Four-wheel drive dynamometer with adjustable front and rear axle distance

Abstract

The utility model relates to the technical field of dynamometers, in particular to a four-wheel-drive dynamometer with an adjustable front and rear axle distance, which comprises a bottom frame, a fixed table arranged on the upper side of the rear end of the bottom frame, a track arranged on the front side of the fixed table, a movable table arranged on the track, a rear roller group arranged on the upper side of the fixed table, a first transmission wheel coaxially arranged at the left end of the rear roller group, and a second transmission wheel coaxially arranged at the right end of the first transmission wheel. A front roller set is arranged on the upper side of the moving table, a third transmission wheel is arranged at the left end of the front roller set, a fifth transmission wheel and a sixth transmission wheel are arranged on the bottom frame, a first tensioning wheel and a second tensioning wheel are arranged below the third transmission wheel, and the first transmission wheel and the sixth transmission wheel are connected through a first synchronous belt. The fifth transmission wheel and the sixth transmission wheel are connected through a second synchronous belt, the third transmission wheel is sleeved with the middle of the second synchronous belt in a transmission mode, and the portions, located on the front side and the rear side of the third transmission wheel, of the second synchronous belt are attached to the opposite sides of the first tensioning wheel and the second tensioning wheel in a transmission mode respectively.

Description

TECHNICAL FIELD

[0001] The utility model relates to dynamometer technical field, concretely relates to four drive dynamometer of front and rear wheel base adjustable. BACKGROUND

[0002] The chassis dynamometer is a kind of indoor bench test equipment for testing the performance such as automobile power performance, multi-working condition emission index and fuel index, and the automobile chassis dynamometer simulates road surface through roller, calculates road simulation equation and uses loading device to simulate, to realize the simulation of each working condition of automobile.

[0003] With the continuous development of automobile technology, four-wheel drive car develops at an alarming rate, and more and more people like four-wheel drive car, in order to meet the increasing detection requirements of four-wheel drive car, dynamometer also needs to detect the front and rear wheels of four-wheel drive car simultaneously, because the front and rear wheel base of different vehicle models is different, therefore, when detecting four-wheel drive car, the dynamometer needs to meet the front and rear adjustment function, so that the distance between the front and rear roller groups of the dynamometer is adjusted to the position that meets the wheel base of the vehicle, and based on this reason, the dynamometer needs to drive the front and rear wheels of the vehicle to rotate simultaneously, currently, there are two kinds of schemes, one is to use double motors to drive the front and rear roller groups to rotate at the same speed to drive the front and rear wheels of the vehicle to rotate, and the other is mechanical synchronization, which uses synchronous belt transmission, chain transmission and other ways to drive the front and rear roller groups to rotate simultaneously by one motor. Although the double motor scheme can realize synchronization, the double motor is expensive. The mechanical synchronization can effectively reduce the cost of the equipment, but in the prior art, the dynamometer using mechanical synchronization basically only uses one synchronous belt or one chain to transmit, and because the distance between the front and rear roller groups needs to be adjusted, the length of the whole synchronous belt or chain is too long. The long synchronous belt or chain is expensive, which increases the maintenance cost. UTILITARIAN CONTENT

[0004] The utility model aims at providing a kind of four drive dynamometer of front and rear wheel base adjustable, solve the problem that in prior art, the dynamometer with front and rear roller group distance adjustment function mostly uses one synchronous belt to complete synchronization, so that the length of synchronous belt is too long, increase procurement cost and maintenance cost.

[0005] To solve the above technical problems, the utility model adopts the following technical scheme:

[0006] The utility model provides a kind of front and rear wheelbase adjustable four-wheel drive dynamometer, including chassis, the upper side of rear end of chassis is equipped with fixed platform, chassis is provided with track in front and rear direction along the front side of fixed platform, mobile platform is slidably arranged on track, the upper side of fixed platform is provided with rear roller group, the left end of rear roller group is coaxially provided with first transmission wheel, the upper side of mobile platform is provided with front roller group, the left end of front roller group is coaxially provided with third transmission wheel, the left side of chassis is provided with fifth transmission wheel and sixth transmission wheel at the front and rear ends of track respectively, the left side of mobile platform is provided with first tensioner and second tensioner at the front and rear intervals below third transmission wheel, first transmission wheel and sixth transmission wheel are connected by first synchronous belt drive, fifth transmission wheel and sixth transmission wheel are connected by second synchronous belt drive, the upper side of second synchronous belt is drivenly sleeved on third transmission wheel in the middle part, and the parts of second synchronous belt on the front and rear sides of third transmission wheel are respectively drivenly fitted with the opposite side of first tensioner and second tensioner.

[0007] Further technical solutions are that the rear roller group includes first rear roller and second rear roller arranged in front and rear, the first transmission wheel is arranged at the left end of the first rear roller, the second transmission wheel is coaxially arranged at the left end of the second rear roller, and the first transmission wheel and the second transmission wheel are connected by the third synchronous belt drive.

[0008] Further technical solutions are that the front roller group includes first front roller and second front roller arranged in front and rear, the third transmission wheel is arranged at the left end of the first front roller, the fourth transmission wheel is coaxially arranged at the left end of the second front roller, the middle part of the upper side of the second synchronous belt is sequentially drivenly sleeved on the third transmission wheel and the fourth transmission wheel, the part of the second synchronous belt on the front side of the third transmission wheel is drivenly fitted with the rear side of the first tensioner, and the part of the second synchronous belt on the rear side of the fourth transmission wheel is drivenly fitted with the front side of the second tensioner.

[0009] Further technical solutions are that the right end of the first rear roller is provided with the first motor for driving the first rear roller to rotate.

[0010] Further technical solutions are that the upper side of the chassis is provided with a lead screw in the front and rear direction, the front end of the lead screw is provided with the second motor for driving the lead screw to rotate, the driving block is drivenly sleeved on the lead screw, the driving block is connected with the lead screw by screw thread drive, and the upper side of the driving block is fixedly connected with the lower side of the mobile platform.

[0011] Further technical solutions are that the lower side of the mobile platform is provided with the moving block corresponding to the position of the track, the lower side of the moving block is recessed to be provided with the sliding groove matched with the track, and the upper side of the track is slidably embedded in the sliding groove.

[0012] Further technical solutions are that the rear end of the chassis is provided with the rotating block, the front side of the rotating block is provided with the rotating hole, the rear end of the lead screw is inserted into the rotating hole and connected with the rotating hole by bearing and rotation.

[0013] Compared with the prior art, the beneficial effects of the utility model are that: the rear roller group and the front roller group realize mechanical synchronous transmission through two synchronous belts, the length of single belt can be reduced, thereby the cost and maintenance cost are controlled. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a state diagram of the four-wheel drive dynamometer with adjustable front and rear wheelbase.

[0015] Figure 2 It is another state diagram of the four-wheel drive dynamometer with adjustable front and rear wheelbase.

[0016] Figure 3 It is a transmission wheel and synchronous belt transmission schematic diagram of the four-wheel drive dynamometer with adjustable front and rear wheelbase.

[0017] Figure 4 It is a cross-sectional schematic diagram of the four-wheel drive dynamometer with adjustable front and rear wheelbase.

[0018] Figure 5 It is Figure 4 It is a local enlarged schematic diagram at the middle mark A.

[0019] Figure 6 It is a whole schematic diagram of the clamping brake assembly.

[0020] Figure 7 It is a left linkage plate and right linkage plate schematic diagram of the whole clamping brake assembly.

[0021] Icon: 101 - base frame, 102 - fixed table, 103 - track, 104 - moving table, 105 - first transmission wheel, 106 - third transmission wheel, 107 - fifth transmission wheel, 108 - sixth transmission wheel, 109 - first tensioning wheel, 110 - second tensioning wheel, 111 - first synchronous belt, 112 - second synchronous belt, 113 - first rear roller, 114 - second rear roller, 115 - second transmission wheel, 116 - third synchronous belt, 117 - first front roller, 118 - second front roller, 119 - fourth transmission wheel, 120 - first motor, 121 - lead screw, 122 - second motor, 123 - drive block, 124 - moving block, 125 - sliding groove, 126 - lead hole, 201 - brake strip, 202 - mounting plate, 203 - left guide plate, 204 - right guide plate, 205 - left sliding hole, 206 - right sliding hole, 207 - left brake lever, 208 - right brake lever, 209 - hydraulic rod, 210 - left linkage plate, 211 - right linkage plate, 212 - left linkage hole, 213 - right linkage hole, 214 - linkage rod, 215 - connecting groove, 216 - first rotating shaft, 217 - first connecting piece, 218 - second connecting piece, 219 - second rotating shaft, 220 - third rotating shaft. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail by combining with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0023] Figures 1 to 7 The utility model discloses an embodiment.

[0024] Example 1:

[0025] As Figures 1-3As shown, a four-wheel drive dynamometer with adjustable front-rear wheelbase comprises a chassis 101, a fixed platform 102 is mounted on the upper side of the rear end of the chassis 101, a track 103 is arranged on the front side of the fixed platform 102 in the front-rear direction, a moving platform 104 is arranged on the track 103 in the front-rear direction, a rear roller set is arranged on the upper side of the fixed platform 102, a first transmission wheel 105 is coaxially arranged at the left end of the rear roller set, a front roller set is arranged on the upper side of the moving platform 104, a third transmission wheel 106 is coaxially arranged at the left end of the front roller set, a fifth transmission wheel 107 and a sixth transmission wheel 108 are arranged on the left side of the chassis 101 at the front and rear ends of the track 103 respectively, a first tensioner 109 and a second tensioner 110 are arranged on the left side of the moving platform 104 below the third transmission wheel 106 in front and rear intervals, the first transmission wheel 105 and the sixth transmission wheel 108 are connected by a first synchronous belt 111, the fifth transmission wheel 107 and the sixth transmission wheel 108 are connected by a second synchronous belt 112, the middle part of the upper side of the second synchronous belt 112 is sleeved on the third transmission wheel 106, and the parts of the second synchronous belt 112 located on the front and rear sides of the third transmission wheel 106 are respectively in transmission fit with the opposite sides of the first tensioner 109 and the second tensioner 110. The rear roller set and the front roller set are mechanically synchronously driven by two synchronous belts, which can reduce the length of a single belt, thereby controlling the cost and maintenance cost. With the cooperation of the third transmission wheel 106, the first tensioner 109 and the second tensioner 110, the moving platform 104 can be moved to any position along the track 103, and the third transmission wheel 106 and the sixth transmission wheel 108 can be kept synchronous rotation by the second synchronous belt 112.

[0026] The rear roller set comprises a first rear roller 113 and a second rear roller 114 arranged in front and rear, the first transmission wheel 105 is arranged at the left end of the first rear roller 113, the second rear roller 114 is coaxially provided with a second transmission wheel 115 at the left end, and the first transmission wheel 105 and the second transmission wheel 115 are connected by a third synchronous belt 116. By arranging the third synchronous belt 116, the first rear roller 113 and the second rear roller 114 can be synchronously rotated, which can drive the rear wheels of the car placed between the first rear roller 113 and the second rear roller 114 to rotate.

[0027] The front roller set comprises a first front roller 117 and a second front roller 118 arranged in front and rear, the third transmission wheel 106 is arranged at the left end of the first front roller 117, the second front roller 118 is coaxially provided with a fourth transmission wheel 119 at the left end, the middle part of the upper side of the second synchronous belt 112 is sequentially sleeved on the third transmission wheel 106 and the fourth transmission wheel 119, the part of the second synchronous belt 112 located on the front side of the third transmission wheel 106 is in transmission fit with the rear side of the first tensioner 109, and the part of the second synchronous belt 112 located on the rear side of the fourth transmission wheel 119 is in transmission fit with the front side of the second tensioner 110.

[0028] The right end of the first rear roller 113 is mounted with a first motor 120 for driving the first rear roller 113 to rotate. When the dynamometer test is performed, the distance between the front roller set and the rear roller set is adjusted according to the front and rear wheel track of the vehicle, and the gap between the moving platform 104 and the fixed platform 102 is filled with an expansion plate, so that the vehicle can run smoothly, and an expansion plate is also arranged at the front side of the moving platform 104, and the two expansion plates are kept at the same height with the upper surfaces of the moving platform 104 and the fixed platform 102. After the adjustment is completed, the front wheels of the vehicle are placed between the first front roller 117 and the second front roller 118, and the rear wheels are placed between the first rear roller 113 and the second rear roller 114. Then the first motor 120 is started to drive the first rear roller 113 to rotate, and the first rear roller 113 rotates synchronously through the first transmission wheel 105, the second transmission wheel 115 and the third synchronous belt 116, and at the same time, the sixth transmission wheel 108 is driven by the first synchronous belt 111, and the fifth transmission wheel 107, the third transmission wheel 106 and the fourth transmission wheel 119 are driven by the second synchronous belt 112. In the process of driving the second synchronous belt 112, the second synchronous belt 112 is tensioned by the first tensioning wheel 109 and the second tensioning wheel 110 by pressing the second synchronous belt 112 from the outside, so that the second synchronous belt 112 can always adhere to the surfaces of the sixth transmission wheel 108, the fifth transmission wheel 107, the third transmission wheel 106 and the fourth transmission wheel 119 for transmission. In order to avoid the first synchronous belt 111, the second synchronous belt 112 and the third synchronous belt 116 from slipping, the first synchronous belt 111, the second synchronous belt 112 and the third synchronous belt 116 are provided with teeth on the inner side, and the circumferential surfaces of the first transmission wheel 105, the second transmission wheel 115, the third transmission wheel 106, the fourth transmission wheel 119, the fourth transmission wheel 119, the fifth transmission wheel 107 and the sixth transmission wheel 108 are provided with matching teeth. The first transmission wheel 105 is connected to the first synchronous belt 111 and the third synchronous belt 116 at the same time, so that two transmission ring grooves are arranged around the circumference of the first transmission wheel 105, and the first synchronous belt 111 and the third synchronous belt 116 are installed in the two transmission ring grooves respectively. Similarly, the sixth transmission wheel 108 is also provided with two transmission ring grooves.

[0029] Example 2:

[0030] On the basis of the foregoing examples, as Figure 4 , 5As shown, the upper side of the chassis 101 is provided with a lead screw 121 in the front-rear direction, the front end of the lead screw 121 is provided with a second motor 122 for driving the lead screw 121 to rotate, a driving block 123 is sleeved on the lead screw 121, the driving block 123 is connected with the lead screw 121 through a thread hole 126 in threaded transmission, and the upper side of the driving block 123 is fixedly connected with the lower side of the moving table 104. The lead screw 121 and the driving block 123 are matched to control the moving position of the moving table 104 with high precision, so that the distance between the front roller group and the rear roller group can be adjusted more accurately to adapt to the front-rear wheel track of different vehicles. When the lead screw 121 rotates under the drive of the second motor 122, the driving block 123 is fixed with the moving table 104 and cannot rotate with the lead screw 121, but can only move linearly along the axial direction of the lead screw 121.

[0031] The lower side of the moving table 104 is provided with a moving block 124 corresponding to the position of the track 103, the lower side of the moving block 124 is recessed to be provided with a sliding groove 125 matched with the track 103, and the upper side of the track 103 is slidingly embedded in the sliding groove 125. Through the cooperation of the moving block 124 and the track 103, the moving table 104 can smoothly move forward and backward along the track 103.

[0032] The rear end of the chassis 101 is provided with a rotating block, the front side of the rotating block is provided with a rotating hole, the rear end of the lead screw 121 penetrates into the rotating hole and is connected with the rotating hole through a bearing. Through the rotating block, stable support force can be provided for the rear end of the lead screw 121, and the lead screw 121 can be smoothly rotated with the help of the bearing.

[0033] Embodiment 3:

[0034] On the basis of the foregoing embodiments, as Figure 6 , 7As shown, the upper side of the chassis 101 is provided with a brake strip 201 along the front-rear direction, and the lower side of the moving table 104 is provided with a clamping brake assembly matched with the brake strip 201. The clamping brake assembly includes a mounting plate 202, and a left guide plate 203 and a right guide plate 204 vertically and spacedly arranged on the lower side of the mounting plate 202. The left guide plate 203 and the right guide plate 204 are respectively arranged on the left side and the right side of the brake strip 201. The mounting plate 202 is mounted on the lower side of the moving table 104. The left guide plate 203 and the right guide plate 204 are respectively provided with a left sliding hole 205 and a right sliding hole 206 matched with the brake strip 201. A left brake rod 207 is slidably arranged in the left sliding hole 205, and a right brake rod 208 is slidably arranged in the right sliding hole 206. The left brake rod 207 and the right brake rod 208 are driven to move relatively by a hydraulic rod 209. During use of the dynamometer, in order to avoid the moving table 104 from moving forward and backward, the clamping brake assembly and the brake strip 201 are used to lock the moving table 104 during use, so as to avoid damage to the lead screw 121 caused by vibration during use. After the moving table 104 is moved to the position, the left brake rod 207 and the right brake rod 208 are driven to move relatively close by the hydraulic rod 209, so as to clamp the brake strip 201 from the left side and the right side of the brake strip 201 to fix the moving table 104. When it is needed to move the moving table 104, the left brake rod 207 and the right brake rod 208 are driven to move relatively far away by the hydraulic rod 209, so that the moving table 104 can be moved under the driving of the driving block 123. By arranging the left sliding hole 205 and the right sliding hole 206, the left brake rod 207 and the right brake rod 208 can be limited in movement, so that they can only move along the holes of the left sliding hole 205 and the right sliding hole 206.

[0035] The left brake lever 207 is rotatably connected with a left linkage plate 210 at the left side of the left guide plate 203, the right brake lever 208 is rotatably connected with a right linkage plate 211 at the right side of the right guide plate 204, the left guide plate 203 and the right guide plate 204 are respectively provided with a left linkage hole 212 and a right linkage hole 213 which penetrate above the left sliding hole 205 and the right sliding hole 206, the hydraulic rod 209 is arranged in the left linkage hole 212 and the right linkage hole 213, a linkage lever 214 is arranged below the hydraulic rod 209, the left end of the linkage lever 214 is rotatably connected with the middle part of the left linkage plate 210, the right end of the linkage lever 214 is rotatably connected with the middle part of the right linkage plate 211, the fixed end of the hydraulic rod 209 is rotatably connected with the upper end of the left linkage plate 210, the telescopic end of the hydraulic rod 209 is rotatably connected with the upper end of the right linkage plate 211. After the mobile station 104 is moved to the position, the left linkage plate 210 and the right linkage plate 211 are respectively rotated around the left and right ends of the linkage lever 214 by the extension of the hydraulic rod 209, so that the upper ends of the left linkage plate 210 and the right linkage plate 211 are away from each other, and the lower ends of the left linkage plate 210 and the right linkage plate 211 are close to each other, so that the left brake lever 207 and the right brake lever 208 are pushed by the lower ends of the left linkage plate 210 and the right linkage plate 211 to move close to each other, so that the left brake lever 207 and the right brake lever 208 can clamp the brake strip 201 to lock the mobile station 104. Conversely, when the mobile station 104 needs to be moved, the hydraulic rod 209 can be shortened.

[0036] The right side of the left linkage plate 210 is vertically provided with a connecting groove 215, the left end of the left brake lever 207 penetrates the lower part of the connecting groove 215, and the front and back sides of the left end are rotatably connected with the front and back groove walls of the connecting groove 215 through a first rotating shaft 216; the fixed end of the hydraulic rod 209 is provided with a first connecting piece 217, the first connecting piece 217 penetrates the upper part of the connecting groove 215, and the front and back sides of the first connecting piece 217 are rotatably connected with the front and back groove walls of the connecting groove 215 through a second rotating shaft 219; the linkage lever 214 is provided with two, the two linkage levers 214 are respectively arranged on the front and back sides of the left linkage plate 210, and the front and back sides of the middle part of the left linkage plate 210 are rotatably connected with the left end side surfaces of the two linkage levers 214 through a third rotating shaft 220. The first rotating shaft 216 can make the left brake lever 207 rotate smoothly in the connecting groove 215, so as to drive the left brake lever 207 to move left and right. The second rotating shaft 219 can be used as a fulcrum to make the upper and lower ends of the left linkage plate 210 rotate around the second rotating shaft 219 when the hydraulic rod 209 is extended and shortened. The third rotating shaft 220 can make the hydraulic rod 209 change the angle when the first connecting piece 217 pushes the left linkage plate 210 when the hydraulic rod 209 is extended and shortened. The left side of the right linkage plate 211 is also provided with a connecting groove 215 to connect the right brake lever 208 and the telescopic end of the hydraulic rod 209, and the telescopic end of the hydraulic rod 209 is connected with a second connecting piece 218.

[0037] The left brake lever 207 is arranged in the connection groove 215, and the front and back sides of the left brake lever 207 are arranged as planes. By arranging the planes, the left brake lever 207 can be rotated by adhering to the groove wall of the connection groove 215.

[0038] While the present application has been described with reference to the preferred embodiments thereof, it is to be understood that the application is not limited to the preferred embodiments and that the application is intended to cover numerous other modifications as will be apparent to those skilled in the art. More particularly, various modifications in the components of the subject combination layout and / or the layout itself can be made without departing from the spirit and scope of the present application. Other than variations which have been mentioned herein, many modifications or changes in detail of the application can be made by those skilled in the art to which the present application pertains. It is therefore desired that applicable scope of the present application be defined by the appended claims rather than the description.

Claims

1. A front-rear wheelbase adjustable four-wheel drive dynamometer, comprising a chassis (101), a fixed table (102) is mounted on the upper side of the rear end of the chassis (101), a track (103) is arranged in the front-rear direction on the front side of the fixed table (102), a moving table (104) is arranged in the front-rear direction on the track (103), a rear roller group is arranged on the upper side of the fixed table (102), a first transmission wheel (105) is coaxially arranged on the left end of the rear roller group, a front roller group is arranged on the upper side of the moving table (104), and a third transmission wheel (106) is coaxially arranged on the left end of the front roller group, characterized in that, The left side of the chassis (101) is provided with a fifth transmission wheel (107) and a sixth transmission wheel (108) at the front and rear ends of the track (103), the left side of the moving table (104) is provided with a first tensioning wheel (109) and a second tensioning wheel (110) at the front and rear of the third transmission wheel (106), the first transmission wheel (105) and the sixth transmission wheel (108) are connected by the first synchronous belt (111), the fifth transmission wheel (107) and the sixth transmission wheel (108) are connected by the second synchronous belt (112), the middle part of the upper side of the second synchronous belt (112) is sleeved on the third transmission wheel (106), and the parts of the second synchronous belt (112) located on the front and rear sides of the third transmission wheel (106) are respectively matched with the opposite sides of the first tensioning wheel (109) and the second tensioning wheel (110).

2. The adjustable wheelbase four-wheel drive dynamometer of claim 1, wherein: The rear roller group includes a first rear roller (113) and a second rear roller (114) arranged in front and back, the first transmission wheel (105) is arranged at the left end of the first rear roller (113), the left end of the second rear roller (114) is coaxially provided with a second transmission wheel (115), and the first transmission wheel (105) and the second transmission wheel (115) are connected by the third synchronous belt (116).

3. The adjustable wheelbase four-wheel drive dynamometer of claim 2, wherein: The front roller group includes a first front roller (117) and a second front roller (118) arranged in front and back, the third transmission wheel (106) is arranged at the left end of the first front roller (117), the left end of the second front roller (118) is coaxially provided with a fourth transmission wheel (119), the middle part of the upper side of the second synchronous belt (112) is sequentially sleeved on the third transmission wheel (106) and the fourth transmission wheel (119), the part of the second synchronous belt (112) located on the front side of the third transmission wheel (106) is matched with the rear side of the first tensioning wheel (109), and the part of the second synchronous belt (112) located on the rear side of the fourth transmission wheel (119) is matched with the front side of the second tensioning wheel (110).

4. The adjustable wheelbase four-wheel drive dynamometer of claim 3, wherein: The right end of the first rear roller (113) is provided with a first motor (120) for driving the first rear roller (113) to rotate.

5. The adjustable wheelbase four-wheel drive dynamometer of claim 1, wherein: The upper side of the chassis (101) is provided with a lead screw (121) in the front-rear direction, the front end of the lead screw (121) is provided with a second motor (122) for driving the lead screw (121) to rotate, a driving block (123) is sleeved on the lead screw (121) in transmission, the driving block (123) is connected with the lead screw (121) in threaded transmission, and the upper side of the driving block (123) is fixedly connected with the lower side of the moving table (104).

6. The adjustable wheelbase four-wheel drive dynamometer of claim 5, wherein: The lower side of the moving table (104) is provided with a moving block (124) corresponding to the position of the track (103), the lower side of the moving block (124) is recessed to be provided with a sliding groove (125) matched with the track (103), and the upper side of the track (103) is slidingly embedded in the sliding groove (125).

7. The adjustable wheelbase four-wheel drive dynamometer of claim 6, wherein: The bottom frame (101) is provided with a rotating block at the rear end of the screw rod (121), the front side of the rotating block is provided with a rotating hole, the rear end of the screw rod (121) penetrates into the rotating hole, and the screw rod (121) is connected with the rotating hole through a bearing and rotation.

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