There are three schemes for drum shape optimization modification of tooth profile, namely, the modification amount of driving wheel is […]
Figure 1 shows the influence curve of the pinion tooth width on the time-varying meshing force of the helical gear
The optimal modification scheme of the top broken line arc of the long tooth profile is the modification amount of
For the dynamics of nonlinear helical gear system, the solid collision method, the finite element transient analysis method and the
The linear optimization modification scheme of long tooth profile addendum is the modification amount of driving gear 3 μ m.
As shown in the figure, the three-dimensional cloud diagram of contact stress of No. 0 unmodified, No. 1 optimization scheme
Figure 1 shows the influence curve of helix angle on the time-varying meshing force of the helical gear pair at
Transmission error belongs to error excitation, which is an important factor affecting the vibration and noise of meshing helical gear
As shown in the figure, the tooth surface load distribution of No. 0 unmodified, No. 1 optimization scheme and No.
Taking the helical gear pair of an electric vehicle gearbox as the research object, the KISSsoft software was used to
Under the ideal oil lubricated meshing condition, the big and small gear teeth will be completely separated by the oil
The three-dimensional model of helical gear is established, and the contact analysis of helical gear is carried out by finite
(1) Gear profile optimization modification+tooth direction drum modification Figures 1, 2, 3, 4 and 5 respectively show the composite modification
(1) Influence of pressure angle on transmission error of helical gears Figure 1 shows the relationship curve between pressure angle
(1) Optimal modification of linear addendum with long tooth profile Figures 1, 2 and 3 respectively show the simultaneous long
Transmission error is an important physical quantity used to describe the deviation degree between the actual angle and the theoretical
(1) Selection of long and short modification methods Long modification refers to the repair and removal of the part from
For helical gear pair transmission, the number of rotation cycles of the pinion is more than that of the big
(1) Time-varying meshing stiffness Because the gear teeth will produce elastic deformation when the gear is engaged, and the gear
At present, most electric vehicle OEMs use motor+gearbox+rear axle (as shown in the figure) instead of motor+rear axle, which not
Under the ideal condition that all components in the gearbox except the helical gear are regarded as absolute rigid bodies
As shown in Figure 1 (a), under ideal or no-load conditions, the helical gear pair can mesh smoothly and bear
In order to solve the problem of serious squealing and knocking noise of helical gears in the reduction gearbox, improve
The design and optimization of helical gears are often complicated, and even involve the solution of some transcendental equations. Therefore,
Knocking mainly occurs on the helical gear box components such as meshing no-load helical gear, synchronizer and sliding sleeve. Due
In the process of shape modification development and application research aimed at the bottleneck problem of helical gear vibration noise
Only on the basis of understanding and mastering the mechanism of transmission noise of electric vehicle reduction gearbox and helical
Helical gear squeal is a kind of pure noise with medium high rate and low sound pressure level, which is
The study of helical gear vibration and noise abroad has a history of more than 100 years. However, it was
In order to verify the reliability of this method, the author carried out experimental verification. The tested helical gears are
The pixel size of the image was measured using the standard 6 × 9 checkerboards, each with a size of
As shown in Fig. 1, due to the special tooth shape of helical gears, the brightness and contrast of the
Helical cylindrical gear is referred to as helical gear for short. The tooth line of helical gear is the combination
The significance of this step is to determine the sign of R and B. First, the connected domain with too
1. Composition of measurement system In order to meet the industrial production environment, the helical gear angle measurement system should
In order to reduce the transmission error below 1, the modification amount of helical gear is analyzed. First, analyze the
The power loss of the gearbox mainly includes oil stirring loss, wind resistance loss, gear meshing loss and bearing loss.
The transmission error of the first stage reduction driving helical gear in the reducer of a pure electric vehicle is
Energy and environmental problems are becoming increasingly serious, and new energy vehicles have attracted much attention. Electric vehicles have become
Parameters Driving wheel Driven wheel Number of teeth 29 48 Modulus 1.75 1.75 Helix angle 16 16 Accuracy class 7
The vibration acceleration in all directions of the helical gear is synthesized into the relative vibration acceleration a in the
Regardless of the deformation, the meshing point of a pair of helical gears at any time should be on the
Taking the high-speed input stage gear pair in the secondary reducer of a pure electric vehicle as the research object,
The overall error is treated as a discrete point on the contact line of the helical gear to indicate the
According to the actual meshing sequence of the helical gear, the overall error curve of the unit helical gear pair
The contact pressure history curve during helical gear meshing is shown in Figure 1. It can be seen that the
The meshing of helical gears can be regarded as line contact, and the load changes and distributes along the contact
1. Law of equivalent stress and time change during helical gear meshing The variation law between the dynamic contact equivalent
The overall error curve of helical gear is a complete error curve of helical gear, which is formed by measuring
Increase the speed of helical gear from 25rad / s to 35rad / s, and keep the torque unchanged. Using
Because the coincidence degree of helical gear is not an integer, its meshing transmission process is alternating between single and
Transmission error is an important excitation that causes the vibration and noise of helical gears. It is a parameter that
(1) This paper breaks through the condition limitation of calculating the time-varying contact line length of helical gear multi tooth
(1) Equivalent stress nephogram of helical gear at 0.0025s It can be seen from Fig. 1 that the contact stress
The load distribution along the contact line is affected by the position and length of the helical gear contact line.
(1) Through analysis, it can be seen that there is no mechanism to determine the size of helical gear drum
Many scholars at home and abroad have put forward a variety of theories and methods for helical gear modification. At
There are many methods to modify the helical gear drum shape. At present, there are mainly the following two methods;
The impact and vibration of helical gear will inevitably occur in the process of transmission meshing, which will increase the
Figure 1 shows the influence curve of friction on the second-order superharmonic resonance. With the increase of friction, the vibration
