WO2018098540A1

WO2018098540A1 - Hydrodynamic continuously variable transmission

Info

Publication number: WO2018098540A1
Application number: PCT/BR2016/000137
Authority: WO
Inventors: Alexandre Marques BEMQUERER
Original assignee: Bemquerer Alexandre Marques
Priority date: 2016-12-02
Filing date: 2016-12-02
Publication date: 2018-06-07

Abstract

The present invention relates to a hydrodynamic continuously variable transmission comprising at least one linear concentric variable displacement pump/motor system comprising two main rotors, each having a central cylindrical hole for receiving a piston guide; two secondary rotors connected by a primary piston, each secondary rotor having a cylindrical channel and a central cylindrical hole; two main rotor synchronizers, each comprising a shaft having a gear attached to one of its ends; two secondary rotor synchronizers, each comprising a rod having a gear attached to one of its ends; two pistons, each piston surrounding its corresponding main rotor and having a central hole for receiving a cylindrical guiding rod; said guiding rod comprising a cylindrical body connecting said two pistons, the guiding rod body being compatible with a chosen actuator system; and a housing comprising two cylindrical inner chambers and having at least two channels which extend inwardly to one of said chambers and a countershaft hole.

Description

"HYDRODYNAMIC CONTINUOUSLY VARIABLE TRANSMISSION"

FIELD OF THE INVENTION

[0001] The present invention relates to a continuously variable transmission, particularly to a hydrodynamic continuously variable transmission of automatic automobiles.

BACKGROUND OF THE INVENTION

[0002] Nowadays, most of hydraulic continuously variable transmissions are based in pump/motor closed circuits. Hydraulic continuously variable transmissions are heavily based on vane pumps.

[0003] The main differences among hydraulic continuously variable transmissions and hydrodynamic continuously variable transmissions are the pumping system and the geometry of the configuration.

[0004] The prior art pumps differ from the one used in the present invention in that in vane pumps, for example, the rotor shaft is eccentric to the chamber and the chamber is not cylindrical, whereas in the pump of the present invention, the rotor is concentric to the chamber, and the chamber has a cylindrical shape. Variable displacement pumps operate by converting mechanical power to hydraulic energy. Several patents have been issued on such concept of variable displacement vane pumps. For example, continuously variable transmissions using variable displacement vane pumps may be found in documents US 5,799,487, GB 3520034 and WO 05/028917515.

[0005] Nevertheless, the above two requirements, namely, the rotor being concentric to the chamber and the chamber having a cylindrical shape, may also be met in lobe pumps. The difference between lobe pumps and the pump used in the present invention is that, while in lobe pumps the blades and grooves are positioned in the same rotor, the pump of the present invention comprises two rotors, one only having blades and the other one only having grooves.

[0006] Continuously variable transmissions based on vane pumps are limited due to the high temperature of the fluid. In these transmissions, the fluid is compressed only if there is resistance at the output. On the contrary, the fluid takes no severe cyclical pressure, which helps the fluid temperature decrease.

[0007] Further, as regards continuously variable transmissions based on vane pumps, the maximum allowed torque is related to the pump output pressure, whereas in the transmissions according to the present invention, maximum allowed torque is determined by the resistance of the materials used in its construction.

[0008] Another important difference between prior art transmissions and the one of the present invention is related to the fact that, since the it is a non-sliding system, the transmission of the present invention may be adjusted to operate with high pressure and low rotation speed., thereby reducing losses and heating.

[0009] Although the known prior art discloses several types of continuously variable transmissions based on variable displacement pumps/motors, these transmissions fail to fix friction issues, which are critical in belt-driven continuously variable transmissions and toroidal or roller-based (extroid) continuously variable transmissions. Prior art continuously variable transmissions also fail to have a high torque capability.

[0010] Those prior art transmissions also have a very short range of operation and, furthermore, they cannot operate at high speed. The control variables of the prior art continuously variable transmissions are hard to be measured, which jeopardizes control of those transmissions.

SUMMARY OF THE INVENTION

[0011] The hydrodynamic continuously variable transmission for vehicles of the present invention uses a closed circuit of two variable displacement pump/motor systems comprising at least one variable displacement pump/motor system, which is hydraulically connected to another pump/motor system, which may be a fixed displacement pump/motor system, and a reservoir or an additional variable displacement pump/motor system. The variable displacement pump/motor used in the present invention is a linear concentric variable displacement pump/motor.

[0012] it is an object of the present invention to provide a hydrodynamic continuously variable transmission with no friction, which reduces construction and cost requirements. [0013] Another object of the present invention is to provide a continuously variable transmission having a virtually endless torque capacity, which is only limited by the resistance of materials thereof and the leakage between the seats.

[0014] A further object of the present invention is providing a continuously variable transmission having a virtually endless range of operation, which can operate at high speeds.

[0015] Still another object of the present invention is having a completely electronic controlled continuously variable transmission providing many control variables which are hard to be measured using conventional prior art continuously variable transmissions.

[00161 Other object of the present invention is to provide a continuously variable transmission having no default pressure cycles inside the pumps, which increases the fluid lifespan significantly.

[0017] An additional object of the present invention is to have a compact continuously variable transmission, which is easy to manufacture, assemble and operate.

[0018] These and other features and advantages of the present invention will be more fully understood from the following description of one or more embodiments of the invention, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1a illustrates an example of a housing of the continuously variable transmission of the present invention.

[0020] Figures 2a to 2c illustrate the sliding system of the continuously variable transmission of the present invention.

[0021] Figures 3a to 3e illustrate the main rotor of the continuously variable transmission of the present invention.

[0022] Figures 4a to 4c illustrate the main rotor synchronizer of the continuously variable transmission of the present invention.

[0023] Figures 5a to 5c illustrate the secondary rotor of the continuously variable transmission of the present invention. [0024] Figures 6a to 6c illustrate the secondary rotor synchronizer of the continuously variable transmission of the present invention.

[0025] Figures 7a and 7b illustrate the piston of the continuously variable transmission of the present invention.

[0026] Figures 8a and 8b illustrate the guiding rod of the continuously variable transmission of the present invention.

[0027] Figure 9 illustrates the continuously variable transmission of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Figure 1a illustrates an example of a configuration of a housing of each pump/motor system of the continuously variable transmission in accordance with the present invention. Each of at least two variable displacement pump/motor systems is enclosed within said housing 100. Each housing comprises two channels 120, 120' connecting the output of one pump/motor system to the input of the other pump/motor system, and vice-versa. The housing 100 further comprises a countershaft hole 130, which is a through hole. A sliding system holds both countershafts in position and move them together with the main piston of each pump/motor system.

[0029] As can be seen from Figures 2a to 2c, the sliding system 200 comprises two primary pistons 210, 220, two secondary pistons 700, 700', a countershaft guide 250 and an actuator system 260. Exemplarily, the actuator system 260 is a rack and pinion system but it should be noted though that a hydraulic system or even a different mechanical system may be used.

[0030] Figures 3a to 3e illustrate the variable displacement pump/motor system main rotor 310 which comprises a cylindrical body 320 having two longitudinal grooves 330, 330' at opposite directions, passing through the radial direction of the rotor 310. These grooves 330, 330' are responsible for receiving the blades of the rotor (not shown). The wall of the cylindrical body 320 of the rotor has through holes 340, 340' which, together with bolts (not shown), are responsible for fixing the blades to the rotor 310. [0031] The cylindrical body 320 of the rotor has two channels 350, 350', perpendicular to the grooves 330, 330' and, consequently, to the blades of the rotor. The channels 350, 350' extend along the entire longitudinal direction of the rotor 310, creating a path to a sliding piston of the rotor to move along. The outer edges of the channels 350, 350' may be slightly slanted to facilitate manufacturing of the matching piston,

[0032] The rotor 310 has a cylindrical hole 360 extending along its center, which is responsible for receiving a piston guide, which will move along the length of the bore 360.

[0033] Figures 4a to 4c illustrate the main rotor synchronizer 400 comprising a shaft 410 having a gear 420 attached to one of its ends. The ratio used in such synchronizer 400 is given by the following formula (1):

wherein

R is the ratio of the main rotor related to a secondary rotor;

B is the number of blades in the main rotor; and

G is the number of grooves in each secondary rotor.

[0034] A secondary rotor is illustrated in Figures 5a to 5c, The secondary rotor 500 also has a cylindrical body 510, similar to the body 320 of the rotor 310. The secondary rotor body 510 has a cylindrical channel 520 extending along its length, in the longitudinal direction of the rotor 500, and a cylindrical hole 530 extending along its center. During the synchronized movement of the main rotor and the secondary rotor, the blades of the main rotor pass through the channel 520 and immediately afterwards seal the passage between both rotors. A grooved bush 140 is located inside the secondary rotor central hole 130, thereby transmitting the rotary movement from the synchronizer to the rotor.

[0035] The secondary rotor synchronizer 600, as shown in Figures 6a to 6c, comprises a rod 610 having a gear 620 attached to one of its ends. The rod 610 has a keyway 630 along part of its entire length, in the longitudinal direction. The keyway 630 is responsible for transmitting the rotary movement to the secondary rotor 500.

[0036] A secondary piston 700, 700', also having a cylindrical shape, surrounds the assembly of the main rotor 310, the blades 390 and the main rotor synchronizer 400, housing ail these elements. Internally, the piston profile matches that of the main rotor and its blades, as can be seen from the view of Figure 7a. The piston has a central hole 710 configured to receive a cylindrical guiding rod 800 which will extend into the center hole 360 of the main rotor 310. Said guiding rod 800 is responsible for sealing the hole walls and allow the secondary piston 700, 700' to longitudinally slide.

[0037] Exemplarily, as seen in Figures 8a and 8b, the guiding rod 800 may have a cylindrical body 840 with two ends 810, 820. The shape of the body 840 is conformed in accordance with actuator system 260 to be used in the continuously variable transmission of the present invention. For example, Figures 8a and 8b illustrate a rack and pinion system.

[0038] Figure 9 illustrates one variable displacement pump/motor system completely assembled to be used in the hydrodynamic continuously variable transmission of the present invention. As can be noted from the figure, the housing 100 encloses two main rotors 310 with blades 390 and two secondary rotors 500 which are mounted to the main rotor synchronizer 400 and the secondary rotor synchronizer 600, respectively, actuating the same. Each of the main rotor synchronizers 400 and the secondary rotor synchronizers 600 are meshed. Each of two secondary pistons 700, 700' then enclose, respectively, each of the main rotors 310.

[0039] The guiding rod 800 extends through the pistons 700, 700', said primary piston 210 and the two main rotors 310 while said primary piston 220 connects the two secondary rotors 500. Externally to the housing, the actuator system 260 is depicted, so as to actuate the sliding system.

[0040] The hydrodynamic continuously variable transmission in accordance with the present invention may work with one of such variable displacement pump/motor system and with another fixed displacement pump/motor system. In this case, a reservoir must be connected to the motor output or pump input in order to store the excess of fluid when the housing chamber varies.

[0041] In another configuration, the hydrodynamic continuously variable transmission may be assembled using two of such variable displacement pump/motor systems. Nevertheless, in this case, a reservoir is used to compensate the excess of fluid when the actuator system 260 moves.

[0042] While this invention has been described by reference to a particular embodiment, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiment, but that it have the full scope permitted by the language of the following claims.

Claims

CLAIMS What is claimed is:

1. Hydrodynamic continuously variable transmission comprising at least one linear concentric variable displacement pump/motor system comprising:

two main rotors (310), each main rotor (310) comprising a cylindrical hole (360) extending along its center for receiving a piston guide and a cylindrical body (320), the cylindrical body (320) having two longitudinal grooves (330, 330') opposite to each other which receive the blades (390) of the rotor, and two channels (350, 350') perpendicular to said grooves (330, 330');

two secondary rotors (500), each secondary rotor (500) comprising a cylindrical body (510) and a cylindrical channel (520) extending along its length in the longitudinal direction of the rotor (500) and a cylindrical hole (530) extending along its center, said two secondary rotors (500) being connected by a primary piston (220);

two main rotor synchronizers (400), each main rotor synchronizer (400) comprising a shaft (410) having a gear (420) attached to one of its ends;

two secondary rotor synchronizers (600), each secondary rotor synchronizer (600) comprising a rod (610) having a gear (620) attached to one of its ends; the rod (610) having a keyway (630) along part of its entire length, in the longitudinal direction;

two pistons (700, 700'), each piston (700, 700') having a cylindrical shape and surrounding its corresponding main rotor (310), said blades (390) and said main rotor synchronizer (400), said piston (700, 700') having a central hole (710) configured to receive a cylindrical guiding rod (800), which also extends through a primary piston (210) which connects said secondary pistons (700, 700'};

said guiding rod (8Q0) comprising a cylindrical body (840) with two ends (810, 820), the ends of the guiding rod connecting said two pistons (700, 700'); and a housing (100) comprising two cylindrical inner chambers and having at least two channels (120, 120') which extend inwardly to one of said chambers and a countershaft hole (130).

2. Hydrodynamic continuously variable transmission as claimed in claim i, wherein the wall of the cylindrical body (320) has through holes (340, 340") for receiving bolts to fix the blades (390) to the rotor (310).

3. Hydrodynamic continuously variable transmission as claimed in claim 1 , wherein said channels (350, 350') extend along the entire longitudinal direction of the rotor (310), creating a path to a sliding piston (700, 700') of the rotor to move along.

4. Hydrodynamic continuously variable transmission as claimed in claim 1, wherein outer edges of the channels (350, 350') are slightly slanted.

5. Hydrodynamic continuously variable transmission as claimed tn claim 1 , wherein a protrusion (540) is provided inside the secondary central hole (530) for transmitting the rotary movement from the synchronizer to the rotor.

6. Hydrodynamic continuously variable transmission as claimed in claim 1_» wherein the inner profile of the piston (700) matches that of the main rotor (310) and its blades (390).

7. Hydrodynamic continuously variable transmission as claimed in claim 1 , further comprising an actuator system (260), actuating the linear concentric variable displacement pump/motor system, received by the countershaft hole (130).

8. Hydrodynamic continuously variable transmission as claimed in claim 7, wherein the shape of the body (840) conforms to that of the actuator system (260).

9. Hydrodynamic continuously variable transmission as claimed in claim 7 or 8, wherein the actuator system (260) is chosen from one among a rack and pinion system, a hydraulic system or any other mechanical system.

10. Hydrodynamic continuously variable transmission as claimed in claim 1, comprising a linear concentric variable displacement pump/motor system; a fixed displacement pump/motor system and a reservoir connected to the motor output or pump input (120, 120').

11. Hydrodynamic continuously variable transmission as claimed in claim 1, comprising two linear concentric variable displacement pump/motor system; and a reservoir to compensate the excess of fluid when the actuator system (260) moves.