover of the variator. This opens up access to the main components, it becomes possible to replace the belt or pulleys of the variator.

The power unit is located transversely in the engine compartment of the car. Its fastening to the body is carried out using three brackets 4, which combine rubber cushions for damping vibrations. Two brackets are attached to the gearbox, one to the engine.

To transmit torque to the wheels of the car, hinges of equal angular speeds are used. They connect the axle gears of the differential and the hubs of the drive wheels. They have advantages over the cardan transmission, such as large steering angles and high reliability.

In the design of a continuously variable transmission, a V-belt variator is used. The transmission of rotation to the wheels when reverse gear is engaged is carried out using a gear transmission, this allows to increase the life of the variator belt. The main gear is located in one housing with other actuators. This solution allows to reduce the overall dimensions of the transmission and reduce the unsprung mass of the car (Fig. 3). The fastening of the mechanisms is carried out using special brackets 4 (Fig. 4).

To remove the variator belt or replace the pulleys, it is necessary to remove the bearing caps 9, which are attached to the housing with screws 10 (Fig. 5).

The bearings 11 are fixed in the cover of the variator 7 using the locking rings 12. The variator cover 7 is attached to the gearbox housing 5 with screws 13 (Fig. 6).

In order to remove the variator belt, it is necessary to remove the snap rings 14, which fix the bearings 11 on the shafts 15 and 16. Remove the movable half of the drive pulley with the centrifugal mechanism 17, remove the belt 18 (Fig. 7).

For overhaul of the variator, it is necessary to disconnect the gearbox from the engine, dismantle the mounting devices from the car body. Remove constant velocity joints. Remove the brackets 4 from the CVT case, which are fastened with bolts 18 and nuts 19 (Fig. 8). Then it is necessary to drain the oil from the crankcase, disconnect the tachometer sensor. Remove traction reverse gear. Remove bolts 2 located around gearbox perimeter. Check the housing for cracked chips, oil smudges. Check the condition of the variator belt, drive and driven pulleys. In case of detection of unacceptable defects, replace damaged parts.

Claims (1)

A continuously variable gearbox for a small car, comprising a housing, a reverse mechanism, a differential, a CVT transmission, characterized in that the driven CVT pulley consists of two sections moving axially relative to each other by means of a splined joint and a locking device to limit the axial movement of the pulley connected to the driven shaft, transmitting rotation to the reverse mechanism using a gear connection and a differential mounted in rolling bearings in the gearbox truncated box for a drive gear of driving wheels, with the change in the mode of operation of the variator and the gear ratio is automatically depending on engine speed and road resistance.

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