| Claims [Claim 1] A axel shaft to transfer the torque for 0 to 90 and 0 to -90 consist of: a) The drive and driven shaft that are connected together (4, 4') b) The inner race that fixes the driven and drive shaft (1) c) Housing that inner race is mount on it (8) d) Gear constraints that limit and couple two drive and driven shaft in all 3-D direction (6, 7, 6', 7') e) The shell that supports the mechanism against dust and helps the system for having a better function (9). [Claim 2] The invention as claimed in claimed 1 characterized in that the drive and driven shaft (4, 4') are used for transferring torque from a drive shaft to the driven shaft (4, 4'). The two shafts are connected to each other utilizing an inner race (1). The inner race (1) fixes two shafts so that they can move in all direction and makes a stable mechanism for the system. For attaching the two shafts, the drive shaft is attached to the inner race (1) and then a pin (3, 3') is passed on tip of the drive shaft (4, 4'). In the end, a ring (5, 5') is attached for maintaining the drive shaft (4, 4') as well as the pin (3, 3') to the inner race (1). The attachment of the ring to the inner race (1) is carried out with two screws (11, 11'). It should be noted that two grooves (13, 13') were made on the inner race (1) as well as the ring (5, 5') for replacing the pin (3, 3'), as it has drawn in Fig. 3. [Claim 3] The invention as claimed in claimed 2 characterized in that the inner race (1) is aligned with housing (8). A ball bearing (2, 2') is used for declining the friction between the inner race (1) and the housing (8). The ball bearing (2, 2') is mounted on the inner race (1). However, it can be utilized a roll bearing instead of the ball bearing (2, 2') for reaching less volume as well as more efficient for the proposed system. [Claim 4] The invention as claimed in claimed 3 characterized in that the drive and driven shaft (4, 4') as well as outer race (1) and housing (8) were attacked. Nonetheless, it is mandatory defining contains in order to have a constant angle between the drive shaft (4) and horizontal line and also the driven shaft (4') and the horizontal line. To this end, two small gear constrains (6, 6') and two large gear constrains (7, 7') were developed. The small gear constraints (6, 6') were considered for horizontal constrains while large gear constraints (7, T) are for vertical constrains. Finally, a shell (9) is put on the mechanism for protection against the dust and moist. |
Technical Field
The proposed invention present an axle shaft (Joint) that transfer the torque for 0 to 90 and 0 to - 90.
Background Art
Joints have greatly simplified human work and can be used for various applications in robotics, machines, and so on. The most famous of the joints are the universal, constant velocity and Thomson. However, the mentioned joints own limitations in the torque transfer range. In the universal joints, the angular velocity of the two drive and driven shafts (co) is not constant, and always a shaft moves at a different speed than another shaft. This will result in vibration in shafts at high velocities, thereby wasting high energy. Although the problem of the unevenness in the velocity of both shafts was fixed at a constant velocity joint, there is high friction at high angles in this joints, resulting in excessive heat in the joint and wasting a lot of energy. Thomson joint benefits of features consist of low waste power, high velocity, and low vibration, so on. However, the joint has a limited angle for transferring torque. In the present invention, a mechanism of a double ball joint is described and developed in detail. This mechanism can be used for other joints such as Thomson and Rzeppa. As it has been mentioned in Fig. 1 -a-c, the outer body is similar for the joints (Ball, Rzeppa and Thomson) while the inner body is different for them.
Summary of Invention
Technical Problem
There are some drawbacks in previous axle shafts that consist of vibrations in the joints and shafts at high velocities, high friction at high angles, emerging crank in high speed, a limited angle for transferring torque.
Solution to Problem
In the present invention, the mentioned drawbacks were solved and a system with high efficiency is proposed. The proposed invention contains five main components consist of the drive and driven shafts, the inner race, the outer, the gear constraint and shell, as they have been shown in Fig. 2. The drive and driven shafts were connected together. Two shafts require the inner race in order to couple two axes and transfer the force and torque. The two shafts with the inner race are mounted inside a housing that its main function is to center the inner race with the housing.
According to the present invention, a ball bearing is used in order to decrease the friction between the inner race and the housing in which makes the two bodies (the inner race and the housing) easily interlocked. With such a mechanism, there is no doubling of the angle because this mechanism is not stable and the drive and driven shafts do not move together at one angle. In the instability, the rotation force causes the centrifugal force in the inner race and the housing than the drive shaft.
In order to solve the problem in the present invention, two gear constraints are designed and made. With the help of these two gear constraints, the shafts move the same angular variations. For example, if the drive shaft is fixed, the driven shaft turn from 0 to 90 degrees (Fig. 4). Also, the drive shaft can turn from 0 to -90 degrees (Fig. 4).
In order to prove the constant velocity in the present invention, a way is performed as follows.
As previously mentioned, the angle of drive and driven shafts are similar because of being large and small gear constrains. Thus, Eq. 1 is obtained.
If tangent of the eq.l is taken, a new equation is acquired as follows:
If the top equation is derived, equation 3 obtain,
Given that theta angle changes than time is the angular velocity (w), the above relations will be as follows:
By the simplicity of the above equation, the new equation is obtained:
Considering the equation (1), the new equation is as below:
Therefore, being a constant velocity in the proposed system is proven. It should be noted that this equality angle is at all angles and is not limited to just a certain angle, because the drive and driven shafts are connected with two gear constrains. However, there is not any constraint for joints of the double-sided hook, CV, Thomson, and Rzappa. Thus, there is the possibility of the shafts angle is unequal, which will cause more shaking and friction in those systems.
Another important issue in the present invention is the ratio of power transmission. To obtain the transmission ratio and the gears, the number of the drive gear is divided into the number of the driven gear. Also, dividing the diameter of the drive gear than the diameter of the driven gear is another way of obtaining a transmission ratio. Two gears that engage with each other and have the same size in teeth, each one with a larger diameter, has more teeth and, conversely, a smaller diameter gear has fewer teeth. In the case of a tooth displacement in each gear constraint, the teeth are displaced in the other direction as much. Therefore, the transmission ratio is 1. Although the number of teeth in one of gear constrain is 12 and the another constrain is 11, but any number of teeth that are involved in one gear constrain is involved with the same teeth in the other.
Advantageous Effects of Invention
With this explanation, the present invention consists of advantages such as transferring of torque at a range of 90 to -90 degrees, which improved by 50 percent, further stability, and a longer life span for the torque transfer system, which reduces costs for users.
Brief Description of Drawings
Fig. 1 : (a) Front view of Ball joint for the present invention, (b) front view of Thomson joint for the invention, and (c) Front view of Rzeppa joint for the invention.
Fig. 2: Front view illustration of whole components in the present invention. Fig. 3 : A prospective view from two shafts and the inner race.
Fig. 4: A prospective view from standing the system in angles of -90 and 90 degrees rather than horizontal axes.
Description of Embodiments
The present invention consists of five main components as has mentioned in Fig. 2: Drive and driven shafts (4, 4'), inner race (1), housing (8), two gear constraints (6, 7, 6', 7'), and shell (9).
Drive and driven shaft (4, 4'), such as current velocity (CV), Thomson and Universal joints, carry the function of the torque transfer. The inner race (1) of the system keeps and guides the various types of joints doubly and symmetrically, includes CV, Universal, and Thompson.
The outer surface of the inner race (1) is designed to fit a ball bearing (2, 2') between this outer surface of the inner race (1) and the inner surface of the housing (8). By adding the ball bearing (2, 2') to the mechanism, the inner race (1) revolve around their axes easily.
One of the important functions of the housing (8) is to align the inner race (1) with this housing (8). Naturally, when two bodies are joined together, friction between them is an issue. To reduce the friction between this housing (8) and the inner race (1), a ball bearing (2, 2') is used to make the system not only less friction at low angles but also working with the lowest stress at high angles and near 90 degrees. Another functions of the housing (8) is to hold vertical and horizontal gear constrains (6, 7, 6', 7') around the pin (3, 3') axis. A suitable surface is designed to accommodate two constraints (6, 7, 6', 7') on the outer surface of the housing (8). In addition, there are bases on the housing (8) for mounting and tightening the shell (9) that the attachment of the housing (8) with the shell (9) is performed by the four screws (11, 1 G).
The gear constrains (6, 7, 6', T) are divide two large and small groups. The phase difference between two constraints (6, 7, 6', 7') is 90 degrees. These constraints (6, 7, 6', 7') were designed to create an angle of equal impact between the drive shaft (4) and the driven shaft (4') at any angle in the horizontal and vertical direction. As a consequence, these two constraints (6, 7, 6', 7') guide the shafts (4, 4') at all angles. According to gear relationships, every displacement in the drive gear (6, 7) is associated with the same amount movement in the driven gear (6', 7'). If the drive gear (6, 7) rotates counterclockwise at a certain angle, because of its involvement with the driven gear (6', 7'), it results in rotating the driven gear (6', 7') at the same angle in the opposite direction.
One of the most important parts in the gear constrains (6, 7, 6', 7') is their alignment. If minimum devotion occurs in the gear constrains (6, 7, 6', 7'), the angles of the drive and driven shafts (4, 4') will be different than the horizon line (two shafts will not be in the same direction) and function of the system will be similar to Universal joint, resulting in high friction when moving. For this purpose, the gear constrains (6, 7, 6', T) were designed to align together and can easily transfer the torque at very low and high angles from the drive shaft (4) to a driven shaft (4') in equal angle. The gear constraints comprise of small and large gear constraints (6, 7, 6', 7'). First, the system uses two small gear constrains (6, 6') which are both facing each other. This two small gear constrains (6, 6') are attached to the shell (9) using two pins (10, 10'). With this connection, these constrains affect each other and are horizontally director of the drive and driven shaft (4, 4'). Second, two large gear constrains (7, 7') are used in the system, both facing each other. Also, these two large gear constraints (7, 7') are attached to the shell (9) by the two pins (10, 10'). This large gear constraints (7, 7') affect each other and guide the drive and driven shafts (4, 4') in a vertical direction.
Another essential part of the proposed invention is a shell (9). The shell (9) protects the mechanism from impact. By having this shell (9), the system is more robust and longer lifetime. Another component of the present invention is a ring (5, 5') for maintaining the pin (3, 3') and drive and driven shaft (4, 4').
Industrial Applicability
One of the key application of the present invention is its use in the car industry. Today, most cars have a 45 angle axil shaft that can transfer the torque from the engine to the wheels. Today, two joints consist of inboard joint and outer joint are used in the axel shaft in the car industry. The nearest joint to the motor (inboard joint) is for moving the cars over a bump in the road while the outer joint is for moving the wheels in different angles. By having this axle shaft, there are some problems for the driver such as double parking in low space, U-turn in low space without the need for using a few gears and a few steering wheels. Nonetheless, the present invention resolves the problem and gives more maneuver for the driver. As a result, it is friendly with them. The present invention is replaced by the outer joint.
Citation List
Patent Literature
[7] US 4509932
[8] US 6,793,582 B2
[9] US 5,425,676
[10] US 7, 846, 030 B2
[11]US 4,799,817
[12] WO9502773
[13] US 5,688,065
[14] US 4,352,276 Non Patent Literature
[1] Machekposhti, D. Farhadi, N. Tolou, and J. L. Herder. "A Fully Compliant Constant Velocity Universal Joint." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, pp. V05AT08A014-V05AT08A014. American Society of Mechanical Engineers, 2015.
[2]Kocabas, Hikmet. "Design and analysis of a spherical constant velocity coupling
mechanism." Journal of Mechanical Design 129, no. 9 (2007): 991-998.
[3]Thompson, Glenn Alexander. "Constant velocity coupling and control system therefor." U.S. Patent 7,144,326, issued December 5, 2006.
[4]Pattakos, Manousos, John Pattakos, and Emmanouel Pattakos. "Constant velocity joint." U.S. Patent 8,747,236, issued June 10, 2014.
[5]Tsujimoto, Fumihiko. "Constant-velocity joint." U.S. Patent 9,951,822, issued April 24,
2018.
[6] Geometric modeling and assembly analysis of 90 degree steering system
[15] DOUBLE UNIVERSAL JOINT - DOUBLE CARDAN JOINT
(https://grabcad.com/library/double-universal-joint-doubl e-cardan-joint- l/details?folder_id=2384453)
[16] double Cardan joint - universal joint - perpendicular output
(https://grabcad.com/library/double-cardan-joint-universal-j oint-perpendicular-output-l)
[17] Alpha degree DOUBLE UNIVERSAL JOINT (https://grabcad.com/library/alpha-degree- double -universal -joint- 1 )
[18]Study of double Cardan universal joint 2a
(https : //www. youtube .com/watch? v=cydmR01X2t8 )
[19] Lego 4R space crank as a 90 degree uniform motion transmitter
(https : //www. youtube .com/watch? v=9cXPk2UB O vM)
[20]Universal Hobson’s joint (https://www.youtube.com/watch?v=0cU5oB8V_08)
[21] Custom Couplings, Assemblies, U-joints (http://heli-cal.com/wp- content/uploads/2008/03/Customs-Assemblies-Generate-Only.pdf )
[22] Optimized Constant Velocity Joint (https://www.youtube.com/watch?v=oOd— N-14jA)
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