I cant find my parsed urdf model in rviz

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I built a robot model in solidworks and exported using plug-in as urdf. Then i parsed the file successfully and tried to visualize it in rviz but it failed to show up the model. below is my urdf file and result in rviz

    <robot
  name="JMbot">
  <link
    name="Base ">
    <inertial>
      <origin
        xyz="-0.331696074009627 -0.719586942429273 -0.402589887484249"
        rpy="0 0 0" />
      <mass
        value="1.56817866517859" />
      <inertia
        ixx="0.0108679476987914"
        ixy="-0.00179135853312012"
        ixz="-2.19999020357412E-16"
        iyy="0.0327160610863439"
        iyz="1.02118292120978E-17"
        izz="0.041347577825996" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/Base .STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.752941176470588 0.752941176470588 0.752941176470588 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/Base .STL" />
      </geometry>
    </collision>
  </link>
  <link
    name="Base plate">
    <inertial>
      <origin
        xyz="5.55111512312578E-17 2.22044604925031E-16 0.00236910483921671"
        rpy="0 0 0" />
      <mass
        value="0.553781193313651" />
      <inertia
        ixx="0.00613802647719325"
        ixy="-7.04731412115578E-19"
        ixz="-7.48283062994103E-18"
        iyy="0.00414996381570526"
        iyz="-1.53613068073911E-17"
        izz="0.0102825986842358" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/Base plate.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.749019607843137 0.749019607843137 0.749019607843137 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/Base plate.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="Base plate"
    type="fixed">
    <origin
      xyz="-0.3317 0.39256 -0.71959"
      rpy="1.5708 0.081268 -4.9871E-18" />
    <parent
      link="Base " />
    <child
      link="Base plate" />
    <axis
      xyz="0 0 0" />
  </joint>
  <link
    name="WheelR">
    <inertial>
      <origin
        xyz="-0.039049 1.1102E-16 2.2204E-16"
        rpy="0 0 0" />
      <mass
        value="0.45064" />
      <inertia
        ixx="0.00091608"
        ixy="-1.27E-19"
        ixz="1.0926E-18"
        iyy="0.00053395"
        iyz="-1.2197E-19"
        izz="0.00053395" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/WheelR.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.74902 0.74902 0.74902 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/WheelR.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="WheelR"
    type="continuous">
    <origin
      xyz="0.13543 0 -0.015"
      rpy="-1.1419 -2.4633E-15 -3.1416" />
    <parent
      link="Base plate" />
    <child
      link="WheelR" />
    <axis
      xyz="1 0 0" />
  </joint>
  <link
    name="WheelL">
    <inertial>
      <origin
        xyz="-0.039049 2.2204E-16 2.498E-15"
        rpy="0 0 0" />
      <mass
        value="0.45064" />
      <inertia
        ixx="0.00091608"
        ixy="-9.7209E-19"
        ixz="-1.737E-18"
        iyy="0.00053395"
        iyz="0"
        izz="0.00053395" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/WheelL.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.74902 0.74902 0.74902 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://JMbot/meshes/WheelL.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="WheelL"
    type="continuous">
    <origin
      xyz="-0.13543 0 -0.015"
      rpy="0 ...