CN214534343U - Cam differential mechanism - Google Patents
Cam differential mechanism Download PDFInfo
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- CN214534343U CN214534343U CN202120827426.XU CN202120827426U CN214534343U CN 214534343 U CN214534343 U CN 214534343U CN 202120827426 U CN202120827426 U CN 202120827426U CN 214534343 U CN214534343 U CN 214534343U
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- cam
- wheel
- axle
- right half
- differential
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Abstract
The utility model provides a cam differential belongs to the differential field. The differential mechanism is composed of a left half-axle wheel, a right half-axle wheel, a power wheel and a cam driven rod which coaxially rotate under the support of a shell, wherein the half-axle wheels are cams, a transmission mechanism for realizing the reverse constant-speed rotation between the left half-axle wheel and the right half-axle wheel is a cam mechanism, when the half-axle wheels on the two sides have no speed difference, the half-axle wheels, the power wheel and the cam driven rod synchronously rotate, and if the half-axle wheels have the speed difference, the cam driven rod slides in a guide groove of the power wheel by the additional force exerted by the cam on one side and drives the cam on the other side to reversely rotate at a constant speed, so that the differential function is realized. The novel differential mechanism provided by the utility model has simple structure, does not need gears, and reduces the manufacturing cost; meanwhile, the cam driven rod structures which are distributed circumferentially and slide axially can obviously reduce the radial size of the differential, thereby improving the trafficability of the motor vehicle and being beneficial to reducing the height of the chassis.
Description
Technical Field
The utility model belongs to the differential mechanism field, concretely relates to no gear drive's cam differential mechanism.
Background
The differential is mainly applied to the transmission of a motor vehicle, so that the left and right (or front and rear) driving wheels move at different rotating speeds when needed, and the driving wheels at two sides can be ensured to perform pure rolling motion. At present, the differential mechanism mainly comprises a classical bevel gear differential mechanism and a Torsen differential mechanism realized by worm gear transmission, and the differential mechanisms are all gear differential mechanisms.
The existing differentials comprise a left half shaft gear and a right half shaft gear which coaxially rotate under the support of a shell, and the core for realizing the differential function of the left half shaft gear and the right half shaft gear is that the differential mechanism also comprises a set of transmission mechanism which is arranged between the left half shaft gear and the right half shaft gear, and the transmission mechanism has the function of keeping the constant-speed reverse rotation relation between the left half shaft gear and the right half shaft gear when no power is input.
Although the differential with gears has wide application, the manufacturing cost is high due to the complex structure.
SUMMERY OF THE UTILITY MODEL
To the problem that prior art exists, the utility model discloses utilize the cam mechanism principle, provide a differential mechanism with cam replacement gear.
The design principle of the utility model is that:
the utility model discloses equally adopt under the shell support coaxial gyration left and right semi-axis wheel, what the institute is different is that left and right semi-axis wheel is the cam, realizes that reverse constant speed pivoted drive mechanism is cam mechanism between left and right semi-axis wheel. The cam is defined as having a complete continuous working profile surface which can generally be characterized as being mathematically derivable from a second or more order. The cam profile has the same number of protrusions and depressions that are spaced apart. One convex portion is referred to as a tooth and the concave portion is correspondingly referred to as a groove.
The technical scheme of the utility model is that:
a cam differential mechanism comprises a differential mechanism shell 1, a left half-axle wheel 2, a right half-axle wheel 3, a power wheel 4 and a cam driven rod 5.
The left and right half-axle wheels 1 and 2 are cam structures, and the cam profile shapes are identical cylindrical end face cams or cylindrical surface groove-shaped cams; the profile surfaces of the left half shaft wheel 1 and the right half shaft wheel 2 are opposite, and convex teeth are arranged on the cam profile. The left and right half-axle wheels 1 and 2 are coaxially and rotatably arranged at two ends in the differential case 1.
The power wheel 4 is arranged in the differential case 1, is positioned between the two left and right half-axle wheels 1 and 2, and is coaxial and rotatable with the two half-axle wheels. The power wheel 4 is uniformly provided with a plurality of guide grooves around the rotary axis, the guide grooves penetrate through the power wheel, the guide direction is parallel to the rotary axis, the cross section of each guide groove is matched with that of the cam driven rod 5, the cross sections of the guide grooves and the cam driven rod 5 can be the same or different, and the cam driven rod 5 can only move in the guide grooves along the rotary axis direction, so that the cam driven rod has various combination forms, for example, the guide grooves and the cam driven rods 5 are triangular sections, or the guide grooves are triangular sections and the cam driven rods 5 are rectangular sections. The number of the guide grooves is the sum of the number of convex teeth on the outlines of the left and right half-shaft wheels 1 and 2.
The cam driven rods 5 are mounted on guide grooves of the power wheel 4 (one cam driven rod 5 is mounted in each guide groove), the cam driven rods can only slide along the axial direction due to the shape of the guide grooves, and the cam driven rods 5 penetrate through the rear two sides of the guide grooves of the power wheel and are respectively meshed with a convex tooth lift profile and a return profile of the left half-axle wheel and the right half-axle wheel (namely, the two sides of the cam driven rods 5 are respectively in point contact with the highest points of convex teeth and the lowest points of grooves of the left half-axle wheel and the right half-axle wheel), so that each cam driven rod 5 and the left half-axle wheel and the right half-axle wheel 1 and 2 form a cam mechanism at the same time. The length of the cam follower lever 5 is equal to the distance between the highest point of the convex teeth and the lowest point of the concave grooves of the left and right axle wheels 1 and 2 for timing.
Furthermore, in order to make the left and right half-axle wheels 1, 2 easy to keep dynamic balance when in operation, the number of the convex teeth arranged on the left and right half-axle wheels should be not less than 2. For example, the number of the selectable teeth is 2,3,4,5,6,7,8,9, 10.
Furthermore, in order to avoid the uncertain state of synchronous abrasion or instantaneous synchronization of the cam driven rods in the work, the motion angles corresponding to two sides of the highest point of the convex teeth of the left half-axle wheel 1 and the right half-axle wheel 2 have a difference value, the difference value is called as a tooth side angle difference value, and the tooth side angle difference value is controlled between 1/20 degrees and 1/10 degrees of the motion angle corresponding to the convex teeth or between 5 degrees and 20 degrees. Such as 6,8,9,10,12,15,18, etc.
Furthermore, the push stroke and return stroke profile design of the cams on the left and right half-axle wheels 1 and 2 is preferably selected to realize the uniform motion of the cam driven rods, smooth transition sections are arranged at the starting positions and the ending positions of the left and right half-axle wheels 1 and 2, and the motion angles corresponding to the transition sections are smaller than half of the difference value of the tooth side angles. The push stroke and return stroke profiles of the cams on the left half-axle wheel and the right half-axle wheel realize that the speed curves of the front half stroke and the rear half stroke of the cam driven rod are just symmetrical, so that the left half-axle wheel and the right half-axle wheel can be stably meshed in the working process.
Further, the maximum angle between the tangent plane of the contour plane of the gear teeth on the left and right half-axle wheels 1, 2 and the vertical plane of the axle line of the half-axle wheels is between 15 and 75 degrees, so that proper transmission performance can be obtained. For example, when the included angle is 45 degrees, the axial component and the like of the acting force between the half-axle wheel and the cam driven rod are basically equal to the tangential component, and the performance is moderate; when the included angle is below 30 degrees, the axial component of the acting force between the half-shaft wheel and the cam driven rod is obviously larger than the tangential component, the contact stress is higher when the same torque is output, but the transmission efficiency is higher; on the contrary, when the included angle is more than 50 degrees, the axial component of the acting force between the half axle wheel and the cam driven rod is obviously smaller than the tangential component, the contact stress is small when the same torque is output, although the transmission efficiency is lower, the differential speed can be realized, and a certain difference value of the output torque of the half axle wheels at two sides is allowed, namely, the partial function with the differential lock is realized.
Further, both ends of the cam follower lever 5 engaging with the teeth of the cam may be formed in a peaked shape, a domed shape, a conical shape or a small flat shape formed by cutting off a portion of the peaked shape.
Further, the cross section of the cam follower lever 5 may be triangular, rectangular, square, trapezoidal, other polygonal, or irregular.
When the cam differential mechanism provided by the utility model is applied, as with other differential mechanisms, the power wheel is input to rotate, the left half axle wheel and the right half axle wheel are simultaneously stirred to rotate along with the power wheel through the cam driven rod on the power wheel, and when the differential mechanism is not needed, the left half axle wheel and the right half axle wheel are synchronously output; when differential is needed, the cam driven rods can enable the left and right axle wheels to respectively superpose rotating speeds with the same magnitude and the opposite directions on the original equal rotating speeds, and differential is achieved.
The differential process can be clearly interpreted when the powered wheels are relatively immobile. Because all the cam driven rods and the left and right cams form a cam mechanism relationship at the same time, and the number of the cam driven rods is equal to the sum of the number of convex teeth of the left and right half-axle wheels, the condition of movable tooth transmission reverse transmission is met, and simultaneously, the number of the convex teeth of the two half-axle wheels is the same, so that the transmission ratio between the left and right half-axle wheels can be calculated to be-1, and the constant-speed reverse transmission relationship can be realized. That is, the increase of the rotational speed of the side half axle wheel in a given direction is equal to the decrease of the rotational speed of the side half axle wheel, thereby realizing the differential speed.
The utility model discloses a novel differential mechanism structure, its beneficial effect is: the structure is simple, gears are not needed, and the manufacturing cost is reduced; the cam driven rod structure which is distributed according to the circumference and slides axially can obviously reduce the radial size of the differential, thereby improving the trafficability of the motor vehicle and being beneficial to reducing the height of the chassis.
Drawings
Fig. 1 is a schematic structural diagram of a cam differential mechanism according to the present invention.
Fig. 2 is a schematic diagram of the arrangement of the guide grooves of the power wheel.
FIG. 3 is a schematic structural view of the left half-axle wheel; fig. 3 (b) is a schematic view along the direction a in fig. 3 (a).
Fig. 4 is a schematic view of the construction of the cam follower lever.
Fig. 5 is a schematic view of the deployment of the cam in engagement with the cam follower lever.
In the figure: 1 a differential housing; 2, a left half-axle wheel; 3 a right half-axle wheel; 4, a power wheel; 5 cam follower lever.
Detailed Description
The invention will be further elucidated with reference to the drawings and the specific examples. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present invention. It should also be noted that, for the convenience of description, only some of the structures related to the present invention are depicted in the drawings, not all of the structures.
In the description of the present invention, unless explicitly specified or limited, the terms "connected", "fixed" and "fixed" are to be understood in a broad sense, e.g. either fixedly or detachably connected or integrated; either directly or through middleware.
As shown in fig. 1 to 5, a cam differential includes a differential case 1, a left half-axle wheel 2, a right half-axle wheel 3, a power wheel 4, and a cam follower lever 5. The cams of the left and right semi-axis wheels are cylindrical end surface cams with the same outline shape, the outline surfaces of the left and right semi-axis wheels are opposite, and the number of convex teeth of the cam outline is 3. Guide grooves are uniformly distributed on the periphery of the axis of the power wheel 4, the guide direction is parallel to the rotation axis, and the number of the guide grooves is 6. The cross section of the cam driven rod 5 and the shape of the guide groove are rectangular, and two ends of the cam driven rod are arc surfaces. The installation relationship is as follows: the left half shaft wheel and the right half shaft wheel are coaxially and rotatably arranged at two ends in the differential case 1, the power wheel 4 is arranged in the differential case 1 and is positioned between the left half shaft wheel and the right half shaft wheel, the power wheel 4 is coaxial and rotatable with the half shaft wheels, the power wheel 4 is fixed with a gear to input power, the cam driven rod 5 is arranged in a guide groove of the power cam 4, and two sides of the cam driven rod 5 are just in point contact with the highest point of a convex tooth and the lowest point of a groove of the left half shaft wheel and the right half shaft wheel respectively, so that the cam driven rod 5 and the left half shaft wheel and the right half shaft wheel form a cam mechanism at the same time.
Differential mechanism's theory of operation:
according to the above description, the cam follower lever 5 always constitutes a cam mechanism together with the left and right half-axle wheels, and assuming that the lift range of the cam of the left half-axle wheel 2 corresponds to the return range of the cam of the right half-axle wheel 3, the return range of the cam of the corresponding left half-axle wheel 2 corresponds to the lift range of the cam of the right half-axle wheel 3, the lift range profile of the cam pushes the meshing end of the cam follower lever 5 from the valley bottom to the peak of the convex teeth, and simultaneously the other side meshing end of the cam follower lever 5 falls back from the peak to the valley bottom of the convex teeth of the cam, so that the condition that the cam follower lever 5 always exists in the lift range or the return range can be satisfied by the plurality of cam follower levers 5, thereby realizing indirect continuous transmission of the left half-axle wheel 2 and the right half-axle wheel 3. After power is input, the power wheel 4 rotates in the differential case 1 to drive the cam driven rod 5 installed in the guide groove to rotate at the same speed, and meanwhile, the left half-axle wheel and the right half-axle wheel rotate under the driving force applied by the cam driven rod 5, so that a two-degree-of-freedom differential system is formed, and the two half-axle wheels drive the wheels to rotate to realize the movement of the automobile. When the motion state of the wheels on the two sides changes, the cam driven rods 5 are correspondingly adjusted so as to realize the function of the differential mechanism.
When the automobile moves linearly, wheels on two sides rotate at the same speed, the left half-axle wheel 2 and the right half-axle wheel 3 are relatively static, the cam driven rod 5 is in a balanced state by being meshed with cams on the two half-axle wheels to transmit power, and the cam driven rod 5 only plays a role in transmitting torque and is in a non-differential state at the moment.
When the automobile turns, the rotating speed difference occurs between the rotating speeds of the wheels on the two sides, the left half-axle wheel 2 and the right half-axle wheel 3 start to move relatively, if the cam on one side which rotates fast is taken as a driving wheel, one side of the cam driven rod 5 which is meshed with the driving wheel is subjected to the axial component of additional force exerted by the cam and moves along the guide groove, the cam on the other side is subjected to the force exerted by the cam driven rod 5 to rotate reversely, and the transmission ratio of the left half-axle wheel 2 and the right half-axle wheel 3 is made to be-1 through the design of the cams on the two sides and the cam driven rod 5, so that the differential rotation of the left half-axle wheel 2 and the right half-axle wheel 3 is realized.
The above-mentioned embodiments only represent the embodiments of the present invention, but can not be understood as the limitation of the scope of the present invention, and it should be noted that, for those skilled in the art, a plurality of variations and improvements can be made without departing from the concept of the present invention, and all of them belong to the protection scope of the present invention.
Claims (8)
1. A cam differential is characterized by comprising a differential shell (1), a left half axle wheel (2), a right half axle wheel (3), a power wheel (4) and a cam driven rod (5);
the left and right half-axle wheels (1) and (2) are of cam structures, and the cam profiles are identical cylindrical end face cams or cylindrical surface groove-shaped cams; the profile surfaces of the left half shaft wheel (1) and the right half shaft wheel (2) are opposite, and convex teeth are arranged on the profile of the cam; the left half shaft wheel and the right half shaft wheel (1) and (2) are coaxially and rotatably arranged at two ends in the differential shell (1);
the power wheel (4) is arranged in the differential shell (1), is positioned between the two left and right half-axle wheels (1) and (2), and is coaxial and rotatable with the two half-axle wheels; a plurality of guide grooves are uniformly formed in the periphery of the rotary axis of the power wheel (4), penetrate through the power wheel, are parallel to the rotary axis in the guide direction, and are matched with the cross section of the cam driven rod (5) in shape; the number of the guide grooves is the sum of the number of convex teeth on the profiles of the left and right half-shaft wheels (1) and (2);
the cam driven rods (5) are arranged on guide grooves of the power wheel (4), the shape of the guide grooves enables the cam driven rods to only slide along the axial direction, and the cam driven rods (5) penetrate through the rear two sides of the guide grooves of the power wheel and are respectively meshed with convex tooth lift profiles and return profiles of the left half shaft wheel and the right half shaft wheel, so that each cam driven rod (5) always forms a cam mechanism with the left half shaft wheel and the right half shaft wheel (1) and (2); the length of the cam driven rod (5) is equal to the distance between the highest point of the convex teeth and the lowest point of the grooves of the left and right axle wheels (1, 2) in point-to-point timing.
2. The cam differential according to claim 1, wherein the number of the convex teeth provided on the left and right half-axle wheels is not less than 2.
3. A cam differential according to claim 1, characterized in that the difference between the corresponding motion angles at the two sides of the highest point of the teeth of the left and right half-axle wheels (1), (2) is the tooth flank angle difference, and the tooth flank angle difference is controlled between 1/20-1/10 of the corresponding motion angle of the teeth.
4. A cam differential according to claim 3 wherein said tooth flank angle difference is between 5 and 20 °.
5. A cam differential according to claim 1, characterized in that smooth transition sections are arranged at the beginning and the end of the left and right half-axle wheels (1), (2), and the motion angle corresponding to the transition sections is less than half of the difference value of the tooth side angle.
6. A cam differential according to claim 1, wherein the maximum angle between the tangent plane to the profile plane of the gear teeth on the left and right half-wheels (1), (2) and the vertical plane of the axle line of the half-wheels is between 15 ° and 75 °.
7. A cam differential according to claim 1, wherein the ends of the cam follower lever (5) engaging with the teeth of the cam are pointed, domed, conical or slightly flat with a part of the pointed cut away.
8. A cam differential according to claim 1, characterised in that the cross-section of the cam follower levers (5) may be triangular, rectangular, square, trapezoidal, other polygonal or irregular.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120827426.XU CN214534343U (en) | 2021-04-22 | 2021-04-22 | Cam differential mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120827426.XU CN214534343U (en) | 2021-04-22 | 2021-04-22 | Cam differential mechanism |
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| Publication Number | Publication Date |
|---|---|
| CN214534343U true CN214534343U (en) | 2021-10-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120827426.XU Expired - Fee Related CN214534343U (en) | 2021-04-22 | 2021-04-22 | Cam differential mechanism |
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| CN (1) | CN214534343U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112943889A (en) * | 2021-04-22 | 2021-06-11 | 大连理工大学 | Cam differential mechanism |
-
2021
- 2021-04-22 CN CN202120827426.XU patent/CN214534343U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112943889A (en) * | 2021-04-22 | 2021-06-11 | 大连理工大学 | Cam differential mechanism |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20211029 |
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| CF01 | Termination of patent right due to non-payment of annual fee |